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Sample records for celleskade ved bilirubin

  1. Bilirubin Test

    MedlinePlus

    ... Also known as: Total Bilirubin; TBIL; Neonatal Bilirubin; Direct Bilirubin; Conjugated Bilirubin; Indirect Bilirubin; Unconjugated Bilirubin Formal ... Hepatitis B ; Hepatitis C ; Complete Blood Count ; Urinalysis ; Direct Antiglobulin Test ; Haptoglobin ; Reticulocyte Count All content on ...

  2. Bilirubin - urine

    MedlinePlus

    ... may be due to: Biliary tract disease Cirrhosis Gallstones in the biliary tract Hepatitis Liver disease Tumors ... duct stricture Biliary system Bilirubin blood test Cirrhosis Gallstones Hepatitis Liver cancer - hepatocellular carcinoma Review Date 5/ ...

  3. Bilirubin Blood Test

    MedlinePlus

    ... precaution. Why do I need a bilirubin blood test? Your health care provider may order a bilirubin blood test: If ... hemolytic anemia What happens during a bilirubin blood test? A health care professional will take a blood sample from a ...

  4. Blood Test: Bilirubin

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Bilirubin KidsHealth > For Parents > Blood Test: Bilirubin A A A What's in this article? What ... Análisis de sangre: bilirrubina What It Is A bilirubin test measures the level of bilirubin (a byproduct ...

  5. Blood Test: Bilirubin

    MedlinePlus

    ... two forms in the body: indirect (unconjugated) and direct (conjugated). Indirect bilirubin, which doesn't dissolve in ... liver to be changed into the soluble form, direct bilirubin. Why It's Done Healthy newborns — especially those ...

  6. Biology of Bilirubin Photoisomers.

    PubMed

    Hansen, Thor Willy Ruud

    2016-06-01

    Phototherapy is the main treatment for neonatal hyperbilirubinemia. In acute treatment of extreme hyperbilirubinemia, intensive phototherapy may have a role in 'detoxifying' the bilirubin molecule to more polar photoisomers, which should be less prone to crossing the blood-brain barrier, providing a 'brain-sparing' effect. This article reviews the biology of bilirubin isomers. Although there is evidence supporting the lower toxicity of bilirubin photoisomers, there are studies showing the opposite. There are methodologic weaknesses in most studies and better-designed experiments are needed. In an infant acutely threatened by bilirubin-induced brain damage, intensified phototherapy should be used expediently and aggressively.

  7. Bilirubin oxidation in brain.

    PubMed

    Hansen, T W

    2000-01-01

    Bilirubin is a product of heme catabolism which by virtue of its lipid solubility can cross the blood-brain barrier and enter the brain. Neonatal jaundice is a common transitional phenomenon which is due to the combination of increased heme catabolism and rate limitations as far as hepatic conjugation and biliary excretion of bilirubin. In the great majority of cases this is an innocuous condition, which is even posited to have some beneficial effects due to the ability of bilirubin to quench free oxygen radicals. However, because bilirubin is neurotoxic, hyperbilirubinemia in the newborn may exceptionally result in death in the neonatal period, or survival with severe neurological sequelae (kernicterus). Bilirubin enters the brain through an intact blood-brain barrier. Clearance of bilirubin from brain partly involves retro-transfer through the blood-brain barrier, and possibly also through the brain-CSF barrier into CSF. Work in our lab during the past 5 years has substantiated earlier work which had suggested that bilirubin may also be metabolized in brain. The responsible enzyme is found on the inner mitochondrial membrane, and oxidizes bilirubin at a rate of 100-300 pmol bilirubin/mg protein/minute. The enzyme activity is lower in the newborn compared with the mature animal, and is also lower in neurons compared with glia. Studies of different rat strains have documented genetic variability. The enzyme is cytochrome-c-dependent, but has as yet not been unequivocally identified. The rate of oxidation of bilirubin is such that this enzyme probably contributes meaningfully to the clearance of bilirubin from brain.

  8. Formation of bilirubin glucoside

    PubMed Central

    Wong, Kim Ping

    1971-01-01

    1. Rat liver microsomal preparation can effect the transglucosylation from UDP-glucose to bilirubin in the presence of Mg2+. 2. Other nucleotides, namely CDP-glucose, ADP-glucose and GDP-glucose, were not active as glucosyl donors. 3. Only trace amounts of galactose, galacturonic acid and N-acetylglucosamine were conjugated to bilirubin when their respective UDP derivatives were used in the reaction mixture. 4. The azobilirubin glucosides produced by coupling with p-diazobenzenesulphonic acid and diazotized ethyl anthranilic acid were separable from the corresponding azobilirubin glucuronides by t.l.c. 5. The glucoside was, however, hydrolysed by both β-glucosidase and various preparations of β-glucuronidase; azobilirubin and glucose were liberated in the process. 6. Kinetic studies showed that the effects of pH and Mg2+ on the two conjugating systems were similar. 7. The specific activities of hepatic bilirubin UDP-glucosyltransferase, expressed as μg of bilirubin `equivalents' conjugated/h per mg of protein, are respectively 1.7 and 2.4 for male and female rats. 8. The Km values for bilirubin and UDP-glucose are 5.7×10−5m and 1.6×10−3m respectively. 9. The glucoside and glucuronide conjugations of bilirubin are discussed in relation to the availability of the conjugating agents and aglycone in the liver. ImagesFig. 1. PMID:5144254

  9. Optical transcutaneous bilirubin detector

    DOEpatents

    Kronberg, J.W.

    1993-11-09

    A transcutaneous bilirubin detector is designed comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient. 6 figures.

  10. Optical transcutaneous bilirubin detector

    DOEpatents

    Kronberg, James W.

    1993-01-01

    A transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient.

  11. Optical transcutaneous bilirubin detector

    DOEpatents

    Kronberg, J.W.

    1991-03-04

    This invention consists of a transcutaneous bilirubin detector comprising a source of light having spectral components absorbable and not absorbable by bilirubin, a handle assembly, electronic circuitry and a fiber optic bundle connecting the assembly to the light source and circuitry. Inside the assembly is a prism that receives the light from one end of the fiber optic bundle and directs it onto the skin and directs the reflected light back into the bundle. The other end of the bundle is trifucated, with one end going to the light source and the other two ends going to circuitry that determines how much light of each kind has been reflected. A relatively greater amount absorbed by the skin from the portion of the spectrum absorbable by bilirubin may indicate the presence of the illness. Preferably, two measurements are made, one on the kneecap and one on the forehead, and compared to determine the presence of bilirubin. To reduce the impact of light absorption by hemoglobin in the blood carried by the skin, pressure is applied with a plunger and spring in the handle assembly, the pressure limited by points of a button slidably carried in the assembly that are perceived by touch when the pressure applied is sufficient.

  12. Bilirubin measurements in neonates

    NASA Astrophysics Data System (ADS)

    Newman, Gregory J.

    2000-04-01

    Infant Jaundice is a physiologic condition of elevated bilirubin in the tissue that affects nearly 60 percent of all term newborns and virtually 100 percent of premature infants. The high production of bilirubin in the newborn circulatory system and the inability of the immature liver to process and eliminate it case the condition. When the bilirubin levels rise, it starts to deposit in the baby's skin and in the brain. The deposits in the brain can cause neurologic impairment and death. The BiliCheck is a handheld, battery-powered device that measures the level of jaundice non-invasively using BioPhotonics at the point of care. The result is displayed on an LCD screen immediately, so physicians can now make treatment decision without waiting for results to return from the lab. The BiliCheck System has been marketed worldwide since April of 1998 and has received FDA clearance for use in the USA on pre-photo therapy infants in March of 1999.

  13. Genetic Disorders of Bilirubin Metabolism

    DTIC Science & Technology

    Chronic idiopathic jaundice and three other entities that share the features of familial disorders of bilirubin metabolism in the absence of hemolytic disease or obstruction of bile passages are discussed.

  14. The Biological Effects of Bilirubin Photoisomers.

    PubMed

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

    2016-01-01

    Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

  15. Bilirubin-albumin binding, bilirubin/albumin ratios, and free bilirubin levels: where do we stand?

    PubMed

    Hulzebos, Christian V; Dijk, Peter H

    2014-11-01

    Treatment for unconjugated hyperbilirubinemia is predominantly based on one parameter, i.e., total serum bilirubin (TSB) levels. Yet, overt kernicterus has been reported in preterm infants at relatively low TSB levels, and it has been repeatedly shown that free unconjugated bilirubin (freeUCB) levels, or bilirubin/albumin (B/A) ratios for that matter, are more closely associated with bilirubin neurotoxicity. In this article, we review bilirubin-albumin binding, UCBfree levels, and B/A ratios in addition to TSB levels to individualize and optimize treatment especially in preterm infants. Methods to measure bilirubin-albumin binding or UCBfree are neither routinely performed in Western clinical laboratories nor incorporated in current management guidelines on unconjugated hyperbilirubinemia. For bilirubin-albumin binding, this seems justified because several of these methods have been challenged, and sufficiently powered prospective trials on the clinical benefits are lacking. Technological advances in the measurement of UCBfree may provide a convenient means for integrating UCBfree measurements into routine clinical management of jaundiced infants. A point-of-care method, as well as determination of UCBfree levels in various newborn populations, is desirable to learn more about variations in time and how various clinical pathophysiological conditions affect UCBfree levels. This will improve the estimation of approximate UCBfree levels associated with neurotoxicity. To delineate the role of UCBfree in the management of jaundiced (preterm) infants, trials are needed using UCBfree as treatment parameter. The additional use of the B/A ratio in jaundiced preterms has been evaluated in the Bilirubin Albumin Ratio Trial (BARTrial; Clinical Trials: ISRCTN74465643) but failed to demonstrate better neurodevelopmental outcome in preterm infants <32 weeks assigned to the study group. Awaiting a study in which infants are assigned to be managed solely on the basis of their B

  16. Bilirubin Binding Capacity in the Preterm Neonate.

    PubMed

    Amin, Sanjiv B

    2016-06-01

    Total serum/plasma bilirubin (TB), the biochemical measure currently used to evaluate and manage hyperbilirubinemia, is not a useful predictor of bilirubin-induced neurotoxicity in premature infants. Altered bilirubin-albumin binding in premature infants limits the usefulness of TB in premature infants. In this article, bilirubin-albumin binding, a modifying factor for bilirubin-induced neurotoxicity, in premature infants is reviewed.

  17. Quantitative imaging of bilirubin by photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Zhou, Yong; Zhang, Chi; Yao, Da-Kang; Wang, Lihong V.

    2013-03-01

    Noninvasive detection of both bilirubin concentration and its distribution is important for disease diagnosis. Here we implemented photoacoustic microscopy (PAM) to detect bilirubin distribution. We first demonstrate that our PAM system can measure the absorption spectra of bilirubin and blood. We also image bilirubin distributions in tissuemimicking samples, both without and with blood mixed. Our results show that PAM has the potential to quantitatively image bilirubin in vivo for clinical applications.

  18. Photoacoustic microscopy of bilirubin in tissue phantoms

    NASA Astrophysics Data System (ADS)

    Zhou, Yong; Zhang, Chi; Yao, Da-Kang; Wang, Lihong V.

    2012-12-01

    Determining both bilirubin's concentration and its spatial distribution are important in disease diagnosis. Here, for the first time, we applied quantitative multiwavelength photoacoustic microscopy (PAM) to detect bilirubin concentration and distribution simultaneously. By measuring tissue-mimicking phantoms with different bilirubin concentrations, we showed that the root-mean-square error of prediction has reached 0.52 and 0.83 mg/dL for pure bilirubin and for blood-mixed bilirubin detection (with 100% oxygen saturation), respectively. We further demonstrated the capability of the PAM system to image bilirubin distribution both with and without blood. Finally, by underlaying bilirubin phantoms with mouse skins, we showed that bilirubin can be imaged with consistent accuracy down to >400 μm in depth. Our results show that PAM has potential for noninvasive bilirubin monitoring in vivo, as well as for further clinical applications.

  19. The Biological Effects of Bilirubin Photoisomers

    PubMed Central

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

    2016-01-01

    Although phototherapy was introduced as early as 1950’s, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells. PMID:26829016

  20. Newborn jaundice technologies: unbound bilirubin and bilirubin binding capacity in neonates.

    PubMed

    Amin, Sanjiv B; Lamola, Angelo A

    2011-06-01

    Neonatal jaundice (hyperbilirubinemia), which is extremely common in neonates, can be associated with neurotoxicity. A safe level of bilirubin has not been defined in either premature or term infants. Emerging evidence suggest that the level of unbound (or "free") bilirubin has a better sensitivity and specificity than total serum bilirubin for bilirubin-induced neurotoxicity. Although recent studies suggest the usefulness of free bilirubin measurements in managing high-risk neonates, including premature infants, no widely available method exists to assay the serum free bilirubin concentration. To keep pace with the growing demand, in addition to reevaluation of old methods, several promising new methods are being developed for sensitive, accurate, and rapid measurement of free bilirubin and bilirubin binding capacity. These innovative methods need to be validated before adopting for clinical use. We provide an overview of some promising methods for free bilirubin and binding capacity measurements with the goal to enhance research in this area of active interest and apparent need.

  1. Bilirubin Binding to PPARα Inhibits Lipid Accumulation.

    PubMed

    Stec, David E; John, Kezia; Trabbic, Christopher J; Luniwal, Amarjit; Hankins, Michael W; Baum, Justin; Hinds, Terry D

    2016-01-01

    Numerous clinical and population studies have demonstrated that increased serum bilirubin levels protect against cardiovascular and metabolic diseases such as obesity and diabetes. Bilirubin is a potent antioxidant, and the beneficial actions of moderate increases in plasma bilirubin have been thought to be due to the antioxidant effects of this bile pigment. In the present study, we found that bilirubin has a new function as a ligand for PPARα. We show that bilirubin can bind directly to PPARα and increase transcriptional activity. When we compared biliverdin, the precursor to bilirubin, on PPARα transcriptional activation to known PPARα ligands, WY 14,643 and fenofibrate, it showed that fenofibrate and biliverdin have similar activation properties. Treatment of 3T3-L1 adipocytes with biliverdin suppressed lipid accumulation and upregulated PPARα target genes. We treated wild-type and PPARα KO mice on a high fat diet with fenofibrate or bilirubin for seven days and found that both signal through PPARα dependent mechanisms. Furthermore, the effect of bilirubin on lowering glucose and reducing body fat percentage was blunted in PPARα KO mice. These data demonstrate a new function for bilirubin as an agonist of PPARα, which mediates the protection from adiposity afforded by moderate increases in bilirubin.

  2. Bilirubin Binding to PPARα Inhibits Lipid Accumulation

    PubMed Central

    Stec, David E.; John, Kezia; Trabbic, Christopher J.; Luniwal, Amarjit; Hankins, Michael W.; Baum, Justin

    2016-01-01

    Numerous clinical and population studies have demonstrated that increased serum bilirubin levels protect against cardiovascular and metabolic diseases such as obesity and diabetes. Bilirubin is a potent antioxidant, and the beneficial actions of moderate increases in plasma bilirubin have been thought to be due to the antioxidant effects of this bile pigment. In the present study, we found that bilirubin has a new function as a ligand for PPARα. We show that bilirubin can bind directly to PPARα and increase transcriptional activity. When we compared biliverdin, the precursor to bilirubin, on PPARα transcriptional activation to known PPARα ligands, WY 14,643 and fenofibrate, it showed that fenofibrate and biliverdin have similar activation properties. Treatment of 3T3-L1 adipocytes with biliverdin suppressed lipid accumulation and upregulated PPARα target genes. We treated wild-type and PPARα KO mice on a high fat diet with fenofibrate or bilirubin for seven days and found that both signal through PPARα dependent mechanisms. Furthermore, the effect of bilirubin on lowering glucose and reducing body fat percentage was blunted in PPARα KO mice. These data demonstrate a new function for bilirubin as an agonist of PPARα, which mediates the protection from adiposity afforded by moderate increases in bilirubin. PMID:27071062

  3. The effect of bilirubin photoisomers on unbound-bilirubin concentrations estimated by the peroxidase method.

    PubMed Central

    Itoh, S; Yamakawa, T; Onishi, S; Isobe, K; Manabe, M; Sasaki, K

    1986-01-01

    Unbound bilirubin is oxidized to nearly colourless substances in the presence of H2O2 or ethyl hydroperoxide and horseradish peroxidase. To predict the risk of kernicterus (degenerated yellow pigmentation of nerve cells), this principle has been widely utilized for estimating the concentration of unbound bilirubin in hyperbilirubinaemic serum. However, the serum contains polar geometric photoisomers of bilirubin. Therefore, to clarify the effect of bilirubin photoisomer concentrations on unbound-bilirubin concentration, the concentration of bilirubin and its photoisomer and of unbound bilirubin in samples obtained from experiments in vivo and in vitro were simultaneously and individually estimated by h.p.l.c. and the peroxidase method. During photoirradiation, both in vivo and in vitro, the serum polar (ZE)-bilirubin IX alpha concentration increased remarkably, but unbound-bilirubin values were not affected at all. However, during experiments in vitro, unbound bilirubin concentrations increased only when concentrations of the rather polar (EZ)- and (EE)-cyclobilirubin IX alpha increased considerably in a human serum albumin-bilirubin solution irradiated with blue light. Thus it is concluded that unbound-bilirubin concentrations, and consequently the initial rate of the peroxidase reaction, is not accelerated by the increase in either (ZE)-bilirubin or (EZ)-cyclobilirubin concentration within the clinically observed range. PMID:3545181

  4. Bilirubin and Its Carbohydrate Conjugates

    NASA Astrophysics Data System (ADS)

    Blanckaert, Norbert J. C.

    In mammals, the open tetrapyrrole bilirubin (structure 2, Fig. 1) is the principal degradation product of iron-protoporphyrin-IX (heme). The latter molecule is a tetrapyrrolic macrocycle and plays a critical role in aerobic metabolism by reversibly binding oxygen in hemoglobin and myoglobin, and by serving as the active site in oxidation reactions catalyzed by hemoprotein enzymes. Important cyclic tetrapyrroles in nature related to heme are chlorophylls, which contain magnesium and are derived from protoporphyrin-IX, and vitamin B12, a corrinoid derived from uroporphyrinogen-III.

  5. Interaction of bilirubin with human erythrocyte membranes. Bilirubin binding to neuraminidase- and phospholipase-treated membranes.

    PubMed

    Sato, H; Aono, S; Semba, R; Kashiwamata, S

    1987-11-15

    Saturable bilirubin binding to human erythrocyte membranes was measured before and after digestion with neuraminidase and phospholipases. Neuraminidase-treated erythrocyte membranes did not show any change in their binding properties, indicating that gangliosides could be excluded as candidates for saturable bilirubin-binding sites on erythrocyte membranes. Although bilirubin-binding properties of the membranes did not change after phospholipase D digestion, either, phospholipase C treatment greatly enhanced bilirubin binding. Thus it is suggested that a negatively charged phosphoric acid moiety of phospholipids on the membrane surface may play a role to prevent a large amount of bilirubin from binding to the membranes. Further saturable bilirubin binding to inside-out sealed erythrocyte membrane vesicles showed values comparable with those of the right-side-out sealed membranes, suggesting that the bilirubin-binding sites may be distributed on both outer and inner surfaces of the membranes, or may exist in the membranes where bilirubin may be accessible from either side.

  6. Functionalized SBA-15 materials for bilirubin adsorption

    NASA Astrophysics Data System (ADS)

    Tang, Tao; Zhao, Yanling; Xu, Yao; Wu, Dong; Xu, Jun; Deng, Feng

    2011-05-01

    To investigate the driving force for bilirubin adsorption on mesoporous materials, a comparative study was carried out between pure siliceous SBA-15 and three functionalized SBA-15 mesoporous materials: CH 3-SBA-15 (MS), NH 2-SBA-15 (AS), and CH 3/NH 2-SBA-15 (AMS) that were synthesized by one-pot method. The obtained materials exhibited large surface areas (553-810 m 2/g) and pore size (6.6-7.1 nm) demonstrated by XRD and N 2-ad/desorption analysis. The SEM images showed that the materials had similar fiberlike morphology. The functionalization extent was calculated according to 29Si MAS NMR spectra and it was close to the designed value (10%). The synthesized mesoporous materials were used as bilirubin adsorbents and showed higher bilirubin adsorption capacities than the commercial active carbon. The adsorption capacities of amine functionalized samples AMS and AS were larger than those of pure siliceous SBA-15 and MS, indicating that electrostatic interaction was the dominant driving force for bilirubin adsorption on mesoporous materials. Increasing the ionic strength of bilirubin solution by adding NaCl would decrease the bilirubin adsorption capacity of mesoporous material, which further demonstrated that the electrostatic interaction was the dominant driving force for bilirubin adsorption. In addition, the hydrophobic interaction provided by methyl groups could promote the bilirubin adsorption.

  7. THE RENAL ELIMINATION OF BILIRUBIN

    PubMed Central

    Haessler, Herbert; Rous, Peyton; Broun, G. O.

    1922-01-01

    The elimination of bile pigment during jaundice is, for practical purposes, unincreased by diuresis from water by mouth. Possibly, though, the flushing of the kidneys tends to lessen pigment accumulation within these organs and thus to diminish a serious potential source of trouble in long continued jaundice. Flood diuresis from intravenous injections of salt solution markedly increases the output of bile pigment. It is important to know the effect of variations in the urinary output on the elimination of bile salts, but methods for the purpose are not available at present. The passage of bile pigment into the kidney cells during jaundice is attested by the presence in the freshly voided urine of desquamated renal elements specifically stained, stippled, or granulated with bilirubin. Pigmentation of this sort is readily to be distinguished from the indiscriminate staining of cellular debris that occurs in icteric urines on standing. It has clinical significance, furnishing direct evidence on the degree of renal change. PMID:19868627

  8. Animal pigment bilirubin discovered in plants.

    PubMed

    Pirone, Cary; Quirke, J Martin E; Priestap, Horacio A; Lee, David W

    2009-03-04

    The bile pigment bilirubin-IXalpha is the degradative product of heme, distributed among mammals and some other vertebrates. It can be recognized as the pigment responsible for the yellow color of jaundice and healing bruises. In this paper we present the first example of the isolation of bilirubin in plants. The compound was isolated from the brilliant orange-colored arils of Strelitzia nicolai, the white bird of paradise tree, and characterized by HPLC-ESMS, UV-visible, (1)H NMR, and (13)C NMR spectroscopy, as well as comparison with an authentic standard. This discovery indicates that plant cyclic tetrapyrroles may undergo degradation by a previously unknown pathway. Preliminary analyses of related plants, including S. reginae, the bird of paradise, also revealed bilirubin in the arils and flowers, indicating that the occurrence of bilirubin is not limited to a single species or tissue type.

  9. Does bilirubin protect against developing diabetes mellitus?

    PubMed

    Breimer, Lars H; Mikhailidis, Dimitri P

    2016-01-01

    After 25 years of evaluating bilirubin as a possible protective agent in neonatal and cardiovascular disease, interest has moved on to a exploring a possible protective role in diabetes mellitus (DM). This review finds conflicting prospective data for a protective relationship though there are retrospective, case-controlled data, that can only show association, which is not causality. Only prospective studies can show causality. Also, it would appear that the underlying biochemical assumptions do not readily translate from the animal to the human setting. Given that many factors impact on circulating bilirubin levels, it is not surprising that a clear-cut answer is not available; the jury is still out. Any relationship between DM and bilirubin might relate to intermediates in bilirubin metabolism, including relationships involving the genes for the enzymes participating in those steps. Nevertheless, the pursuit of bilirubin in disease causation is opening new avenues for research and if it is established that serum bilirubin can predict risks, much will have been achieved. The answer may have to come from molecular genetic analyses.

  10. Intermolecular interactions in the bilirubin-cholate-silica system

    NASA Astrophysics Data System (ADS)

    Vlasova, N. N.; Golovkova, L. P.; Severinovskaya, O. V.

    2007-06-01

    Bilirubin-cholate interactions in aqueous solutions were studied. The constants of binding of bilirubin with taurocholate dimers and taurodeoxycholate trimers were calculated. The adsorption of bilirubin and cholates on the surface of highly dispersed silica was studied. It was shown that taurine-conjugated cholates are poorly adsorbed from micellar solutions on the silica surface, the specific amount of bilirubin adsorbed decreases with increasing concentration of cholates in the solution, the affinity of free bilirubin for the silica surface is independent of the nature of the cholic acid, and that the affinity of cholate-bilirubin complexes for the silica surface is lower than the affinity of free bilirubin.

  11. The nonerythropoietic component of early bilirubin

    PubMed Central

    Levitt, M.; Schacter, B. A.; Zipursky, A.; Israels, L. G.

    1968-01-01

    The early labeled bilirubin consists of two primary components. The more rapidly synthesized of the two is independent of erythropoiesis (nonerythropoietic), whereas the second fraction is related to red cell production (erythyropoietic). The present studies concern the origin of the nonerythropoietic component. The nonerythropoietic, early labeled bilirubin was studied in bile fistula rats with (delta ALA)-4-14C delta aminolevulinic acid and glycine-2-14C as precursors. That nephrectomy did not reduce the size of this component despite the large and rapidly turning over pool of renal heme suggests that this pool may be of minor importance in its production. Intoxication with lead to a level that reduced hepatic heme synthesis was associated with a decrease in early bilirubin formation. The synthesis of this bilirubin was assessed in animals with phenobarbital-induced heme protein and cycloheximide-suppressed protein synthesis. Rats pretreated with phenobarbital at a dose level of 60 mg/kg with induction of cytochrome P-450 synthesis showed a minor increase in early labeling when glycine-2-14C but not when delta ALA-4-14C was used as precursor. Rats given cycloheximide at a dose level that markedly reduced hepatic protein and cytochrome P-450 synthesis but allowed heme synthesis to continue at 60% of its pretreatment level synthesized normal or increased amounts of early bilirubin from delta ALA-4-14C. Allylisopropylacetamide intoxication caused little change in early bilirubin formation, whereas aminotriazole given at a time after maximal hepatic heme labeling produced a small but significant increase in the appearance of labeled bilirubin. These findings indicate that early bilirubin production is little influenced by increased hepatic porphyrin synthesis or by changes in the rapidly turning over heme protein P-450. A minimal increase attends catalase inactivation by aminotriazole. Normal or increased synthesis takes place in the presence of suppression of

  12. Supramolecular Complexes Formed in Systems Bile Salt-Bilirubin-Silica

    NASA Astrophysics Data System (ADS)

    Vlasova, N. N.; Severinovskaya, O. V.; Golovkova, L. P.

    The formation of supramolecular complexes between bilirubin and primary micelles of bile salts has been studied. The association constants of bile salts and binding of bilirubin with these associates have been determined. The adsorption of bilirubin and bile salts from individual and mixed aqueous solutions onto hydrophobic silica surfaces has been investigated. The interaction of bilirubin with primary bile salt micelles and the strong retention in mixed micelles, which are supramolecular complexes, result in the adsorption of bilirubin in free state only.

  13. PPARα: A Master Regulator of Bilirubin Homeostasis

    PubMed Central

    Kaeding, Jenny; El Husseini, Diala; Rudkowska, Iwona; Verreault, Mélanie

    2014-01-01

    Hypolipidemic fibrates activate the peroxisome proliferator-activated receptor (PPAR) α to modulate lipid oxidation and metabolism. The present study aimed at evaluating how 3 PPARα agonists, namely, fenofibrate, gemfibrozil, and Wy14,643, affect bilirubin synthesis and metabolism. Human umbilical vein epithelial cells (HUVEC) and coronary artery smooth muscle cells (CASMC) were cultured in the absence or presence of the 3 activators, and mRNA, protein, and/or activity levels of the bilirubin synthesizing heme oxygenase- (HO-) 1 and biliverdin reductase (BVR) enzymes were determined. Human hepatocytes (HH) and HepG2 cells sustained similar treatments, except that the expression of the bilirubin conjugating UDP-glucuronosyltransferase (UGT) 1A1 enzyme and multidrug resistance-associated protein (MRP) 2 transporter was analyzed. In HUVECs, gemfibrozil, fenofibrate, and Wy14,643 upregulated HO-1 mRNA expression without affecting BVR. Wy14,643 and fenofibrate also caused HO-1 protein accumulation, while gemfibrozil and fenofibrate favored the secretion of bilirubin in cell media. Similar positive regulations were also observed with the 3 PPARα ligands in CASMCs where HO-1 mRNA and protein levels were increased. In HH and HepG2 cells, both UGT1A1 and MRP2 transcripts were also accumulating. These observations indicate that PPARα ligands activate bilirubin synthesis in vascular cells and metabolism in liver cells. The clinical implications of these regulatory events are discussed. PMID:25147562

  14. PPARα: A Master Regulator of Bilirubin Homeostasis.

    PubMed

    Bigo, Cyril; Kaeding, Jenny; El Husseini, Diala; Rudkowska, Iwona; Verreault, Mélanie; Vohl, Marie Claude; Barbier, Olivier

    2014-01-01

    Hypolipidemic fibrates activate the peroxisome proliferator-activated receptor (PPAR) α to modulate lipid oxidation and metabolism. The present study aimed at evaluating how 3 PPARα agonists, namely, fenofibrate, gemfibrozil, and Wy14,643, affect bilirubin synthesis and metabolism. Human umbilical vein epithelial cells (HUVEC) and coronary artery smooth muscle cells (CASMC) were cultured in the absence or presence of the 3 activators, and mRNA, protein, and/or activity levels of the bilirubin synthesizing heme oxygenase- (HO-) 1 and biliverdin reductase (BVR) enzymes were determined. Human hepatocytes (HH) and HepG2 cells sustained similar treatments, except that the expression of the bilirubin conjugating UDP-glucuronosyltransferase (UGT) 1A1 enzyme and multidrug resistance-associated protein (MRP) 2 transporter was analyzed. In HUVECs, gemfibrozil, fenofibrate, and Wy14,643 upregulated HO-1 mRNA expression without affecting BVR. Wy14,643 and fenofibrate also caused HO-1 protein accumulation, while gemfibrozil and fenofibrate favored the secretion of bilirubin in cell media. Similar positive regulations were also observed with the 3 PPARα ligands in CASMCs where HO-1 mRNA and protein levels were increased. In HH and HepG2 cells, both UGT1A1 and MRP2 transcripts were also accumulating. These observations indicate that PPARα ligands activate bilirubin synthesis in vascular cells and metabolism in liver cells. The clinical implications of these regulatory events are discussed.

  15. Can Excess Bilirubin Levels Cause Learning Difficulties?

    ERIC Educational Resources Information Center

    Pretorius, E.; Naude, H.; Becker, P. J.

    2002-01-01

    Examined learning problems in South African sample of 7- to 14-year-olds whose mothers reported excessively high infant bilirubin shortly after the child's birth. Found that this sample had lowered verbal ability with the majority also showing impaired short-term and long-term memory. Findings suggested that impaired formation of astrocytes…

  16. Can Excess Bilirubin Levels Cause Learning Difficulties?

    ERIC Educational Resources Information Center

    Pretorius, E.; Naude, H.; Becker, P. J.

    2002-01-01

    Examined learning problems in South African sample of 7- to 14-year-olds whose mothers reported excessively high infant bilirubin shortly after the child's birth. Found that this sample had lowered verbal ability with the majority also showing impaired short-term and long-term memory. Findings suggested that impaired formation of astrocytes…

  17. Bilirubin is an Endogenous Antioxidant in Human Vascular Endothelial Cells

    PubMed Central

    Ziberna, Lovro; Martelanc, Mitja; Franko, Mladen; Passamonti, Sabina

    2016-01-01

    Bilirubin is a standard serum biomarker of liver function. Inexplicably, it is inversely correlated with cardiovascular disease risk. Given the role of endothelial dysfunction in originating cardiovascular diseases, direct analysis of bilirubin in the vascular endothelium would shed light on these relationships. Hence, we used high-performance liquid chromatography coupled with thermal lens spectrometric detection and diode array detection for the determination of endogenous cellular IXα-bilirubin. To confirm the isomer IXα-bilirubin, we used ultra-performance liquid chromatography coupled with a high-resolution mass spectrometer using an electrospray ionization source, as well as tandem mass spectrometric detection. We measured bilirubin in both arterial and venous rat endothelium (0.9–1.5 pmol mg−1 protein). In the human endothelial Ea.hy926 cell line, we demonstrated that intracellular bilirubin (3–5 pmol mg−1 protein) could be modulated by either extracellular bilirubin uptake, or by up-regulation of heme oxygenase-1, a cellular enzyme related to endogenous bilirubin synthesis. Moreover, we determined intracellular antioxidant activity by bilirubin, with EC50 = 11.4 ± 0.2 nM, in the range of reported values of free serum bilirubin (8.5–13.1 nM). Biliverdin showed similar antioxidant properties as bilirubin. We infer from these observations that intra-endothelial bilirubin oscillates, and may thus be a dynamic factor of the endothelial function. PMID:27381978

  18. Detection of bilirubin conjugates in faeces of germfree rats.

    PubMed

    Saxerholt, H; Midtvedt, T; Gustafsson, B E

    1983-10-01

    The presence of bilirubin conjugates in faeces from germfree (GF) and conventional (CONV) rats was tested after using affinity chromatography and Porapak Q chromatography as clean-up procedures. The bilirubin conjugates were detected as their ethyl anthranilate azopigments after separation by thin layer chromatography (tlc). Azopigments prepared from bile of GF and CONV rats served as a reference material for the tlc analysis. After tlc of the faecal azopigment preparations it was concluded that GF rat faeces contains bilirubin conjugates, while faeces from CONV rats is devoid of conjugated bilirubin. The findings suggest that the main bilirubin conjugates present in faeces from GF rats are of the glucuronic acid type.

  19. Bilirubin in coronary artery disease: Cytotoxic or protective?

    PubMed Central

    Gupta, Nancy; Singh, Tavankit; Chaudhary, Rahul; Garg, Sushil K; Sandhu, Gurprataap Singh; Mittal, Varun; Gupta, Rahul; Bodin, Roxana; Sule, Sachin

    2016-01-01

    Bilirubin has traditionally been considered a cytotoxic waste product. However, recent studies have shown bilirubin to have anti-oxidant, anti-inflammatory, vasodilatory, anti-apoptotic and anti-proliferative functions. These properties potentially confer bilirubin a new role of protection especially in coronary artery disease (CAD), which is a low grade inflammatory process exacerbated by oxidative stress. In fact, recent literature reports an inverse relationship between serum concentration of bilirubin and the presence of CAD. In this article, we review the current literature exploring the association between levels of bilirubin and risk of CAD. We conclude that current evidence is inconclusive regarding the protective effect of bilirubin on CAD. A causal relationship between low serum bilirubin level and increased risk of CAD is not currently established. PMID:27867680

  20. Limitations and opportunities of transcutaneous bilirubin measurements.

    PubMed

    Bosschaart, Nienke; Kok, Joke H; Newsum, Astrid M; Ouweneel, Dagmar M; Mentink, Rosaline; van Leeuwen, Ton G; Aalders, Maurice C G

    2012-04-01

    Although transcutaneous bilirubinometers have existed for over 30 years, the clinical utility of the technique is limited to a screening method for hyperbilirubinemia, rather than a replacement for invasive blood sampling. In this study, we investigate the reason for this limited clinical value and address possibilities for improvement. To obtain better insight into the physiology of bilirubin measurements, we evaluated a transcutaneous bilirubinometer that determines not only the cutaneous bilirubin concentration (TcB) but also the blood volume fraction (BVF) in the investigated skin volume. For 49 neonates (gestational age 30 ± 3.1 weeks, postnatal age 6 [4-10] days) at our NICU, we performed 124 TcB and 55 BVF measurements. The TcB correlated well with the total serum bilirubin concentration (TSB) (r = 0.88) with an uncertainty of 55 µmol/L. The BVF in the measured skin volume ranged between 0.1% and 0.75%. The performance of our bilirubinometer is comparable to existing transcutaneous devices. The limited clinical value of current bilirubinometers can be explained by the low BVF in the skin volume that is probed by these devices. Because the TcB depends for over 99% on the contribution of extravascular bilirubin, it is a physiologically different parameter from the TSB. Hence, the standard method of evaluation that compares the TcB to the TSB is insufficient to fully investigate the clinical value of transcutaneous bilirubinometers, ie, their predictive value for kernicterus. We suggest that the clinical value may be improved considerably by changing either the method of evaluation or the technological design of transcutaneous bilirubinometers.

  1. Mortality associated with bilirubin levels in insurance applicants.

    PubMed

    Fulks, Michael; Stout, Robert L; Dolan, Vera F

    2009-01-01

    Determine the relationship between bilirubin levels with and without other liver function test (LFT) elevations and relative mortality in life insurance applicants. By use of the Social Security Death Master File mortality was determined in 1,905,664 insurance applicants for whom blood samples were submitted to the Clinical Reference Laboratory. There were 50,174 deaths observed in this study population. Results were stratified by 3 age/sex groups: females, age <60; males, age <60; and all, age 60+. The median follow-up was 12 years. Relative mortality increased as bilirubin decreased below bilirubin levels seen for the middle 50% of the population. The known association of smoking with lower bilirubin values explained only part of the additional elevated risk at low bilirubin levels. In the absence of other LFT elevations, relative mortality remained unchanged as bilirubin increased beyond levels seen for the middle 50% of the population. When a bilirubin elevation was combined with other LFT elevations, mortality further increased only at the highest elevations of other LFTs, seen only in <2.5% of applicants. Isolated elevations of bilirubin in this healthy screening population were not associated with excess mortality but values below the midpoint were. Other investigations have suggested a cardiovascular cause may underlie the excess mortality associated with low bilirubin. In association with other LFT elevations, bilirubin elevation further increases the mortality risk only at the highest elevations of other LFTs.

  2. Photocatabolism of labeled bilirubin in the congenitally jaundiced (Gunn) rat

    PubMed Central

    Ostrow, J. Donald

    1971-01-01

    To elucidate the mechanism by which phototherapy reduces serum bilirubin, studies were performed on the catabolism of labeled bilirubin in homozygous jaundiced Gunn rats before, during, and after a period of exposure to 1700 foot candles of daylight fluorescent light. Following equilibration with the body pool of an intravenously administered tracer dose of 3H- or 14C-bilirubin, radioactive and diazo reactive compounds were excreted in the bile at a slow, steady rate and plasma specific activity declined semilogarithmically. Subsequent exposure to light caused a marked increase in the biliary excretion of radioactive and diazoreactive compounds. Fecal and urinary radioactivity increased also but remained minor fractions of the total excreted radioactivity. After extinguishing the lights, these variables reverted gradually to control values. Spectral and chromotographic analysis of the excreted pigments and their azopigments demonstrated that the increased biliary radioactivity during phototherapy consisted of two roughly equal fractions: (a) unconjugated bilirubin, excreted at rates comparable to the output of conjugated bilirubin in the bile of normal nonjaundiced rats; and (b) water-soluble bilirubin derivatives, chromatographically identical with those found in Gunn rat bile under control lighting conditions but different from the products of photodecomposition of bilirubin in vitro. In some animals, phototherapy produced little decline in plasma bilirubin despite comparable acceleration of bilirubin catabolism. This was attributed tentatively to increased synthesis of early labeled bilirubin in these animals. PMID:5545128

  3. Role of human skin in the photodecomposition of bilirubin

    PubMed Central

    Kapoor, Chiranjiv L.; Murti, Coimbatore R. Krishna; Bajpai, Prakash C.

    1974-01-01

    1. Human skin epithelium and human skin were found to absorb both free bilirubin and serum-bound bilirubin from an aqueous buffered medium. The serum-bound bilirubin thus absorbed was readily released when human skin epithelium or human skin were transferred to media containing no bilirubin. 2. The Km values for serum-bound bilirubin were 1.8×10−3m and 2.2×10−3m respectively for human skin epithelium and human skin; corresponding Km values for free bilirubin were 3.0×10−4m and 5×10−4m. The Vmax. for bound and free bilirubin was of the same magnitude, the apparent Vmax. being 1.0 and 1.66μmol/g of tissue for human skin epithelium and human skin respectively. 3. When human skin that had acquired a yellow tinge by absorbing bilirubin was incubated in a buffered medium and exposed to a mercury-vapour light, the yellow colour disappeared and decomposition products of bilirubin accumulated in the medium. 4. Experiments with [3H]bilirubin indicated that the pigment absorbed by skin was photo-oxidized to products that were soluble in water and the quantity and number of such products increased with the time of exposure of human skin to the light-source. Under similar conditions [3H]bilirubin alone in buffered medium was also oxidized and gave products which by paper chromatography appeared to be different from those released by human skin that had absorbed bilirubin. 5. The results suggest that by virtue of its large surface area human skin can act as a matrix for the degradative action of light on bilirubin. PMID:4464841

  4. Atazanavir–bilirubin interaction: a pharmacokinetic–pharmacodynamic model

    PubMed Central

    Lozano, Roberto; Domeque, Nieves; Apesteguia, Alberto-Fermin

    2013-01-01

    Purpose The aim of this work was to analyze the atazanavir–bilirubin relationship, using a new mathematical approach to pharmacokinetic–pharmacodynamic models, for competitive drug interactions based on Michaelis–Menten equations. Patients and methods Because atazanavir induces an increase of plasma bilirubin levels, in a concentration-dependent manner, we developed a mathematical model, based on increments of atazanavir and bilirubin concentrations at steady state, in HIV infected (HIV+) patients, and plotted the corresponding nomogram for detecting suboptimal atazanavir exposure. Results By applying the obtained model, the results indicate that an absolute value or an increment of bilirubin at steady state below 3.8 μmol/L, are predictive of suboptimal atazanavir exposure and therapeutic failure. Conclusion We have successfully implemented a new mathematical approach to pharmacokinetic–pharmacodynamic model for atazanavir–bilirubin interaction. As a result, we found that bilirubin plasma levels constitute a good marker of exposure to atazanavir and of viral suppression. PMID:24106429

  5. Preliminary Development of a Fiber Optic Sensor for Measuring Bilirubin

    PubMed Central

    Babin, Steven M; Sova, Raymond M

    2014-01-01

    Preliminary development of a fiber optic bilirubin sensor is described, where an unclad sensing portion is used to provide evanescent wave interaction of the transmitted light with the chemical environment. By using a wavelength corresponding to a bilirubin absorption peak, the Beer–Lambert Law can be used to relate the concentration of bilirubin surrounding the sensing portion to the amount of absorbed light. Initial testing in vitro suggests that the sensor response is consistent with the results of bulk absorption measurements as well as the Beer–Lambert Law. In addition, it is found that conjugated and unconjugated bilirubin have different peak absorption wavelengths, so that two optical frequencies may potentially be used to measure both types of bilirubin. Future development of this device could provide a means of real-time, point-of-care monitoring of intravenous bilirubin in critical care neonates with hyperbilirubinemia. PMID:25057239

  6. Enzymatic assay for conjugated bilirubin (Bc) in serum using bilirubin oxidase (BOD).

    PubMed

    Kimura, S; Iyama, S; Yamaguchi, Y; Hayashi, S; Yanagihara, T

    1999-01-01

    We described an automated enzymatic assay for conjugated bilirubin (Bc) in serum using the Iatro D-Bil kit, with bilirubin oxidase (EC 1.3.3.5 BOD) from Myrothecium species. The specificity of the enzyme in the Iatro D-Bil kit was examined by analyzing unconjugated bilirubin (Bu), delta bilirubin (Bdelta), and Bc with high-performance liquid chromatography (HPLC), before and after the enzymatic reaction using BOD. The within-assay coefficients of variation (CV) of this method were 0.58 to 5.00% (n = 20) at 1.4 to 155.8 micromol/L. Day-to-day Cvs ranged from 1.61 to 7.14% at 1.2 to 182.1 micromol/L. The analytical recovery was 96 to 101%. The presence of ascorbic acid, reduced glutathione, L-cysteine, uric acid, urea, creatinine, glucose, lipemic material, anticoagulants, hemoglobin, or human serum albumin did not affect this assay system. The correlation coefficient between values obtained with the Iatro D-Bil kit (y) and HPLC method as reference for conjugated fractions (x) was; r = 0.983, y = 0.952x + 8.851 micromol/L, Sy/x = 11.97 (n = 56). We studied serum Bc levels, not including Bu and Bdelta, in patients with hepatic diseases or autoimmune hemolytic anemia. Levels of Bc obtained by the proposed method changed more rapidly than did those of direct bilirubin (D-Bil) obtained by diazo-dye method during the course of the diseases. Copyright 1999 Wiley-Liss, Inc.

  7. Bilirubin chemistry, ionization and solubilization by bile salts.

    PubMed

    Ostrow, J D; Celic, L

    1984-01-01

    Bilirubin is a linear tetrapyrrole whose conformation is affected by internal hydrogen bonds formed between the carboxyl side chains and dipyrromethenone rings. Structural variations include: constitutional isomerism of the vinyl or carboxyethyl side chains, geometric isomerism of the methene bridges, tautomerism of the lactam groups, conformational rotations about the central methylene bridge and ionization of one or both carboxyl groups. Aggregation of the dianion into dimers and multimers may occur. The pKa' values of the two carboxyl groups are affected greatly by the environment and may differ widely in micellar solutions like bile. Solubility of bilirubin in water is less than 1 nM at pH = 7 and about 0.1 microM at pH = 8. Nonetheless, it dissolves poorly in most lipid solvents, except for asymmetrical chloroalkanes. Hydrogen bond-breaking solvents, especially dimethyl sulfoxide, are most effective in solubilizing bilirubin. In bile salt solutions, solubility of bilirubin is well above the concentrations of unconjugated bilirubin found in normal human gallbladder bile, and is impaired by lecithin but unaffected by cholesterol. At physiological pH in bile salt solutions, bilirubin is predominantly in its monoanion form that binds readily to the micelles. In such solutions, addition of physiological concentrations of calcium precipitates calcium bilirubinate, leaving residual bilirubin concentrations of up to 15 microM in 50 mM taurocholate or close to the maximum bilirubin concentrations in normal bile. Studies in which disodium bilirubinate is dissolved in bile salt solutions and pH is adjusted to the physiological range reveal that metastable supersaturation with bilirubin may occur and that a mesophase may also form in the presence of lecithin, akin to that seen with cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Bilirubin and Stroke Risk Using a Mendelian Randomization Design.

    PubMed

    Lee, Sun Ju; Jee, Yon Ho; Jung, Keum Ji; Hong, Seri; Shin, Eun Soon; Jee, Sun Ha

    2017-05-01

    Circulating bilirubin, a natural antioxidant, is associated with decreased risk of stroke. However, the nature of the relationship between the two remains unknown. We used a Mendelian randomization analysis to assess the causal effect of serum bilirubin on stroke risk in Koreans. The 14 single-nucleotide polymorphisms (SNPs) (<10(-7)) including rs6742078 of uridine diphosphoglucuronyl-transferase were selected from genome-wide association study of bilirubin level in the KCPS-II (Korean Cancer Prevention Study-II) Biobank subcohort consisting of 4793 healthy Korean and 806 stroke cases. Weighted genetic risk score was calculated using 14 SNPs selected from the top SNPs. Both rs6742078 (F statistics=138) and weighted genetic risk score with 14 SNPs (F statistics=187) were strongly associated with bilirubin levels. Simultaneously, serum bilirubin level was associated with decreased risk of stroke in an ordinary least-squares analysis. However, in 2-stage least-squares Mendelian randomization analysis, no causal relationship between serum bilirubin and stroke risk was found. There is no evidence that bilirubin level is causally associated with risk of stroke in Koreans. Therefore, bilirubin level is not a risk determinant of stroke. © 2017 American Heart Association, Inc.

  9. Enzymic oxidation of unconjugated bilirubin by rat liver.

    PubMed Central

    Cardenas-Vazquez, R; Yokosuka, O; Billing, B H

    1986-01-01

    The presence of the enzyme bilirubin oxidase, which degrades bilirubin in vitro, was demonstrated in the liver. Subcellular-fractionation experiments indicate that bilirubin oxidase is located in both the inner and outer membranes of the mitochondria. The mean rate of the reaction is 1.57 +/- 0.38 (S.D.) nmol of bilirubin degraded/min per mg of mitochondrial protein (munits/mg of protein). With respect to the overall breakdown of bilirubin, the enzyme has a Km' of 136 microM-bilirubin and a Vmax.' of 9.13 munits/mg of protein. Its activity is influenced by the ionic strength of the media and is inhibited by KCN, thiol reagents, NADH and albumin. The enzyme is aerobic, and between 1 and 1.5 mol of O2 are consumed per mol of bilirubin degraded. The products of the reaction include propentdyopents. The hepatic bilirubin oxidase activity of the jaundiced Gunn-rat liver is not significantly different from that of the Sprague-Dawley rat, and it is not induced by beta-naphthoflavone. PMID:3790083

  10. Serum bilirubin levels and cardiovascular disease risk: a Janus Bifrons?

    PubMed

    Franchini, Massimo; Targher, Giovanni; Lippi, Giuseppe

    2010-01-01

    This review examines in vitro and in vivo studies, indicating that bilirubin inhibits lipid oxidation and oxygen radical formation. Experimental and epidemiological evidence is presented that suggests that bilirubin may serve as a physiological antioxidant providing protection against cardiovascular disease. Special attention is focused on large prospective studies that noted a strong, inverse relationship between serum bilirubin concentrations and cardiovascular morbidity and mortality even after adjustment for traditional risk factors. Overall, the evidence from these studies suggests that bilirubin, via its antioxidant potential, has antiatherogenic properties, and that serum bilirubin concentrations in the upper portion of the reference interval for the general population may provide some protection against cardiovascular disease, whereas concentrations in the lower portion of the reference interval indicate increased cardiovascular risk.

  11. Conjugated Bilirubin Triggers Anemia by Inducing Erythrocyte Death

    PubMed Central

    Lang, Elisabeth; Gatidis, Sergios; Freise, Noemi F; Bock, Hans; Kubitz, Ralf; Lauermann, Christian; Orth, Hans Martin; Klindt, Caroline; Schuier, Maximilian; Keitel, Verena; Reich, Maria; Liu, Guilai; Schmidt, Sebastian; Xu, Haifeng C; Qadri, Syed M; Herebian, Diran; Pandyra, Aleksandra A; Mayatepek, Ertan; Gulbins, Erich; Lang, Florian; Häussinger, Dieter; Lang, Karl S; Föller, Michael; Lang, Philipp A

    2015-01-01

    Hepatic failure is commonly associated with anemia, which may result from gastrointestinal bleeding, vitamin deficiency, or liver-damaging diseases, such as infection and alcohol intoxication. At least in theory, anemia during hepatic failure may result from accelerated clearance of circulating erythrocytes. Here we show that bile duct ligation (BDL) in mice leads to severe anemia despite increased reticulocyte numbers. Bilirubin stimulated suicidal death of human erythrocytes. Mechanistically, bilirubin triggered rapid Ca2+ influx, sphingomyelinase activation, formation of ceramide, and subsequent translocation of phosphatidylserine to the erythrocyte surface. Consistent with our in vitro and in vivo findings, incubation of erythrocytes in serum from patients with liver disease induced suicidal death of erythrocytes in relation to their plasma bilirubin concentration. Consistently, patients with hyperbilirubinemia had significantly lower erythrocyte and significantly higher reticulocyte counts compared to patients with low bilirubin levels. Conclusion: Bilirubin triggers suicidal erythrocyte death, thus contributing to anemia during liver disease. (Hepatology 2015;61:275–284) PMID:25065608

  12. Conjugated bilirubin in neonates with glucose-6-phosphate dehydrogenase deficiency.

    PubMed

    Kaplan, M; Rubaltelli, F F; Hammerman, C; Vilei, M T; Leiter, C; Abramov, A; Muraca, M

    1996-05-01

    We used a system capable of measuring conjugated bilirubin and its monoconjugated and diconjugated fractions in serum to assess bilirubin conjugation in 29 glucose-6-phosphate dehydrogenase (G6PD)-deficient, term, male newborn infants and 35 control subjects; all had serum bilirubin levels > or = 256 mumol/L (15 mg/dI). The median value for diconjugated bilirubin was lower in the G6PD-deficient neonates than in control subjects (0.06 (range 0.00 to 1.84) vs 0.21 (range 0.00 to 1.02) mumol/L, p = 0.006). Diglucuronide was undetectable in 11 (38.9%) of the G6PD-deficient infants versus 3 (8.6%) of the control subjects (p = 0.015). These findings imply a partial defect of bilirubin conjugation not previously demonstrated in G6PD-deficient newborn infants.

  13. Laser Transcutaneous Bilirubin Meter: A New Device For Bilirubin Monitoring In Neonatal Jaundice

    NASA Astrophysics Data System (ADS)

    Hamza, Mostafa; Hamza, Mohammad

    1988-06-01

    Neonates with jaundice require monitoring of serum bilirubin which should be repeated at frequent intervals. However, taking blood samples from neonates is not always an easy job, plus being an invasive and traumatising procedure with the additional risk of blood loss. In this paper the authors present the theory and design of a new noninvasive device for transcutaneous bilirubinometry, using a differential absorption laser system. The new technique depends upon illuminating the skin of the neonate with radiation from a two wave-length oscillation laser. The choice of the wavelengths follows the principles of optical bilirubinometry. For obtaining more accurate measurements, different pairs of two wave-lengths are incorporated in the design. The presence of hemoglobin is corrected for by appropriate selection of the laser wavelengths. The new design was tested for accuracy and precision using an argon ion laser. Correlation study between serum bilirubin determination by laser transcutaneous bilirubinometry and by American optical bilirubinometer was highly significant.

  14. Bilirubin conjugates of human bile. Isolation of phenylazo derivatives of bile bilirubin

    PubMed Central

    Kuenzle, Clive C.

    1970-01-01

    A method is presented that allows the isolation of eight different phenylazo derivatives of bile bilirubin. In step I of the isolation procedure, three bilirubin fractions (bilirubin fractions 1, 2 and 3) from human hepatic bile are separated by reverse-phase partition chromatography on silicone-treated Celite with the use of a solvent system prepared from butan-1-ol and 5mm-phosphate buffer, pH6.0. Azo coupling is then performed with diazotized aniline. The three azo pigment mixtures are subjected to step II, in which the above chromatography system is used again. With each azo pigment mixture this step brings about the separation of a non-polar and a polar azo pigment fraction (azo 1A and azo 1B, azo 2A and azo 2B, and azo 3A and azo 3B from bilirubin fractions 1, 2 and 3 respectively). Approximately equal amounts of non-polar and polar pigments are obtained from bilirubin fractions 1 and 2, whereas bilirubin fraction 3 yields azo 3B almost exclusively. In step IIIA the non-polar azo pigment fractions are fractionated further by adsorption chromatography on anhydrous sodium sulphate with the use of chloroform followed by a gradient of ethyl acetate in chloroform. Three azo pigments are thus obtained from both azo 2A (azo 2A1, azo 2A2 and azo 2A3) and azo 3A (azo 3A1, azo 3A2 and azo 3A3). The 2A pigments occur in approximately the following proportions: azo 2A1, 90%; azo 2A2, 10%; azo 2A3, traces. The pigments are purified by crystallization, except for the A3 pigments, which are probably degradation products arising from the corresponding A2 pigments. In step IIIB the polar azo pigment fractions are subjected to reverse-phase partition chromatography on silicone-treated Celite with the use of a solvent system prepared from octan-1-ol–di-isopropyl ether–ethyl acetate–methanol–0.2m-acetic acid (1:2:2:3:4, by vol.). Azo pigment fractions 2B and 3B each yield six azo pigments (azo 2B1 to azo 2B6 and azo 3B1 to azo 3B6 respectively) together with small

  15. Trans-Cutaneous Bilirubinometery versus Serum Bilirubin in Neonatal Jaundice.

    PubMed

    Mahram, Manoochehr; Oveisi, Sonia; Jaberi, Najmeh

    2015-12-01

    Hyperbilirubinemia is a common problem in neonates and causes serious complications. Thus, serial measurements of bilirubin should be done. This assessment is done through two methods of laboratory measurement in serum sample and transcutaneous bilirubinometer. This descriptive study compared transcutaneous bilirubin assessment and laboratory serum bilirubin. Bilirubin level was assessed among 256 neonates admitted to the Qods Children's Hospital in Qazvin- Iran, because of neonatal indirect jaundice, through two methods of transcutaneous bilirubinometery from two sites of forehead and sternum and laboratory measurement of bilirubin in serum. The cases were non-hemolytic icteric term neonates weighing 2500 gram or more and had not received phototherapy or other treatments. Neonates with hemolytic forms of jaundice, sepsis and suspicious to metabolic disorders were excluded. Assessments by means of KJ-8000 transcutaneous bilirubinometer from two sites of forehead and sternum and through laboratory measurement of serum bilirubin were registered and analyzed. The results of the current study showed that there was a correlation of 0.82 between serum bilirubin and transcutaneous forehead bilirubin assessment and for the used device sensitivity of 0.844; specificity of 0.842, Youden Index of 0.709 and Shortest of 0.042 for a cut-off of 12.4 in bilirubin of participants. Furthermore, Likelihood Ratio positive and negative (LR) were 5.665 and 0.164, respectively and diagnostic Odds Ratio (LR+/LR-) was 34.56. Transcutaneous bilirubinometery can be considered as a reliable tool to assess bilirubin for the screening of neonatal jaundice in term neonates.

  16. The Bilirubin Binding Panel: A Henderson-Hasselbalch Approach to Neonatal Hyperbilirubinemia.

    PubMed

    Ahlfors, Charles E

    2016-10-01

    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.

  17. The Relationship Between Serum Bilirubin Concentration and Atrial Fibrillation

    PubMed Central

    Demir, Mehmet; Demir, Canan; Uyan, Umut; Melek, Mehmet

    2013-01-01

    Background Several studies have demonstrated that higher serum bilirubin inhibits the inflammation and proliferation of vascular smooth muscle cells; also there is a relationship between serum bilirubin and cardiovascular disease. However, the relationship between bilirubin and atrial fibrillation (AF) is still unknown. In our study, we compared serum bilirubin, between nonvalvular AF patients and controls. Materials and Method One hundred and two patients with nonvalvular chronic AF without any other cardiovascular disease (mean age 62.51 ± 5.88) were included in our study. One hundred age-matched healthy people with sinus rhythm were accepted as control groups (mean age 61.35 ± 5.44). Routine biochemical parameters and serum bilirubin levels were performed. Results No statistically significant difference was found between two groups in terms of basic characteristics. Total, direct and indirect serum bilirubin levels were significantly lower among persons with AF compared to controls (0.82 ± 0.8 vs. 0.48 ± 0.5, 0.30 ± 0.2 vs. 0.19 ± 0.1 and 0.52 ± 0.5 vs. 0.29 ± 0.3 mg/dL; all P < 0.001, respectively). Conclusion As a result, our study revealed a relationship between serum bilirubin and nonvalvular AF.

  18. Influence of assessment site in measuring transcutaneous bilirubin

    PubMed Central

    da Conceição, Cristiane Maria; Dornaus, Maria Fernanda Pellegrino da Silva; Portella, Maria Aparecida; Deutsch, Alice D'Agostini; Rebello, Celso Moura

    2014-01-01

    ABSTRACT Objective: To investigate the influence of the site of measurement of transcutaneous bilirubin (forehead or sternum) in reproducibility of results as compared to plasma bilirubin. Methods: A cohort study including 58 term newborns with no hemolytic disease. Transcutaneous measurements were performed on the forehead (halfway between the headline and the glabella, from the left toward the right side, making consecutive determinations, one-centimeter apart) and the sternum (five measurements, from the suprasternal notch to the xiphoid process with consecutive determinations, one-centimeter apart) using Bilicheck® (SpectRx Inc, Norcross, Georgia, USA). The correlation and agreement between both methods and plasma bilirubin were calculated. Results: There was a strong linear correlation between both determinations of serum bilirubin at the forehead and sternum (r=0.704; p<0.01 and r=0.653; p<0.01, respectively). There was correspondence of the mean values of transcutaneous bilirubin measured on the sternum (9.9±2.2mg/dL) compared to plasma levels (10.2±1.7mg/dL), but both differ from the values measured on the forehead (8.6±2.0mg/dL), p<0.05. Conclusion: In newborn term infants with no hemolytic disease, measuring of transcutaneous bilirubin on the sternum had higher accuracy as compared to serum bilirubin measurement on the forehead. PMID:24728239

  19. Association of abnormal plasma bilirubin with aggressive HCC phenotype

    PubMed Central

    Carr, Brian I.; Guerra, Vito; Giannini, Edoardo G.; Farinati, Fabio; Ciccarese, Francesca; Rapaccini, Gian Ludovico; Marco, Maria Di; Benvegnù, Luisa; Zoli, Marco; Borzio, Franco; Caturelli, Eugenio; Chiaramonte, Maria; Trevisani, Franco

    2014-01-01

    Background Cirrhosis-related abnormal liver function is associated with predisposition to HCC, features in several HCC classification systems and is an HCC prognostic factor. Aims To examine the phenotypic tumor differences in HCC patients with normal or abnormal plasma bilirubin levels. Methods A 2,416 patient HCC cohort was studied and dichotomized into normal and abnormal plasma bilirubin groups. Their HCC characteristics were compared for tumor aggressiveness features, namely blood AFP levels, tumor size, presence of PVT and tumor multifocality. Results In the total cohort, elevated bilirubin levels were associated with higher AFP levels, increased PVT and multifocality and lower survival, despite similar tumor sizes. When different tumor size terciles were compared, similar results were found, even for small tumor size patients. A multiple logistic regression model for PVT or tumor multifocality showed increased OddsRatios for elevated levels of GGTP, bilirubin and AFP and for larger tumor sizes. Conclusions HCC patients with abnormal bilirubin levels had worse prognosis than patients with normal bilirubin. They also had increased incidence of PVT and tumor multifocality and higher AFP levels, in patients with both small and larger tumors. The results show an association between bilirubin levels and indices of HCC aggressiveness. PMID:24787296

  20. ABC and VED Analysis in Medical Stores Inventory Control.

    PubMed

    Gupta, R; Gupta, K K; Jain, B R; Garg, R K

    2007-10-01

    The basic principle of inventory control is ABC based on cost criteria and VED on criticality. Based on ABC-VED matrix, economic analysis of drug expenditure of priced vocabulary of medical stores (PVMS) section 01 for the year 2003 of a 190 bedded service hospital was under taken. Out of 493 drugs in PVMS section 01, only 325 drugs were being used in the reference hospital. The total cost of drugs used was Rupees 55,23,503. Of these 325 drugs, 47(14.4%) drugs were Category A, consuming 70% of total expenditure, 73 (22.46 %) drugs Category B consuming 20% and rest 205 drugs (63.7 %) Category C drugs cost only 10% of expenditure. VED categorization done by consensus opinion of medical officers, found 24 (7.3%) drugs vital, 160 (49.3%) essential and rest 141 (43.3 %) desirable. On coupling the two techniques ABC-VED matrix was made and drugs were classified in to Category I (AV+BV+CV+AE+AD) comprising 68 drugs, Category II (BE + CE +BD) 159 and Category III (CD) 98 drugs. The management of Category I drugs was monitored by top management resulting in better control on the annual expenses and at the same time making available the vital Category II by middle and Category III at lower mangerial level.

  1. Transcutaneous bilirubin nomograms in African neonates

    PubMed Central

    Mabogunje, Cecilia A.; Imosemi, Donald O.; Emokpae, Abieyuwa A.

    2017-01-01

    Background The use of transcutaneous bilirubin (TcB) as a screening tool, based on relevant population-specific nomogram, or proxy for total serum bilirubin (TSB) levels in assessing the risk of subsequent hyperbilirubinemia is supported by several clinical guidelines on the management of neonatal hyperbilirubinemia. However, while TcB has been found to significantly over-estimate TSB in neonates of African-American ancestry, with variations across TcB devices, no nomogram has been specifically reported for this racial group. This study therefore set out to develop TcB nomograms for healthy late pre-term and term black African neonates derived from two widely used bilirubinometers. Methods A retrospective analysis of 12,377 TcB measurements obtained from 6,373 neonates in the first postnatal week, over a period of 48 months using Bilichek and JM-103 bilirubinometers. TcB percentiles were computed from hour-specific TcB values and nomograms developed for each of the screening devices. Predictive ability of the 75th and 95th percentiles to detect significant hyperbilirubinemia was evaluated between 24–96 hours of age. The 95th percentile curve was compared with those from other populations. Results The velocity of TcB rise at 75th and 95th percentiles was generally higher with JM-103 than Bilichek. Both percentiles also peaked at higher TcB levels with JM-103. The 95th percentile for both instruments showed a downward trend as from approximately 114 hours. Both instruments had high negative predictive values across the selected time-epochs and lower discriminatory ability than reported in non-black populations. Conclusions The predictive utility of TcB as a potential screening tool varies across devices in black African neonates with or without risk of significant hyperbilirubinemia, and lower than levels reported in non-black populations. Equipment-specific nomograms should be considered for TcB monitoring in this racial population where TSB is not routinely

  2. [Relationship of bilirubin to diseases caused by increased oxidative stress].

    PubMed

    Vítek, L

    2013-07-01

    Oxidative stress contributes importantly to pathogenesis of numerous civilization diseases, including cardiovascular diseases, cancer, as well as autoimmune and neurodegenerative conditions. Bilirubin is the major product of the heme catabolic pathway in the intravascular compartment. For long time, bilirubin was considered to be only a waste product, however, recent data from the last 2 decades have proved its important antioxidant properties, which contributes to defense against increased oxidative stress. Numerous experimental as well as clinical studies have demonstrated association between low bilirubin concentrations and cardiovascular diseases, diabetes, certain cancers, autoimunne diseases, such as lupus erythematodes, or rheumatoid arthritis or neurological psychiatric disorders, such as schizofrenia. On the other hand, subjects with mildly elevated blood bilirubin levels, typical for Gilbert syndrome, have decreased risk of these diseases.

  3. Methods for determination of conjugated bilirubin in rat faeces.

    PubMed

    Saxerholt, H; Midtvedt, T; Gustafsson, B E

    1984-10-01

    Conjugated bilirubin was prepared from the faeces of germ-free (GF) rats by three different preparative methods. The bilirubin conjugate preparations were coupled with diazotized ethyl anthranilate and the formed ethyl anthranilate azopigments were quantified spectrophotometrically and separated by thin-layer chromatography (tlc). The most polar azopigment was purified by tlc and subjected to ammonolysis followed by tlc of the released saccaride. As a result of this procedure, only glucuronic acid was detected as the conjugating saccaride thus indicating that the most polar azopigment prepared from GF rat faeces was the delta ethyl anthranilate azopigment. Reference azopigments were prepared from GF rat small intestinal contents and subjected to separation by tlc. The azopigment pattern was very similar to the pattern obtained with the faecal azopigment preparations and a maximum of ten separated azopigment spots were detected. The findings indicated that, in addition to bilirubin glucuronides, other bilirubin conjugates with unknown structure are excreted with the faeces of GF rats. One of the preparative methods used for the preparation of conjugated bilirubin from GF rat faeces was tested on faeces from conventional (CONV) rats. From these preparations, no ethyl anthranilate azopigments were formed, thus indicating that faeces from CONV rats is devoid of conjugated bilirubin.

  4. The clinical syndrome of bilirubin-induced neurologic dysfunction.

    PubMed

    Bhutani, Vinod K; Johnson-Hamerman, Lois

    2015-02-01

    Clinicians have hypothesized a spectrum of minor neurologic manifestations, consistent with neuroanatomical reports and collectively termed as a "syndrome of bilirubin-induced neurologic dysfunction (BIND)," which can occur in the absence of classical kernicterus. The current review builds on these initial reports with a focus on clinical signs and symptoms that are assessed by standardized tools and manifest from neonatal age to childhood. These clinical manifestations are characterized by the following domains: (i) neuromotor signs; (ii) muscle tone abnormalities; (iii) hyperexcitable neonatal reflexes; (iv) variety of neurobehavior manifestations; (v) speech and language abnormalities; and (vi) evolving array of central processing abnormalities, such as sensorineural audiology and visuomotor dysfunctions. Concerns remain that the most vulnerable infants are likely to acquire BIND, either because their exposure to bilirubin is not identified as severe enough to need treatment or is prolonged but slightly below current threshold levels for intervention. Knowing that a total serum/plasma bilirubin (TB) level is not the most precise indicator of neurotoxicity, the role of expanded biomarkers or a "bilirubin panel" has yet to be validated in prospective studies. Future studies that correlate early "toxic" bilirubin exposure to long-term academic potential of children are needed to explore new insights into bilirubin's effect on the structural and functional maturation of an infant's neural network topology.

  5. Influence of drugs on albumin and bilirubin interaction.

    PubMed

    Funato, M; Lee, Y; Onishi, S; Cashore, W J

    1989-02-01

    Twenty-eight drugs, including cephem antibiotics and anti-inflammatory agents currently used or considered potentially useful in neonatal intensive care nurseries in Japan, were examined to determine their influence on albumin and bilirubin interaction by means of a glucose oxidase - peroxidase method, using an automated analyzer (Arrows) for unbound bilirubin (U.B.). The apparent binding constant for drugs to the high-affinity site on albumin (KD) was determined. Of cephem antibiotics, latamoxef sodium (LMOX) and cefazolin sodium (CEZ) were found to displace bilirubin from albumin (KD = 5.9 x 10(3) M-1 and 4.5 x 10(3) M-1, respectively) as strongly as Na salicylate (KD = 6.8 x 10(3) M-1). Mephenamate and indomethacin, which are used for medical closure of patent ductus arteriosus in premature infants, were also found to be stronger bilirubin displacers (KD = 1.3 x 10(5) M-1 and 1.2 x 10(5) M-1, respectively) than sulfisoxazole (KD = 1.6 x 10(4) M-1). Maximal displacement factors (MDF's) were also estimated in reference to protein binding (%) and effective serum concentration (M) of each drug in human adults. Of these drugs, mephenamate showed a higher risk of bilirubin displacement (MDF = 3.79) than sulfisoxazole (MDF = 2.58) and LMOX had a higher risk of displacement (MDF = 1.97) than Na salicylate (MDF = 1.85). On the other hand, indomethacin and CEZ showed minimal effects on displacement at therapeutic levels (MDF = 1.03 and 1.00, respectively). At therapeutic serum levels, mephenamate and LMOX may possess the potential for displacing bilirubin from albumin and increasing the risk of bilirubin encephalopathy, in a manner similar to sulfisoxazole.

  6. New insights in bilirubin metabolism and their clinical implications

    PubMed Central

    Sticova, Eva; Jirsa, Milan

    2013-01-01

    Bilirubin, a major end product of heme breakdown, is an important constituent of bile, responsible for its characteristic colour. Over recent decades, our understanding of bilirubin metabolism has expanded along with the processes of elimination of other endogenous and exogenous anionic substrates, mediated by the action of multiple transport systems at the sinusoidal and canalicular membrane of hepatocytes. Several inherited disorders characterised by impaired bilirubin conjugation (Crigler-Najjar syndrome type I and type II, Gilbert syndrome) or transport (Dubin-Johnson and Rotor syndrome) result in various degrees of hyperbilirubinemia of either the predominantly unconjugated or predominantly conjugated type. Moreover, disrupted regulation of hepatobiliary transport systems can explain jaundice in many acquired liver disorders. In this review, we discuss the recent data on liver bilirubin handling based on the discovery of the molecular basis of Rotor syndrome. The data show that a substantial fraction of bilirubin conjugates is primarily secreted by MRP3 at the sinusoidal membrane into the blood, from where they are subsequently reuptaken by sinusoidal membrane-bound organic anion transporting polypeptides OATP1B1 and OATP1B3. OATP1B proteins are also responsible for liver clearance of bilirubin conjugated in splanchnic organs, such as the intestine and kidney, and for a number of endogenous compounds, xenobiotics and drugs. Absence of one or both OATP1B proteins thus may have serious impact on toxicity of commonly used drugs cleared by this system such as statins, sartans, methotrexate or rifampicin. The liver-blood cycling of conjugated bilirubin is impaired in cholestatic and parenchymal liver diseases and this impairment most likely contributes to jaundice accompanying these disorders. PMID:24151358

  7. Validation of a transcutaneous bilirubin meter in Mongolian neonates: comparison with total serum bilirubin.

    PubMed

    Akahira-Azuma, Moe; Yonemoto, Naohiro; Ganzorig, Battsengel; Mori, Rintaro; Hosokawa, Shinichi; Matsushita, Takeji; Bavuusuren, Bayasgalantai; Shonkhuuz, Enkhtur

    2013-09-27

    Neonatal hyperbilirubinemia, especially kernicterus, can be prevented by screening for neonatal jaundice. The transcutaneous bilirubin (TcB) meter is a non-invasive medical device for screening neonates. The study aimed to investigate the validity of a TcB meter in a resource-limited setting such as Mongolia. Term and late preterm neonates from the National Center for Maternal and Child Health of Ulaanbaatar in Mongolia who met the inclusion criteria (gestational age ≥35 weeks, birth weight ≥2000 g, postnatal age ≤ 1 month) were enrolled in the study. We used a TcB meter, JM-103 to screen for neonatal jaundice. TcB measurements at the infant's forehead and midsternum were performed within 3 h of obtaining samples for total serum bilirubin (TSB) measurement. We analyzed the correlation between TcB measurements and TSB measurements to validate the meter. A total of 47 term and six late preterm neonates were included in the study. TcB measured by the meter at both the forehead and the midsternum showed a strong correlation with TSB measured in the laboratory. The correlation equations were TSB = 1.409+0.8655 × TcB (R2=0.78871) at the forehead, and TSB = 0.7555+0.8974 × TcB (R2=0.78488) at the midsternum. Bland-Altman plots and the Bradley-Blackwood test showed no significant differences between the two methods at all measured ranges of bilirubin. The mean areas under the curves of TcB at the forehead and midsternum at three TSB levels (>10 mg/dL, >13 mg/dL, >15 mg/dL) of TcB were greater than 0.9, and all had high sensitivity and specificity. This study established the validity of the JM-103 meter as a screening tool for neonatal jaundice in term and late preterm infants in Mongolia. Future studies are needed, including the establishment of a TcB hour-specific nomogram, for more effective clinical practice to prevent severe hyperbilirubinemia.

  8. Influence of hemoglobin on non-invasive optical bilirubin sensing

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Gong, Qiliang; Zou, Da; Xu, Kexin

    2012-03-01

    Since the abnormal metabolism of bilirubin could lead to diseases in the human body, especially the jaundice which is harmful to neonates. Traditional invasive measurements are difficult to be accepted by people because of pain and infection. Therefore, the real-time and non-invasive measurement of bilirubin is of great significance. However, the accuracy of currently transcutaneous bilirubinometry(TcB) is generally not high enough, and affected by many factors in the human skin, mostly by hemoglobin. In this talk, absorption spectra of hemoglobin and bilirubin have been collected and analyzed, then the Partial Least Squares (PLS) models have been built. By analyzing and comparing the Correlation and Root Mean Square Error of Prediction(RMSEP), the results show that the Correlation of bilirubin solution model is larger than that of the mixture solution added with hemoglobin, and its RMSEP value is smaller than that of mixture solution. Therefore, hemoglobin has influences on the non-invasive optical bilirubin sensing. In next step, it is necessary to investigate how to eliminate the influence.

  9. Chromatographic analysis and structure determination of biliverdins and bilirubins.

    PubMed

    Heirwegh, K P; Fevery, J; Blanckaert, N

    1989-11-10

    Recent applications of thin-layer chromatographic (TLC) and high-performance liquid chromatographic (HPLC) procedures has revealed an unexpected wide variety of naturally occurring unconjugated and conjugated bilirubins. Biliverdins seems to occur only in unconjugated forms, mainly as the IX alpha isomer. Several synthetic biliverdins and bilirubins present interesting models for biochemical and metabolic studies. Owing to recent recognition of the astounding heterogeneity of natural bilirubins and to the various artifactual changes that bile pigments can undergo, considerable confusion has existed, and still exists, with regard to the nomenclature of the bile pigments and their derivatives. To set a background for further discussion, the present review starts with a brief discussion of nomenclature and of the various characteristic forms of lability of the bile pigments. TLC and HPLC procedures for preparation and analysis of unconjugated biliverdins and bilirubins and their methyl ester and sugar ester conjugates, as well as procedures for analysis of bilirubin-protein conjugates, are then discussed. Since, in view of the lability and pronounced heterogeneity of bile pigments, it is important to assess the composition and nature of chromatographically isolated pigments, the review is concluded by a brief evaluation of various structural tests.

  10. Functional polyethersulfone particles for the removal of bilirubin.

    PubMed

    Jiang, Xin; Xiang, Tao; Xie, Yi; Wang, Rui; Zhao, Weifeng; Sun, Shudong; Zhao, Chang-Sheng

    2016-02-01

    In this study, polyethersulfone/poly (glycidyl methacrylate) particles are prepared via in situ cross-linked polymerization coupled with a phase inversion technique. The surfaces of these particles are then further modified by grafting amino groups using tetraethylenepentamine, dethylenetriamine, ethylenediamine, or 1,6-hexanediamine for the removal of bilirubin. The particles are characterized by Flourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Batch adsorption experiments are performed to verify the adsorption capability, and the effect of bilirubin initial concentration, bovine serum albumin concentration, and solution ionic strength on the adsorption is also investigated. In addition, both adsorption kinetic and isotherm models are applied to analyze the adsorption process of bilirubin, and a particle column is used to further study the bilirubin removal ability.To prove that the method was a universal portal to prepare functional particles, polysulfone, polystyrene, and poly(vinylidene fluoride) based functional particles were also prepared and used for the removal of bilirubin. This study and the results indicated that the particles had a great potential to be used in hemoperfusion treatment for hyperbilirubinemia.

  11. Conjugated bilirubin triggers anemia by inducing erythrocyte death.

    PubMed

    Lang, Elisabeth; Gatidis, Sergios; Freise, Noemi F; Bock, Hans; Kubitz, Ralf; Lauermann, Christian; Orth, Hans Martin; Klindt, Caroline; Schuier, Maximilian; Keitel, Verena; Reich, Maria; Liu, Guilai; Schmidt, Sebastian; Xu, Haifeng C; Qadri, Syed M; Herebian, Diran; Pandyra, Aleksandra A; Mayatepek, Ertan; Gulbins, Erich; Lang, Florian; Häussinger, Dieter; Lang, Karl S; Föller, Michael; Lang, Philipp A

    2015-01-01

    Hepatic failure is commonly associated with anemia, which may result from gastrointestinal bleeding, vitamin deficiency, or liver-damaging diseases, such as infection and alcohol intoxication. At least in theory, anemia during hepatic failure may result from accelerated clearance of circulating erythrocytes. Here we show that bile duct ligation (BDL) in mice leads to severe anemia despite increased reticulocyte numbers. Bilirubin stimulated suicidal death of human erythrocytes. Mechanistically, bilirubin triggered rapid Ca(2+) influx, sphingomyelinase activation, formation of ceramide, and subsequent translocation of phosphatidylserine to the erythrocyte surface. Consistent with our in vitro and in vivo findings, incubation of erythrocytes in serum from patients with liver disease induced suicidal death of erythrocytes in relation to their plasma bilirubin concentration. Consistently, patients with hyperbilirubinemia had significantly lower erythrocyte and significantly higher reticulocyte counts compared to patients with low bilirubin levels. Bilirubin triggers suicidal erythrocyte death, thus contributing to anemia during liver disease. © 2014 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases.

  12. Blood-brain interfaces and bilirubin-induced neurological diseases.

    PubMed

    Ghersi-Egea, J F; Gazzin, S; Strazielle, N

    2009-01-01

    The endothelium of the brain microvessels and the choroid plexus epithelium form highly specialized cellular barriers referred to as blood-brain interfaces through which molecular exchanges take place between the blood and the neuropil or the cerebrospinal fluid, respectively. Within the brain, the ependyma and the pia-glia limitans modulate exchanges between the neuropil and the cerebrospinal fluid. All these interfaces are key elements of neuroprotection and fulfill trophic functions; both properties are critical to harmonious brain development and maturation. By analogy to hepatic bilirubin detoxification pathways, we review the transport and metabolic mechanisms which in all these interfaces may participate in the regulation of bilirubin cerebral bioavailability in physiologic conditions, both in adult and in developing brain. We specifically address the role of ABC and OATP transporters, glutathione-S-transferases, and the potential involvement of glucuronoconjugation and oxidative metabolic pathways. Regulatory mechanisms are explored which are involved in the induction of these pathways and represent potential pharmacological targets to prevent bilirubin accumulation into the brain. We then review the possible alteration of the neuroprotective and trophic barrier functions in the course of bilirubin-induced neurological dysfunctions resulting from hyperbilirubinemia. Finally, we highlight the role of the blood-brain and blood-CSF barriers in regulating the brain biodisposition of candidate drugs for the treatment or prevention of bilirubin-induced brain injury.

  13. Fluorescent protein-based detection of unconjugated bilirubin in newborn serum

    PubMed Central

    Iwatani, Sota; Nakamura, Hajime; Kurokawa, Daisuke; Yamana, Keiji; Nishida, Kosuke; Fukushima, Sachiyo; Koda, Tsubasa; Nishimura, Noriyuki; Nishio, Hisahide; Iijima, Kazumoto; Miyawaki, Atsushi; Morioka, Ichiro

    2016-01-01

    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 out to compare unconjugated bilirubin levels measured by UnaG and conventional bilirubin oxidase methods. Unconjugated bilirubin levels in the serum of newborns who were untreated or treated with phototherapy were compared. Effects of interfering factors in the serum (conjugated bilirubin, hemoglobin, and lipid) on unconjugated bilirubin concentration measured by the UnaG method were also evaluated. Unconjugated bilirubin levels measured by the UnaG method were highly correlated with those determined by the bilirubin oxidase assay. Unconjugated bilirubin levels determined by bilirubin oxidase and UnaG assays were similar in serum samples containing conjugated bilirubin. The performance of the UnaG assay was unaffected by phototherapy and the presence of serum hemoglobin and lipid emulsion. These results demonstrate the clinical applicability of the UnaG method for direct measurement of unconjugated bilirubin levels in newborn serum. PMID:27324682

  14. Enhanced removal of bilirubin on molecularly imprinted titania film.

    PubMed

    Yang, Zheng-peng; Yan, Jin-long; Zhang, Chun-jing; Luo, Shu-qiong

    2011-10-01

    Titania film imprinted by bilirubin molecule at the surface of quartz crystal was prepared using molecular imprinting and surface sol-gel process. The molecularly imprinted titania film was characterized by FTIR spectra, and the interaction between bilirubin and imprinted film was investigated using quartz crystal microbalance (QCM) technique. Compared with pure titania film, the molecularly imprinted titania film exhibits a much higher adsorption capacity for the target molecule, and the adsorption kinetic parameter estimated from the in situ frequency measurement is about 1.6×10(8) M(-1), which is ten times higher than that obtained on pure titania film. The photocatalytic measurements indicate that the bilirubin adsorbed on molecularly imprinted titania film can be completely removed under UV illumination. Moreover, our study indicates that the molecularly imprinted titania film possesses a better stability and reusability.

  15. Bilirubin oxidation products, oxidative stress, and intracerebral hemorrhage

    PubMed Central

    Clark, J. F.; Loftspring, M.; Wurster, W. L.; Beiler, S.; Beiler, C; Wagner, K. R.; Pyne-Geithman, G. J.

    2009-01-01

    Summary Hematoma and perihematomal regions after intracerebral hemorrhage (ICH) are biochemically active environments known to undergo potent oxidizing reactions. We report facile production of bilirubin oxidation products (BOXes) via hemoglobin/Fenton reaction under conditions approximating putative in vivo conditions seen following ICH. Using a mixture of human hemoglobin, physiological buffers, unconjugated solubilized bilirubin, and molecular oxygen and/or hydrogen peroxide, we generated BOXes, confirmed by spectral signature consistent with known BOXes mixtures produced by independent chemical synthesis, as well as HPLC-MS of BOX A and BOX B. Kinetics are straightforward and uncomplicated, having initial rates around 0.002 μM bilirubin per μM hemoglobin per second under normal experimental conditions. In hematomas from porcine ICH model, we observed significant production of BOXes, malondialdehyde, and superoxide dismutase, indicating a potent oxidizing environment. BOX concentrations increased from 0.084 ± 0.01 in fresh blood to 22.24 ± 4.28 in hematoma at 72 h, and were 11.22 ± 1.90 in adjacent white matter (nmol/g). Similar chemical and analytical results are seen in ICH in vivo, indicating the hematoma is undergoing similar potent oxidations. This is the first report of BOXes production using a well-defined biological reaction and in vivo model of same. Following ICH, amounts of unconjugated bilirubin in hematoma can be substantial, as can levels of iron and hemoglobin. Oxidation of unconjugated bilirubin to yield bioactive molecules, such as BOXes, is an important discovery, expanding the role of bilirubin in pathological processes seen after ICH. PMID:19066073

  16. Galactosaemia: an unusual cause of chronic bilirubin encephalopathy

    PubMed Central

    Sahoo, Tanushree; Thukral, Anu; Agarwal, Ramesh; Sankar, Mari Jeeva

    2015-01-01

    Galactosaemia is a disorder of galactose metabolism in which raised levels of galactose and galactose-1-phosphate damage various organs. Although galactosaemia is a common metabolic liver disease in childhood, it is a rare cause of neonatal hyperbilirubinemia requiring intervention. We report an unusual case of neonatal galactosaemia that at presentation had features of acute bilirubin encephalopathy requiring exchange transfusion and at discharge had features of chronic bilirubin encephalopathy. This case report emphasises the need for timely suspicion and diagnosis of this disease for prevention of chronic morbidity. PMID:25618877

  17. Galactosaemia: an unusual cause of chronic bilirubin encephalopathy.

    PubMed

    Sahoo, Tanushree; Thukral, Anu; Agarwal, Ramesh; Sankar, Mari Jeeva

    2015-01-23

    Galactosaemia is a disorder of galactose metabolism in which raised levels of galactose and galactose-1-phosphate damage various organs. Although galactosaemia is a common metabolic liver disease in childhood, it is a rare cause of neonatal hyperbilirubinemia requiring intervention. We report an unusual case of neonatal galactosaemia that at presentation had features of acute bilirubin encephalopathy requiring exchange transfusion and at discharge had features of chronic bilirubin encephalopathy. This case report emphasises the need for timely suspicion and diagnosis of this disease for prevention of chronic morbidity.

  18. Studies on the molecular significance in the interaction of bilirubin with collagen.

    PubMed

    Nagarajan, Usharani; Gladstone Christopher, Jayakumar; Chandrasekaran, Bangaru; Jonnalagadda, Raghava Rao; Balachandran, Unni Nair; Kohsaku, Kawakami

    2013-10-01

    The present investigation is aimed to understand the physiological significance of bilirubin interaction with collagen. In human skin, collagen absorbs both free bilirubin and serum bound bilirubin from the human system. Interaction between bilirubin and collagen depends on time, temperature and concentration of bilirubin. There is an increase in the aggregation rate of collagen in the presence of biliruibin. At physiological condition, 125 nM of bilirubin is the maximum concentration absorbed by per mg of collagen molecule. Bilirubin accelerates the lateral growth of collagen fibrils by shifting its rate of nucleation. Moreover, collagen-bilirubin complex exhibit a tendency to undergo adsorption onto the surface of the fibroblast cells, showing detrimental effects on fibroblasts proliferations. Based on the collagen binding assays, the binding of bilirubin to collagen is found to be electrostatic in nature, which confirms binding between the amino acid fragment of α1 (I) region of collagen and carboxyl group of bilirubin. The biotinylated bilirubin derivatives show better binding to α1 (I) chain rather than α2 (I) chains which clearly designates that bilirubin shows greater affinity to α1 chains of collagen. This novel approach directs to reduce the occurrence of bilirubin in hyperbilirubinemia patients.

  19. Interaction of bilirubin with Ag and Au ions: green synthesis of bilirubin-stabilized nanoparticles

    NASA Astrophysics Data System (ADS)

    Shukla, Shashi P.; Roy, Mainak; Mukherjee, Poulomi; Tyagi, A. K.; Mukherjee, Tulsi; Adhikari, Soumyakanti

    2012-07-01

    We report a simple green chemistry to synthesize and stabilize monodispersed silver and gold nanoparticles sols by reducing aqueous solution of the respective metal salts in the presence of bilirubin (BR). No additional capping agent was used in the process of stabilization of the nanoparticles. As a completely new finding, we have observed that BR known to be toxic at higher concentration in one hand and conversely an antioxidant at physiological concentration reduces these metal ions to form the respective metal nanoparticles. Moreover, BR and its oxidized products also serve as capping agents to the nanoparticles. The particles were characterized by transmission electron microscopy. BR and its oxidized products capped nanoparticles are stable for months. The UV-Vis absorption spectra of the silver sol show the plasmon peak of symmetric spherical particles which was further reflected in the TEM images. The sizes of the silver particles were about 5 nm. These silver particles showed reasonably high antibacterial activity in Gram negative wild type E. coli. In the case of interaction of BR with gold ions, we could obtain cubic gold nanoparticles of average sizes 20-25 nm. Possible modes of anchorage of BR and/its oxidized products to silver nanoparticles were demonstrated by surface-enhanced resonance Raman spectroscopy (SERS) that in turn demonstrated the feasibility of using these nanoparticles as SERS substrates.

  20. Nanofibrous polymeric beads from aramid fibers for efficient bilirubin removal.

    PubMed

    Peng, Zihang; Yang, Ye; Luo, Jiyue; Nie, Chuanxiong; Ma, Lang; Cheng, Chong; Zhao, Changsheng

    2016-08-16

    Polymer based hemoperfusion has been developed as an effective therapy to remove the extra bilirubin from patients. However, the currently applied materials suffer from either low removal efficiency or poor blood compatibility. In this study, we report the development of a new class of nanofibrous absorbent that exhibited high bilirubin removal efficiency and good blood compatibility. The Kevlar nanofiber was prepared by dissolving micron-sized Kevlar fiber in proper solvent, and the beads were prepared by dropping Kevlar nanofiber solutions into ethanol. Owing to the nanofiborous structure of the Kevlar nanofiber, the beads displayed porous structures and large specific areas, which would facilitate the adsorption of toxins. In the adsorption test, it was noticed that the beads possessed an adsorption capacity higher than 40 mg g(-1) towards bilirubin. In plasma mimetic solutions, the beads still showed high bilirubin removal efficiency. Furthermore, after incorporating with carbon nanotubes, the beads were found to have increased adsorption capacity for human degradation waste. Moreover, the beads showed excellent blood compatibility in terms of a low hemolysis ratio, prolonged clotting times, suppressed coagulant activation, limited platelet activation, and inhibited blood related inflammatory activation. Additionally, the beads showed good compatibility with endothelial cells. In general, the Kevlar nanofiber beads, which integrated with high adsorption capacity, good blood compatibility and low cytotoxicity, may have great potential for hemoperfusion and some other applications in biomedical fields.

  1. Solar Irradiation of Bilirubin: An Experiment in Photochemical Oxidation

    ERIC Educational Resources Information Center

    Pillay A. E.; Salih, F. M.

    2006-01-01

    An experiment in photochemical oxidation, which deals with bilirubin, a well-known light-sensitive biological compound that is pedagogically ideal for photochemical experiments at tertiary institutes, is presented. The experiment would benefit students in chemistry who eventually branch out into the health sciences or biochemistry.

  2. Visual inspection versus spectrophotometry in detecting bilirubin in cerebrospinal fluid

    PubMed Central

    Linn, F; Voorbij, H; Rinkel, G; Algra, A; van Gijn, J

    2005-01-01

    Methods: Clinicians and students assessed CSF specimens with seven degrees of extinction between 0.00 and 0.09 at 450–460 nm as "yellow," "doubtful," or "colourless" after random presentation under standard conditions. The assessments were compared with spectrophotometry, with 0.05 being taken as the cut off level for the presence of bilirubin. Results were compared between the two groups and explored by means of receiver operating characteristic (ROC) curves. Results: All 51 clinicians and 50 of 51 students scored the tubes with extinction of 0.06 or higher as "yellow" or "doubtful." Tubes without any bilirubin were scored as "yellow" by three of the students only. The ROC curves confirmed that the diagnostic properties of the visual inspection versus spectrophotometry were slightly better for the clinicians than for the students. Conclusions: If CSF is considered colourless, the extinction of bilirubin is too low to be compatible with a diagnosis of recent subarachnoid haemorrhage. If CSF is not considered colourless, spectrophotometry should be carried out to determine the level of extinction of bilirubin. PMID:16170095

  3. Solar Irradiation of Bilirubin: An Experiment in Photochemical Oxidation

    ERIC Educational Resources Information Center

    Pillay A. E.; Salih, F. M.

    2006-01-01

    An experiment in photochemical oxidation, which deals with bilirubin, a well-known light-sensitive biological compound that is pedagogically ideal for photochemical experiments at tertiary institutes, is presented. The experiment would benefit students in chemistry who eventually branch out into the health sciences or biochemistry.

  4. Enzymatic Removal of Bilirubin from Blood: A Potential Treatment for Neonatal Jaundice

    NASA Astrophysics Data System (ADS)

    Lavin, Arthur; Sung, Cynthia; Klibanov, Alexander M.; Langer, Robert

    1985-11-01

    Current treatments for severe jaundice can result in major complications. Neonatal jaundice is caused by excessive accumulation of bilirubin in the blood. A small blood filter containing immobilized bilirubin oxidase was developed to reduce serum bilirubin concentrations. When human or rat blood was passed through the enzyme filter, more than 90 percent of the bilirubin was degraded in a single pass. This procedure may have important applications in the clinical treatment of neonatal jaundice.

  5. The biliverdin-bilirubin antioxidant cycle of cellular protection: Missing a wheel?

    PubMed

    McDonagh, Antony F

    2010-09-01

    Bilirubin reportedly protects cultured cells from the toxicity of a 10,000-fold molar excess of H(2)O(2). A bilirubin-biliverdin cycling mechanism has been proposed to explain this remarkable effect whereby bilirubin reacts with oxyradicals specifically generating biliverdin, which is then reduced back to bilirubin by NADPH/biliverdin reductase. Chemical evidence for this mechanism was formation of biliverdin during incubation of bilirubin-albumin with 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) in vitro and the assumption that biliverdin was formed by the reaction of peroxyl radicals with bilirubin. This paper describes spectroscopic studies on the reaction of bilirubin with AAPH in the presence and absence of human serum albumin. Reactions were run in air and also under oxygen-depleted and oxygen-saturated solutions, the former to inhibit peroxyl radical formation, the latter to augment it. The results confirm that degradation of bilirubin, rather than dehydrogenation to biliverdin, predominates in the reaction of bilirubin with peroxyl radicals generated by AAPH thermolysis. They also suggest that biliverdin produced in the presence of albumin is not formed by the reaction of bilirubin with alkyl peroxyl radicals, as previously assumed. The observations undermine the plausibility of the bilirubin-biliverdin recycling mechanism proposed to explain the reported hyperprotective effect of bilirubin on mammalian cells exposed to excess H(2)O(2). Copyright 2010 Elsevier Inc. All rights reserved.

  6. Distant Determination of Bilirubin Distribution in Skin by Multi-Spectral Imaging

    NASA Astrophysics Data System (ADS)

    Saknite, I.; Jakovels, D.; Spigulis, J.

    2011-01-01

    For mapping the bilirubin distribution in bruised skin the multi-spectral imaging technique was employed, which made it possible to observe temporal changes of the bilirubin content in skin photo-types II and III. The obtained results confirm the clinical potential of this technique for skin bilirubin diagnostics.

  7. Determination of bilirubin by thermal lens spectrometry and studies of its transport into hepatic cells

    NASA Astrophysics Data System (ADS)

    Margon, A.; Terdoslavich, M.; Cocolo, A.; Decorti, G.; Passamonti, S.; Franko, M.

    2005-06-01

    The liver is responsible for clearance of bilirubin, the end product of heme catabolism, from the bloodstream. The main aim of our investigation was to determine the role of the carrier protein bilitranslocase in bilirubin uptake into the liver. Our experiments consisted of exposing cell cultures to bilirubin solutions under different conditions and measuring the uptake of bilirubin into the cells. However, since bilirubin is only slightly soluble in aqueous solution (< 70 nM at pH 7.4), we had to use bilirubin concentrations that are far below the limit of detection of the commonly used techniques (e.g. LOD for HPLC with UV-Vis detection \\cong 10 μM). TLS showed up to be a suitable technique for investigation of bilirubin uptake with an LOD of 2 nM. Under basal conditions, bilirubin uptake did not occur. However, increase of cytosolic NADH due to catabolism of specific substrates (e.g. lactate or ethanol) seemed to trigger bilirubin uptake. Furthermore, bilirubin uptake was completely inhibited by addition of specific anti-bilitranslocase antibodies. We can thus infer that, under these conditions, bilitranslocase is the main bilirubin transporter.

  8. Bilirubin exerts pro-angiogenic property through Akt-eNOS-dependent pathway.

    PubMed

    Ikeda, Yasumasa; Hamano, Hirofumi; Satoh, Akiho; Horinouchi, Yuya; Izawa-Ishizawa, Yuki; Kihira, Yoshitaka; Ishizawa, Keisuke; Aihara, Ken-Ichi; Tsuchiya, Koichiro; Tamaki, Toshiaki

    2015-11-01

    Low serum bilirubin levels are associated with the risk of cardiovascular diseases including peripheral artery disease. Bilirubin is known to exert its property such as antioxidant effect or the enhancement of flow-mediated vasodilation, however, bilirubin action on angiogenesis remains unclear. To investigate the molecular mechanism of bilirubin on angiogenic effect, we first employed C57BL/6J mice with unilateral hindlimb ischemia surgery and divided the mice into two groups (vehicle-treated group and bilirubin-treated group). The analysis of laser speckle blood flow demonstrated the enhancement of blood flow recovery in response to ischemia of mice with bilirubin treatment. The density of capillaries was significantly higher in ischemic-adductor muscles of bilirubin-treated mice. The phosphorylated levels of endothelial nitric oxide synthase (eNOS) and Akt were increased in ischemic skeletal muscles of mice with bilirubin treatment compared with vehicle treatment. In in vitro experiments by using human aortic endothelial cells, bilirubin augmented eNOS and Akt phosphorylation, cell proliferation, cell migration and tube formation. These bilirubin actions on endothelial cell activation were inhibited by LY294002, a phosphatidylinositol 3-kinase inhibitor. In conclusion, bilirubin promotes angiogenesis through endothelial cells activation via Akt-eNOS-dependent manner.

  9. Photodamage of the cells in culture sensitized with bilirubin

    NASA Astrophysics Data System (ADS)

    Kozlenkova, O. A.; Plavskaya, L. G.; Mikulich, A. V.; Leusenko, I. A.; Tretyakova, A. I.; Plavskii, V. Yu

    2016-08-01

    It has been shown that exposure to radiation of LED sources of light with an emission band maximum at about 465 and 520 nm having substantially identical damaging effects on animal cells in culture, that are in a logarithmic growth phase and preincubated with pigment. Photobiological effect is caused by photodynamic processes involving singlet oxygen generated by triplet excited sensitizer. Mono-exponential type dependence of cell survival on the energy dose indicates that it is bilirubin that acts as a sensitizer but not its photoproducts. The inclusion of bilirubin in the cells, where it is primarily localized in the mitochondria cells, it is accompanied by multiple amplification photochemical stability compared to pigment molecules bound with albumin

  10. In Vitro Determination of Skin Bilirubin Using Chromatic Modulation

    DTIC Science & Technology

    2007-11-02

    bilirubi- nometry: Its role in the assessment of neonatal jaundice ,” Clinical Biochemistry, vol. 30, pp. 1-9, 1997. [4] H. Varley, Practical...serum bilirubin (SB) and a chromatic parameter, namely Hue angle (H). The chromatic TcB results are highly predictive of SB levels in neonatal babies...The proposed chromatic system can be used to make decisions about transfusions or phototherapy in neonates , hence acting as a screening device to

  11. Study on dissolution and disintegration of calcium bilirubinate stone.

    PubMed

    Nakamura, Y; Suzuki, N; Takahashi, W; Sato, T

    1978-06-01

    When a slice of calcium bilirubinate stone was incubated in a solution of tetrasodium salt of ethylendiamine-tetraacetic acid (EDTA.4Na), a potent chelating agent, the solution exhibited a yellow brown tint, which was spectroscopically characteristic of bilirubin. Microscopic examination of the slice revealed dissolution of granules of calcium bilirubinate, leaving behind a reticular matrix of PAS-positive substance. The effect of EDTA.4Na was influenced by pH, being fully effective only at pH 10 or more, and by temperature and concentration as well. Simultaneous application of bile salt enhanced the activity of EDTA.4Na, hydrophilizing the gallstone surface to facilitate chelating reaction and also dissolving minor fatty components of the stone. Heparin at proper concentrations also promoted disintegration of the stone, changing surface potential of its constituent particles to the dispersion-prone charge. The effect of composite EDTA.4Na-bile salt-heparin was thus significantly greater than that of single EDTA.4Na. This mixture is promising for clinical application as a means of direct dissolution of residual gallstones.

  12. Bilirubin oxidation products (BOXes): synthesis, stability and chemical characteristics

    PubMed Central

    Wurster, W. L.; Pyne-Geithman, G. J.; Peat, I. R.; Clark, J. F.

    2009-01-01

    Summary Bilirubin oxidation products (BOXes) have been a subject of interest in neurosurgery because they are purported to be involved in subarachnoid hemorrhage induced cerebral vasospasm. There is a growing body of information concerning their putative role in vasospasm; however, there is a dearth of information concerning the chemical and biochemical characteristics of BOXes. A clearer understanding of the synthesis, stability and characteristics of BOXes will be important for a better understanding of the role of BOXes post subarachnoid hemorrhage. We used hydrogen peroxide to oxidize bilirubin and produce BOXes. BOXes were extracted and analyzed using conventional methods such as HPLC and mass spectrometry. Characterization of the stability BOXes demonstrates that light can photodegrade BOXes with a t1/2 of up to 10 h depending upon conditions. Mixed isomers of BOXes have an apparent extinction coefficient of ε = 6985, and a λmax of 310 nm. BOXes are produced by the oxidation of bilirubin, yielding a mixture of isomers: 4-methyl-5-oxo-3-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide (BOX A) and 3-methyl-5-oxo-4-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide (BOX B). The BOXes are photodegraded by ambient light and can be analyzed spectrophotometrically with their extinction coefficient as well as with HPLC or mass spectrometry. Their small molecular weight and photodegradation may have made them difficult to characterize in previous studies. PMID:18456996

  13. Plasma bilirubin level and oxidative stress in preterm infants

    PubMed Central

    Dani, C; Martelli, E; Bertini, G; Pezzati, M; Filippi, L; Rossetti, M; Rizzuti, G; Rubaltelli, F

    2003-01-01

    Objective: To assess the hypothesis that changes in plasma total bilirubin levels (Btot) can influence the antioxidant system and oxidative stress in preterm infants. Methods: Twenty two healthy preterm infants who presented with visible non-haemolytic hyperbilirubinaemia were studied at the mean (SD) age of 3.7 (1.5) days. Btot, plasma total hydroperoxide concentration (TH), plasma protein SH group concentration, and total antioxidant capacity of the plasma (TAC) were measured at study entry and after 24 hours. Results: Btot did not correlate with TH, TAC, or protein SH group concentration, but a significant correlation was found between TH and TAC, TH and protein SH groups, and TAC and protein SH groups, both at study entry and after 24 hours. Conclusion: The decrease in plasma bilirubin was contemporary with an increase in plasma antioxidant capacity and decrease in oxidative stress in preterm infants. This may be the result of the pro-oxidant effect of haem oxygenase, mediated by iron release, which may outcompete the antioxidant properties of bilirubin. PMID:12598500

  14. Plasma bilirubin level and oxidative stress in preterm infants.

    PubMed

    Dani, C; Martelli, E; Bertini, G; Pezzati, M; Filippi, L; Rossetti, M; Rizzuti, G; Rubaltelli, F F

    2003-03-01

    To assess the hypothesis that changes in plasma total bilirubin levels (Btot) can influence the antioxidant system and oxidative stress in preterm infants. Twenty two healthy preterm infants who presented with visible non-haemolytic hyperbilirubinaemia were studied at the mean (SD) age of 3.7 (1.5) days. Btot, plasma total hydroperoxide concentration (TH), plasma protein SH group concentration, and total antioxidant capacity of the plasma (TAC) were measured at study entry and after 24 hours. Btot did not correlate with TH, TAC, or protein SH group concentration, but a significant correlation was found between TH and TAC, TH and protein SH groups, and TAC and protein SH groups, both at study entry and after 24 hours. The decrease in plasma bilirubin was contemporary with an increase in plasma antioxidant capacity and decrease in oxidative stress in preterm infants. This may be the result of the pro-oxidant effect of haem oxygenase, mediated by iron release, which may outcompete the antioxidant properties of bilirubin.

  15. Hepatic disposition and biliary excretion of bilirubin and bilirubin glucuronides in intact rats. Differential processing of pigments derived from intra- and extrahepatic sources.

    PubMed Central

    Crawford, J M; Ransil, B J; Potter, C S; Westmoreland, S V; Gollan, J L

    1987-01-01

    Mechanisms for transport of bilirubin and its conjugates in hepatocytes have not been defined. We investigated the hepatic processing of bilirubin glucuronides and their precursors, and characterized the disposition of bile pigments arising from intraversus extrahepatic sources. Tracer doses of purified radiolabeled biliverdin, bilirubin, bilirubin monoglucuronide (BMG) or diglucuronide (BDG) were administered intravenously to intact normal or jaundiced homozygous Gunn rats. Rapid sequential analysis of radiolabeled BMG and BDG in bile revealed comparable excretion patterns following biliverdin and bilirubin injection, with BDG as the major pigment. Biliary excretion of radiolabeled conjugates from injected BMG was more rapid, with BMG predominating. Excretion of injected BDG in normal rats and BMG or BDG in Gunn rats was virtually identical to that of unaltered BMG in normal rats. Model independent analysis by deconvolution provided objective comparison of the disposition of radiolabeled pigments from the different sources. These findings indicate that bilirubin glucuronides formed in the liver from endogenous (hepatic) and exogenous (extrahepatic) sources of bilirubin follow a similar excretory pathway. BMG formed endogenously is converted preferentially to BDG, whereas circulating BMG is excreted predominantly unchanged. Exogenous conjugated bilirubins are excreted more rapidly than those generated intrahepatically, by a transcellular pathway that is largely independent of the conjugation system. PMID:3558820

  16. Effect of bilirubin on the spectrophotometric and radionuclide assay for serum angiotensin-converting enzyme

    SciTech Connect

    Saxe, A.W.; Hollinger, M.A.; Essam, T.

    1986-01-01

    The effect of bilirubin on serum angiotensin-converting enzyme (ACE) activity was studied with spectrophotometric and radionuclide assays. In the spectrophotometric assay addition of bilirubin to normal serum from dog, mouse, and human produced a dose-related inhibition of ACE activity. A 50% decrease in human ACE activity was produced by the addition of approximately 250 mg/L in vitro. Serum from icteric patients with elevated bilirubin was also associated with a reduction in ACE activity in the spectrophotometric assay. A 50% decrease in ACE activity in these samples was associated with a serum bilirubin of approximately 220 mg/L. In the radionuclide assay, however, addition of bilirubin to normal human serum failed to reduce measured ACE activity. The use of a radionuclide assay for serum ACE in clinical samples offers the advantage of less interference from serum bilirubin.

  17. Association between flavonoid-rich fruit and vegetable consumption and total serum bilirubin.

    PubMed

    Loprinzi, Paul D; Mahoney, Sara E

    2015-03-01

    Emerging work demonstrates that serum bilirubin is a novel biomarker implicated in cardiovascular and metabolic diseases. However, we have a limited understanding of the influence of flavonoid-rich fruit and vegetable consumption on bilirubin levels, which was the purpose of this study. Data from the 2003 to 2006 National Health and Nutrition Examination survey were used (n = 1783; 18-85 years of age), with analyses performed in 2014. Total serum bilirubin was measured from a blood sample. Using a food frequency questionnaire (FFQ), a flavonoid index variable was created summing the frequency of consumption of flavonoid-rich foods. After adjustments, greater consumption of flavonoid-rich fruits and vegetables was positively associated with bilirubin levels. Our findings suggest an association between flavonoid-rich fruit and vegetable consumption and bilirubin levels. If confirmed by prospective and experimental studies, then regular consumption of flavonoid-rich fruits and vegetables should be promoted to increase levels of bilirubin.

  18. Factors influencing naproxen metabolite interference in total bilirubin assays.

    PubMed

    Saifee, Nabiha Huq; Ranjitkar, Pratistha; Greene, Dina N

    2016-04-01

    The factors influencing naproxen metabolite O-desmethylnaproxen (ODMN) positive interference in diazo-based Jendrassik and Grof (JG) total bilirubin (Tbil) assays and lack of interference in direct bilirubin (Dbil) assays have not been resolved. The objective of this study was to understand the conditions causing this interference pattern. Pooled normal and ultra-filtered plasma samples spiked with ODMN and naproxen were measured on the Beckman Coulter DxC and AU instruments. Absorbance spectra were obtained for ODMN mixed with Dbil reagent at original and adjusted pH. Absorbance spectra were also obtained for ODMN and bilirubin samples mixed with Tbil assay reagents. ODMN produces a positive interference in the DxC JG Tbil assays, but not the AU Tbil or Dbil assays or the DxC Dbil assay. Neutralizing the acidic pH of AU and DxC Dbil reagents allows ODMN to react with diazo salts. ODMN samples mixed with DxC and AU Tbil reagents produce broad peaks from 450 to 560nm and 400 to 540nm, respectively. The DxC JG Tbil assay monitors a change in absorbance at 520nm close to peak absorbance wavelength of diazo-reacted ODMN, whereas the AU Tbil assay monitors a change in absorbance at 570/660nm, beyond the peak absorbance wavelengths of diazo-reacted ODMN. The acidic pH of diazo-based Dbil assay reagents inhibits the reaction of ODMN with diazo salts. The AU JG Tbil assay is a reliable method to measure Tbil in the setting of naproxen overdose. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  19. Life and consciousness – The Vedāntic view

    PubMed Central

    Shanta, Bhakti Niskama

    2015-01-01

    In the past, philosophers, scientists, and even the general opinion, had no problem in accepting the existence of consciousness in the same way as the existence of the physical world. After the advent of Newtonian mechanics, science embraced a complete materialistic conception about reality. Scientists started proposing hypotheses like abiogenesis (origin of first life from accumulation of atoms and molecules) and the Big Bang theory (the explosion theory for explaining the origin of universe). How the universe came to be what it is now is a key philosophical question. The hypothesis that it came from Nothing (as proposed by Stephen Hawking, among others), proves to be dissembling, since the quantum vacuum can hardly be considered a void. In modern science, it is generally assumed that matter existed before the universe came to be. Modern science hypothesizes that the manifestation of life on Earth is nothing but a mere increment in the complexity of matter — and hence is an outcome of evolution of matter (chemical evolution) following the Big Bang. After the manifestation of life, modern science believed that chemical evolution transformed itself into biological evolution, which then had caused the entire biodiversity on our planet. The ontological view of the organism as a complex machine presumes life as just a chance occurrence, without any inner purpose. This approach in science leaves no room for the subjective aspect of consciousness in its attempt to know the world as the relationships among forces, atoms, and molecules. On the other hand, the Vedāntic view states that the origin of everything material and nonmaterial is sentient and absolute (unconditioned). Thus, sentient life is primitive and reproductive of itself – omne vivum ex vivo – life comes from life. This is the scientifically verified law of experience. Life is essentially cognitive and conscious. And, consciousness, which is fundamental, manifests itself in the gradational forms of all

  20. Life and consciousness - The Vedāntic view.

    PubMed

    Shanta, Bhakti Niskama

    2015-01-01

    In the past, philosophers, scientists, and even the general opinion, had no problem in accepting the existence of consciousness in the same way as the existence of the physical world. After the advent of Newtonian mechanics, science embraced a complete materialistic conception about reality. Scientists started proposing hypotheses like abiogenesis (origin of first life from accumulation of atoms and molecules) and the Big Bang theory (the explosion theory for explaining the origin of universe). How the universe came to be what it is now is a key philosophical question. The hypothesis that it came from Nothing (as proposed by Stephen Hawking, among others), proves to be dissembling, since the quantum vacuum can hardly be considered a void. In modern science, it is generally assumed that matter existed before the universe came to be. Modern science hypothesizes that the manifestation of life on Earth is nothing but a mere increment in the complexity of matter - and hence is an outcome of evolution of matter (chemical evolution) following the Big Bang. After the manifestation of life, modern science believed that chemical evolution transformed itself into biological evolution, which then had caused the entire biodiversity on our planet. The ontological view of the organism as a complex machine presumes life as just a chance occurrence, without any inner purpose. This approach in science leaves no room for the subjective aspect of consciousness in its attempt to know the world as the relationships among forces, atoms, and molecules. On the other hand, the Vedāntic view states that the origin of everything material and nonmaterial is sentient and absolute (unconditioned). Thus, sentient life is primitive and reproductive of itself - omne vivum ex vivo - life comes from life. This is the scientifically verified law of experience. Life is essentially cognitive and conscious. And, consciousness, which is fundamental, manifests itself in the gradational forms of all

  1. Studies on the chemico-biological characteristics of bilirubin binding with collagen.

    PubMed

    Nagarajan, Usharani; Christopher, Jayakumar Gladstone; Jonnalagadda, Raghava Rao; Chandrasekaran, Bangaru; Balachandran, Unni Nair

    2013-12-01

    The clinical impact of bilirubin on collagen is investigated using various physical, chemical and biological methods. Thermo gravimetric analysis and differential scanning analysis of collagen-bilirubin complex matrices indicate that crosslinking does not alter their thermal behavior of collagen. The polydispersity of collagen-bilirubin complex increases in the reacting medium suggesting that there is an increase in the number of interacting points between them. Based on the zeta potential values, the rate of mobility of interacted complex decreases by inferring the extent of binding compared to the control collagen. Emission intensity begins to increase with increase in concentration of bilirubin which ascribes the conformational changes around the aromatic amino acids in collagen. Binding is indicated by an increase in resonance units and the responses are corrected by subtraction of those obtained for native collagen. Bilirubin showed a higher affinity for collagen at a concentration of about 25 nM/mg. In this study, the association rate has been calculated which depicts the increased affinity of bilirubin to collagen. Affinity for bilirubin to collagen has been found to be 8.89×10(-3) s(-1). The greater part of binding of bilirubin to collagen is found to be electrostatic in nature. The investigation leads to comprehend the affinity of collagen-bilirubin complex during jaundice diseased tissues.

  2. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test...

  3. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test...

  4. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test...

  5. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test...

  6. Bilirubin Increases Insulin Sensitivity by Regulating Cholesterol Metabolism, Adipokines and PPARγ Levels.

    PubMed

    Liu, Jinfeng; Dong, Huansheng; Zhang, Yong; Cao, Mingjun; Song, Lili; Pan, Qingjie; Bulmer, Andrew; Adams, David B; Dong, Xiao; Wang, Hongjun

    2015-05-28

    Obesity can cause insulin resistance and type 2 diabetes. Moderate elevations in bilirubin levels have anti-diabetic effects. This study is aimed at determining the mechanisms by which bilirubin treatment reduces obesity and insulin resistance in a diet-induced obesity (DIO) mouse model. DIO mice were treated with bilirubin or vehicle for 14 days. Body weights, plasma glucose, and insulin tolerance tests were performed prior to, immediately, and 7 weeks post-treatment. Serum lipid, leptin, adiponectin, insulin, total and direct bilirubin levels were measured. Expression of factors involved in adipose metabolism including sterol regulatory element-binding protein (SREBP-1), insulin receptor (IR), and PPARγ in liver were measured by RT-PCR and Western blot. Compared to controls, bilirubin-treated mice exhibited reductions in body weight, blood glucose levels, total cholesterol (TC), leptin, total and direct bilirubin, and increases in adiponectin and expression of SREBP-1, IR, and PPARγ mRNA. The improved metabolic control achieved by bilirubin-treated mice was persistent: at two months after treatment termination, bilirubin-treated DIO mice remained insulin sensitive with lower leptin and higher adiponectin levels, together with increased PPARγ expression. These results indicate that bilirubin regulates cholesterol metabolism, adipokines and PPARγ levels, which likely contribute to increased insulin sensitivity and glucose tolerance in DIO mice.

  7. The kinetics of oxidation of bilirubin and ascorbic acid in solution

    NASA Astrophysics Data System (ADS)

    Solomonov, A. V.; Rumyantsev, E. V.; Kochergin, B. A.; Antina, E. V.

    2012-07-01

    The results of a comparative study of the oxidation of bilirubin, ascorbic acid, and their mixture in aqueous solutions under the action of air oxygen and hydrogen peroxide are presented. The observed and true rate constants for the oxidation reactions were determined. It was shown that the oxidation of tetrapyrrole pigment occurred under these conditions bypassing the stage of biliverdin formation to monopyrrole products. Simultaneous oxidation of bilirubin and ascorbic acid was shown to be accompanied by the inhibition of ascorbic acid oxidation by bilirubin, whereas ascorbic acid itself activated the oxidation of bilirubin.

  8. Unconjugated bilirubin mediates heme oxygenase-1-induced vascular benefits in diabetic mice.

    PubMed

    Liu, Jian; Wang, Li; Tian, Xiao Yu; Liu, Limei; Wong, Wing Tak; Zhang, Yang; Han, Quan-Bin; Ho, Hing-Man; Wang, Nanping; Wong, Siu Ling; Chen, Zhen-Yu; Yu, Jun; Ng, Chi-Fai; Yao, Xiaoqiang; Huang, Yu

    2015-05-01

    Heme oxygenase-1 (HO-1) exerts vasoprotective effects. Such benefit in diabetic vasculopathy, however, remains unclear. We hypothesize that bilirubin mediates HO-1-induced vascular benefits in diabetes. Diabetic db/db mice were treated with hemin (HO-1 inducer) for 2 weeks, and aortas were isolated for functional and molecular assays. Nitric oxide (NO) production was measured in cultured endothelial cells. Hemin treatment augmented endothelium-dependent relaxations (EDRs) and elevated Akt and endothelial NO synthase (eNOS) phosphorylation in db/db mouse aortas, which were reversed by the HO-1 inhibitor SnMP or HO-1 silencing virus. Hemin treatment increased serum bilirubin, and ex vivo bilirubin treatment improved relaxations in diabetic mouse aortas, which was reversed by the Akt inhibitor. Biliverdin reductase silencing virus attenuated the effect of hemin. Chronic bilirubin treatment improved EDRs in db/db mouse aortas. Hemin and bilirubin reversed high glucose-induced reductions in Akt and eNOS phosphorylation and NO production. The effect of hemin but not bilirubin was inhibited by biliverdin reductase silencing virus. Furthermore, bilirubin augmented EDRs in renal arteries from diabetic patients. In summary, HO-1-induced restoration of endothelial function in diabetic mice is most likely mediated by bilirubin, which preserves NO bioavailability through the Akt/eNOS/NO cascade, suggesting bilirubin as a potential therapeutic target for clinical intervention of diabetic vasculopathy.

  9. Bilirubin as an antioxidant: kinetic studies of the reaction of bilirubin with peroxyl radicals in solution, micelles, and lipid bilayers.

    PubMed

    Hatfield, Gillian L; Barclay, L Ross C

    2004-05-13

    Bilirubin (BR) showed very weak antioxidant activity in a nonpolar medium of styrene or cumene in chlorobenzene. In contrast, BR exhibited strong antioxidant activity in polar media such as aqueous lipid bilayers or SDS micelles/methyl linoleate (pH 7.4), where the rate with peroxyl radicals, k(inh) = 5.0 x 10(4) M(-)(1) s(-)(1), was comparable to that with vitamin E analogues, Trolox, or PMHC. An electron-transfer mechanism accounts for the effect of the medium on the antioxidant properties of BR.

  10. Characterization of copper atoms in bilirubin oxidase by spectroscopic analyses.

    PubMed

    Gotoh, Y; Kondo, Y; Kaji, H; Takeda, A; Samejima, T

    1989-10-01

    Bilirubin oxidase [EC 1.3.3.5], purified from the culture medium of Myrothecium verrucaria, was found to contain two blue copper atoms per protein molecule with a molecular weight of ca. 52 kDa. The two copper atoms were estimated to be in the all cupric state by the cuproine colorimetric method and also atomic absorption analysis. We could remove the reduce cuprous ions from the holo enzyme by adding ascorbate, followed by a KCN solution, yielding an apo-enzyme with no activity. The apo-enzyme can be reconstituted with Cu or other divalent cations such as Co, Fe, and Cd, with accompanying recovery of the enzyme activity. The activity recovery depended upon the species of cation employed; Cu being most effective, an almost 100% recovery, and Cd the least, only a 25% recovery. We could obtain information on the copper ions and their coordination structure by spectroscopic analyses of the apo- and reconstituted enzymes, obtaining such as absorption, CD, MCD, and XPS spectra. The bilirubin oxidase catalyzed-reaction was a second order reaction with respect to copper bound with protein. The donor set was of the CuSS*N2 (S = Cys, S* = Met, N = His) type, i.e., the same as in the case of blue copper proteins. On studying the Co-substituted enzyme, it was revealed that the copper site of the enzyme had a 4-coordinated structure.

  11. Clinical decision limits for interpretation of direct bilirubin--a CALIPER study of healthy multiethnic children and case report reviews.

    PubMed

    Devgun, Manjit S; Chan, Man Khun; El-Nujumi, Adil M; Abara, Rosemary; Armbruster, David; Adeli, Khosrow

    2015-01-01

    Measurement of total and direct bilirubin is routinely performed for the differential diagnosis of hyperbilirubinemias. The diagnostic efficiency of a test is dependent on the chosen clinical decision limit. This study is designed to address the clinical decision limits for direct bilirubin. Routine laboratory method was used to measure total and direct bilirubin in children up to the age of 18years. Case study data and serum from a group of healthy children were analyzed and statistical exercise was performed to establish decision limits. The reference interval for total bilirubin was 1-12μmol/L and for direct bilirubin 1-9μmol/L with the median direct bilirubin of 3μmol/L. In 17% of children with non-pathological jaundice, median total bilirubin was 173μmol/L, median direct bilirubin was 8μmol/L and median direct bilirubin percent was 49%. From birth direct bilirubin percentage decreased until total bilirubin was 41μmol/L, then it remained at ≤10%. Albumin increased with age, and was on average 2.4g/L higher when measured using bromocresol-green compared with bromocresol-purple. An increased amount of direct bilirubin was observed when albumin (detected using the bromocresol-purple method) was >35g/L. Direct bilirubin concentration of ≥10μmol/L should be used to consider the presence of conjugated hyperbilirubinemia provided that total bilirubin is also above the reference interval. A high direct bilirubin percentage is unlikely to offer any clinical value when total bilirubin is not increased. It is, however, a useful diagnostic tool when there is a persistence of hyperbilirubinemia or when total bilirubin increases during times of stress with direct bilirubin >10%. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  12. Limitations and opportunities of whole blood bilirubin measurements by GEM premier 4000®.

    PubMed

    Wang, Li; Albert, Arianne Y K; Jung, Benjamin; Hadad, Keyvan; Lyon, Martha E; Basso, Melanie

    2017-03-29

    Neonatal hyperbilirubinemia has traditionally been screened by either total serum bilirubin or transcutaneous bilirubin. Whole blood bilirubin (TwB) by the GEM Premier 4000® blood gas analyzer (GEM) is a relatively new technology and it provides fast bilirubin results with a small sample volume and can measure co-oximetry and other analytes. Our clinical study was to evaluate the reliability of TwB measured by the GEM and identify analytical and clinical factors that may contribute to possible bias. 440 consecutive healthy newborn samples that had plasma bilirubin ordered for neonatal hyperbilirubinemia screening were included. TwB was first measured using the GEM, after which the remainder of the blood was spun and plasma neonatal bilirubin was measured using the VITROS 5600® (VITROS). 62 samples (14%) were excluded from analysis due to failure in obtaining GEM results. Passing-Bablok regression suggested that the GEM results were negatively biased at low concentrations of bilirubin and positively biased at higher concentrations relative to the VITROS results (y = 1.43x-61.13). Bland-Altman plots showed an overall negative bias of the GEM bilirubin with a wide range of differences compared to VITROS. Both hemoglobin concentration and hemolysis affected the accuracy of the GEM results. Clinically, male infants had higher mean bilirubin levels, and infants delivered by caesarean section had lower hemoglobin levels. When comparing the number of results below the 40th percentile and above the 95th percentile cut-offs in the Bhutani nomogram which would trigger discharge or treatment, GEM bilirubin exhibited poor sensitivity and poor specificity in contrast to VITROS bilirubin. An imperfect correlation was observed between whole blood bilirubin measured on the GEM4000® and plasma bilirubin on the VITROS 5600®. The contributors to the observed differences between the two instruments were specimen hemolysis and the accuracy of hemoglobin measurements, the latter

  13. Development of bilirubin transport and metabolism in the newborn rhesus monkey.

    PubMed

    Gartner, L M; Lee, K S; Vaisman, S; Lane, D; Zarafu, I

    1977-04-01

    Hepatic transport and metabolism of bilirubin have been examined in term, premature, and postmature newborn Macaca mulatta (rhesus) monkeys with and without prior phenobarbital treatment of pregnant mother and neonate. In untreated neonates a biphasic pattern of physiologic unconjugated hyperbilirubinemia has been observed. Phase I was characterized by a rapid increase in serum bilirubin concentration to 4.5 mg/dl by 19 hours and an equally rapid decline to 1.0 mg/dl by 48 hours of age. Phase II was characterized by a stable elevation at 1.0 mg/dl (four times greater than in the adult) from 48 to 96 hourse of age, followed by a decline to normal adult concentrations thereafter. An identical pattern was observed in 29 normal, term human neonates, but the duration of each phase was approximately three times as long as that in the monkey. Phase I hyperbilirubinemia appears to result from a sixfold increase in bilirubin load presented to the liver in the neonatal period, combined with marked deficieny in hepatic bilirubin conjugation, the rate-limiting step during Phase I. Hepatic uptake of bilirubin is not rate limiting during Phase I but may contribute to Phase II hyperbilirubinemia. An increased bilirubin load persists throughout the first 19 days of life in the monkey. Phase I physiologic jaundice in the monkey neonate was completely eliminated by prenatal maternal and neonatal administration of phenobarbital. A threefold enhancement of hepatic conjugation of bilirubin (glucuronyl transferase activity) during Phase I entirely accounted for the prevention of hyperbilirubinemia. The bilirubin load was unaffected by administration of phenobarbital. Whereas in control neonates the bilirubin load slightly exceeded hepatic bilirubin conjugating capacity and resulted in retention of bilirubin, in phenobarbital-treated neonates, hepatic conjugating capacity slightly exceeded that required for the bilirubin load. Administration of phenobarbital failed to alter Phase II

  14. Bilirubin inhibits iNOS expression and NO production in response to endotoxin in rats.

    PubMed

    Wang, Weizheng W; Smith, Darcey L H; Zucker, Stephen D

    2004-08-01

    The inducible isoform of heme oxygenase (HO), HO-1, has been shown to play an important role in attenuating tissue injury. Because HO-1 catalyzes the rate-limiting step in bilirubin synthesis, we examined the hypothesis that bilirubin is a key mediator of HO-1 cytoprotection, employing a rat model of endotoxemia. Bilirubin treatment resulted in improved survival and attenuated liver injury in response to lipopolysaccharide infusion. Serum levels of NO and tumor necrosis factor alpha, key mediators of endotoxemia, and hepatic inducible nitric oxide synthase (iNOS) expression were significantly lower in bilirubin-treated rodents versus control animals. Both intraperitoneal and local administration of bilirubin also was found to ameliorate hindpaw inflammation induced by the injection of lambda-carrageenan. Consistent with in vivo results, bilirubin significantly inhibited iNOS expression and suppressed NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. In contrast, bilirubin treatment induced a threefold increase in LPS-mediated prostaglandin synthesis in the absence of significant changes in cyclooxygenase expression or activity, suggesting that bilirubin enhances substrate availability for eicosanoid synthesis. Bilirubin had no effect on LPS-mediated activation of nuclear factor kappaB or p38 mitogen-activated protein kinase, consistent with a nuclear factor kappaB-independent mechanism of action. Taken together, these data support a cytoprotective role for bilirubin that is mediated, at least in part, through the inhibition of iNOS expression and, potentially, through stimulation of local prostaglandin E2 production. In conclusion, our findings suggest a role for bilirubin in mollifying tissue injury in response to inflammatory stimuli and support the possibility that the phenomenon of "jaundice of sepsis" represents an adaptive physiological response to endotoxemia. Supplementary material for this article can be found on the

  15. Low serum bilirubin concentration is associated with coronary artery calcification (CAC).

    PubMed

    Tanaka, Muhei; Fukui, Michiaki; Tomiyasu, Ki-ichiro; Akabame, Satoshi; Nakano, Koji; Hasegawa, Goji; Oda, Yohei; Nakamura, Naoto

    2009-09-01

    Bilirubin is a potent antioxidant and previous studies have reported the relationship between low serum bilirubin concentration and atherosclerosis. The purpose of this study was to assess the correlation between serum bilirubin concentration and coronary artery calcification (CAC). This study consisted of 637 participants and we evaluated the relationship between CAC score determined by multislice computed tomography and serum bilirubin concentration. An inverse correlation was found between serum bilirubin concentration and log(CAC+1) (r=-0.361, P<0.0001). Multiple regression analysis also demonstrated that age (beta=0.261, P=0.0125), systolic blood pressure (beta=0.153, P=0.0237), uric acid (beta=0.126, P=0.0441), estimated glomerular filtration rate (beta=-0.139, P=0.0416) and serum bilirubin concentration (beta=-0.281, P<0.0001) were independent determinants of log(CAC+1). An increment of 1 micromol/L in serum bilirubin concentration was associated with 14% decrease in the odds for CAC score > or =400 after adjustment for several risk factors. Both age and SBP were also positively associated with CAC score > or =400, but the odds ratio for CAC score > or =400 was greater for every 1 micromol/L increment in serum bilirubin concentration than for every 1-year increment in age and 1-mmHg increment in SBP. Low serum bilirubin concentration is associated with coronary artery calcification. Serum bilirubin concentration can be measured easily in the clinical laboratory and applied in medical practice, and low serum bilirubin concentration would be useful as a provisional new risk factor of CAC.

  16. Clinical system model for monitoring the physiological status of jaundice by extracting bilirubin components from skin diffuse reflectance spectra

    NASA Astrophysics Data System (ADS)

    Kumar, Alla S.; Clark, Joseph; Beyette, Fred R., Jr.

    2009-02-01

    Neonatal jaundice is a medical condition which occurs in newborns as a result of an imbalance between the production and elimination of bilirubin. The excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. As the bilirubin levels rise in the blood stream, there is a continuous exchange between the extra vascular bilirubin and bilirubin in the blood stream. Exposure to phototherapy alters the concentration of bilirubin in the vascular and extra vascular regions by causing bilirubin in the skin layers to be broken down. Thus, the relative concentration of extra vascular bilirubin is reduced leading to a diffusion of bilirubin out of the vascular region. Diffuse reflectance spectra from human skin contains physiological and structural information of the skin and nearby tissue. A diffuse reflectance spectrum must be captured before and after blanching in order to isolate the intravascular and extra vascular bilirubin. A new mathematical model is proposed with extra vascular bilirubin concentration taken into consideration along with other optical parameters in defining the diffuse reflectance spectrum from human skin. A nonlinear optimization algorithm has been adopted to extract the optical properties (including bilirubin concentration) from the skin reflectance spectrum. The new system model and nonlinear algorithm have been combined to enable extraction of Bilirubin concentrations within an average error of 10%.

  17. Purification, characterization and decolorization of bilirubin oxidase from Myrothecium verrucaria 3.2190

    USDA-ARS?s Scientific Manuscript database

    Myrothecium verrucaria 3.2190 is a nonligninolytic fungus that produces bilirubin oxidase. Both Myrothecium verrucaria and the extracellular bilirubin oxidase were tested for their ability to decolorize indigo carmine. The biosorption and biodegradation of the dye were detected during the process of...

  18. Ammonia-induced energy disorders interfere with bilirubin metabolism in hepatocytes.

    PubMed

    Wang, Qiongye; Wang, Yanfang; Yu, Zujiang; Li, Duolu; Jia, Bin; Li, Jingjing; Guan, Kelei; Zhou, Yubing; Chen, Yanling; Kan, Quancheng

    2014-08-01

    Hyperammonemia and jaundice are the most common clinical symptoms of hepatic failure. Decreasing the level of ammonia in the blood is often accompanied by a reduction in bilirubin in patients with hepatic failure. Previous studies have shown that hyperammonemia can cause bilirubin metabolism disorders, however it is unclear exactly how hyperammonemia interferes with bilirubin metabolism in hepatocytes. The purpose of the current study was to determine the mechanism or mechanisms by which hyperammonemia interferes with bilirubin metabolism in hepatocytes. Cell viability and apoptosis were analyzed in primary hepatocytes that had been exposed to ammonium chloride. Mitochondrial morphology and permeability were observed and analyzed, intermediates of the tricarboxylic acid (TCA) cycle were determined and changes in the expression of enzymes related to bilirubin metabolism were analyzed after ammonia exposure. Hyperammonemia inhibited cell growth, induced apoptosis, damaged the mitochondria and hindered the TCA cycle in hepatocytes. This led to a reduction in energy synthesis, eventually affecting the expression of enzymes related to bilirubin metabolism, which then caused further problems with bilirubin metabolism. These effects were significant, but could be reversed with the addition of adenosine triphosphate (ATP). This study demonstrates that ammonia can cause problems with bilirubin metabolism by interfering with energy synthesis.

  19. Relationship of Bilirubin Levels in Infancy to Later Intellectual Development. Interim Report No. 20.

    ERIC Educational Resources Information Center

    Rubin, Rosalyn A.; And Others

    The relationship of bilirubin (a red bile pigment that is sometimes found in the urine and occurs in the blood and tissues in jaundice) in infancy to later intellectual development was investigated in 241 infants with moderately elevated and high bilirubin levels. Ss were administered motor, psycholinguistic, and intelligence tests at age 8…

  20. Relationship of Bilirubin Levels in Infancy to Later Intellectual Development. Interim Report No. 20.

    ERIC Educational Resources Information Center

    Rubin, Rosalyn A.; And Others

    The relationship of bilirubin (a red bile pigment that is sometimes found in the urine and occurs in the blood and tissues in jaundice) in infancy to later intellectual development was investigated in 241 infants with moderately elevated and high bilirubin levels. Ss were administered motor, psycholinguistic, and intelligence tests at age 8…

  1. Effect of bilirubin on triglyceride synthesis in streptozotocin-induced diabetic nephropathy.

    PubMed

    Xu, Jianwei; Lee, Eun Seong; Baek, Seon Ha; Ahn, Shin-Young; Kim, Sejoong; Na, Ki Young; Chae, Dong-Wan; Chin, Ho Jun

    2014-09-01

    We aimed to elucidate the effect of bilirubin on dyslipidemia and nephropathy in a diabetes mellitus (DM) type I animal model. Sprague-Dawley rats were separated into control, DM, and bilirubin-treated DM (Bil) groups. The Bil group was injected intraperitoneally with 60 mg/kg bilirubin 3 times per week and hepatoma cells were cultured with bilirubin at a concentration of 0.3 mg/dL. The Bil group showed lower serum creatinine levels 5 weeks after diabetes onset. Bilirubin treatment also decreased the amount of mesangial matrix, lowered the expression of renal collagen IV and transforming growth factor (TGF)-β1, and reduced the level of apoptosis in the kidney, compared to the DM group. These changes were accompanied by decreased tissue levels of hydrogen superoxide and NADPH oxidase subunit proteins. Bilirubin decreased serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), free fatty acids, and triglycerides (TGs), as well as the TG content in the liver tissues. Bilirubin suppressed protein expression of LXRα, SREBP-1, SCD-1, and FAS, factors involved in TG synthesis that were elevated in the livers of DM rats and hepatoma cells under high-glucose conditions. In conclusion, bilirubin attenuates renal dysfunction and dyslipidemia in diabetes by suppressing LXRα and SREBP-1 expression and oxidative stress.

  2. Metabolism of bilirubin by human cytochrome P450 2A6

    SciTech Connect

    Abu-Bakar, A'edah; Arthur, Dionne M.; Wikman, Anna S.; Rahnasto, Minna; Juvonen, Risto O.; Vepsäläinen, Jouko; Raunio, Hannu; Ng, Jack C.; Lang, Matti A.

    2012-05-15

    The mouse cytochrome P450 (CYP) 2A5 has recently been shown to function as hepatic “Bilirubin Oxidase” (Abu-Bakar, A., et al., 2011. Toxicol. Appl. Pharmacol. 257, 14–22). To date, no information is available on human CYP isoforms involvement in bilirubin metabolism. In this paper we provide novel evidence for human CYP2A6 metabolising the tetrapyrrole bilirubin. Incubation of bilirubin with recombinant yeast microsomes expressing the CYP2A6 showed that bilirubin inhibited CYP2A6-dependent coumarin 7-hydroxylase activity to almost 100% with an estimated K{sub i} of 2.23 μM. Metabolite screening by a high-performance liquid chromatography/electrospray ionisation mass spectrometry indicated that CYP2A6 oxidised bilirubin to biliverdin and to three other smaller products with m/z values of 301, 315 and 333. Molecular docking analyses indicated that bilirubin and its positively charged intermediate interacted with key amino acid residues at the enzyme's active site. They were stabilised at the site in a conformation favouring biliverdin formation. By contrast, the end product, biliverdin was less fitting to the active site with the critical central methylene bridge distanced from the CYP2A6 haem iron facilitating its release. Furthermore, bilirubin treatment of HepG2 cells increased the CYP2A6 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A6 compared to cells treated only with CHX. Collectively, the observations indicate that the CYP2A6 may function as human “Bilirubin Oxidase” where bilirubin is potentially a substrate and a regulator of the enzyme. -- Highlights: ► Human CYP2A6 interacts with bilirubin with a high affinity. ► Bilirubin docking to the CYP2A6 active site is more stable than biliverdin docking. ► Recombinant CYP2A6 microsomes metabolised bilirubin to biliverdin. ► Bilirubin increased the hepatic CYP2

  3. Metabolism of heme and bilirubin in rat and human small intestinal mucosa.

    PubMed Central

    Hartmann, F; Bissell, D M

    1982-01-01

    Formation of heme, bilirubin, and bilirubin conjugates has been examined in mucosal cells isolated from the rat upper small intestine. Intact, viable cells were prepared by enzymatic dissociation using a combined vascular and luminal perfusion and incubated with an isotopically labeled precursor, delta-amino-[2,3-3H]levulinic acid. Labeled heme and bile pigment were formed with kinetics similar to those exhibited by hepatocytes. Moreover, the newly formed bilirubin was converted rapidly to both mono- and diglucuronide conjugates. In addition, cell-free extracts of small intestinal mucosa from rats or humans exhibited a bilirubin-UDP-glucuronyl transferase activity that was qualitatively similar to that present in liver. The data suggest that the small intestinal mucosa normally contributes to bilirubin metabolism. PMID:6806320

  4. The effect of oral contraceptive steroids on bile secretion and bilirubin Tm in rats

    PubMed Central

    Heikel, T. A. J.; Lathe, G. H.

    1970-01-01

    1. The effect of oestrogens and progestogens and their 17α-ethinyl derivatives on bile flow, maximum rate of bilirubin secretion, serum and liver bilirubin has been studied. 2. Both 17α-ethinyl substituted oestrogens and progestogens greatly reduced the basal bile flow. The parent compounds, oestradiol-17β and 19-nortestosterone had little or no effect. 3. A much larger dose of progestogens (40 mg/kg) than oestrogens (5 mg/kg) was needed. 4. Between 12 and 48 h were required for 17α-ethinyloestradiol to produce the effect. 5. Bilirubin maximum secretion rate (Tm) was little affected, the only significant reduction being produced by the 3-methyl ether of 17α-ethinyloestradiol (mestranol). 6. Rises in serum conjugated bilirubin following infusion of bilirubin were produced by 17α-ethinyloestradiol and mestranol but not by the progestogens. PMID:5441412

  5. [The influence of bilirubin on the mechanogram of isolated, spontaneously beating frog heart].

    PubMed

    Mittelstädt, U; Biester, J; Sandhage, K

    1976-06-08

    It was shown that bilirubin in its unconjugated form does not only harm the central nervous system. Clinical observations indicate that the toxic effect under certain conditions affects also the heart. In a simple experimental model the influence of free bilirubin on the activity of the heart was investigated. In 69 adult frogs the heart was isolated and exposed sequentially to solutions of different bilirubin concentrations while the heart actions were registered. There was no significant change in the activity of the heart under the influence of bilirubin although concentrations were reached which according to the results of other authors harm cell cultures or evoke in the newborn disturbances in various organs. As a possible explanation, the nonsusceptibility of the heart muscle to bilirubin, the short duration of exposure, and the different behavior of newborn and adult organs is discussed.

  6. Bilirubin adsorption properties of water-soluble adsorbents with different cyclodextrin cavities in plasma dialysis system.

    PubMed

    Wang, Zhi; Cao, Yaming; Wei, Houliang; Jia, Lingyun; Xu, Li; Xie, Jian

    2012-02-01

    In this study, we explored the use of α-, β- or γ-cyclodextrin (CD)-grafted polyethyleneimine (PEI) as water-soluble adsorbent for removing excess plasma bilirubin. To evaluate the bilirubin-binding capacity of these adsorbents, bovine serum albumin (BSA) solution or plasma with high level of bilirubin were dialyzed against CD-PEI-spiked dialysate. In BSA solution with an initial biliurbin concentration of 171.5mg/L, α-CD-PEI, β-CD-PEI and γ-CD-PEI achieved adsorption capacities of 2.5, 5.8 and 3.8 mg/g, respectively. In a plasma dialysis system, 45.6% of bilirubin (260 mg/L) was removed from 200 mL plasma by 1L dialysate spiked with 10mg/mL β-CD-PEI, which was significantly higher than that removed by the same volume of BSA-spiked dialysate (P<0.05), demonstrating the strong bilirubin-binding ability of β-CD-PEI. The key feature of bilirubin adsorption was related to the CD functional group, not the PEI matrix. Subsequent molecular docking study indicated that the size of CD cavity could affect the affinity energy of CD-bilirubin complex. The cavity of β-CD was most suitable for accommodating the pyrrole rings of bilirubin. The inclusion complex of bilirubin and β-CD in the molar ratio of 1:2 was more logical in terms of affinity energy. All the results demonstrated the potential of β-CD-PEI (water-soluble adsorbent) as an effective agent for removing of bilirubin from plasma in dialysis system. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Elevated bilirubin levels are associated with a better renal prognosis and ameliorate kidney fibrosis.

    PubMed

    Park, Sehoon; Kim, Do Hyoung; Hwang, Jin Ho; Kim, Yong-Chul; Kim, Jin Hyuk; Lim, Chun Soo; Kim, Yon Su; Yang, Seung Hee; Lee, Jung Pyo

    2017-01-01

    Bilirubin has been reported to protect against kidney injury. However, further studies highlighting the beneficial effects of bilirubin on renal fibrosis and chronic renal function decline are necessary. We assessed a prospective cohort with a reference range of total bilirubin levels. The primary outcome was a 30% reduction in the estimated glomerular filtration rate (eGFR) from baseline, and the secondary outcome was a doubling of the serum creatinine levels, halving of the eGFR and the initiation of dialysis. In addition, experiments with tubular epithelial cells and C57BL/6 mice were performed to investigate the protective effects of bilirubin on kidney fibrosis. As a result, 1,080 patients were included in the study cohort. The study group with relative hyperbilirubinemia (total bilirubin 0.8-1.2 mg/dL) showed a better prognosis in terms of the primary outcome (adjusted hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.19-0.59, P < 0.001) and the secondary outcome (adjusted HR 0.20, 95% CI 0.05 to 0.71, P = 0.01) than that of the control group. Moreover, the bilirubin-treated mice showed less fibrosis in the unilateral ureteral obstruction (UUO) model (P < 0.05). In addition, bilirubin treatment decreased fibronectin expression in tubular epithelial cells in a dose-dependent manner (P < 0.05). Mildly elevated serum bilirubin levels were associated with better renal prognosis, and bilirubin treatment induced a beneficial effect on renal fibrosis. Therefore, bilirubin could be a potential therapeutic target to delay fibrosis-related kidney disease progression.

  8. Bilirubin treatment suppresses pulmonary inflammation in a rat model of smoke-induced emphysema.

    PubMed

    Wei, Jingjing; Zhao, Hui; Fan, Guoquan; Li, Jianqiang

    2015-09-18

    Cigarette smoking is a significant risk factor for emphysema, which is characterized by airway inflammation and oxidative damage. To assess the capacity of bilirubin to protect against smoke-induced emphysema. Smoking status and bilirubin levels were recorded in 58 patients with chronic obstructive pulmonary diseases (COPD) and 71 non-COPD participants. The impact of smoking on serum bilirubin levels and exogenous bilirubin (20 mg/kg/day) on pulmonary injury was assessed in a rat model of smoking-induced emphysema. At sacrifice lung histology, airway leukocyte accumulation and cytokine and chemokine levels in serum, bronchoalveolar lavage fluid (BALF) and lung were analyzed. Oxidative lipid damage and anti-oxidative components was assessed by measuring malondialdehyde, superoxide dismutase (SOD) activity and glutathione. Total serum bilirubin levels were lower in smokers with or without COPD than non-smoking patients without COPD (P < 0.05). Indirect serum bilirubin levels were lower in COPD patients than patients without COPD (P < 0.05). In rats, cigarette smoke reduced serum total and indirect bilirubin levels. Administration of bilirubin reduced mean linear intercept and mean alveoli area, increased mean alveoli number, reduced macrophage, neutrophil and TNF-α content of BALF, and increased BALF and serum IL-10 level, but lowered local and systemic CCL2, CXCL2, CXCL8 and IL-17 levels. Bilirubin suppressed the smoke-induced systemic and regional oxidative lipid damage associated with increased SOD activity. Bilirubin attenuated smoking-induced pulmonary injury by suppressing inflammatory cell recruitment and pro-inflammatory cytokine secretion, increasing anti-inflammatory cytokine levels, and anti-oxidant SOD activity in a rat model of smoke-induced emphysema. Copyright © 2015. Published by Elsevier Inc.

  9. Elevated bilirubin levels are associated with a better renal prognosis and ameliorate kidney fibrosis

    PubMed Central

    Hwang, Jin Ho; Kim, Yong-Chul; Kim, Jin Hyuk; Lim, Chun Soo; Kim, Yon Su; Yang, Seung Hee; Lee, Jung Pyo

    2017-01-01

    Background Bilirubin has been reported to protect against kidney injury. However, further studies highlighting the beneficial effects of bilirubin on renal fibrosis and chronic renal function decline are necessary. Methods We assessed a prospective cohort with a reference range of total bilirubin levels. The primary outcome was a 30% reduction in the estimated glomerular filtration rate (eGFR) from baseline, and the secondary outcome was a doubling of the serum creatinine levels, halving of the eGFR and the initiation of dialysis. In addition, experiments with tubular epithelial cells and C57BL/6 mice were performed to investigate the protective effects of bilirubin on kidney fibrosis. Results As a result, 1,080 patients were included in the study cohort. The study group with relative hyperbilirubinemia (total bilirubin 0.8–1.2 mg/dL) showed a better prognosis in terms of the primary outcome (adjusted hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.19–0.59, P < 0.001) and the secondary outcome (adjusted HR 0.20, 95% CI 0.05 to 0.71, P = 0.01) than that of the control group. Moreover, the bilirubin-treated mice showed less fibrosis in the unilateral ureteral obstruction (UUO) model (P < 0.05). In addition, bilirubin treatment decreased fibronectin expression in tubular epithelial cells in a dose-dependent manner (P < 0.05). Conclusions Mildly elevated serum bilirubin levels were associated with better renal prognosis, and bilirubin treatment induced a beneficial effect on renal fibrosis. Therefore, bilirubin could be a potential therapeutic target to delay fibrosis-related kidney disease progression. PMID:28225832

  10. Effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease.

    PubMed

    Bian, Lu-Qin; Li, Rong-Zhen; Zhang, Zheng-Yun; Jin, Yan-Ji; Kang, Hyung-Wook; Fang, Zhen-Zhu; Park, Youn-Soo; Choi, Yoon-Ho

    2013-11-01

    It is still uncertain whether total bilirubin per se is a risk factor for osteoporosis in postmenopausal women and no study has so far examined this important issue. This study was designed to assess the sheer effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease. In the present study, postmenopausal female subjects without potential liver disease (n = 918) who underwent measurement of bone mineral density were enrolled. Correlation and logistic regression analysis were used to assess the relationship between total bilirubin and other variables. As a result, subjects with osteoporosis had a significantly lower total bilirubin level (P = 0.005). A 0.1 mg/dl increase in total bilirubin was associated with reduced odds ratio of the risk by 38 % for osteoporosis [OR 0.62 (95 % CI 0.52-0.88), P = 0.012] after adjustment for several variables. Total bilirubin was independently associated with BMD [coefficient = 0.41, 95 % CI (0.35-0.47), P < 0.001 for lumbar spine and coefficient = 0.44, 95 % CI (0.36-0.48), P < 0.001 for femur neck]. A positive correlation could be observed with significant difference between total bilirubin and z-score (r = 0.33, P < 0.001 for lumbar spine and r = 0.37, P < 0.001 for femur neck) and total bilirubin was positively correlated with serum calcium (r = 0.13, P < 0.001) as well. Therefore, this study demonstrates an independent inverse association between total bilirubin and the prevalence of osteoporosis in postmenopausal women without potential liver disease. Total bilirubin would be useful as a provisional new risk factor of osteoporosis in such a population.

  11. Inverse Association between Serum Bilirubin Levels and Retinopathy in Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Venkatesan, Raghuram; Thankappan, Lekha; Andavar, Raghuram; Devisundaram, Sundar

    2017-01-01

    Introduction Oxidative stress plays a central role in the pathogenesis of Diabetic Retinopathy (DR) and serum bilirubin has been shown to have antioxidant properties. Aim To investigate the association between serum bilirubin concentration and DR in patients with Type 2 Diabetes Mellitus (DM). Materials and Methods This was a hospital based, cross- sectional study where in 86 patients with Type 2 DM and 30 controls were recruited. The study was conducted at a tertiary care centre in Southern India between January 2014 and December 2014. The presence and the severity of DR were determined by fundus examination and grading of colour fundus photographs using the international clinical disease severity scale for DR. Serum total, direct and indirect bilirubin levels were determined in all subjects and the association between bilirubin levels and severity of DR was studied. Results Among the 86 diabetics, 24 had no retinopathy and 62 had DR of varying grades. The mean total bilirubin level among diabetic subjects (0.52±0.17) and controls (0.51±0.19) were found to be similar. The mean total as well as direct bilirubin levels were found to be lower in patients with retinopathy as compared to no retinopathy group (p<0.001). The severity of DR was inversely proportional to the serum bilirubin levels (p=0.010). Serum total bilirubin was found to have a negative association with glycosylated haemoglobin and served as an independent determinant of DR even after adjusting for risk factors known to be associated with DR (p=0.001). Conclusion Low serum bilirubin levels are significantly associated with increased risk of DR independent of classic risk factors. Serum bilirubin can serve as a useful biomarker in identifying patients at risk for developing proliferative DR. PMID:28384901

  12. Inverse association of serum bilirubin with metabolic syndrome and insulin resistance in Polish population.

    PubMed

    Guzek, Marek; Jakubowski, Zenon; Bandosz, Piotr; Wyrzykowski, Bogdan; Smoczyński, Marian; Jabloiska, Anna; Zdrojewski, Tomasz

    2012-01-01

    Bilirubin has got a potential anti-oxidant, anti-inflammatory and cytoprotective effect. It has been shown that its concentration is inversely related to cardiometabolic diseases. Recent studies have revealed the association between serum bilirubin concentrations and metabolic syndrome (MS) among children and adolescents in U.S. and among Korean adults. The aim of this study was to evaluate the association of total serum bilirubin level with MS and insulin resistance in Poland. We examined 1568 patients aged 18 to 93 years. The tested population was a nationally representative sample of Polish adults. They were derived from cross-sectional study, when serum total bilirubin level and risk factors of cardiovascular diseases were determined. The prevalence of MS in bilirubin level quartiles (95% CI in parentheses) was 28.9% (24.5%-33.3%), 32.6% (28.3%-36.9%), 23.4% (19.0%-27.8%), 21.8% (17.5%-26.2%) respectively for quartiles 1-4 (p = 0.002) The multivariate analysis showed odds ratio for MS in third and fourth quartile of bilirubin level equal to 0.70 (0.50-0.99) and 0.68 (0.48-0.95) respectively in comparison to the lowest quartile. The more criteria of metabolic syndrome were fulfilled by the patient, the lower was mean total bilirubin level (p = 0.012). In study group there was also a strong, independent association of bilirubin level with fasting insulin level and insulin resistance (HOMA-IR). The odds ratio of insulin resistance was 0.53 (0.38-0.74) for the fourth quartile in reference to the lowest quartile of bilirubin. In Polish adults serum total bilirubin level is inversely related to the prevalence of MS and insulin resistance.

  13. Extreme bilirubin levels as a causal risk factor for symptomatic gallstone disease.

    PubMed

    Stender, Stefan; Frikke-Schmidt, Ruth; Nordestgaard, Børge G; Tybjærg-Hansen, Anne

    2013-07-08

    In individuals without blockage of their bile ducts, levels of plasma bilirubin likely reflect levels of biliary bilirubin; higher biliary bilirubin levels may increase the risk of gallstone disease. To test the hypothesis that a lifelong increase in plasma bilirubin levels is a causal risk factor for symptomatic gallstone disease in the general population. In a prospective study of the Danish general population (N = 61,212), we first tested whether elevated levels of plasma bilirubin predicted greater risk of symptomatic gallstone disease. Second, taking advantage of mendelian randomization, we tested whether a genetic variant in the bilirubin glucoronidating enzyme UGT1A1 (rs6742078) was associated with increased plasma bilirubin levels and, in turn, with an increased risk of symptomatic gallstone disease. Plasma bilirubin level and symptomatic gallstone disease. During 34 years of follow-up, 3374 individuals developed symptomatic gallstone disease. In adjusted analyses, persons with plasma bilirubin levels in the 10th decile had a greater risk of symptomatic gallstone disease compared with those with plasma bilirubin levels in deciles 1 through 9; the hazard ratios (HRs) (95% CIs) were 1.57 (1.26-1.96) overall, 1.36 (1.02-1.82) in women, and 2.00 (1.41-2.83) in men. UGT1A1 genotype explained 20% of the total variation in plasma bilirubin levels and was associated with increases in the mean plasma bilirubin level overall of +16% (+0.09 mg/dL) in GT heterozygotes and +90% (+0.50 mg/dL) in TT homozygotes compared with GG homozygotes, with similar effects in women and men (P for trend <.001 for all). The corresponding HRs (95% CIs) for symptomatic gallstone disease were 1.09 (1.02-1.17) for GT heterozygotes and 1.22 (1.09-1.36) for TT homozygotes vs GG homozygotes and similar in women and men (P for trend = .04-<.001). These results are compatible with a causal association between extreme levels of plasma bilirubin and increased risk of symptomatic gallstone disease.

  14. Statins alter the hepatobiliary transport of unconjugated and conjugated bilirubin in sandwich-cultured rat hepatocytes.

    PubMed

    Szabó, Mónika; Veres, Zsuzsa; Bátai-Konczos, Attila; Kékesi, Orsolya; Kis, Emese; Szabó, Kitti; Jemnitz, Katalin

    2014-09-01

    Several studies have reported that statins occasionally cause impairment of liver functions characterized by elevated serum bilirubin levels, which might be due to altered function of the multidrug resistance-associated proteins (Mrp2/3). We aimed to study the modulation of the hepatobiliary transport of bilirubin by four statin derivatives, atorvastatin, fluvastatin, pravastatin, and rosuvastatin in sandwich-cultured rat hepatocytes. All statins except pravastatin significantly inhibited the uptake of bilirubin. The biliary efflux of bilirubin conjugates was increased by pravastatin and rosuvastatin concentration dependently. Rosuvastatin stimulated not only the Mrp2 mediated biliary, but the Mrp3 mediated sinusoidal elimination, resulting in decreased intracellular bilirubin accumulation. The significantly induced Mrp2/3 protein levels (ranging from 1.5 to 1.8-fold) accounted for the elevated efflux. Cell polarization, the formation of biliary network was also significantly increased by fluvastatin, pravastatin and rosuvastatin (151%, 216% and 275% of the control, respectively). The simultaneous inhibition of the uptake and the stimulation of the sinusoidal and canalicular elimination may explain, at least in part, the clinical observation of elevated serum bilirubin levels. In conclusion, our results suggest that in spite of the elevated serum bilirubin levels, the altered Mrp2 and Mrp3 functions by statins is probably not associated with hepatotoxic effects.

  15. Formation of photoproducts and cytotoxicity of bilirubin irradiated with turquoise and blue phototherapy light.

    PubMed

    Roll, Ellen Bruzell; Christensen, Terje

    2005-10-01

    To compare a new turquoise ("green") fluorescent phototherapy lamp (490 nm) with a conventional blue phototherapy lamp (450 nm) with respect to cytotoxicity and photochemical effects of bilirubin. Mouse lymphoma cells (L5178Y-R) in the presence of bilirubin solutions were exposed to phototherapy light. Occurrence of necrosis and apoptosis, reduction of mitotic index and inhibited cell growth was assayed by appropriate methods. The presence of bilirubin and its photoisomers was measured by high-pressure liquid chromatography analysis and absorption spectroscopy. At constant and equal light irradiances, the cytotoxic effects in the presence of bilirubin bound to human serum albumin showed that the green lamp caused significantly less necrosis (n = 4, p < 0.05) and less inhibition of cell multiplication (n = 3, p < 0.05) than the blue lamp. A slightly lower apoptotic fraction, although not statistically significant, was observed in cells exposed to the blue lamp. Photo-oxidation of bilirubin was more prominent with blue light irradiation. The photoequilibria between geometric isomers of bilirubin were different for the two lamps; more geometric photoisomers were formed by blue irradiation (n = 6, p < 0.05). The amounts of the most water-soluble isomers (presumably mainly lumirubin) were rather similar for the two lamps. The two lamps were similar in the formation of therapeutically relevant photoproducts, but the blue lamp showed potential in forming more photo-oxidation products and in causing more severe cellular damage in the presence of bilirubin.

  16. Bilirubin conjugates of human bile. Nuclear-magnetic-resonance, infrared and optical spectra of model compounds

    PubMed Central

    Kuenzle, Clive C.

    1970-01-01

    N.m.r., i.r. and optical spectra of model compounds were recorded. These were to help in elucidating the structures of the phenylazo derivatives of bilirubin conjugates isolated from human bile. Model compounds included commercial and human bile bilirubin, mesobilirubin, bilirubin dimethyl ester, dimethoxybilirubin dimethyl ester and the corresponding phenylazo derivatives. The phenylazo derivative of vinylneoxanthobilirubinic acid was also investigated. All compounds were of the type IXα, and no other isomer could be detected with the spectroscopic methods employed. The compounds crystallize as the lactams, except for dimethoxybilirubin dimethyl ester and its phenylazo derivative, which are held in the lactim ether configuration. With all other compounds no tautomeric forms other than the lactams could be detected, although small proportions of bilirubin must exist as the lactim. Bilirubin does not form a betaine, a structure that has been proposed by von Dobeneck & Brunner (1965) to explain the bathochromic shift of its optical spectrum as compared with the expected position of the absorption maximum at 420nm. However, this shift to 453nm can be explained on the basis of internal hydrogen bonds occurring between the carboxylic protons and the pyrrole rings of bilirubin, as proposed by Fog & Jellum (1963), and new evidence for such a bonding has been accumulated. The bilirubin sulphate described by Watson (1958), which is formed by treatment of bilirubin with concentrated sulphuric acid and acetic anhydride, was also investigated. The main product of this reaction was isolated as its phenylazo derivative, and was shown to be 3,18-di(ethylidene sulphate)-2,7,13,17-tetramethylbiladiene-ac-8,12-dipropionic acid. The reaction leading to this compound is an addition of sulphuric acid to the vinyl side chains of bilirubin according to Markownikoff's rule. PMID:5500301

  17. Serum bilirubin levels are inversely associated with nonalcoholic fatty liver disease

    PubMed Central

    Kwak, Min-Sun; Chung, Goh Eun; Kang, Seung Joo; Park, Min Jung; Kim, Yoon Jun; Yoon, Jung-Hwan; Lee, Hyo-Suk

    2012-01-01

    Background/Aims Serum bilirubin exerts antioxidant and cytoprotective effects. In addition, elevated serum bilirubin levels are associated with a decreased risk of metabolic and cardiovascular diseases. However, few studies have evaluated whether serum bilirubin is associated with non-alcoholic fatty liver disease (NAFLD), which is closely associated with other metabolic diseases. The aim of this study was thus to elucidate the association between serum total bilirubin levels and NAFLD. Methods A cross-sectional study of 17,348 subjects undergoing a routine health check-up was conducted. Subjects positive for hepatitis B or hepatitis C virus, or with other hepatitis history were excluded. NAFLD was diagnosed on the basis of typical ultrasonographic findings and an alcohol consumption of less than 20 g/day. Results The mean age of the subjects was 49 years and 9,076 (52.3%) were men. The prevalence of NAFLD decreased steadily as the serum bilirubin level increased in both men and women (P<0.001 for both). Multivariate regression analysis adjusted for other metabolic risk factors showed that serum bilirubin level was inversely associated with the prevalence of NAFLD [odds ratio (OR)=0.88, 95% confidence interval (CI)=0.80-0.97]. Furthermore, there was an inverse, dose-dependent association between NAFLD and serum total bilirubin levels (OR=0.83, 95% CI=0.75-0.93 in the third quartile; OR=0.80, 95% CI=0.71-0.90 in the fourth quartile vs. lowest quartile, P for trend <0.001). Conclusions Serum bilirubin levels were found to be inversely associated with the prevalence of NAFLD independent of known metabolic risk factors. Serum bilirubin might be a protective marker for NAFLD. PMID:23323254

  18. Enterohepatic circulation of nonconjugated bilirubin in rats fed with human milk

    SciTech Connect

    Alonso, E.M.; Whitington, P.F.; Whitington, S.H.; Rivard, W.A.; Given, G. )

    1991-03-01

    To test the hypothesis that enhanced intestinal absorption of bilirubin may contribute to prolonged nonconjugated hyperbilirubinemia in human milk-fed infants, we studied a cross-section of 36 healthy infants and mothers. Milk from mothers and serum from infants were collected at 16.3 +/- 2.4 days. Milk was studied for its effect on the absorption of bilirubin labeled with carbon 14 in rats and compared with buffer and iron-fortified infant formula (Similac With Iron). The percentage of a 1 mg bilirubin dose absorbed by the rat was 25.29 +/- 4.0% when it was administered into the duodenum with buffer, 4.67 +/- 2.4% with Similac formula, and 7.7 +/- 2.9% with human milk. Linear regression analysis, using the infant's serum nonconjugated bilirubin level as the dependent variable and the percentage of (14C)bilirubin absorbed by the rat with the corresponding mother's milk as the independent variable, revealed a significant correlation (r = 0.40; p = 0.016). Inspection of the data suggested that absorptive permissiveness correlated closely with infant serum bilirubin values greater than 24 mumol/L (1.4 mg/dl) (r = 0.55; p = 0.007), whereas in those with bilirubin values less than or equal to 24 mumol/L, there was no apparent correlation. Milk was also analyzed for beta-glucuronidase, nonesterified fatty acids, and the ability to inhibit glucuronosyltransferase activity of rat liver microsomes in vitro, none of which correlated with the infant's serum bilirubin. These data support the theory that enhanced intestinal absorption of bilirubin contributes to the jaundice associated with breast-feeding.

  19. High preoperative bilirubin values protect against reperfusion injury after live donor liver transplantation.

    PubMed

    Spetzler, Vinzent N; Goldaracena, Nicolas; Kaths, Johann M; Marquez, Max; Selzner, Nazia; Cattral, Mark S; Greig, Paul D; Lilly, Les; McGilvray, Ian D; Levy, Gary A; Ghanekar, Anand; Renner, Eberhard L; Grant, David R; Selzner, Markus

    2015-11-01

    Heme Oxygenase-1 and its product biliverdin/bilirubin have been demonstrated to protect against ischemia/reperfusion injury (IRI). We investigated whether increased preoperative bilirubin values of transplant recipients decrease IRI. Preoperative bilirubin levels of live donor liver recipients were correlated to postoperative liver transaminase as a marker of IRI. Additionally, two recipient groups with pretransplant bilirubin levels >24 μmol/l (n = 348) and ≤24 μmol/l (n = 118) were compared. Post-transplant liver function, complications, length of hospital stay, and patient and graft survival were assessed. Preoperative bilirubin levels were negatively correlated to the postoperative increase in transaminases suggesting a protective effect against IRI. The maximal rise of ALT after transplantation in high versus low bilirubin patients was 288 (-210-2457) U/l vs. 375 (-11-2102) U/l, P = 0.006. Bilirubin remained a significant determining factor in a multivariate linear regression analysis. The MELD score and its individual components as a marker of severity of chronic liver disease were significantly higher in the high versus low bilirubin group (P < 0.001). Despite this, overall complication rate (21.0% vs. 21.2%, P = 0.88), hospital stay [13 (4-260) vs. 14 (6-313) days, P = 0.93), and 1-year graft survival (90.8% vs. 89.0%, P = 0.62) were similar in both groups. High bilirubin levels of liver recipients before live donor transplantation is associated with decreased postoperative IRI.

  20. Relation of Pre-anthracycline Serum Bilirubin Levels to Left Ventricular Ejection Fraction After Chemotherapy.

    PubMed

    Vera, Trinity; D'Agostino, Ralph B; Jordan, Jennifer H; Whitlock, Matthew C; Meléndez, Giselle C; Lamar, Zanetta S; Porosnicu, Mercedes; Bonkovsky, Herbert L; Poole, Leslie B; Hundley, W Gregory

    2015-12-01

    Myocardial injury because of oxidative stress manifesting through reductions in left ventricular ejection fraction (LVEF) may occur after the administration of anthracycline-based chemotherapy (A-bC). We hypothesized that bilirubin, an effective endogenous antioxidant, may attenuate the reduction in LVEF that sometimes occurs after receipt of A-bC. We identified 751 consecutively treated patients with cancer who underwent a pre-A-bC LVEF measurement, exhibited a serum total bilirubin level <2 mg/dl, and then received a post-A-bC LVEF assessment because of symptomatology associated with heart failure. Analysis of variance, Tukey's Studentized range test, and chi-square tests were used to evaluate an association between bilirubin and LVEF changes. The LVEF decreased by 10.7 ± 13.7%, 8.9 ± 11.8%, and 7.7 ± 11.5% in group 1 (bilirubin at baseline ≤0.5 mg/dl), group 2 (bilirubin 0.6 to 0.8 mg/dl), and group 3 (bilirubin 0.9 to 1.9 mg/dl), respectively. More group 1 patients experienced >15% decrease in LVEF compared with those in group 3 (p = 0.039). After adjusting for age, coronary artery disease/myocardial infarction, diabetes mellitus, hematocrit, and the use of cardioactive medications, higher precancer treatment bilirubin levels and lesser total anthracycline doses were associated with LVEF preservation (p = 0.047 and 0.011, respectively). In patients treated with anthracyclines who subsequently develop symptoms associated with heart failure, pre-anthracycline treatment serum bilirubin levels inversely correlate with subsequent deterioration in post-cancer treatment LVEF. In conclusion, these results suggest that increased levels of circulating serum total bilirubin, an intrinsic antioxidant, may facilitate preservation of LVEF in patients receiving A-bC for cancer.

  1. Evaluation of oxidant and antioxidant status in term neonates: a plausible protective role of bilirubin.

    PubMed

    Shekeeb Shahab, M; Kumar, Praveen; Sharma, Neeraj; Narang, Anil; Prasad, Rajendra

    2008-10-01

    In vitro studies have shown unequivocally that bilirubin is an antioxidant. We hypothesized that bilirubin serves a physiological role of an antioxidant in vivo. To investigate the probable protective role of bilirubin in vivo, term babies with clinical jaundice were grouped into four categories-serum total bilirubin (STB) <160 mg/l, 160-200 mg/l, >200 mg/l, and kernicterus. Serum bilirubin, serum albumin, plasma glucose-6-phosphate dehydrogenase (G6PD), lipid peroxidation in blood cells, and reduced glutathione (GSH) content in whole blood were investigated. We also measured superoxide dismutase (SOD) and catalase in hemolysate and total plasma antioxidant capacity (TAC). Lipid peroxidation and antioxidant enzymes were significantly lower in babies with STB <200 mg/l compared to controls. TAC had a positive and MDA had a negative correlation with STB till 200 mg/l. However, TAC had a negative and MDA had a positive correlation with bilirubin >200 mg/l and in babies with bilirubin encephalopathy. Elevated levels of MDA, SOD, and catalase and significantly decreased levels of reduced glutathione and total antioxidant capacity were observed in STB >200 mg/l group. Antioxidant enzymes were also significantly inhibited in bilirubin encephalopathy babies. Post phototherapy, MDA production and antioxidant levels were significantly increased whilst total antioxidant capacity and reduced glutathione were significantly decreased compared to pre-phototherapy values. Exchange transfusion resulted in reduced oxidative stress in subjects with encephalopathy, whereas no significant difference was observed in other babies with STB >200 mg/l. Taken together, the present study propounds that bilirubin acts as a physiological antioxidant till 200 mg/l concentration in full-term normal neonates. It is conjectured that beyond 200 mg/l, it can no longer be considered physiologic. However, the cause of pathological jaundice needs to be identified and treated. The present data documents

  2. [Haemolysis and turbidity influence on three analysis methods of quantitative determination of total and conjugated bilirubin on ADVIA 1650].

    PubMed

    Gobert De Paepe, E; Munteanu, G; Schischmanoff, P O; Porquet, D

    2008-01-01

    Plasma bilirubin testing is crucial to prevent the occurrence of neonatal kernicterus. Haemolysis may occur during sampling and interfere with bilirubin determination. Moreover, lipidic infusions may induce plasma lipemia and also interfere with bilirubin measurement. We evaluated the interference of haemolysis and lipemia with three methods of total and direct bilirubin measurement adaptated on an Advia 1650 analyser (Siemens Medical Solutions Diagnostics) : Synermed (Sofibel), Bilirubin 2 (Siemens) and Bilirubin Auto FS (Diasys). The measurement of total bilirubin was little affected by haemolysis with all three methods. The Bilirubin 2 (Siemens) method was the less sensitive to haemolysis even at low bilirubin levels. The measurement of conjugated bilirubin was significantly altered by low heamoglobin concentrations for Bilirubin Auto FS(R) (30 microM or 0,192 g/100 mL haemoglobin) and for Synermed (60 microM or 0,484 g/100 mL haemoglobin). In marked contrast, we found no haemoglobin interference with the Direct Bilirubin 2 reagent which complied with the method validation criteria from the French Society for Biological Chemistry. The lipemia up to 2 g/L of Ivelip did not affect neither the measurement of total bilirubin for all three methods nor the measurement of conjugated bilirubin with the Diasys and Siemens reagents. However, we observed a strong interference starting at 0,5 g/L of Ivelip with the Synermed reagent. Our data suggest that both Siemens and Diasys methods allow to measure accurately total and conjugated bilirubin in hemolytic and lipemic samples, nevertheless, the Siemens methodology is less affected by these interferences.

  3. Unconjugated bilirubin effect on 3H-ouabain binding to human fetal red cells.

    PubMed

    Corchs, J L; Corchs, M J; Serrani, R E

    1994-03-01

    Human fetal red cells show heterogeneity of 3H-ouabain binding sites. These cells were chosen as a model to look into unconjugated bilirubin effects on the primary active Na(+)-K+ transport mechanism. Evidences are presented suggesting that unconjugated bilirubin affects 3H-ouabain binding but not through a direct effect. This is supported by the fact that the "low affinity" subgroup sites of the last mentioned ligand persists after unconjugated bilirubin treatment of cells, whereas the "high-affinity" subgroup disappears.

  4. Conformational analysis and circular dichroism of bilirubin, the yellow pigment of jaundice

    NASA Astrophysics Data System (ADS)

    Lightner, David A.; Person, Richard; Peterson, Blake; Puzicha, Gisbert; Pu, Yu-Ming; Bojadziev, Stefan

    1991-06-01

    Conformational analysis of (4Z, 15Z)-bilirubin-IX(alpha) by molecular mechanics computations reveals a global energy minimum folded conformation. Powerful added stabilization is achieved through intramolecular hydrogen bonding. Theoretical treatment of bilirubin as a molecular exciton predicts an intense bisignate circular dichroism spectrum for the folded conformation: (Delta) (epsilon) is congruent to 270 L (DOT) mole-1 (DOT) cm-1 for the $OM450 nm electronic transition(s). Synthesis of bilirubin analogs with propionic acid groups methylated at the (alpha) or (beta) position introduces an allosteric effect that allows for an optical resolution of the pigments, with enantiomers exhibiting the theoretically predicted circular dichroism.

  5. Physical measurements of Cu{sup 2+}-complexes of bilirubin

    SciTech Connect

    Ferraro, J.R.; Wu, J.G.; Li, W.H.; Xu, Y.Z.; Xu, D.F.; Shen, G.R.; Soloway, R.D.

    1995-12-31

    Copper is known to form complexes with bilirubin (H{sub 2}BR). Such complexes have received increased attention due to their clinical significance as free-radical scavengers. The purpose of this study was to examine a series of Cu{sup 2+}BR complexes to ascertain the nature of the binding between Cu{sup 2+} and BR. Several physical measurements of the salts were made, such as Fourier Transform Infrared (FT-IR), Fourier Transform Raman spectroscopy (FT-R), and Electron Paramagnetic Resonance (EPR). The complexes were prepared by dissolving protonated BR in NaOH, and adding different ratios of aqueous CuCl{sub 2}. At ratios of Cu{sup 2+}:H{sub 2}BR of 1:1 and 2:1, soluble complexes were formed. In solution EPR spectra demonstrated 9 hyperfine peaks, which from the splitting, is indicative of Cu{sup 2+} coordinated to 4 nitrogen atoms coming from 2 molecules of BR.

  6. Highly Sensitive and Selective Sensing of Free Bilirubin Using Metal-Organic Frameworks-Based Energy Transfer Process.

    PubMed

    Du, Yaran; Li, Xiqian; Lv, Xueju; Jia, Qiong

    2017-09-13

    Free bilirubin, a key biomarker for jaundice, was detected with a newly designed fluorescent postsynthetically modified metal organic framework (MOF) (UIO-66-PSM) sensor. UiO-66-PSM was prepared based on the aldimine condensation reaction of UiO-66-NH2 with 2,3,4-trihydroxybenzaldehyde. The fluorescence of UIO-66-PSM could be effectively quenched by free bilirubin via a fluorescent resonant energy transfer process, thus achieving its recognition of free bilirubin. It was the first attempt to design a MOF-based fluorescent probe for sensing free bilirubin. The probe exhibited fast response time, low detection limit, wide linear range, and high selectivity toward free bilirubin. The sensing system enabled the monitor of free bilirubin in real human serum. Hence, the reported free bilirubin sensing platform has potential applications for clinical diagnosis of jaundice.

  7. A comparison between transcutaneous and total serum bilirubin in healthy-term greek neonates with clinical jaundice.

    PubMed

    Neocleous, Charalambos; Adramerina, Alkistis; Limnaios, Stefanos; Symeonidis, Symeon; Spanou, Chrysoula; Malakozi, Marina; Mpampalis, Evangelos

    2014-01-01

    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 neonatal jaundice. Clinically jaundiced newborns requiring total serum bilirubin level estimation were recruited prospectively. 368 pairs of total serum bilirubin/transcutaneous bilirubin measurements were taken in 222 newborns, using a direct spectrophotometric device and the BiliCheck device, respectively. The level of agreement between the obtained transcutaneous bilirubin and total serum bilirubin values was assessed. Our data were analysed using the Stata/SE 12.0 (StataCorp LP, USA) statistical programme. The mean (± SD) TSB was 225.4 ± 25.4 μmol/l and the mean (± SD) TcB was 237.9 ± 21.0 μmol/l. The correlation between the values was poor (Pearson's correlation coefficient 0.439; Lin's concordance coefficient 0.377 [95% CI 0.301 to 0.453]; P<0.001). The Bland-Altman analysis demonstrated that transcutaneous bilirubin measurements tended to overestimate the total serum bilirubin value (mean difference 12.5 ± 24.9 μmol/l), with wide 95% limits of agreement (-36.2 μmol/l to 61.3 μmol/l). Transcutaneous bilirubin values did not correlate well with total serum bilirubin values, being often imprecise in predicting the actual total serum bilirubin levels. This permits us to continue estimating total serum bilirubin in clinically jaundiced newborns according to our local guidelines, in order to safely decide the appropriate care plan.

  8. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system. (a...

  9. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system. (a...

  10. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system. (a...

  11. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system. (a...

  12. The effect of bilirubin on lipid peroxidation and antioxidant enzymes in cumene hydroperoxide-treated erythrocytes.

    PubMed

    Yeşilkaya, A; Yeğin, A; Ozdem, S; Aksu, T A

    1998-01-01

    Recently, it has been suggested that bilirubin may act as a potent biological chain-breaking antioxidant. To observe the effects of free bilirubin on antioxidant reactions in cumene hydroperoxide-treated erythrocytes (15 g hemoglobin/dl), we added bilirubin at four different concentrations (0.5, 1, 5, and 10 mg/dl). We measured the thiobarbituric acid-reactive substance and reduced glutathione levels, and some antioxidant enzyme activities, namely superoxide dismutase, catalase, and glucose-6-phosphate dehydrogenase. Thiobarbituric acid-reactive substance and chemiluminescent signals decreased during the incubation. Superoxide dismutase activities also decreased but not as much as in the control group. Glucose-6-phosphate dehydrogenase activities and reduced glutathione levels increased, but catalase activities remained the same as the control group. Our results suggest that bilirubin--in the concentrations we have used--partially prevented the oxidant effects of cumene hydroperoxide.

  13. Computational chemical analysis of unconjugated bilirubin anions and insights into pKa values clarification

    NASA Astrophysics Data System (ADS)

    Vega-Hissi, Esteban G.; Estrada, Mario R.; Lavecchia, Martín J.; Pis Diez, Reinaldo

    2013-01-01

    The pKa, the negative logarithm of the acid dissociation equilibrium constant, of the carboxylic acid groups of unconjugated bilirubin in water is a discussed issue because there are quite different experimental values reported. Using quantum mechanical calculations we have studied the conformational behavior of unconjugated bilirubin species (in gas phase and in solution modeled implicitly and explicitly) to provide evidence that may clarify pKa values because of its pathophysiological relevance. Our results show that rotation of carboxylate group, which is not restricted, settles it in a suitable place to establish stronger interactions that stabilizes the monoanion and the dianion to be properly solvated, demonstrating that the rationalization used to justify the high pKa values of unconjugated bilirubin is inappropriate. Furthermore, low unconjugated bilirubin (UCB) pKa values were estimated from a linear regression analysis.

  14. High serum bilirubin is associated with the reduced risk of diabetes mellitus and diabetic nephropathy.

    PubMed

    Han, Seung Seok; Na, Ki Young; Chae, Dong-Wan; Kim, Yon Su; Kim, Suhnggwon; Chin, Ho Jun

    2010-06-01

    Several studies have suggested a potential effect of serum bilirubin as an antioxidant and cytoprotectant factor. For the results presented here, we evaluated the correlation between serum bilirubin and diabetes mellitus (DM) or chronic kidney disease originated from DM (DMCKD) in a Korean population. We used a cross-sectional, population-based design to examine 93,909 subjects (aged 18-96 years, 53.0% male). The trend of P values in the odds ratios for being DM and DMCKD was calculated using patients separated into five groups based on individual serum bilirubin concentrations. The prevalence of DM and DMCKD was 6.7% and 0.8%, respectively. Higher serum bilirubin levels were significantly associated with decreased prevalence of DM in both men (P trend < 0.001) and women (P trend = 0.014). The risk of DMCKD also decreased as bilirubin levels increased in women (P trend = 0.011), but not in men (P trend = 0.467). Serum bilirubin level was inversely related to insulin resistance using the homeostasis model assessment (HOMA-IR), serum insulin, and C-reactive protein (CRP) levels in multiple linear regression analyses. The regression coefficients (B) of log-HOMA-IR, log-insulin, and log-CRP were as follows: -0.09, -0.13, and -0.60 in men; -0.07, -0.09, and -0.50 in women, respectively. All the regressions were statistically significant (P < 0.001). These results indicate that serum bilirubin might have some protective function against DM and DMCKD, although the association between high serum bilirubin and decreased prevalence of DMCKD is observed only in women.

  15. Serum bilirubin levels, UGT1A1 polymorphisms and risk for coronary artery disease.

    PubMed

    Lingenhel, Arno; Kollerits, Barbara; Schwaiger, Johannes P; Hunt, Steven C; Gress, Richard; Hopkins, Paul N; Schoenborn, Veit; Heid, Iris M; Kronenberg, Florian

    2008-12-01

    Low levels of the antioxidative serum bilirubin are associated with vascular aging and an increased risk for coronary artery disease (CAD). UGT1A1 is the major gene influencing bilirubin concentrations. Therefore, we investigated an association of bilirubin levels and two polymorphisms in the promoter of UGT1A1 (-53(TA-repeat) polymorphism and T-3279G) in 477 patients with premature, familial CAD and 619 age- and sex-matched controls. Bilirubin concentrations were significantly lower in cases than in controls (0.62+/-0.36 vs. 0.76+/-0.41 mg/dl for men, p=1.2 x 10(-10); and 0.42+/-0.29 vs. 0.55+/-0.23 mg/dl, p=1.9 x 10(-9) for women). Both polymorphisms showed a strong association with bilirubin levels with higher levels for homozygote carriers of the minor allele. These associations were most pronounced in male controls and patients (p=5.9 x 10(-26) and p=3.4 x 10(-16), respectively, for the -53(TA-repeat) polymorphism). Logistic regression analysis revealed low bilirubin levels but not the UGT1A1 polymorphisms to be significantly associated with CAD: OR (95% CI) 0.90 (0.86-0.94), p=2.6 x 10(-6) for men and 0.77 (0.68-0.87), p=3.2 x 10(-5) for women, respectively for each 0.1mg/dl increase of bilirubin. These results indicate that it is rather decreased bilirubin levels in general than the changes in the genetic variation of this gene that increase the risk for CAD.

  16. Constituents of Bile, Bilirubin and TUDCA, Protect Against Oxidative Stress-Induced Retinal Degeneration

    PubMed Central

    Oveson, Brian C.; Iwase, Takeshi; Hackett, Sean F.; Lee, Sun Young; Usui, Shinichi; Sedlak, Thomas W.; Snyder, Solomon H.; Campochiaro, Peter A.; Sung, Jennifer U.

    2014-01-01

    Two constituents of bile, bilirubin and tauroursodeoxycholic acid (TUDCA), have antioxidant activity. However, bilirubin can also cause damage to some neurons and glial cells, particularly immature neurons. In this study, we tested the effects of bilirubin and TUDCA in two models in which oxidative stress contributes to photoreceptor cell death, prolonged light exposure and rd10+/+ mice. In albino BALB/c mice, intraperitoneal (IP) injection of 5 mg/kg of bilirubin or 500 mg/kg of TUDCA prior to exposure to 5,000 lux of white light for 8 hours significantly reduced loss of rod and cone function assessed by electroretinograms (ERGs). Both treatments also reduced light-induced accumulation of superoxide radicals in the outer retina, rod cell death assessed by outer nuclear layer (ONL) thickness, and disruption of cone inner and outer segments. In rd10+/+ mice, IP injections of 5 or 50 mg/kg of bilirubin or 500 mg/kg of TUDCA every 3 days starting at postnatal day (P) 6, caused significant preservation of cone cell number and cone function at P50. Rods were not protected at P50, but both bilirubin and TUDCA provided modest preservation of ONL thickness and rod function at P30. These data suggest that correlation of serum bilirubin levels with rate of vision loss in patients with retinitis pigmentosa (RP) could provide a useful strategy to test the hypothesis that cones die from oxidative damage in patients with RP. If proof-of-concept is established, manipulation of bilirubin levels and administration of TUDCA could be tested in interventional trials. PMID:21054389

  17. Elevated serum bilirubin levels are inversely associated with coronary artery atherosclerosis.

    PubMed

    Kang, Seung Joo; Kim, Donghee; Park, Hyo Eun; Chung, Goh Eun; Choi, Seung Ho; Choi, Su-Yeon; Lee, Whal; Kim, Joo Sung; Cho, Sang-Heon

    2013-10-01

    Inverse correlations of high serum bilirubin with metabolic and cardiovascular disease have been suggested. However, anti-atherogenic effects of bilirubin have not been well-established in terms of the presence of plaques and stenosis identified in coronary computed tomography (CT). A cross-sectional study was conducted on 2862 men who were free of cardiovascular disease and underwent coronary CT as part of a routine medical screening examination. Coronary stenotic lesions were considered to be incidences of coronary atherosclerosis, and stenosis was classified as stenosis <50% or ≥50%, according to degree of stenosis. The prevalences of coronary atherosclerosis and stenosis ≥50% in subjects with elevated bilirubin levels (>1.2 mg/dL) were lower than those in subjects with normal bilirubin levels (≤1.2 mg/dL) (19.9% vs. 27.9%, p < 0.001, 8.5% vs. 10.3%, p = 0.044). Bilirubin was inversely associated with total plaques (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.48-0.73 in the 4th quartile vs. 1st quartile) and calcified plaques (OR 0.60, 95% CI 0.49-0.75) in univariate analysis. After adjusting for traditional risk factors, it was found that coronary atherosclerosis (OR 0.73, 95% CI 0.56-0.94 in the 4th quartile vs. 1st quartile) and calcified plaque (OR 0.66, 95% CI 0.53-0.84) were inversely associated with the bilirubin grade in a dose-dependent manner. The serum bilirubin level was inversely associated with coronary atherosclerosis and calcified plaques in a dose-dependent manner. These results suggested that serum bilirubin could be used as a protective biomarker of coronary artery disease. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. The effect of delayed transportation of blood samples on serum bilirubin values in neonates.

    PubMed

    Saththasivam, Poovendran; Voralu, Kirtanaa; Ramli, Noraida; Mustapha, Mohd Rafi; Omar, Julia; Van Rostenberghe, Hans

    2010-07-01

    Delays in transporting blood samples may cause inaccurate results. Samples may be exposed to light or heat during delays, resulting in the degradation of analytes, for example, bilirubin. This study was done to determine the effect of delays in the transportation of blood samples on serum bilirubin test results. Samples taken from neonates admitted to a tertiary hospital with jaundice were included in the study. The samples were collected through venipuncture in 3 labelled containers. The first container was sent immediately to the laboratory, while the second and third containers were sent after being kept in the ward for 1 and 3 hours, respectively. Bilirubin values were measured colourimetrically at a wavelength of 578 nm using a Roche Hitachi 912 Chemistry Analyser upon arrival in the laboratory. A total of 36 serum samples were studied. The mean of the indirect bilirubin measurements for 0-, 1-, and 3-hour samples were 174 (SD 68.65), 186.97 (SD 60.47), and 184.56 (SD 66.93), respectively. There was a significant difference in the mean indirect bilirubin measurement of 1-hour samples (P = 0.047, 95% CI -24.66 to -1.18) and 3-hour samples (P = 0.045, 95% CI -19.77 to -0.23) compared with 0-hour samples. There were no significant differences observed in either the mean total bilirubin or the mean direct bilirubin measurements of different time intervals. This study confirms that delays in the transportation of blood samples influence the bilirubin test results.

  19. Association of serum bilirubin with oxidant damage of human atherosclerotic plaques and the severity of atherosclerosis.

    PubMed

    Lapenna, Domenico; Ciofani, Giuliano; Pierdomenico, Sante Donato; Giamberardino, Maria Adele; Ucchino, Sante; Davì, Giovanni

    2017-09-25

    Bilirubin has protective effects against atherosclerotic cardiovascular diseases hypothetically due to its antioxidant-antilipoperoxidative properties. Thus, we investigated whether serum bilirubin is associated with oxidant damage, namely lipid peroxidation, of human atherosclerotic plaques and the severity of atherosclerosis. In this regard, we correlated the levels of serum total bilirubin (STB), direct (conjugated) bilirubin (SDB) and indirect (unconjugated) bilirubin (SIB) with those of fluorescent damage products of lipid peroxidation (FDPL) and lipid hydroperoxides (LOOH) of 32 endarterectomy-derived carotid atherosclerotic plaques. Moreover, we compared the levels of serum bilirubin and plaque lipoperoxides between two groups of patients of the study population with different severity of atherosclerosis as judged by the carotid stenosis degree, i.e., <90% (group A, n = 23) and ≥90% (group B, n = 9). Remarkably, the levels of STB were strongly inversely correlated with those of plaque FDPL (rS = -0.70, P < 0.0001) and LOOH (rS = -0.66, P < 0.0001), as were those of SIB (FDPL: rS = -0.68, P < 0.0001; LOOH: rS = -0.63, P < 0.0001). SDB had a weaker association with plaque FDPL (rS = -0.41, P < 0.05) and LOOH (rS = -0.35, P < 0.05). Moreover, the levels of STB, SDB and SIB were lower and those of plaque lipoperoxides higher in group B than in group A, pointing to the association of serum bilirubin and plaque oxidant burden with the severity of atherosclerosis. In conclusion, lowered serum bilirubin is associated with oxidant damage of human atherosclerotic plaques and the severity of atherosclerosis.

  20. The utility of inpatient rebound bilirubin levels in infants readmitted after birth hospitalization for hyperbilirubinemia.

    PubMed

    Berkwitt, Adam; Osborn, Rachel; Grossman, Matthew

    2015-02-01

    There are few data evaluating the role of inpatient rebound bilirubin levels in the management of infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. The goal of the present study was to evaluate the clinical utility of inpatient rebound bilirubin levels within this patient population. A retrospective cohort study was conducted of 226 infants readmitted after their birth hospitalization for indirect hyperbilirubinemia. Data from 130 infants with rebound bilirubin levels drawn at a mean of 6.1±2.4 hours after discontinuation of phototherapy were compared with data from 96 infants without rebound bilirubin levels. The primary outcome was readmission to the hospital, and secondary outcomes included length of stay and discharge time. A subgroup analysis compared characteristics of children who required repeat phototherapy versus those who did not. Overall, 5 of 130 patients from the rebound group were readmitted compared with 4 of 96 patients from the no-rebound group (P=.98). Length of stay was significantly longer for patients with rebound bilirubin levels (27.7 vs 23.2 hours; P=.001). Patients with bilirubin levels lowered to ≤14 mg/dL were less likely to receive repeat phototherapy than those with levels>14 mg/dL (2 of 129 vs 12 of 97; P=.001). Early inpatient rebound bilirubin levels do not successfully predict which patients will require hospital readmission for repeat phototherapy. Children with bilirubin levels lowered to ≤14 mg/dL with phototherapy are unlikely to receive repeat phototherapy. Copyright © 2015 by the American Academy of Pediatrics.

  1. Potential role of conjugated bilirubin and copper in the metabolism of lipid peroxides in bile.

    PubMed Central

    Stocker, R; Ames, B N

    1987-01-01

    Conjugated bilirubin and copper ions at their physiological concentrations in bile may play an important role in hydroperoxide and other detoxification. Conjugated bilirubin may also be an important chain-breaking antioxidant preventing lipid peroxidation. Bilirubin ditaurine (BR-DT), a water-soluble model compound of conjugated bilirubin, completely prevents the peroxyl radical-induced oxidation of phosphatidylcholine in either multilamellar liposomes or micelles. This antioxidant activity is associated with the bilirubin moiety of BR-DT, since taurine alone is inefficient in scavenging peroxyl radicals. The number of peroxyl radicals trapped per molecule of BR-DT is 1.9, compared to 4.7 trapped per molecule of biliverdin, the water-soluble physiological precursor of bilirubin. Peroxyl radical-induced oxidation of BR-DT results in a spectral shift in maximal absorbance toward shorter wavelengths; biliverdin is not formed as a major oxidation product. BR-DT, but neither taurine nor biliverdin, greatly accelerates the cupric ion-catalyzed decomposition of linoleic acid hydroperoxide. In the presence of ferric ion, BR-DT shows no lipid hydroperoxide-degrading activity. Addition of cupric ion to BR-DT results in formation of a complex with spectral features similar to that of a biliverdin-cupric ion complex, indicating that BR-DT and cupric ion undergo redox reactions. PMID:3479781

  2. Quantitative assessment of the multiple processes responsible for bilirubin homeostasis in health and disease

    PubMed Central

    Levitt, David G; Levitt, Michael D

    2014-01-01

    Serum bilirubin measurements are commonly obtained for the evaluation of ill patients and to screen for liver disease in routine physical exams. An enormous research effort has identified the multiple mechanisms involved in the production and metabolism of conjugated (CB) and unconjugated bilirubin (UB). While the qualitative effects of these mechanisms are well understood, their expected quantitative influence on serum bilirubin homeostasis has received less attention. In this review, each of the steps involved in bilirubin production, metabolism, hepatic cell uptake, and excretion is quantitatively examined. We then attempt to predict the expected effect of normal and defective function on serum UB and CB levels in health and disease states including hemolysis, extra- and intrahepatic cholestasis, hepatocellular diseases (eg, cirrhosis, hepatitis), and various congenital defects in bilirubin conjugation and secretion (eg, Gilbert’s, Dubin–Johnson, Crigler–Najjar, Rotor syndromes). Novel aspects of this review include: 1) quantitative estimates of the free and total UB and CB in the plasma, hepatocyte, and bile; 2) detailed discussion of the important implications of the recently recognized role of the hepatic OATP transporters in the maintenance of CB homeostasis; 3) discussion of the differences between the standard diazo assay versus chromatographic measurement of CB and UB; 4) pharmacokinetic implications of the extremely high-affinity albumin binding of UB; 5) role of the enterohepatic circulation in physiologic jaundice of newborn and fasting hyperbilirubinemia; and 6) insights concerning the clinical interpretation of bilirubin measurements. PMID:25214800

  3. Surface-modified anodic aluminum oxide membrane with hydroxyethyl celluloses as a matrix for bilirubin removal.

    PubMed

    Xue, Maoqiang; Ling, Yisheng; Wu, Guisen; Liu, Xin; Ge, Dongtao; Shi, Wei

    2013-01-01

    Microporous anodic aluminum oxide (AAO) membranes were modified by 3-glycidoxypropyltrimethoxysilane to produce terminal epoxy groups. These were used to covalently link hydroxyethyl celluloses (HEC) to amplify reactive groups of AAO membrane. The hydroxyl groups of HEC-AAO composite membrane were further modified with 1,4-butanediol diglycidyl ether to link arginine as an affinity ligand. The contents of HEC and arginine of arginine-immobilized HEC-AAO membrane were 52.1 and 19.7mg/g membrane, respectively. As biomedical adsorbents, the arginine-immobilized HEC-AAO membranes were tested for bilirubin removal. The non-specific bilirubin adsorption on the unmodified HEC-AAO composite membranes was 0.8mg/g membrane. Higher bilirubin adsorption values, up to 52.6mg/g membrane, were obtained with the arginine-immobilized HEC-AAO membranes. Elution of bilirubin showed desorption ratio was up to 85% using 0.3M NaSCN solution as the desorption agent. Comparisons equilibrium and dynamic capacities showed that dynamic capacities were lower than the equilibrium capacities. In addition, the adsorption mechanism of bilirubin and the effects of temperature, initial concentration of bilirubin, albumin concentration and ionic strength on adsorption were also investigated.

  4. Successive determination of urinary bilirubin and creatinine employing simultaneous injection effective mixing flow analysis.

    PubMed

    Ponhong, Kraingkrai; Teshima, Norio; Grudpan, Kate; Vichapong, Jitlada; Motomizu, Shoji; Sakai, Tadao

    2015-02-01

    A novel four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for successive determination of bilirubin and creatinine in urinary samples. The chemical variables and physical parameters in the flow system were optimized for the enhancement of successive analytical performances. The interferences from urine matrices on the determination of bilirubin and creatinine were eliminated to dilute urine samples. The calibration graphs with the optimum conditions were achieved to be in 0.024-5.0 mg L(-1) for bilirubin and 2-100 mg L(-1) for creatinine. The relative standard deviations (RSDs) at 3 mg L(-1) of bilirubin and at 50 mg L(-1) of creatinine for 11 runs were 1.5 and 1.0%, respectively. The limits of detections (3σ of blank) for bilirubin and creatinine were 7 µg L(-1) and 0.6 mg L(-1), respectively. The sample throughput for stepwise detection was 22 h(-1). The proposed method was applied to the successive determination of bilirubin and creatinine in urine samples.

  5. Higher direct bilirubin levels during mid-pregnancy are associated with lower risk of gestational diabetes mellitus.

    PubMed

    Liu, Chaoqun; Zhong, Chunrong; Zhou, Xuezhen; Chen, Renjuan; Wu, Jiangyue; Wang, Weiye; Li, Xiating; Ding, Huisi; Guo, Yanfang; Gao, Qin; Hu, Xingwen; Xiong, Guoping; Yang, Xuefeng; Hao, Liping; Xiao, Mei; Yang, Nianhong

    2017-01-01

    Bilirubin concentrations have been recently reported to be negatively associated with type 2 diabetes mellitus. We examined the association between bilirubin concentrations and gestational diabetes mellitus. In a prospective cohort study, 2969 pregnant women were recruited prior to 16 weeks of gestation and were followed up until delivery. The value of bilirubin was tested and oral glucose tolerance test was conducted to screen gestational diabetes mellitus. The relationship between serum bilirubin concentration and gestational weeks was studied by two-piecewise linear regression. A subsample of 1135 participants with serum bilirubin test during 16-18 weeks gestation was conducted to research the association between serum bilirubin levels and risk of gestational diabetes mellitus by logistic regression. Gestational diabetes mellitus developed in 8.5 % of the participants (223 of 2969). Two-piecewise linear regression analyses demonstrated that the levels of bilirubin decreased with gestational week up to the turning point 23 and after that point, levels of bilirubin were increased slightly. In multiple logistic regression analysis, the relative risk of developing gestational diabetes mellitus was lower in the highest tertile of direct bilirubin than that in the lowest tertile (RR 0.60; 95 % CI, 0.35-0.89). The results suggested that women with higher serum direct bilirubin levels during the second trimester of pregnancy have lower risk for development of gestational diabetes mellitus.

  6. Serum total bilirubin levels are negatively correlated with metabolic syndrome in aged Chinese women: a community-based study

    PubMed Central

    Zhong, P.; Sun, D.M.; Wu, D.H.; Li, T.M.; Liu, X.Y.; Liu, H.Y.

    2017-01-01

    We evaluated serum total bilirubin levels as a predictor for metabolic syndrome (MetS) and investigated the relationship between serum total bilirubin levels and MetS prevalence. This cross-sectional study included 1728 participants over 65 years of age from Eastern China. Anthropometric data, lifestyle information, and previous medical history were collected. We then measured serum levels of fasting blood-glucose, total cholesterol, triglycerides, and total bilirubin, as well as alanine aminotransferase activity. The prevalence of MetS and each of its individual component were calculated per quartile of total bilirubin level. Logistic regression was used to assess the correlation between serum total bilirubin levels and MetS. Total bilirubin level in the women who did not have MetS was significantly higher than in those who had MetS (P<0.001). Serum total bilirubin quartiles were linearly and negatively correlated with MetS prevalence and hypertriglyceridemia (HTG) in females (P<0.005). Logistic regression showed that serum total bilirubin was an independent predictor of MetS for females (OR: 0.910, 95%CI: 0.863–0.960; P=0.001). The present study suggests that physiological levels of serum total bilirubin might be an independent risk factor for aged Chinese women, and the prevalence of MetS and HTG are negatively correlated to serum total bilirubin levels. PMID:28146216

  7. Change in Serum Bilirubin Level as a Predictor of Incident Metabolic Syndrome

    PubMed Central

    Lee, You-Bin; Lee, Seung-Eun; Jun, Ji Eun; Jee, Jae Hwan; Bae, Ji Cheol; Jin, Sang-Man; Kim, Jae Hyeon

    2016-01-01

    Aim Serum bilirubin level was negatively associated with the prevalence of metabolic syndrome (MetS) in previous cross-sectional studies. However, bilirubin variance preceding the development of MetS has yet to be investigated. We aimed to determine the effect of change in bilirubin concentration on the risk of incident MetS in healthy Korean adults. Methods We conducted a retrospective longitudinal study of subjects who had undergone at least four yearly health check-ups between 2006 and 2012. Of 24,185 total individuals who received annual check-ups, 11,613 non-MetS participants with a baseline bilirubin level not exceeding 34.2 μmol/l were enrolled. We evaluated the association between percent change in bilirubin and risk of incident MetS. Results During 55,407 person-years of follow-up, 2,439 cases of incident MetS developed (21.0%). Baseline serum bilirubin level clearly showed no association with the development of MetS in men but an independent significant inverse association in women which attenuated (hence may be mediated) by elevated homeostatic model assessment index 2 for insulin resistance (HOMA2-IR). However, increased risk for incident MetS was observed in higher percent change in bilirubin quartiles, with hazard ratios of 2.415 (95% CI 2.094–2.785) in men and 2.156 (95% CI 1.738–2.675) in women in the fourth quartile, compared to the lowest quartile, after adjusting for age, smoking status, medication history, alanine aminotransferase, uric acid, estimated glomerular filtration rate, fasting glucose, baseline diabetes mellitus prevalence, systolic blood pressure, waist circumference, and body mass index. The hazard ratios per one standard deviation increase in percent change in bilirubin as a continuous variable were 1.277 (95% CI 1.229–1.326) in men and 1.366 (95% CI 1.288–1.447) in women. Conclusions Increases in serum bilirubin concentration were positively associated with a higher risk of incident MetS. Serum bilirubin increment might

  8. Performance of viscoelastic dampers (VED) under various temperatures and application of magnetorheological dampers (MRD) for seismic control of structures

    NASA Astrophysics Data System (ADS)

    Bhatti, Abdul Qadir

    2013-08-01

    A number of studies have been carried out to investigate the performance of viscoelastic dampers (VEDs) and magnetorheological dampers (MRDs) in controlling the seismic response of buildings, but very few of them regarding the effect of temperature on the behavior of those dampers. The energy absorption properties of the VEDs are dependent on the ambient temperature, excitation frequency and strain amplitude. Several mathematical models have been investigated for reproducing the experimental behavior of single degree of freedom VEDs and MEDs. Of these, only the fractional derivative model can reflect the influence of temperature which is, however, so complex that it is difficult to apply in structural analysis. In order to verify the effect of temperature, two case studies of structural element have been conducted: once using VED and once using MRD. Kelvin-Voigt mathematical model applied, they were investigated and after analyzing the results, the force vs. displacement showed that MRD achieved a high force capacity and a better performance than VED. Furthermore, the effect of the temperature in case of VED observed via plotting the dissipated energy hysteresis at different temperatures. These results validate the effect of the temperature as the lower the temperature the more viscous the dashpot element becomes, hence improving damping, but this is up to a specific low temperature.

  9. ABC and VED Analysis of the Pharmacy Store of a Tertiary Care Teaching, Research and Referral Healthcare Institute of India.

    PubMed

    Devnani, M; Gupta, Ak; Nigah, R

    2010-04-01

    The ABC and VED (vital, essential, desirable) analysis of the pharmacy store of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India, was conducted to identify the categories of items needing stringent management control. The annual consumption and expenditure incurred on each item of pharmacy for the year 2007-08 was analyzed and inventory control techniques, i.e. ABC, VED and ABC-VED matrix analysis, were applied. The drug formulary of the pharmacy consisted of 421 items. The total annual drug expenditure (ADE) on items issued in 2007-08 was Rs. 40,012,612. ABC analysis revealed 13.78%, 21.85% and 64.37% items as A, B and C category items, respectively, accounting for 69.97%, 19.95% and 10.08% of ADE of the pharmacy. VED analysis showed 12.11%, 59.38% and 28.51% items as V, E, and D category items, respectively, accounting for 17.14%, 72.38% and 10.48% of ADE of the pharmacy. On ABC-VED matrix analysis, 22.09%, 54.63% and 23.28% items were found to be category I, II and III items, respectively, accounting for 74.21%, 22.23% and 3.56% of ADE of the pharmacy. The ABC and VED techniques need to be adopted as a routine practice for optimal use of resources and elimination of out-of-stock situations in the hospital pharmacy.

  10. ABC and VED Analysis of the Pharmacy Store of a Tertiary Care Teaching, Research and Referral Healthcare Institute of India

    PubMed Central

    Devnani, M; Gupta, AK; Nigah, R

    2010-01-01

    The ABC and VED (vital, essential, desirable) analysis of the pharmacy store of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India, was conducted to identify the categories of items needing stringent management control. The annual consumption and expenditure incurred on each item of pharmacy for the year 2007-08 was analyzed and inventory control techniques, i.e. ABC, VED and ABC-VED matrix analysis, were applied. The drug formulary of the pharmacy consisted of 421 items. The total annual drug expenditure (ADE) on items issued in 2007-08 was Rs. 40,012,612. ABC analysis revealed 13.78%, 21.85% and 64.37% items as A, B and C category items, respectively, accounting for 69.97%, 19.95% and 10.08% of ADE of the pharmacy. VED analysis showed 12.11%, 59.38% and 28.51% items as V, E, and D category items, respectively, accounting for 17.14%, 72.38% and 10.48% of ADE of the pharmacy. On ABC-VED matrix analysis, 22.09%, 54.63% and 23.28% items were found to be category I, II and III items, respectively, accounting for 74.21%, 22.23% and 3.56% of ADE of the pharmacy. The ABC and VED techniques need to be adopted as a routine practice for optimal use of resources and elimination of out-of-stock situations in the hospital pharmacy. PMID:21264126

  11. Associations between serum total bilirubin levels and functional dependence in the elderly.

    PubMed

    Kao, T W; Chou, C H; Wang, C C; Chou, C C; Hu, J; Chen, W L

    2012-11-01

    Many studies support the role of bilirubin as a cytoprotector in chronic inflammatory diseases, such as stroke and atherosclerosis. To investigate the relationship between serum total bilirubin levels and functional dependence in older adults. Data from the National Health and Nutrition Examination Survey (1999-2002) pertaining to 2235 old adults were analysed. All participants had given a household interview, providing information of five major domains on self-reported functional status (activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility and general physical activities), had completed serum total bilirubin measurement, and a questionnaire regarding personal health. Poor performance was defined as experiencing difficulty with one or more items in a given domain. Functional dependence was defined as having three or more poor performances in the five major domains. Multiple logistic regression was performed together with quartile-based stratified odds ratio (OR) comparison and trend tests. The OR of functional dependence for each standard deviation increment in the serum total bilirubin level was 0.56 (P = 0.002). After additional adjustment, the inverse association remained essentially unchanged. In quartile-based analysis, participants with higher quartiles of serum total bilirubin tended to have lower ORs of functional dependence. The trends of lower likelihood of functional dependence across increasing quartiles of the serum total bilirubin level were statistically significant (P < 0.05 for all trends). Higher serum total bilirubin levels were associated with lower likelihood of functional dependence in older adults. © 2011 The Authors; Internal Medicine Journal © 2011 Royal Australasian College of Physicians.

  12. Development of a System Model for Non-Invasive Quantification of Bilirubin in Jaundice Patients

    NASA Astrophysics Data System (ADS)

    Alla, Suresh K.

    Neonatal jaundice is a medical condition which occurs in newborns as a result of an imbalance between the production and elimination of bilirubin. Excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. An optical system integrated with a signal processing system is used as a platform to noninvasively quantify bilirubin concentration through the measurement of diffuse skin reflectance. Initial studies have lead to the generation of a clinical analytical model for neonatal jaundice which generates spectral reflectance data for jaundiced skin with varying levels of bilirubin concentration in the tissue. The spectral database built using the clinical analytical model is then used as a test database to validate the signal processing system in real time. This evaluation forms the basis for understanding the translation of this research to human trials. The clinical analytical model and signal processing system have been successful validated on three spectral databases. First spectral database is constructed using a porcine model as a surrogate for neonatal skin tissue. Samples of pig skin were soaked in bilirubin solutions of varying concentrations to simulate jaundice skin conditions. The resulting skins samples were analyzed with our skin reflectance systems producing bilirubin concentration values that show a high correlation (R2 = 0.94) to concentration of the bilirubin solution that each porcine tissue sample is soaked in. The second spectral database is the spectral measurements collected on human volunteers to quantify the different chromophores and other physical properties of the tissue such a Hematocrit, Hemoglobin etc. The third spectral database is the spectral data collected at different time periods from the moment a bruise is induced.

  13. Serum total bilirubin levels and coronary heart disease--Causal association or epiphenomenon?

    PubMed

    Kunutsor, Setor K

    2015-12-01

    Observational epidemiological evidence supports a linear inverse and independent association between serum total bilirubin levels and coronary heart disease (CHD) risk, but whether this association is causal remains to be ascertained. A Mendelian randomization approach was employed to test whether serum total bilirubin is causally linked to CHD. The genetic variant rs6742078--well known to specifically modify levels of serum total bilirubin and accounting for up to 20% of the variance in circulating serum total bilirubin levels--was used as an instrumental variable. In pooled analysis of estimates reported from published genome-wide association studies, every copy of the T allele of rs6742078 was associated with 0.42 standard deviation (SD) higher levels of serum total bilirubin (95% confidence interval, 0.40 to 0.43). Based on combined data from the Coronary Artery Disease Genome wide Replication and Meta-analyses and the Coronary Artery Disease (C4D) Genetics Consortium involving a total of 36,763 CHD cases and 76,997 controls, the odds ratio for CHD per copy of the T allele was 1.01 (95% confidence interval, 0.99 to 1.04). The odds ratio of CHD for a 1 SD genetically elevated serum total bilirubin level was 1.03 (95% confidence interval, 0.98 to 1.09). The current findings casts doubt on a strong causal association of serum total bilirubin levels with CHD. The inverse associations demonstrated in observational studies may be driven by biases such as unmeasured confounding and/or reverse causation. However, further research in large-scale consortia is needed.

  14. The effect of elimination of environmental light on the metabolism of unconjugated bilirubin in the Gunn rat

    SciTech Connect

    Zenone, E.A.; Stoll, M.S.; Ostrow, J.D.

    1982-12-01

    In the homozygous jaundiced Gunn rat, bilirubin catabolism is augmented by intense illumination (phototherapy) and by induction of microsomal cytochrome P448. To assess the relative importance of less intense environmental light versus intrinsic mechanisms in the maintenance of bilirubin turnover, Gunn rats were kept for three weeks under either ordinary laboratory lighting (0.3-0.8 mW/cm2, wavelength range 400-600 nm) or in absolute darkness. No differences in plasma concentration, miscible pool, turnover of bilirubin, or in hepatic cytochrome P448 activity were noted between the two groups over this period. A greater than twofold increase in the biliary excretion of unconjugated bilirubin was noted in the animals maintained under light, but this represented only 2% of total bilirubin turnover. These results suggest that intrinsic(enzymatic .) pathways are of primary importance in the maintenance of bilirubin metabolism in the glucuronyltransferase-deficient state under ordinary levels of environmental light.

  15. Vedāntic view of life: Reply to Gustavo Caetano-Anollés

    PubMed Central

    2016-01-01

    ABSTRACT The author would like to thank Professor Gustavo Caetano-Anollés from Department of Crop Sciences, University of Illinois for his interest in his work. We may sometimes observe that there is a noticeable difference between the anecdote people narrate about the implications of a scientific paper and the real conclusion of the paper. Prof. Gustavo Caetano-Anollés's response1 is an ideal example of the same, where he has tried to make great hay about the implications of the article “Life and consciousness – The Vedāntic view.”2 The Vedāntic view subscribes neither to the views of ‘Creationist Movement’/‘Intelligent Design’, nor it supports some splendid anti-science proposal. Vedāntic view refutes the dominant reductionistic view of life in modern biology by proposing a viable alternative concept of ‘Organic Whole’ and thus serves a scientific critique to the nescience (avidyā) that is practiced on the name of science. PMID:27195069

  16. Vedāntic view of life: Reply to Gustavo Caetano-Anollés.

    PubMed

    Shanta, Bhakti Niskama

    2016-01-01

    The author would like to thank Professor Gustavo Caetano-Anollés from Department of Crop Sciences, University of Illinois for his interest in his work. We may sometimes observe that there is a noticeable difference between the anecdote people narrate about the implications of a scientific paper and the real conclusion of the paper. Prof. Gustavo Caetano-Anollés's response(1) is an ideal example of the same, where he has tried to make great hay about the implications of the article "Life and consciousness - The Vedāntic view."(2) The Vedāntic view subscribes neither to the views of 'Creationist Movement'/'Intelligent Design', nor it supports some splendid anti-science proposal. Vedāntic view refutes the dominant reductionistic view of life in modern biology by proposing a viable alternative concept of 'Organic Whole' and thus serves a scientific critique to the nescience (avidyā) that is practiced on the name of science.

  17. Terahertz-Regime, Micro-VEDs: Evaluation of Micromachined TWT Conceptual Designs

    NASA Technical Reports Server (NTRS)

    Booske, John H.; Kory, Carol L.; Gallagher, D.; van der Weide, Daniel W.; Limbach, S; Gustafson, P; Lee, W.-J.; Gallagher, S.; Jain, K.

    2001-01-01

    Summary form only given. The Terahertz (THz) region of the electromagnetic spectrum (approx.300-3000 GHz) has enormous potential for high-data-rate communications, spectroscopy, astronomy, space research, medicine, biology, surveillance, remote sensing, industrial process control, etc. The most critical roadblock to full exploitation of the THz band is lack of coherent radiation sources that are powerful (0.01-10.0 W continuous wave), efficient (>1 %), frequency agile (instantaneously tunable over 1% bandwidths or more), reliable, and relatively inexpensive. Micro-machined Vacuum Electron Devices (micro-VEDs) represent a promising solution. We describe prospects for miniature, THz-regime TWTs fabricated using micromachining techniques. Several approx.600 GHz conceptual designs are compared. Their expected performance has been analyzed using SD, 2.51), and 3D TWT codes. A folded waveguide (FWG) TWT forward-wave amplifier design is presented based on a Northrop Grumman (NGC) optimized design procedure. This conceptual device is compared to the simulated performance of a novel, micro-VED helix TWT. Conceptual FWG TWT backward-wave amplifiers and oscillators are also discussed. A scaled (100 GHz) FWG TWT operating at a relatively low voltage (-12 kV) is under development at NGC. Also, actual-size micromachining experiments are planned to evaluate the feasibility of arrays of micro-VED TWTs. Progress and results of these efforts are described. This work was supported, in part by AFOSR, ONR, and NSF.

  18. ABC-VED analysis of expendable medical stores at a tertiary care hospital.

    PubMed

    Kumar, Sushil; Chakravarty, A

    2015-01-01

    The modern system of medicine has evolved into a complex, sophisticated and expensive treatment modality in terms of cost of medicines and consumables. In any hospital, approximately 33% of total annual budget is spent on buying materials and supplies including medicines. ABC (Always, Better Control)-VED (Vital, Essential, Desirable) analysis of medical stores of a large teaching, tertiary care hospital of the Armed Forces was carried out to identify the categories of drugs needing focused managerial control. Annual consumption and expenditure data of expendable medical stores for one year was extracted from the drug expense book, followed by classification on its annual usage value. Subsequently, the factor of criticality was applied to arrive at a decision matrix for understanding the need for selective managerial control. The study revealed that out of 1536 items considered for the study, 6.77% (104), 19.27% (296) and 73.95% (1136) items were found to be A, B and C category items respectively. VED analysis revealed that vital items (V) accounted for 13.14% (201), essential items (E) for 56.37% (866) and desirable accounted for 30.49% items (469). ABC-VED matrix analysis of the inventory reveals that only 322 (21%) items out of an inventory of 1536 drugs belonging to category I will require maximum attention. Scientific inventory management tools need to be applied routinely for efficient management of medical stores, as it contributes to judicious use of limited resources and resultant improvement in patient care.

  19. Terahertz-Regime, Micro-VEDs: Evaluation of Micromachined TWT Conceptual Designs

    NASA Technical Reports Server (NTRS)

    Booske, John H.; Kory, Carol L.; Gallagher, D.; van der Weide, Daniel W.; Limbach, S; Gustafson, P; Lee, W.-J.; Gallagher, S.; Jain, K.

    2001-01-01

    Summary form only given. The Terahertz (THz) region of the electromagnetic spectrum (approx.300-3000 GHz) has enormous potential for high-data-rate communications, spectroscopy, astronomy, space research, medicine, biology, surveillance, remote sensing, industrial process control, etc. The most critical roadblock to full exploitation of the THz band is lack of coherent radiation sources that are powerful (0.01-10.0 W continuous wave), efficient (>1 %), frequency agile (instantaneously tunable over 1% bandwidths or more), reliable, and relatively inexpensive. Micro-machined Vacuum Electron Devices (micro-VEDs) represent a promising solution. We describe prospects for miniature, THz-regime TWTs fabricated using micromachining techniques. Several approx.600 GHz conceptual designs are compared. Their expected performance has been analyzed using SD, 2.51), and 3D TWT codes. A folded waveguide (FWG) TWT forward-wave amplifier design is presented based on a Northrop Grumman (NGC) optimized design procedure. This conceptual device is compared to the simulated performance of a novel, micro-VED helix TWT. Conceptual FWG TWT backward-wave amplifiers and oscillators are also discussed. A scaled (100 GHz) FWG TWT operating at a relatively low voltage (-12 kV) is under development at NGC. Also, actual-size micromachining experiments are planned to evaluate the feasibility of arrays of micro-VED TWTs. Progress and results of these efforts are described. This work was supported, in part by AFOSR, ONR, and NSF.

  20. Bilirubin modulated cytokines, growth factors and angiogenesis to improve cutaneous wound healing process in diabetic rats.

    PubMed

    Ram, Mahendra; Singh, Vishakha; Kumawat, Sanjay; Kant, Vinay; Tandan, Surendra Kumar; Kumar, Dinesh

    2016-01-01

    Bilirubin has shown cutaneous wound healing potential in some preliminary studies. Here we hypothesize that bilirubin facilitates wound healing in diabetic rats by modulating important healing factors/candidates and antioxidant parameters in a time-dependent manner. Diabetes was induced in male Wistar rats by streptozotocin. In all diabetic rats wounds were created under pentobarbitone anesthesia. All the rats were divided into two groups, of which one (control) was treated with ointment base and other with bilirubin ointment (0.3%). Wound closer measurement and tissue collection were done on days 3, 7, 14 and 19 post-wounding. The relative expressions of hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 alpha (SDF-1α), transforming growth factor- beta1 (TGF-β1()), tumor necrosis factor-α (TNF-α) and interlukin-10 (IL-10) mRNA and proteins and the mRNA of interlukin-1 beta (IL-1β) and matrix metalloprteinase-9 (MMP-9) were determined in the wound tissues. CD-31 staining and collagen content were evaluated by immunohistochemistry and picrosirius red staining, respectively. Histopathological changes were assessed by H&E staining. The per cent wound closer was significantly higher from day 7 onwards in bilirubin-treated rats. HIF-1α, VEGF, SDF-1α, TGF-β1, IL-10 mRNA and protein levels were significantly higher on days 3, 7 and 14 in bilirubin-treated rats. The mRNA expression and protein level of TNF-α and the mRNA of IL-1β and MMP-9 were progressively and markedly reduced in bilirubin-treated rats. The collagen deposition and formation of blood vessels were greater in bilirubin-treated rats. Bilirubin markedly facilitated cutaneous wound healing in diabetic rats by modulating growth factors, cytokines, neovasculogenesis and collagen contents to the wound site. Topical application of bilirubin ointment might be of great use in cutaneous wound healing in diabetic patients.

  1. A Genome-Wide Association Study of Total Bilirubin and Cholelithiasis Risk in Sickle Cell Anemia

    PubMed Central

    Milton, Jacqueline N.; Sebastiani, Paola; Solovieff, Nadia; Hartley, Stephen W.; Bhatnagar, Pallav; Arking, Dan E.; Dworkis, Daniel A.; Casella, James F.; Barron-Casella, Emily; Bean, Christopher J.; Hooper, W. Craig; DeBaun, Michael R.; Garrett, Melanie E.; Soldano, Karen; Telen, Marilyn J.; Ashley-Koch, Allison; Gladwin, Mark T.; Baldwin, Clinton T.; Steinberg, Martin H.; Klings, Elizabeth S.

    2012-01-01

    Serum bilirubin levels have been associated with polymorphisms in the UGT1A1 promoter in normal populations and in patients with hemolytic anemias, including sickle cell anemia. When hemolysis occurs circulating heme increases, leading to elevated bilirubin levels and an increased incidence of cholelithiasis. We performed the first genome-wide association study (GWAS) of bilirubin levels and cholelithiasis risk in a discovery cohort of 1,117 sickle cell anemia patients. We found 15 single nucleotide polymorphisms (SNPs) associated with total bilirubin levels at the genome-wide significance level (p value <5×10−8). SNPs in UGT1A1, UGT1A3, UGT1A6, UGT1A8 and UGT1A10, different isoforms within the UGT1A locus, were identified (most significant rs887829, p = 9.08×10−25). All of these associations were validated in 4 independent sets of sickle cell anemia patients. We tested the association of the 15 SNPs with cholelithiasis in the discovery cohort and found a significant association (most significant p value 1.15×10−4). These results confirm that the UGT1A region is the major regulator of bilirubin metabolism in African Americans with sickle cell anemia, similar to what is observed in other ethnicities. PMID:22558097

  2. Point Spectroscopy System for Noncontact and Noninvasive Prediction of Transcutaneous Bilirubin Concentration

    NASA Astrophysics Data System (ADS)

    Ong, P. E.; K. C Huong, Audrey

    2017-08-01

    This paper presents the use of a point spectroscopy system to determine one’s transcutaneous bilirubin level using Modified Lambert Beer model and the developed fitting routine. This technique required a priori knowledge of extinction coefficient of bilirubin and hemoglobin components in the wavelength range of 440-500 nm for the prediction of the required parameter value. This work was conducted on different skin sites of six healthy Asians namely on the thenar region of the palm of their hand, back of the hand, posterior and anterior forearm. The obtained results revealed the lowest mean transcutaneous bilirubin concentration of 0.44±0.3 g/l predicted for palm site while the highest bilirubin level of 0.98±0.2 g/l was estimated for posterior forearm. These values were also compared with that presented in the literature. This study found considerably good consistency in the value predicted for different subjects especially at the thenar region of the palm. This work concluded that the proposed system and technique may be suitably served as an alternative means to noncontact and noninvasive measurement of one’s transcutaneous bilirubin level at palm site.

  3. The effect of steroids and nucleotides on solubilized bilirubin uridine diphosphate glucuronyltransferase

    PubMed Central

    Adlard, B. P. F.; Lathe, G. H.

    1970-01-01

    1. It was confirmed that bilirubin glucuronyltransferase can be obtained in solubilized form from rat liver microsomes. 2. Michaelis–Menten kinetics were not followed by the enzyme with bilirubin as substrate when the bilirubin/albumin ratio was varied. High concentrations of bilirubin were inhibitory. 3. The Km for UDP-glucuronic acid at the optimum bilirubin concentration was 0.46mm. 4. Low concentrations of Ca2+ were inhibitory in the absence of Mg2+ but stimulatory in its presence; the converse applied for EDTA. 5. UDP-N-acetylglucosamine and UDP-glucose enhanced conjugation by untreated, but not by solubilized microsomes. 6. The apparent 9.5-fold increase in activity after solubilization was probably due to the absence of UDP-glucuronic acid pyrophosphatase activity in the solubilized preparation. 7. The activation of solubilized enzyme activity by ATP was considered to be a result of chelation of inhibitory metal ions. 8. The solubilized enzyme activity was inhibited by UMP and UDP. The effect of UMP was not competitive with respect to UDP-glucuronic acid. 9. A number of steroids inhibited the solubilized enzyme activity. The competitive effects of stilboestrol, oestrone sulphate and 3β-hydroxyandrost-5-en-17-one, with respect to UDP-glucuronic acid, may be explained on an allosteric basis. PMID:4251180

  4. Potential Cardiovascular Risk Protection of Bilirubin in End-Stage Renal Disease Patients under Hemodialysis

    PubMed Central

    do Sameiro-Faria, Maria; Kohlova, Michaela; Ribeiro, Sandra; Rocha-Pereira, Petronila; Teixeira, Laetitia; Nascimento, Henrique; Reis, Flávio; Miranda, Vasco; Bronze-da-Rocha, Elsa; Quintanilha, Alexandre; Belo, Luís; Costa, Elísio; Santos-Silva, Alice

    2014-01-01

    We evaluated the potential cardiovascular risk protection of bilirubin in hemodialysis (HD) patients. An enlarged set of studies were evaluated in 191 HD patients, including hematological study, lipid profile, iron metabolism, nutritional, inflammatory markers, and dialysis adequacy. The TA duplication screening in the UDP-glucuronosyltransferase 1 A1 (UGT1A1) promoter region was also performed. The UGT1A1 genotype frequencies in HD patients were 49.2%, 42.4%, and 8.4% for 6/6, 6/7, and 7/7 genotypes, respectively. Although no difference was found in UGT1A1 genotype distribution between the three tertiles of bilirubin, significant differences were found with increasing bilirubin levels, namely, a decrease in platelet, leukocyte, and lymphocyte counts, transferrin, oxidized low-density lipoprotein (ox-LDL), ox-LDL/low-density lipoprotein cholesterol ratio, apolipoprotein (Apo) A, Apo B, and interleukin-6 serum levels and a significant increased concentration of hemoglobin, hematocrit, erythrocyte count, iron, transferrin saturation, Apo A/Apo B ratio, adiponectin, and paraoxonase 1 serum levels. After adjustment for age these results remained significant. Our data suggest that higher bilirubin levels are associated with beneficial effects in HD patients, by improving lipid profile and reducing the inflammatory grade, which might contribute to increase in iron availability. These results suggest a potential cardiovascular risk protection of bilirubin in HD patients. PMID:25276769

  5. Evaluation of region selective bilirubin-induced brain damage as a basis for a pharmacological treatment

    PubMed Central

    Dal Ben, Matteo; Bottin, Cristina; Zanconati, Fabrizio; Tiribelli, Claudio; Gazzin, Silvia

    2017-01-01

    The neurologic manifestations of neonatal hyperbilirubinemia in the central nervous system (CNS) exhibit high variations in the severity and appearance of motor, auditory and cognitive symptoms, which is suggestive of a still unexplained selective topography of bilirubin-induced damage. By applying the organotypic brain culture (OBC: preserving in vitro the cellular complexity, connection and architecture of the in vivo brain) technique to study hyperbilirubinemia, we mapped the regional target of bilirubin-induced damage, demonstrated a multifactorial toxic action of bilirubin, and used this information to evaluate the efficacy of drugs applicable to newborns to protect the brain. OBCs from 8-day-old rat pups showed a 2–13 fold higher sensitivity to bilirubin damage than 2-day-old preparations. The hippocampus, inferior colliculus and cerebral cortex were the only brain regions affected, presenting a mixed inflammatory-oxidative mechanism. Glutamate excitotoxicity was appreciable in only the hippocampus and inferior colliculus. Single drug treatment (indomethacin, curcumin, MgCl2) significantly improved cell viability in all regions, while the combined (cocktail) administration of the three drugs almost completely prevented damage in the most affected area (hippocampus). Our data may supports an innovative (complementary to phototherapy) approach for directly protecting the newborn brain from bilirubin neurotoxicity. PMID:28102362

  6. Relationship Between the Serum Total Bilirubin and Inflammation in Patients With Psoriasis Vulgaris.

    PubMed

    Zhou, Zhen-Xing; Chen, Jian-Kui; Hong, Yan-Ying; Zhou, Ru; Zhou, Dong-Mei; Sun, Li-Yun; Qin, Wen-Li; Wang, Tian-Cheng

    2016-09-01

    Psoriasis is a chronic and recurrent inflammatory skin disease. Previous studies have shown that bilirubin has anti-inflammation and antioxidant effects. However, the various roles of bilirubin in psoriasis patients are still unclear. To investigate the serum total bilirubin (TB) level in the individuals with psoriasis vulgaris and further evaluate the relationship between serum TB concentration and C-reactive protein (CRP) to clarify the effect of bilirubin on inflammation. A total of 214 patients with psoriasis vulgaris and 165 age- and gender-matched healthy control subjects were recruited. The peripheral leukocyte count (white blood cell, WBC) and differential, serum biochemical and immunologic indexes including serum TB, immunoglobulin (Ig) G, IgA, IgM, complement C3 and C4 , as well as serum CRP concentrations were measured. Results showed that the serum TB level decreased significantly and peripheral WBC, neutrophil, and serum CRP concentrations increased significantly in patients with psoriasis vulgaris. Meanwhile, the serum CRP was negatively correlated with serum TB levels but positively correlated with peripheral WBC and the Psoriasis Area and Severity Index (PASI). Logistic regression analysis showed that the serum TB was a protective factor for psoriasis vulgaris. The present study suggests that lower serum TB is associated with the enhancement of the inflammatory response in psoriasis vulgaris. Therefore, lower serum TB has a prognostic significance for worsening psoriasis vulgaris. Bilirubin may play a crucial role in inflammation by contributing to the inhibition of the inflammatory response. © 2016 Wiley Periodicals, Inc.

  7. An amperometric bilirubin biosensor based on a conductive poly-terthiophene-Mn(II) complex.

    PubMed

    Rahman, Md Aminur; Lee, Kyung-Sun; Park, Deog-Su; Won, Mi-Sook; Shim, Yoon-Bo

    2008-01-18

    An amperometric bilirubin biosensor was fabricated by complexing the Mn(II) ion with a conducting polymer and the final biosensor surface was coated with a thin polyethyleneimine (PEI) film containing an enzyme, ascorbate oxidase (AsOx). The complexation between poly-5,2'-5',2''-terthiophene-3-carboxylic acid (PolyTTCA) and Mn(II) through the formation of Mn-O bond was confirmed by XPS. The PolyTTCA-Mn(II) complex was also characterized using cyclic voltammetry. The PolyTTCA-Mn(II)/PEI-AsOx biosensor specifically detect bilirubin through the mediated electron transfer by the Mn(II) ion. To optimize the experimental condition, various experimental parameters such as pH, temperature, and applied potential were examined. A linear calibration plot for bilirubin was obtained between 0.1 microM and 50 microM with the detection limit of 40+/-3.8 nM. Interferences from other biological compounds, especially ascorbate and dopamine were efficiently minimized by coating the biosensor surface with PEI-AsOx. The bilirubin sensor exhibited good stability and fast response time (<5s). The applicability of this bilirubin sensor was tested in a human serum sample.

  8. The impact of the UGT1A1*60 allele on bilirubin serum concentrations.

    PubMed

    Pasternak, Amy L; Crews, Kristine R; Caudle, Kelly E; Smith, Colton; Pei, Deqing; Cheng, Cheng; Broeckel, Ulrich; Gaur, Aditya H; Hankins, Jane; Relling, Mary V; Haidar, Cyrine E

    2017-01-01

    Identify the functional status of the uridine-diphosphate glucuronyl transferase 1A1 (UGT1A1) -3279T>G (*60) variant. Retrospective review of clinically obtained serum bilirubin concentrations in pediatric patients to evaluate the association of the UGT1A1 -3279T>G (*60) variant with bilirubin concentrations and assessed linkage disequilibrium of the UGT1A1 -3279T>G (*60) and A(TA)7TAA (*28) variants. Total bilirubin concentration did not differ between patients who had a UGT1A1*1/*1 diplotype and patients homozygous for the UGT1A1 -3279T>G (*60/*60) variant. Total bilirubin concentration was lower in patients homozygous for the UGT1A1 -3279T>G (*60/*60) variant than in patients homozygous for the UGT1A1 A(TA)7TAA (*28/*28) variant (p < 0.01). The -3279T>G (*60) and A(TA)7TAA (*28) variants were in strong incomplete linkage disequilibrium in both black and white patients. The presence of the UGT1A1 -3279T>G (*60) variant is not associated with increased bilirubin concentrations.

  9. Bilirubin production in healthy term infants as measured by carbon monoxide in breath.

    PubMed

    Stevenson, D K; Vreman, H J; Oh, W; Fanaroff, A A; Wright, L L; Lemons, J A; Verter, J; Shankaran, S; Tyson, J E; Korones, S B

    1994-10-01

    To describe total bilirubin production in healthy term infants, we measured the end-tidal breath CO, corrected for ambient CO (ETCOc), with an automated sampler and electrochemical (EC) CO instrument. For infants of mothers with a negative Coombs' test, the ETCOc was 1.3 +/- 0.7 microL/L (n = 397) and the serum bilirubin on day 3 postpartum was 73 +/- 35 mg/L (n = 381). In contrast, the ETCOc for infants with ABO or Rh incompatibility, a positive direct Coombs' test, and bilirubin > 130 mg/L (n = 9) was significantly higher, 1.8 +/- 0.8 microL/L, than for those who had a positive Coombs' test result but whose bilirubin was < or = 130 mg/L (n = 12), 1.0 +/- 0.5 microL/L (P < 0.05). At 2 to 8 h postpartum seven term babies from mothers with insulin-dependent diabetes had ETCOc of 1.8 +/- 0.7 microL/L, significantly higher than that in the other term infants [1.3 +/- 0.7 microL/L (n = 390), P < 0.04]. Their bilirubin concentration at 72 +/- 12 h was also higher: 121 +/- 45 mg/L (n = 7) vs 73 +/- 34 mg/L (n = 374; P = 0.03). We conclude that ETCOc measurements may be helpful in understanding the mechanisms of jaundice in healthy term infants in a variety of conditions.

  10. The association between indirect bilirubin levels and liver fibrosis due to chronic hepatitis C virus infection.

    PubMed

    Cengiz, Mustafa; Yılmaz, Guldal; Ozenirler, Seren

    2014-08-01

    We proposed to evaluate the association between serum indirect bilirubin levels and liver fibrosis in patients with chronic hepatitis C (CHC) genotype 1b. Biopsy proven CHC genotype 1b patients' demographics, clinical and histopathological characteristics were evaluated. Logistic regression analysis was done to evaluate the clinical, laboratory and demographic features of the histologically proven liver fibrosis in CHC patients. A total of 112 biopsy proven CHC genotype 1b patients were enrolled into the study. Liver fibrosis scores were measured by using Ishak fibrosis scores and were divided into two groups; fibrosis scores ≤ 2 were categorized as mild fibrosis, 82 patients (73.2%), whereas fibrosis scores >2 were categorized as advanced fibrosis group, 30 patients (26.8%). Patients with advanced fibrosis had lower indirect bilirubin levels than the mild fibrosis group (0.28 ± 0.02 mg/dl vs. 0.44 ± 0.032 mg/dl, p<0.001, respectively). Indirect bilirubin level was negatively correlated with advanced fibrosis scores (r=-0.416 and p<0.001). In multivariate logistic regression analysis, low indirect bilirubin level was an independent predicting factor of advanced liver fibrosis (OR: 0.001, 95% CI: 0.0-0.005, p<0.001). There is an inverse relationship between indirect bilirubin levels and advanced liver fibrosis caused by CHC genotype 1b.

  11. Bilirubin degradation in methanol induced by continuous UV-B irradiation: a UHPLC--ESI-MS study.

    PubMed

    Stanojević, J S; Zvezdanović, J B; Marković, D Z

    2015-04-01

    Degradation of bilirubin in aerobic methanol solution by continuous UV-B irradiation has been investigated in this work. The purpose of this study was to shed more light on bilirubin interaction with the UV-B component of natural sunlight, since bilirubin is a very efficient UV-B absorber located in the skin epidermis. The degradation products have been detected and studied by a combined method of Ultra High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (UHPLC-ESI-MS). Bilirubin, a toxic pigment which itself is a product of (hemoglobin) degradation in organisms, undergoes its own degradation under aerobic conditions of UV-B continuous irradiation (e.g. photooxidation) that can be partly self-sensitized. Two dipyrrolic structures have been identified as a result of the bilirubin degradation, not including the bilirubin derivative biliverdin whose increase in the irradiated system is synchronous with a time dynamics of bilirubin degradation. It appears that one of dipyrrolic products originates directly from bilirubin and biliverdin molecules, while the other one is probably connected to bilirubin self-sensitized degradation. The precursor role of biliverdin in the degradation process--related to the detected dipyrroles--has not been confirmed.

  12. Efficient voltammetric discrimination of free bilirubin from uric acid and ascorbic acid by a CVD nanographite-based microelectrode.

    PubMed

    Taurino, Irene; Van Hoof, Viviane; Magrez, Arnaud; Forró, László; De Micheli, Giovanni; Carrara, Sandro

    2014-12-01

    We report a novel electrochemical sensor based on nanographite grown on platinum microelectrodes for the determination of bilirubin in the presence of normal concentrations of albumin. The albumin is a protein with an intrinsic ability to bind the bilirubin therefore reducing the concentration of the free electroactive metabolite in human fluids. In addition, the proposed device permits the discrimination of free bilirubin from two interferents, uric acid and ascorbic acid, by the separation of their oxidation peaks in voltammetry. Preliminary measurements in human serum prove that the proposed nanostructured platform can be used to detect bilirubin.

  13. Continuous de novo biosynthesis of haem and its rapid turnover to bilirubin are necessary for cytoprotection against cell damage.

    PubMed

    Takeda, Taka-aki; Mu, Anfeng; Tai, Tran Tien; Kitajima, Sakihito; Taketani, Shigeru

    2015-05-20

    It is well known that haem serves as the prosthetic group of various haemoproteins that function in oxygen transport, respiratory chain, and drug metabolism. However, much less is known about the functions of the catabolites of haem in mammalian cells. Haem is enzymatically degraded to iron, carbon monoxide (CO), and biliverdin, which is then converted to bilirubin. Owing to difficulties in measuring bilirubin, however, the generation and transport of this end product remain unclear despite its clinical importance. Here, we used UnaG, the recently identified bilirubin-binding fluorescent protein, to analyse bilirubin production in a variety of human cell lines. We detected a significant amount of bilirubin with many non-blood cell types, which was sensitive to inhibitors of haem metabolism. These results suggest that there is a basal level of haem synthesis and its conversion into bilirubin. Remarkably, substantial changes were observed in the bilirubin generation when cells were exposed to stress insults. Since the stress-induced cell damage was exacerbated by the pharmacological blockade of haem metabolism but was ameliorated by the addition of biliverdin and bilirubin, it is likely that the de novo synthesis of haem and subsequent conversion to bilirubin play indispensable cytoprotective roles against cell damage.

  14. Amine-functionalized PVA-co-PE nanofibrous membrane as affinity membrane with high adsorption capacity for bilirubin.

    PubMed

    Wang, Wenwen; Zhang, Hao; Zhang, Zhifeng; Luo, Mengying; Wang, Yuedan; Liu, Qiongzhen; Chen, Yuanli; Li, Mufang; Wang, Dong

    2017-02-01

    In this study, poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membrane was activated by sodium hydroxide and cyanuric chloride, and then the activated membranes were functionalized by 1,3-propanediamine, hexamethylenediamine and diethylenetriamine to be affinity membranes for bilirubin removal, respectively. The chemical structures and morphologies of membranes were investigated by SEM, FTIR and XPS. And the adsorption ability of different amine-functionalized nanofibrous membranes for bilirubin was characterized. Furthermore, the effects of temperature, initial concentration of bilirubin, NaCl concentration and BSA concentration on the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane were studied. Results indicated that the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane could reach 85mg/g membrane when the initial bilirubin concentration was 200mg/L while the adsorption capacity could be increased to 110mg/g membrane if the initial bilirubin concentration was more than 400mg/L. The dynamic adsorption of diethylenetriamine-functionalized nanofibrous membrane showed that the ligands of amine groups on the membrane surface could be used as far as possible by recirculating the plasma with certain flow rates. Therefore, the diethylenetriamine-functionalized PVA-co-PE nanofibrous membrane possessed high adsorption capacity for bilirubin and it can be candidate as affinity membrane for bilirubin removal.

  15. Anemia, bilirubin, and cardiovascular autonomic neuropathy in patients with type 2 diabetes.

    PubMed

    Chung, Jin Ook; Park, Seon-Young; Cho, Dong Hyeok; Chung, Dong Jin; Chung, Min Young

    2017-04-01

    To investigate the relationship among anemia, physiological serum bilirubin levels, and cardiovascular autonomic neuropathy (CAN) in subjects with type 2 diabetes. In total, 2230 subjects with type 2 diabetes were evaluated in this cross-sectional study. CAN was diagnosed with a cardiovascular reflex test. The prevalence of anemia was greater in subjects with CAN. In multivariable analysis, the relationship between anemia and CAN remained statistically significant after adjusting for the risk factors (odds ratio [OR] 1.39; 95% confidence interval [CI] 1.07-1.80, P = .015). Additional adjustment for serum bilirubin concentrations abolished this relationship (OR 1.20, 95% CI 0.91-1.58, P = .189). Anemia is positively associated with the prevalence of CAN in subjects with type 2 diabetes. In addition, our results suggest that the putative increased CAN risk associated with anemia might be mediated by a correlated decrease in serum bilirubin levels.

  16. Conical intersection in a bilirubin model A possible pathway for phototherapy of neonatal jaundice

    NASA Astrophysics Data System (ADS)

    Zietz, Burkhard; Blomgren, Fredrik

    2006-03-01

    Phototherapy of neonatal jaundice involves Z- E-isomerisation around an exocyclic double bond in bilirubin. Our results of a CASSCF study on dipyrrinone, a bilirubin model, show a conical intersection between the ground and first excited singlet states associated with the Z- E-isomerisation. The conical intersection, located ca. 50 kJ/mol below the Franck-Condon-point, together with the S 1 minimum, ca. 50 kJ/mol below the conical intersection, are able to explain the available time-resolved spectroscopic data (the very short lifetime of the initially excited state and transient 'dark state' intermediate) as well as bilirubin's very low fluorescence quantum yield and the medium-efficient photoisomerisation reaction.

  17. [Clinical characteristics of bilirubin encephalopathy in Chinese newborn infants-a national multicenter survey].

    PubMed

    2012-05-01

    Bilirubin encephalopathy continued to be reported worldwide. This multicenter study was conducted to explore the clinical characteristics, comorbidities and prognosis of bilirubin encephalopathy in China. The survey was conducted in 33 level III hospitals. Clinical charts of infants with diagnosis of bilirubin encephalopathy or kernicterus at discharge were reviewed. The data were collected by a detaild questionnaire and analyzed. From January to December in 2009, 348 cases of bilirubin encephalopathy were reported from 28 hospitals. The mean birth weight was (3112.4 ± 599.6) grams, mean gestational age was (38.3 ± 2.3) weeks; 291 (83.6%) cases were term infants, 40 (11.5%) cases were late-preterm infants, and 11 (3.2%) cases were early preterm infants. After admission, the highest bilirubin level was (478.1 ± 175.8) µmol/L. Of all the 348 cases, the age at admission was (7.3 ± 5.4) days; 247 (71.0%) cases were admitted before 7 days of age, 24 (6.9%) cases were admitted after 14 days of age. Most of the cases (86.2%) were complicated with other conditions, including bacterial infection (52.6%), ABO incompatibility (29.9%), and perinatal asphyxia (10.1%). A total of 131 infants (37.6%) underwent an exchange transfusion. Use of albumin, intravenous immunoglobulin was also common (68.7% and 44.0% respectively). A total of 52 cases were of minority ethnic groups, with significantly higher rate of G6PD deficiency than Han ethnicity cases. During the hospitalization and follow up, 36 infants died, and 125 infants (35.9%) were lost to follow up. Bilirubin encephalopathy is still not rare in China, the establishment of a population-based reporting system and prevention of kernicterus remain a high priority among public health institutions.

  18. Parental infant jaundice colour card design successfully validated by comparing it with total serum bilirubin.

    PubMed

    Xue, Guo-Chang; Ren, Ming-Xing; Shen, Lin-Na; Zhang, Li-Wen

    2016-12-01

    We designed a jaundice colour card that could be used by the parents of neonates and validated it by comparing it with total serum bilirubin levels. There were 106 term Chinese neonates in the study. The majority weighed between 2500 g and 3499 g (63%) and had a gestational age of 37-40 weeks (77%). The jaundice colour card and photometric determination were used to screen for neonatal jaundice and compared with serum bilirubin. The bilirubin levels were measured by mothers using the jaundice colour card, and 67% of the measurements were taken at 11-20 days (range 3-30). The measurements at the infant's forehead, cheek and sternum showed strong correlations with total serum bilirubin. The mean differences between the total serum bilirubin and the jaundice colour card measurements from the forehead, cheek and sternum were 1.9 mg/dL, 0.3 mg/dL and 1.5 mg/dL, respectively. When total serum bilirubin >13 mg/dL was used as the cut-off point, the areas under the receiver operating characteristics curves were 0.934 for the forehead, 0.985 for the cheek and 0.966 for the sternum. We established the validity of the jaundice colour card as a parental measurement tool for jaundice in Chinese neonates, and the cheek was the best measurement site. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  19. Genetic influences on serum bilirubin in American Indians: The Strong Heart Family Study.

    PubMed

    Melton, Phillip E; Haack, Karin; Göring, Harald H; Laston, Sandy; Umans, Jason G; Lee, Elisa T; Fabsitz, Richard R; Devereux, Richard B; Best, Lyle G; Maccluer, Jean W; Almasy, Laura; Cole, Shelley A

    2011-01-01

    To identify genetic variation influencing serum bilirubin levels in American Indians, we performed genome-wide screening and association analyses in the Strong Heart Family Study. Bilirubin is an endogenous antioxidant that has demonstrated an inverse relationship with cardiovascular disease. Genetic variation within the promoter region of uridine diphosphate glucuronosyltransferase (UGT1A1) on chromosome 2q has been associated with elevated serum bilirubin levels in European populations. However, no study has investigated the UGT1A1 promoter in American Indians. Statistical analyses were carried out with 3,484 participants aged 14 to 93 years recruited from three geographic areas in the United States; Arizona, Oklahoma, and North and South Dakota. Variance components linkage analysis detected a quantitative trait locus (QTL) for bilirubin on chromosome 2q in the combined centers (LOD = 6.61, P = 4.24 × 10⁻⁶) and in Oklahoma (LOD = 5.65, P = 4.57 24 × 10⁻⁵). Genetic association of the UGT1A1 promoter polymorphism was significant for all geographic locations. After adjustment using conditional linkage for UGT1A1 promoter variance, the linkage signal dropped to 1.10 in the combined sample and to 3.32 (P = 0.02) in Oklahoma, indicating this polymorphism is not completely responsible for the linkage signal in American Indians. We also detected suggestive linkage signals in the Dakotas on chromosome 10p12 (LOD = 2.18) and in the combined centers (LOD = 2.24) on chromosome 10q21. Replication of a serum bilirubin QTL on chromosome 2q in American Indians implicates UGT1A1 but further genotyping is warranted to identify additional causative polymorphisms. Evidence also supports a potential novel locus for bilirubin on chromosome 10. © 2010 Wiley-Liss, Inc.

  20. Influence of light and time on bilirubin degradation in CSF spectrophotometry for subarachnoid haemorrhage.

    PubMed

    Foroughi, Mansoor; Parikh, Dhruv; Wassell, Julie; Hatfield, Richard

    2010-08-01

    Investigation of the influence of light on bilirubin degradation over time in cerebrospinal fluid (CSF) specimens from patients with computed tomography (CT) positive subarachnoid haemorrhage (SAH). Twenty-nine CSF samples were analysed from 23 patients with CT-positive SAH. Samples were divided into two cohorts - one half being stored in the dark, the other in normal room light conditions. Samples were assayed by spectrophotometry 0, 1, 2, 6, 19, 24 and 48 h post-storage. Net bilirubin absorbance (NBA) was measured in absorbance units (AU) by determining the optical density at 476 nm. In 27 of 28 (96%) samples stored in light conditions and 21 of 29 (72%) samples stored in dark, a decline in the amount of bilirubin detected in CSF over time was observed. The rate of bilirubin degradation over 24 h for CSF samples stored in the light ranged from 0.0001 to 0.0048 AU/h (mean 0.0020 AU/h), and was significantly greater (p < 0.01) than the rate of degradation in the dark, which ranged from 0 to 0.0024 AU/h (mean 0.0005 AU/h). CSF bilirubin samples are susceptible to the same photodegradation as shown in serum bilirubin samples. The rate of degradation is not predictable or consistent. This photodegradation may potentially produce false-negative results in the diagnosis of SAH. If spectrophotometry cannot be carried out immediately, all such CSF samples should at least be centrifuged immediately, the supernatant protected from light as soon as possible and the collection and analysis times provided in the report.

  1. Analysis of wavelength-dependent photoisomerization quantum yields in bilirubins by fitting two exciton absorption bands

    NASA Astrophysics Data System (ADS)

    Mazzoni, M.; Agati, G.; Troup, G. J.; Pratesi, R.

    2003-09-01

    The absorption spectra of bilirubins were deconvoluted by two Gaussian curves of equal width representing the exciton bands of the non-degenerate molecular system. The two bands were used to study the wavelength dependence of the (4Z, 15Z) rightarrow (4Z, 15E) configurational photoisomerization quantum yield of the bichromophoric bilirubin-IXalpha (BR-IX), the intrinsically asymmetric bile pigment associated with jaundice and the symmetrically substituted bilirubins (bilirubin-IIIalpha and mesobilirubin-XIIIalpha), when they are irradiated in aqueous solution bound to human serum albumin (HSA). The same study was performed for BR-IX in ammoniacal methanol solution (NH4OH/MeOH). The quantum yields of the configurational photoprocesses were fitted with a combination function of the two Gaussian bands normalized to the total absorption, using the proportionality coefficients and a scaling factor as parameters. The decrease of the (4Z, 15Z) rightarrow (4Z, 15E) quantum yield with increasing wavelength, which occurs for wavelengths longer than the most probable Franck-Condon transition of the molecule, did not result in a unique function of the exciton absorptions. In particular we found two ranges corresponding to different exciton interactions with different proportionality coefficients and scaling factors. The wavelength-dependent photoisomerization of bilirubins was described as an abrupt change in quantum yield as soon as the resulting excitation was strongly localized in each chromophore. The change was correlated to a variation of the interaction between the two chromophores when the short-wavelength exciton absorption became vanishingly small. With the help of the circular dichroism (CD) spectrum of BR-IX in HSA, a small band was resolved in the bilirubin absorption spectrum, delivering part of the energy required for the (4Z, 15Z) rightarrow (4Z, 15E) photoisomerization of the molecule.

  2. Sensitizing effect of Z,Z-bilirubin IXα and its photoproducts on enzymes in model solutions

    NASA Astrophysics Data System (ADS)

    Plavskii, V. Yu.; Mostovnikov, V. A.; Tret'yakova, A. I.; Mostovnikova, G. R.

    2008-05-01

    In model systems, we have studied side effects which may be induced by light during phototherapy of hyperbilirubinemia (jaundice) in newborn infants, with the aim of reducing the Z,Z-bilirubin IXα (Z,Z-BR IXα) level. We have shown that the sensitizing effect of Z,Z-BR IXα, localized at strong binding sites of the human serum albumin (HSA) macromolecule, is primarily directed at the amino acid residues of the carrier protein and does not involve the molecules of the enzyme (lactate dehydrogenase (LDH)) present in the buffer solution. The detected photodynamic damage to LDH is due to sensitization by bilirubin photoisomers, characterized by lower HSA association constants and located (in contrast to native Z,Z-BR IXα) on the surface of the HSA protein globule. Based on study of the spectral characteristics of the photoproducts of Z,Z-BR IXα and comparison of their accumulation kinetics in solution and the enzyme photo-inactivation kinetics, we concluded that the determining role in sensitized damage to LDH is played by lumirubin. The photosensitization effect depends on the wavelength of the radiation used for photoconversion of bilirubin. When (at the beginning of exposure) we make sure that identical numbers of photons are absorbed by the pigment in the different spectral ranges, the side effect is minimal for radiation corresponding to the long-wavelength edge of the bilirubin absorption band. We have shown that for a bilirubin/HSA concentration ratio >2 (when some of the pigment molecules are sorbed on the surface of the protein globule), the bilirubin can act as a photosensitizing agent for the enzyme present in solution. We discuss methods for reducing unfavorable side effects of light on the body of newborn infants during phototherapy of hyperbilirubinemia.

  3. Protein-encapsulated bilirubin: paving the way to a useful probe for singlet oxygen.

    PubMed

    Pimenta, Frederico M; Jensen, Jan K; Etzerodt, Michael; Ogilby, Peter R

    2015-04-01

    When dissolved in a bulk solvent, bilirubin efficiently removes singlet molecular oxygen, O2(a(1)Δg), through a combination of chemical reactions and by promoting the O2(a(1)Δg)→O2(X(3)Σg(-)) nonradiative transition to populate the ground state of oxygen. To elucidate how such processes can be exploited in the development of a biologically useful fluorescent probe for O2(a(1)Δg), pertinent photophysical and photochemical parameters of bilirubin encapsulated in a protein were determined. The motivation for studying a protein-encapsulated system reflects the ultimate desire to (a) use genetic engineering to localize the probe at a specific location in a living cell, and (b) provide a controlled environment around the chromophore/fluorophore. Surprisingly, explicit values of oxygen- and O2(a(1)Δg)-dependent parameters that characterize the behavior of a given chromophore/fluorophore encased in a protein are not generally available. To the end of quantifying the effects of such an encasing protein, a recently discovered bilirubin-binding protein isolated from a Japanese eel was used. The data show that this system indeed preferentially responds to O2(a(1)Δg) and not to the superoxide ion. However, this protein not only shields bilirubin such that the rate constants for interaction with O2(a(1)Δg) decrease relative to what is observed in a bulk solvent, but the fraction of the total O2(a(1)Δg)-bilirubin interaction that results in a chemical reaction between O2(a(1)Δg) and bilirubin also decreases appreciably. The rate constants thus obtained provide a useful starting point for the general design and development of reactive protein-encased fluorescent probes for O2(a(1)Δg).

  4. Spectral fluorescence and polarization characteristics of Z,Z-bilirubin IXα

    NASA Astrophysics Data System (ADS)

    Plavskii, V. Yu.; Mostovnikov, V. A.; Mostovnikova, G. R.; Tret'yakova, A. I.

    2007-01-01

    We have studied the spectral fluorescence and polarization characteristics of Z,Z-bilirubin IXα, at room temperature in chloroform and in aqueous buffer medium, within an equilibrium complex with human serum albumin (HSA), and also under low temperature conditions (T = -100°C) in isobutyl alcohol. We have observed a bathochromic shift of the fluorescence spectra, which is most pronounced for the bilirubin-albumin complex. The following are considered as possible reasons for the observed dependence of the position of the fluorescence (fluorescence excitation) spectra on the excitation (detection) wavelength: structural and spectral differences between the chromophores making up the bilirubin molecule; conformational heterogeneity of the pigment in solution; a contribution to the fluorescence from molecules which have not completed the vibrational relaxation process; inhomogeneous orientational broadening of the levels; heterogeneity of the microenvironment of the chromophores in the protein matrix. We show that polarized fluorescence of bilirubin occurs at room temperature, due to the anomalously short fluorescence lifetime τ (picosecond or subpicosecond ranges). Despite such a short τ, the absorption and emission polarization spectra suggest the presence of intramolecular nonradiative singlet-singlet energy transfer when bilirubin is excited to high vibrational sublevels of the S1 state (degree of polarization p = 0.11-0.12). When fluorescence is excited on the long-wavelength slope of the absorption band, no transfer occurs: the degree of polarization (p = 0.46-0.47) is close to the limiting value (p = 0.50). We discuss the question of the role played by exciton interactions between chromophores in the bilirubin molecule when it is excited.

  5. Age-dependent pattern of cerebellar susceptibility to bilirubin neurotoxicity in vivo in mice.

    PubMed

    Bortolussi, Giulia; Baj, Gabriele; Vodret, Simone; Viviani, Giulia; Bittolo, Tamara; Muro, Andrés F

    2014-09-01

    Neonatal jaundice is caused by high levels of unconjugated bilirubin. It is usually a temporary condition caused by delayed induction of UGT1A1, which conjugates bilirubin in the liver. To reduce bilirubin levels, affected babies are exposed to phototherapy (PT), which converts toxic bilirubin into water-soluble photoisomers that are readily excreted out. However, in some cases uncontrolled hyperbilirubinemia leads to neurotoxicity. To study the mechanisms of bilirubin-induced neurological damage (BIND) in vivo, we generated a mouse model lacking the Ugt1a1 protein and, consequently, mutant mice developed jaundice as early as 36 hours after birth. The mutation was transferred into two genetic backgrounds (C57BL/6 and FVB/NJ). We exposed mutant mice to PT for different periods and analyzed the resulting phenotypes from the molecular, histological and behavioral points of view. Severity of BIND was associated with genetic background, with 50% survival of C57BL/6‑Ugt1(-/-) mutant mice at postnatal day 5 (P5), and of FVB/NJ-Ugt1(-/-) mice at P11. Life-long exposure to PT prevented cerebellar architecture alterations and rescued neuronal damage in FVB/NJ-Ugt1(-/-) but not in C57BL/6-Ugt1(-/-) mice. Survival of FVB/NJ-Ugt1(-/-) mice was directly related to the extent of PT treatment. PT treatment of FVB/NJ-Ugt1(-/-) mice from P0 to P8 did not prevent bilirubin-induced reduction in dendritic arborization and spine density of Purkinje cells. Moreover, PT treatment from P8 to P20 did not rescue BIND accumulated up to P8. However, PT treatment administered in the time-window P0-P15 was sufficient to obtain full rescue of cerebellar damage and motor impairment in FVB/NJ-Ugt1(-/-) mice. The possibility to modulate the severity of the phenotype by PT makes FVB/NJ-Ugt1(-/-) mice an excellent and versatile model to study bilirubin neurotoxicity, the role of modifier genes, alternative therapies and cerebellar development during high bilirubin conditions.

  6. A Hypothesis for Using Pathway Genetic Load Analysis for Understanding Complex Outcomes in Bilirubin Encephalopathy

    PubMed Central

    Riordan, Sean M.; Bittel, Douglas C.; Le Pichon, Jean-Baptiste; Gazzin, Silvia; Tiribelli, Claudio; Watchko, Jon F.; Wennberg, Richard P.; Shapiro, Steven M.

    2016-01-01

    Genetic-based susceptibility to bilirubin neurotoxicity and chronic bilirubin encephalopathy (kernicterus) is still poorly understood. Neonatal jaundice affects 60–80% of newborns, and considerable effort goes into preventing this relatively benign condition from escalating into the development of kernicterus making the incidence of this potentially devastating condition very rare in more developed countries. The current understanding of the genetic background of kernicterus is largely comprised of mutations related to alterations of bilirubin production, elimination, or both. Less is known about mutations that may predispose or protect against CNS bilirubin neurotoxicity. The lack of a monogenetic source for this risk of bilirubin neurotoxicity suggests that disease progression is dependent upon an overall decrease in the functionality of one or more essential genetically controlled metabolic pathways. In other words, a “load” is placed on key pathways in the form of multiple genetic variants that combine to create a vulnerable phenotype. The idea of epistatic interactions creating a pathway genetic load (PGL) that affects the response to a specific insult has been previously reported as a PGL score. We hypothesize that the PGL score can be used to investigate whether increased susceptibility to bilirubin-induced CNS damage in neonates is due to a mutational load being placed on key genetic pathways important to the central nervous system's response to bilirubin neurotoxicity. We propose a modification of the PGL score method that replaces the use of a canonical pathway with custom gene lists organized into three tiers with descending levels of evidence combined with the utilization of single nucleotide polymorphism (SNP) causality prediction methods. The PGL score has the potential to explain the genetic background of complex bilirubin induced neurological disorders (BIND) such as kernicterus and could be the key to understanding ranges of outcome severity

  7. A Hypothesis for Using Pathway Genetic Load Analysis for Understanding Complex Outcomes in Bilirubin Encephalopathy.

    PubMed

    Riordan, Sean M; Bittel, Douglas C; Le Pichon, Jean-Baptiste; Gazzin, Silvia; Tiribelli, Claudio; Watchko, Jon F; Wennberg, Richard P; Shapiro, Steven M

    2016-01-01

    Genetic-based susceptibility to bilirubin neurotoxicity and chronic bilirubin encephalopathy (kernicterus) is still poorly understood. Neonatal jaundice affects 60-80% of newborns, and considerable effort goes into preventing this relatively benign condition from escalating into the development of kernicterus making the incidence of this potentially devastating condition very rare in more developed countries. The current understanding of the genetic background of kernicterus is largely comprised of mutations related to alterations of bilirubin production, elimination, or both. Less is known about mutations that may predispose or protect against CNS bilirubin neurotoxicity. The lack of a monogenetic source for this risk of bilirubin neurotoxicity suggests that disease progression is dependent upon an overall decrease in the functionality of one or more essential genetically controlled metabolic pathways. In other words, a "load" is placed on key pathways in the form of multiple genetic variants that combine to create a vulnerable phenotype. The idea of epistatic interactions creating a pathway genetic load (PGL) that affects the response to a specific insult has been previously reported as a PGL score. We hypothesize that the PGL score can be used to investigate whether increased susceptibility to bilirubin-induced CNS damage in neonates is due to a mutational load being placed on key genetic pathways important to the central nervous system's response to bilirubin neurotoxicity. We propose a modification of the PGL score method that replaces the use of a canonical pathway with custom gene lists organized into three tiers with descending levels of evidence combined with the utilization of single nucleotide polymorphism (SNP) causality prediction methods. The PGL score has the potential to explain the genetic background of complex bilirubin induced neurological disorders (BIND) such as kernicterus and could be the key to understanding ranges of outcome severity in

  8. Regression approach to non-invasive determination of bilirubin in neonatal blood

    NASA Astrophysics Data System (ADS)

    Lysenko, S. A.; Kugeiko, M. M.

    2012-07-01

    A statistical ensemble of structural and biophysical parameters of neonatal skin was modeled based on experimental data. Diffuse scattering coefficients of the skin in the visible and infrared regions were calculated by applying a Monte-Carlo method to each realization of the ensemble. The potential accuracy of recovering the bilirubin concentration in dermis (which correlates closely with that in blood) was estimated from spatially resolved spectrometric measurements of diffuse scattering. The possibility to determine noninvasively the bilirubin concentration was shown by measurements of diffuse scattering at λ = 460, 500, and 660 nm at three source-detector separations under conditions of total variability of the skin biophysical parameters.

  9. Association between bilirubin and risk of Non-Alcoholic Fatty Liver Disease based on a prospective cohort study

    PubMed Central

    Tian, Jianbo; Zhong, Rong; Liu, Cheng; Tang, Yuhan; Gong, Jing; Chang, Jiang; Lou, Jiao; Ke, Juntao; Li, Jiaoyuan; Zhang, Yi; Yang, Yang; Zhu, Ying; Gong, Yajie; Xu, Yanyan; Liu, Peiyi; Yu, Xiao; Xiao, Lin; Du, Min; Yang, Ling; Yuan, Jing; Wang, Youjie; Chen, Weihong; Wei, Sheng; Liang, Yuan; Zhang, Xiaomin; He, Meian; Wu, Tangchun; Yao, Ping; Miao, Xiaoping

    2016-01-01

    The study aimed to assess the association between total, direct, and indirect bilirubin and nonalcoholic fatty live disease (NAFLD) risk given its high prevalence and serious clinical prognosis. Among 27,009 subjects who participated in a healthy screening program from the Dongfeng-Tongji cohort study in 2008, 8189 eligible subjects (aged 35–86 years; males, 43.95%) were ultimately enrolled. The incidence rates of NAFLD in 2013 were compared with respect to baseline bilirubin levels among subjects free of NAFLD, and the effect sizes were estimated by logistic regression analysis. During 5 years follow-up, we observed 1956 cases of newly developed NAFLD with the overall incidence of 23.88%. Direct bilirubin was presented to inversely associate with NAFLD risk. Compared with quartile 1 of direct bilirubin, the multivariable-adjusted ORs (95% CIs) for NAFLD of quartile 2 to 4 were 1.104 (0.867–1.187), 0.843 (0.719–0.989), and 0.768 (0.652–0.905), respectively, P for trend 0.002). Similarly, inverse effects of direct bilirubin on NAFLD incidence were also observed when stratified by sex and BMI. However, no significant associations were found between total, and indirect bilirubin and NAFLD risk. Direct bilirubin reduced NAFLD risk independent of possible confounders among middle-aged and elderly Chinese population, probably based on the endogenous antioxidation of bilirubin. PMID:27484402

  10. Hexanediamine functionalized poly (glycidyl methacrylate-co-N-vinylpyrrolidone) particles for bilirubin removal.

    PubMed

    Jiang, Xing; Zhou, Dongxu; Huang, Xueliang; Zhao, Weifeng; Zhao, Changsheng

    2017-10-15

    In this study, we provided a facile method to prepare adsorbents with high content of amino groups for bilirubin removal. Poly (glycidyl methacrylate-co-N-vinylpyrrolidone) particle adsorbents were prepared through free radical solution copolymerization followed by a phase inversion technique. Amino groups were further introduced onto the particles by grafting 1,6-hexanediamine molecules. The porosity and specific surface area of the functional particles were 92.9% and 11.8m(2)/g, respectively. Flourier transform infrared spectroscopy and elemental analysis confirmed the successful functionalization of polymeric particles. The cross-linker content and N-vinylpyrrolidone ratios had significant influence on the pore structure of the polymeric particles, as observed by scanning electron microscopy. Batch adsorption experiments were performed to verify bilirubin adsorption behavior of the particles, and a particle column was fabricated to further study the bilirubin removal. The particles exhibited good adsorption capacity of bilirubin without procoagulant activity, and had great potential to be used in hemoperfusion. The study opens a new route to fabricate functional polymer adsorbents. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Transcutaneous bilirubin measurement at the time of hospital discharge in a multiethnic newborn population

    PubMed Central

    Campbell, Douglas M; Danayan, Karoon C; McGovern, Valleverdina; Cheema, Sohail; Stade, Brenda; Sgro, Michael

    2011-01-01

    BACKGROUND: Severe neonatal hyperbilirubinemia continues to occur in healthy newborns. Recent guidelines have supported using transcutaneous devices in estimating bilirubin levels. Previous studies using these devices are limited. METHODS: Newborns requiring serum bilirubin level measurements before hospital discharge were recruited prospectively. The agreement between a transcutaneous bilirubin (TCB) and total serum bilirubin (TSB) level was assessed. Sensitivity analysis was conducted. RESULTS: A total of 430 infants were enrolled. Correlation between the values was high (Pearson’s correlation coefficient 0.83; Lin’s concordance coefficient 0.81 [95% CI 0.77 to 0.84]; P<0.001). The mean (± SD) TSB level was 194±60 μmol/L. The TCB measurement tended to overestimate the value (mean difference 12.7), with wide 95% limits of agreement (−52 μmol/L to 77 μmol/L). Sensitivity and specificity analysis of TCB values allowed estimation of clinically important TSB levels. CONCLUSIONS: The TCB correlated, but was imprecise in predicting TSB. TCB values can be used at the time of discharge to safely plan care for jaundiced infants if the limits of agreement are considered and clinical judgment is maintained. PMID:22379376

  12. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  13. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urinary bilirubin and its conjugates (nonquantitative) test system. 862.1115 Section 862.1115 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES...

  14. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bilirubin (total and unbound) in the neonate test system. 862.1113 Section 862.1113 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical...

  15. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  16. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  17. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  18. 21 CFR 862.1110 - Bilirubin (total or direct) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  19. Deracemization of bilirubin as the marker of the chirality of micellar aggregates.

    PubMed

    Sorrenti, Alessandro; Altieri, Barbara; Ceccacci, Francesca; Di Profio, Pietro; Germani, Raimondo; Giansanti, Luisa; Savelli, Gianfranco; Mancini, Giovanna

    2012-01-01

    The deracemization of bilirubin in micellar aggregates of structurally correlated chiral surfactants was studied by circular dichroism experiments and exploited as the marker of the expression of chirality of the aggregates. The obtained results suggest that the hydrophobic interactions control the transfer of chirality from the monomers to the aggregates, and that different regions of the same aggregate might feature opposite enantiorecognition capabilities.

  20. EKTACHEM bilirubin fraction Bc as a predictor of liver transplant rejection.

    PubMed

    Cox, C J; Valdiserri, R O; Zerbe, T R; Genter, J L

    1987-10-01

    Bilirubin fractions Bc and DELTA, not routinely available prior to the EKTACHEM Chemistry Analyzer and its slide methodology, were studied in an outpatient population of liver transplant recipients. A preliminary evaluation by the authors has shown that direct bilirubin (DBILI) levels in the normal range consist almost exclusively of DELTA (protein-bound conjugated bilirubin), while at elevated DBILI levels, an increasing amount of Bc (non-protein-bound conjugated bilirubin) is measured as well. The present study evaluated the clinical significance of Bc in the serum of 80 liver transplant recipients as a means of identifying episodes of rejection. Each patient was classified into rejection or nonrejection categories based on clinical status, liver biopsy results, and/or response to therapy. Eighteen patients were classified as experiencing an episode of rejection during the period of this study. Fourteen of these (77.8%) had Bc levels that ranged from 0.1 to 6.8 mg/dl. Sixty two patients were classified in the nonrejection category. Fourteen (22.6%) of these patients had Bc levels that ranged from 0.1 to 0.6 mg/dl. In our outpatient liver transplant recipients with Bc greater than or equal to 0.1 mg/dl, the relative risk of rejection (% of rejection patients with Bc/% of nonrejection patients with Bc) was 3.44. This value indicates that Bc determination may be a helpful adjunct in the assessment of rejection.

  1. Immune response to lentiviral bilirubin UDP-glucuronosyltransferase gene transfer in fetal and neonatal rats.

    PubMed

    Seppen, J; van Til, N P; van der Rijt, R; Hiralall, J K; Kunne, C; Elferink, R P J Oude

    2006-04-01

    Gene therapy for inherited disorders might cause an immune response to the therapeutic protein. A solution would be to introduce the gene in the fetal or neonatal period, which should lead to tolerization. Lentiviral vectors mediate long-term gene expression, and are well suited for gene therapy early in development. A model for fetal or neonatal gene therapy is the inherited disorder of bilirubin metabolism, Crigler-Najjar disease (CN). The absence of bilirubin UDP-glucoronyltransferase (UGT1A1) activity in CN patients causes high serum levels of unconjugated bilirubin and brain damage in infancy. CN is attractive for the development of gene therapy because the mutant Gunn rat closely mimics the human disease. Injection of UGT1A1 lentiviral vectors corrected the hyperbilirubinemia for more than a year in rats injected as fetuses and for up to 18 weeks in rats injected the day of birth. UGT1A1 gene transfer was confirmed by the presence of bilirubin glucuronides in bile. All animals injected with UGT1A1 lentiviral vectors developed antibodies to UGT1A1. Animals injected with green fluorescent protein (GFP) lentiviral vectors did not develop antibodies to GFP. Our results indicate that fetal and neonatal gene therapy with immunogenic proteins such as UGT1A1 does not necessarily lead to tolerization.

  2. Functionalized Magnetic Fe3O4-β-Cyclodextran Nanoparticles for Efficient Removal of Bilirubin.

    PubMed

    Han, Lulu; Chu, Simin; Wei, Houliang; Ren, Jun; Xu, Li; Jia, Lingyun

    2016-06-01

    Bilirubin (BR), as a lipophilic toxin, can binds and deposits in various tissues, especially the brain tissue, leading to hepatic coma and even death. Magnetic nanoparticles adsorbent modified by β-cyclodextran (Fe3O4-β-CD) was developed to remove the BR from the plasma. Fe3O4-β-CD nanoparticles was prepared through Schiff base reaction between the polyethylenimine (PEI)-modified Fe3O4 and aldehyde-functionalized β-CD, and characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and dynamic light scattering (DLS). Under optimized conditions, the Fe3O4-β-CD adsorbent could adsorb 225.6 mg/g free BR in PBS and reach the adsorption equilibrium within 90 min mainly through hydrophobic interaction; Moreover, the adsorbent displayed better adsorption capability in a dialysis system for BSA-bound bilirubin, plasma bilirubin and total bile acid, and the removal rates of those were 66%, 31% and 41% respectively. Because of the advantages of fast separation and purification process, low preparation cost, good adsorption capability for plasma bilirubin, Fe3O4-β-CD may become an economical and promising absorbent of BR for clinical applications.

  3. Kinetics of oxidation of bilirubin and its protein complex by hydrogen peroxide in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Solomonov, A. V.; Rumyantsev, E. V.; Antina, E. V.

    2010-12-01

    A comparative study of oxidation reactions of bilirubin and its complex with albumin was carried out in aqueous solutions under the action of hydrogen peroxide and molecular oxygen at different pH values. Free radical oxidation of the pigment in both free and bound forms at pH 7.4 was shown not to lead to the formation of biliverdin, but to be associated with the decomposition of the tetrapyrrole chromophore into monopyrrolic products. The effective and true rate constants of the reactions under study were determined. It was assumed that one possible mechanism of the oxidation reaction is associated with the interaction of peroxyl radicals and protons of the NH groups of bilirubin molecules at the limiting stage with the formation of a highly reactive radical intermediate. The binding of bilirubin with albumin was found to result in a considerable reduction in the rate of the oxidation reaction associated with the kinetic manifestation of the protein protection effect. It was found that the autoxidation of bilirubin by molecular oxygen with the formation of biliverdin at the intermediate stage can be observed with an increase in the pH of solutions.

  4. Toxic epidermal necrolysis with severe hyperbilirubinemia: complete re-epithelialization after bilirubin reduction therapies.

    PubMed

    Kamada, Noriaki; Yoneyama, Kei; Togawa, Yaei; Suehiro, Keisuke; Shinkai, Hiroshi; Yokota, Masaya; Matsuda, Kenichi; Oda, Shigeto; Hirasawa, Hiroyuki; Matsue, Hiroyuki

    2010-06-01

    Toxic epidermal necrolysis is a life-threatening skin disorder, and its mortality rate is estimated to be approximately 20-30%. It is characterized that more than 30% of the skin surface is eroded, however, skin lesions are usually re-epithelialized within 2-3 weeks. Previously, we reported a fatal case of toxic epidermal necrolysis with hyperbilirubinemia, and more than 60% of body surface areas had been eroded for 9 weeks. For the reason of delayed re-epithelialization, we hypothesized that hyperbilirubinemia was the culprit because bilirubin damaged cultured keratinocytes in vitro. In this case, we had an opportunity to treat another case of toxic epidermal necrolysis with severe hyperbilirubinemia. In order to reduce serum bilirubin levels, we performed bilirubin adsorption therapies, and skin lesions were successfully re-epithelialized within 4 weeks. Though further studies are required, we considered that bilirubin adsorption therapies are worth trying for toxic epidermal necrolysis with hyperbilirubinemia, especially for the cases suffering from delayed re-epithelialization.

  5. Circular dichroism study of the interaction between mutagens and bilirubin bound to different binding sites of serum albumins.

    PubMed

    Orlov, Sergey; Goncharova, Iryna; Urbanová, Marie

    2014-05-21

    Although recent investigations have shown that bilirubin not only has a negative role in the organism but also exhibits significant antimutagenic properties, the mechanisms of interactions between bilirubin and mutagens are not clear. In this study, interaction between bilirubin bound to different binding sites of mammalian serum albumins with structural analogues of the mutagens 2-aminofluorene, 2,7-diaminofluorene and mutagen 2,4,7-trinitrofluorenone were investigated by circular dichroism and absorption spectroscopy. Homological human and bovine serum albumins were used as chiral matrices, which preferentially bind different conformers of bilirubin in the primary binding sites and make it observable by circular dichroism. These molecular systems approximated a real system for the study of mutagens in blood serum. Differences between the interaction of bilirubin bound to primary and to secondary binding sites of serum albumins with mutagens were shown. For bilirubin bound to secondary binding sites with low affinity, partial displacement and the formation of self-associates were observed in all studied mutagens. The associates of bilirubin bound to primary binding sites of serum albumins are formed with 2-aminofluorene and 2,4,7-trinitrofluorenone. It was proposed that 2,7-diaminofluorene does not interact with bilirubin bound to primary sites of human and bovine serum albumins due to the spatial hindrance of the albumins binding domains. The spatial arrangement of the bilirubin bound to serum albumin along with the studied mutagens was modelled using ligand docking, which revealed a possibility of an arrangement of the both bilirubin and 2-aminofluorene and 2,4,7-trinitrofluorenone in the primary binding site of human serum albumin. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Relationship between total bilirubin, endothelial function, inflammation and oxidative stress in HIV-infected adults on stable antiretroviral therapy

    PubMed Central

    Hileman, Corrilynn O.; Longenecker, Chris T.; Carman, Teresa L.; Milne, Ginger L.; Labbato, Danielle E.; Storer, Norma J.; White, Cynthia A.; McComsey, Grace A.

    2012-01-01

    Objective Enhanced inflammation is evident in HIV, even with virologic suppression. Outside HIV, studies show an independent association between higher total bilirubin and better endothelial function as well as lower prevalence of coronary heart disease possibly due to the anti-inflammatory and antioxidant effect of bilirubin. Methods A cross-sectional study was performed in HIV-1 infected adults on stable antiretroviral therapy (ART) to determine if a relationship exists between total bilirubin and endothelial function (flow mediated dilation (FMD) of the brachial artery), inflammation (interleukin-6 (IL-6), soluble tumor necrosis factor receptors, C-reactive protein, adhesion molecules), coagulation markers (fibrinogen and D-Dimer) and oxidative stress (F2-Isoprostanes). Endpoints were compared based on total bilirubin levels and atazanavir status using distributionally-appropriate, two-sample tests. Correlation coefficients were determined between total bilirubin and end points. Linear regression was used to model the relationship between total bilirubin (and atazanavir status) and FMD. Results 98 adults were included. Total bilirubin was higher in atazanavir group (median (IQR) 1.8 (1.1–2.6) vs. 0.6 (0.4–1.4) mg/dL; p<0.01) as was insulin, HOMA-IR and fibrinogen. Total bilirubin was positively correlated with fibrinogen and was not correlated with other outcomes. After adjustment, neither total bilirubin nor atazanavir status was associated with FMD. Conclusions In virologically-suppressed, HIV-infected adults on stable ART, neither total bilirubin nor atazanavir use was associated with improved endothelial function as measured by FMD, inflammation or oxidative stress as measured by biomarkers. PMID:22624591

  7. Circular dichroism study of the interaction between mutagens and bilirubin bound to different binding sites of serum albumins

    NASA Astrophysics Data System (ADS)

    Orlov, Sergey; Goncharova, Iryna; Urbanová, Marie

    Although recent investigations have shown that bilirubin not only has a negative role in the organism but also exhibits significant antimutagenic properties, the mechanisms of interactions between bilirubin and mutagens are not clear. In this study, interaction between bilirubin bound to different binding sites of mammalian serum albumins with structural analogues of the mutagens 2-aminofluorene, 2,7-diaminofluorene and mutagen 2,4,7-trinitrofluorenone were investigated by circular dichroism and absorption spectroscopy. Homological human and bovine serum albumins were used as chiral matrices, which preferentially bind different conformers of bilirubin in the primary binding sites and make it observable by circular dichroism. These molecular systems approximated a real system for the study of mutagens in blood serum. Differences between the interaction of bilirubin bound to primary and to secondary binding sites of serum albumins with mutagens were shown. For bilirubin bound to secondary binding sites with low affinity, partial displacement and the formation of self-associates were observed in all studied mutagens. The associates of bilirubin bound to primary binding sites of serum albumins are formed with 2-aminofluorene and 2,4,7-trinitrofluorenone. It was proposed that 2,7-diaminofluorene does not interact with bilirubin bound to primary sites of human and bovine serum albumins due to the spatial hindrance of the albumins binding domains. The spatial arrangement of the bilirubin bound to serum albumin along with the studied mutagens was modelled using ligand docking, which revealed a possibility of an arrangement of the both bilirubin and 2-aminofluorene and 2,4,7-trinitrofluorenone in the primary binding site of human serum albumin.

  8. Microchip capillary electrophoresis for frontal analysis of free bilirubin and study of its interaction with human serum albumin.

    PubMed

    Nie, Zhou; Fung, Ying Sing

    2008-05-01

    To meet the need for bedside monitoring of free bilirubin for neonates under critical conditions, a microfluidic chip was fabricated and tested for its coupling with CE/frontal analysis (FA) to determine free bilirubin and study of its binding interaction with HSA, which regulated its concentration in plasma. The poly(methyl methacrylate) (PMMA) multichannel chip was fabricated by CO2 laser ablation and bonded with a fused-silica separation capillary for CE/FA separation with UV detection. The chip was designed to allow a complete assay of four electrophoretic runs using preconditioned channels to speed up the determination of free bilirubin and to deliver quick results for bedside monitoring. Under optimized conditions, the linear working range for free bilirubin was from 10 to 200 micromol with RSDs from 2.1 to 5.0% for n=3, and the LOD at 9 micromol for S/N=3. From a binding study between bilirubin and HSA under FA condition, the second binding constant for bilirubin-HSA was determined as 1.07x10(5) L/mol and the number of binding sites per HSA as 3.46. The results enabled the calculation of free bilirubin for jaundiced infants based on the clinically significant level of total bilirubin, producing a range of 118.3-119.4 micromol/L. The developed method is shown to meet the clinical requirement with additional margin of protection to detect the early rising level of free bilirubin prior to jaundice condition. The low-cost microchip CE/FA device is shown to produce quick results with high potential to deliver a suitable bed-side monitoring method for bilirubin management in neonates.

  9. Consciousness, cognition and the cognitive apparatus in the vedānta tradition.

    PubMed

    Balasubramanian, R

    2011-01-01

    A human being is a complex entity consisting of the Self (also known as Consciousness), mind, senses and the body. The Vedānta tradition holds that the mind, the senses and the body are essentially different from the Self or Consciousness. It is through consciousness that we are able to know the things of the world, making use of the medium of the mind and the senses. Furthermore, the mind, though material, is able to reveal things, borrowing the light from consciousness. From the phenomenological point of view, we have to answer the following questions: how does one know the mind/the mental operations/the cogitations of the mind? Does the mind know itself? Is it possible? There is, again, the problem of the intentionality of consciousness. Is consciousness intentional? According to Vedānta, consciousness by its very nature is not intentional, but it becomes intentional through the mind. The mind or the ego is not part of the consciousness; on the contrary, it is transcendent to consciousness. It is difficult to spell out the relation between consciousness and the mind. How does consciousness, which is totally different from the mind, get related to the mind in such a way that it makes the latter capable of comprehending the things of the world? The Vedānta tradition provides the answer to this question in terms of the knower-known relation. Consciousness is pure light, self-luminous by its very nature, that is, although it reveals other objects, it is not revealed by anything else. When Sartre describes it as nothingness, bereft of even ego, it is to show that it is pure light revealing objects outside it.

  10. Consciousness, Cognition and the Cognitive Apparatus in the Vedānta Tradition

    PubMed Central

    Balasubramanian, R.

    2011-01-01

    A human being is a complex entity consisting of the Self (also known as Consciousness), mind, senses and the body. The Vedānta tradition holds that the mind, the senses and the body are essentially different from the Self or Consciousness. It is through consciousness that we are able to know the things of the world, making use of the medium of the mind and the senses. Furthermore, the mind, though material, is able to reveal things, borrowing the light from consciousness. From the phenomenological point of view, we have to answer the following questions: how does one know the mind/the mental operations/the cogitations of the mind? Does the mind know itself? Is it possible? There is, again, the problem of the intentionality of consciousness. Is consciousness intentional? According to Vedānta, consciousness by its very nature is not intentional, but it becomes intentional through the mind. The mind or the ego is not part of the consciousness; on the contrary, it is transcendent to consciousness. It is difficult to spell out the relation between consciousness and the mind. How does consciousness, which is totally different from the mind, get related to the mind in such a way that it makes the latter capable of comprehending the things of the world? The Vedānta tradition provides the answer to this question in terms of the knower-known relation. Consciousness is pure light, self-luminous by its very nature, that is, although it reveals other objects, it is not revealed by anything else. When Sartre describes it as nothingness, bereft of even ego, it is to show that it is pure light revealing objects outside it. PMID:21694962

  11. ABC–VED analysis of expendable medical stores at a tertiary care hospital

    PubMed Central

    Kumar, Sushil; Chakravarty, A.

    2014-01-01

    Background The modern system of medicine has evolved into a complex, sophisticated and expensive treatment modality in terms of cost of medicines and consumables. In any hospital, approximately 33% of total annual budget is spent on buying materials and supplies including medicines. ABC (Always, Better Control)–VED (Vital, Essential, Desirable) analysis of medical stores of a large teaching, tertiary care hospital of the Armed Forces was carried out to identify the categories of drugs needing focused managerial control. Methods Annual consumption and expenditure data of expendable medical stores for one year was extracted from the drug expense book, followed by classification on its annual usage value. Subsequently, the factor of criticality was applied to arrive at a decision matrix for understanding the need for selective managerial control. Results The study revealed that out of 1536 items considered for the study, 6.77% (104), 19.27% (296) and 73.95% (1136) items were found to be A, B and C category items respectively. VED analysis revealed that vital items (V) accounted for 13.14% (201), essential items (E) for 56.37% (866) and desirable accounted for 30.49% items (469). ABC–VED matrix analysis of the inventory reveals that only 322 (21%) items out of an inventory of 1536 drugs belonging to category I will require maximum attention. Conclusion Scientific inventory management tools need to be applied routinely for efficient management of medical stores, as it contributes to judicious use of limited resources and resultant improvement in patient care. PMID:25609859

  12. Simple, Reagentless Quantification of Total Bilirubin in Blood Via Microfluidic Phototreatment and Image Analysis.

    PubMed

    Thompson, Brandon L; Wyckoff, Sarah L; Haverstick, Doris M; Landers, James P

    2017-03-07

    Total bilirubin (T-Bil) is an important clinical diagnostic marker that is measured frequently by physicians to assist in the diagnosis, treatment, and monitoring of multiple medical conditions. The work demonstrated here utilizes the 48-year-old mechanism of phototherapy that is commonly implemented in the treatment of infants with exaggerated physiologic and pathologic jaundice but adapts it to the microfluidic level for the ultimate purpose of total bilirubin quantitation. After acquisition of a small volume of blood (<10 μL) and through subsequent separation (plasma + red blood cells), a 3 μL plasma sample was imaged by a portable scanner and analyzed through a custom algorithm for color intensity. After blue light irradiation for 10 min at 470 nm, the sample was reimaged and analyzed. The resulting intensities obtained pre- and postimaging (clearly observed through a color change from yellow to clear) were then utilized to calculate the total bilirubin concentration. A total of 34 blood samples were analyzed with microfluidic photo treatment-image analysis (μPIA) and were found to have a Deming-regression slope of 0.97 (R(2) = 0.960) when compared to the total bilirubin values determined in the clinical laboratory. We demonstrate the implementation of a centrifugal microdevice fabricated through the Print, Cut, and Laminate (PCL) method that accepts eight whole blood samples and provides the capabilities to not only quantitate total bilirubin (Deming-regression slope of 0.95, R(2) = 0.990) but allow future integration with excess plasma sufficient for additional downstream clinical assays. This work will highlight the inexpensive nature of the analysis (absence of caustic, viscous, or additional reagents), the simplicity (does not require any chemical reactions), speed (sample-to-answer in <15 min), insusceptibility to biofouling (no protein matrix effects, hemoglobin interferences, and minimized turbidity), low volume plasma requirement (3 μL), and the

  13. The Role of Bilirubin in Diabetes, Metabolic Syndrome, and Cardiovascular Diseases

    PubMed Central

    Vítek, Libor

    2012-01-01

    Bilirubin belongs to a phylogenetically old superfamily of tetrapyrrolic compounds, which have multiple biological functions. Although for decades bilirubin was believed to be only a waste product of the heme catabolic pathway at best, and a potentially toxic compound at worst; recent data has convincingly demonstrated that mildly elevated serum bilirubin levels are strongly associated with a lower prevalence of oxidative stress-mediated diseases. Indeed, serum bilirubin has been consistently shown to be negatively correlated to cardiovascular diseases (CVD), as well as to CVD-related diseases and risk factors such as arterial hypertension, diabetes mellitus, metabolic syndrome, and obesity. In addition, the clinical data are strongly supported by evidence arising from both in vitro and in vivo experimental studies. This data not only shows the protective effects of bilirubin per se; but additionally, of other products of the heme catabolic pathway such as biliverdin and carbon monoxide, as well as its key enzymes (heme oxygenase and biliverdin reductase); thus, further underlining the biological impacts of this pathway. In this review, detailed information on the experimental and clinical evidence between the heme catabolic pathway and CVD, and those related diseases such as diabetes, metabolic syndrome, and obesity is provided. All of these pathological conditions represent an important threat to human civilization, being the major killers in developed countries, with a steadily increasing prevalence. Thus, it is extremely important to search for novel markers of these diseases, as well as for novel therapeutic modalities to reverse this unfavorable situation. The heme catabolic pathway seems to fulfill the criteria for both diagnostic purposes as well as for potential therapeutical interventions. PMID:22493581

  14. Measurement of unbound bilirubin by the peroxidase test using Zone Fluidics.

    PubMed

    Ahlfors, Charles E; Marshall, Graham D; Wolcott, Duane K; Olson, Don C; Van Overmeire, Bart

    2006-03-01

    Measuring plasma unbound bilirubin concentration by the peroxidase test is useful in the management of jaundiced newborns. However, the commercially available peroxidase technology is manual, and the unbound bilirubin may be seriously underestimated at the 42-fold sample dilution and single peroxidase concentration used. We investigated improving the test by adapting it to Zone Fluidics, which is a system for automating reactant handling that requires small sample volumes and dilution. A computer-directed Zone Fluidics system was constructed using small diameter tubing to connect in series a water-surfactant reservoir, a bi-directional pump, a multiport selection valve to which peroxidase test reactants (45 mul of sample) are attached with one port open to air, and a spectrophotometer flow cell. Test reactants and air are sequentially aspirated through the valve into the tubing connecting the pump and valve to form a reactant "zone" surrounded by air. The zone is advanced to the spectrophotometer flow cell where total and unbound bilirubin are determined (37 degrees C) from the absorbance at 460 nm at a 2-fold sample dilution and 4 peroxidase concentrations. Imprecision was assessed in artificial controls and newborn plasma. Plasma results were compared with those obtained using the commercial method. The CV for unbound bilirubin in the various controls ranged from 11% to 38% (within day) and 12% to 27% (between days). Triplicate CV measurements for newborn plasma measurements ranged from 0.6% to 31% (mean 11%, n=47). Mean unbound bilirubin by Zone Fluidics was 5-fold higher than that by the commercial method. Zone Fluidics can be used to automate the peroxidase test and overcome many of the limitations of the commercially available peroxidase technology.

  15. Lower Serum Bilirubin and Uric Acid Concentrations in Patients with Parkinson's Disease in China.

    PubMed

    Qin, Xiao-Ling; Zhang, Qing-Shan; Sun, Li; Hao, Meng-Wei; Hu, Zhao-Ting

    2015-05-01

    The objective of the study is to investigate the correlation between bilirubin and uric acid (UA) concentrations and symptoms of Parkinson's disease (PD) in Chinese population. A total of 425 PD patients and 460 controls were included in the current study. Patients were diagnosed by a neurologist and assessed using the Hoehn & Yahr (H&Y) scale. Venous blood samples were collected, and bilirubin and UA concentrations were analyzed. Compared to controls, indirect bilirubin (IBIL) and UA concentrations were lower in PD patients (P IBIL = 0.015, P UA = 0.000). Serum IBIL in different age subgroups and H&Y stage subgroups were also lower compared to the control group (P IBIL = 0.000, P UA = 0.000) but were not significantly different among these subgroups. Females in the control group had significantly lower serum IBIL and UA concentrations than males (P IBIL = 0.000, P UA = 0.000) and the PD group (P IBIL = 0.027, P UA = 0.000). In early PD (patients with <2-year medical history and no treatment), serum IBIL and UA concentrations were also lower than the controls (P IBIL = 0.013, P UA = 0.000). Although IBIL concentration was positively correlated with UA concentration in controls (R IBIL = 0.229, P IBIL = 0.004), this positive association was not observed in the PD group (R IBIL = -0.032, P IBIL = 0.724). Decreased levels of serum IBIL and UA were observed in PD patients. It is possible that individuals with decreased serum bilirubin and UA concentrations lack the endogenous defense system to prevent peroxynitrite and other free radicals from damaging and destroying dopaminergic cells in the substantia nigra. Our results provide a basis for further investigation into the role of bilirubin in PD.

  16. Selective nonenzymatic bilirubin detection in blood samples using a Nafion/Mn-Cu sensor.

    PubMed

    Noh, Hui-Bog; Won, Mi-Sook; Shim, Yoon-Bo

    2014-11-15

    The specific detection of biological organics without the use of an enzyme is challenging, and it is crucial for analytical and clinical chemistry. We report specific nonenzymatic bilirubin detection through the catalytic oxidation of bilirubin molecule on the Nafion/Mn-Cu surface. The catalytic ability, true surface area, morphology, crystallinity, composition, and oxidation state of the sensor surface were assessed using voltammetry, coulometry, XPS, XRD, Brunauer-Emmett-Teller (BET), SEM, EDXS, and TOF-SIMS experiments. The results showed that the surface was composed of microporous Mn-Cu bimetallic crystal in flake shape with a large BET surface area (3.635 m(2)g(-1)), where the surface area and crystallinity mainly affected the sensor performance. Product analysis of the catalytic reaction on the sensor probe revealed a specific two-electron oxidation of dipyrromethane moiety to dipyrromethene in the bilirubin molecule. Experimental variables affecting the analysis of bilirubin were optimized in terms of probe composition, temperature, pH, and potential. At the optimized condition, the dynamic range was between 1.2 μM and 0.42 mM, which yielded the equation of ΔI (μA)=(1.03 ± 0.72)+(457.0 ± 4.03) [C] (mM) with 0.999 of correlation coefficient, and the detection limit was 25.0 ± 1.8 nM (n=5, k=3). The stability test, interference effects, and analysis of real clinical samples, human whole blood and certified serum samples were demonstrated to confirm the reliability of the proposed bilirubin sensor.

  17. Increased bilirubin levels in neonates after induction of labour by intravenous prostaglandin E2 or oxytocin.

    PubMed

    Calder, A A; Ounsted, M K; Moar, V A; Turnbull, A C

    1974-12-07

    4 groups of 30 primigravidas and their infants were studied prospectively. No patient with rhesus incompatibility was included in the study. The 4 groups went into labor in the following ways: 1) induced by intravenous oxytocin; 2) induced by intravenous prostagladin (PG)E2; 3) induced by extraamniotic PGE2; and 4) spontaneous labor. Mean infant bilirubin levels on day 5 were significantly higher (p.005 and p.025 respectively) for the 1st 2 groups than for the spontaneous group. Levels for the group whose labor was induced with extraamniotic PGE2 infusion were not significantly different from those in the 1st 2 groups or the spontaneous group. The mean serum-bilirubin level was significantly lower (p.025) after caesarean section than after assisted vaginal delivery. Serum-bilirubin levels were not affected by previous maternal use of oral contraceptives, maternal smoking, or methods of infant feeding. Serum bilirubin levels below 10 mg/100 ml. are considered within the normal phsyiological limits during the neonatal period. Measured by this criteria, 14, 10, 9, and 6 babies in groups 1-4 respectively had abnormally high levels. The difference between groups 1 and 4 was significant at the p.05 level. Mean Apgar scores were significantly lower for the babies whose mothers had induced delivery with extraamniotic PGE2 infusion. These results suggest that the observed hyperbilirubinemia may be due to interruption of pregnancy rather than to any direct drug effect. There is no evidence to suggest that such high bilirubin levels are harmful to the child in the long run.

  18. Bilirubin clearance and antioxidant activities of ethanol extract of Phyllanthus amarus root in phenylhydrazine-induced neonatal jaundice in mice.

    PubMed

    Maity, Soumya; Nag, Nivedita; Chatterjee, Suchandra; Adhikari, Soumyakanti; Mazumder, Santasree

    2013-09-01

    The ability of ethanol extract of Phyllanthus amarus root (EEPA) to decrease bilirubin level and oxidative stress in phenylhydrazine-induced neonatal jaundice in mice was investigated. Administration of phenylhydrazine (75 mg/kg b.w.) significantly elevated total and unconjugated serum bilirubin level compared to control mice. EEPA (5, 10, and 20 mg/kg b.w., oral) dose-dependently reduced the bilirubin level. EEPA treatment also upregulated hepatic CAR and CYP3A1, accounting for its ability to facilitate bilirubin clearance. A single dose of EEPA (20 mg/kg b.w.) induced higher level of bilirubin clearance than phototherapy, widely used for treating neonatal jaundice. Furthermore, phenylhydrazine administration significantly increased MDA, protein carbonyl, and total thiol content and lowered the GSH level along with superoxide dismutase and catalase activity in erythrocyte compared to the control group. Single administration of EEPA (20 mg/kg b.w.) significantly reversed the trend. Presence of gallic acid, gentisic acid, and ortho-coumaric acid in EEPA was identified by HPLC analysis. Amongst these, the major phenolic constituent, gallic acid, exhibited significant bilirubin-lowering effect. These results suggested that P. amarus may be beneficial in reducing bilirubin level as well as oxidative stress in neonatal jaundice.

  19. Dual Effects of Bilirubin on the Proliferation of Rat Renal NRK52E Cells and ITS Association with Gap Junctions

    PubMed Central

    Wang, Yanling; Zhu, Qiongfang; Luo, Chenfang; Zhang, Ailan; Hei, Ziqing; Su, Guangjie; Xia, Zhengyuan; Irwin, Michael G.

    2013-01-01

    Objective: The effect of bilirubin on renal pathophysiology is controversial. This study aimed to observe the effects of bilirubin on the proliferation of normal rat renal tubular epithelial cell line (NRK52E) and its potential interplay with gap junction function. Methods: Cultured NRK52E cells, seeded respectively at high- or low- densities, were treated with varying concentrations of bilirubin for 24 hours. Cell injury was assessed by measuring cell viability and proliferation, and gap junction function was assessed by Parachute dye-coupling assay. Connexin 43 protein was assessed by Western blotting. Results: At doses from 17.1 to 513μmol/L, bilirubin dose-dependently enhanced cell viability and colony-formation rates when cells were seeded at either high- or low- densities (all p<0.05 vs. solvent group) accompanied with enhanced intercellular fluorescence transmission and increased Cx43 protein expression in high-density cells. However, the above effects of BR were gradually reversed when its concentration increased from 684 to 1026μmol/L. In high-density cells, gap junction inhibitor 12-O-tetradecanoylphorbol 13-acetate attenuated bilirubin-induced enhancement of colony-formation and fluorescence transmission. However, in the presence of high concentration bilirubin (1026μmol/L), activation of gap junction with retinoid acid decreased colony-formation rates. Conclusion: Bilirubin can confer biphasic effects on renal NRK52E cell proliferation potentially by differentially affecting gap junction functions. PMID:23930103

  20. Three-dimensionally porous graphene: A high-performance adsorbent for removal of albumin-bonded bilirubin.

    PubMed

    Ma, Chun Fang; Gao, Qiang; Xia, Kai Sheng; Huang, Zhi Yuan; Han, Bo; Zhou, Cheng Gang

    2017-01-01

    The development of bilirubin adsorbents with high adsorption efficiencies towards albumin-bonded bilirubin is still a considerable challenge. In this work, a three-dimensionally porous graphene (3D-pGR) has been fabricated through a simple carbon dioxide (CO2) activation of thermally exfoliated graphite oxide (EGO). Intriguingly, the resultant 3D-pGR material showed hierarchically micro-meso-macroporous structure, high specific surface area of up to 843m(2)g(-1), and large pore volume as high as 2.71cm(3)g(-1). Besides, the large planar π-configuration structure of 3D-pGR made it possible to compete effectively with albumin for bilirubin binding. Taking advantages of these fantastic characteristics, the 3D-pGR was demonstrated to be extraordinarily efficient for bilirubin removal from a bovine serum albumin (BSA)-rich solution. Under optimized conditions, the maximum adsorption capacity of 3D-pGR for BSA-bonded bilirubin was up to 126.1mgg(-1), which is not only significantly higher than the adsorption capacities of currently available adsorbents towards albumin-bonded bilirubin, but also superior to those of many reported adsorbents towards free bilirubin. In addition, the hemolysis assay of 3D-pGR indicated that this material had negligible hemolysis effect. Findings from this study may open up important new possibilities for removal of protein-bonded toxins.

  1. The effect of bilirubin on the excitability of mitral cells in the olfactory bulb of the rat

    PubMed Central

    Chen, Xiao-Juan; Zhou, Hui-Qun; Ye, Hai-bo; Li, Chun-Yan; Zhang, Wei-Tian

    2016-01-01

    Olfactory dysfunction is a common clinical phenomenon observed in various liver diseases. Previous studies have shown a correlation between smell disorders and bilirubin levels in patients with hepatic diseases. Bilirubin is a well-known neurotoxin; however, its effect on neurons in the main olfactory bulb (MOB), the first relay in the olfactory system, has not been examined. We investigated the effect of bilirubin (>3 μM) on mitral cells (MCs), the principal output neurons of the MOB. Bilirubin increased the frequency of spontaneous firing and the frequency but not the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs). TTX completely blocked sEPSCs in almost all of the cells tested. Bilirubin activity was partially blocked by N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepro pionic acid (AMPA) receptor antagonists. Furthermore, we found that bilirubin increased the frequency of intrinsic firing independent of synaptic transmission in MCs. Our findings suggest that bilirubin enhances glutamatergic transmission and strengthens intrinsic firing independent of synaptic transmission, all of which cause hyperexcitability in MCs. Our findings provide the basis for further investigation into the mechanisms underlying olfactory dysfunction that are often observed in patients with severe liver disease. PMID:27611599

  2. Evaluation of bilirubin interference and accuracy of six creatinine assays compared with isotope dilution-liquid chromatography mass spectrometry.

    PubMed

    Nah, Hyunjin; Lee, Sang-Guk; Lee, Kyeong-Seob; Won, Jae-Hee; Kim, Hyun Ok; Kim, Jeong-Ho

    2016-02-01

    The aim of this study was to estimate bilirubin interference and accuracy of six routine methods for measuring creatinine compared with isotope dilution-liquid chromatography mass spectrometry (ID-LC/MS). A total of 40 clinical serum samples from 31 patients with serum total bilirubin concentration >68.4μmol/L were collected. Serum creatinine was measured using two enzymatic reagents and four Jaffe reagents as well as ID-LC/MS. Correlations between bilirubin concentration and percent difference in creatinine compared with ID-LC/MS were analyzed to investigate bilirubin interference. Bias estimations between the six reagents and ID-LC/MS were performed. Recovery tests using National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 967a were also performed. Both the enzymatic methods showed no bilirubin interference. However, three of the four Jaffe methods demonstrated significant bilirubin concentration-dependent interference in samples with creatinine levels <53μmol/L, and two of them showed significant bilirubin interference in samples with creatinine levels ranging from 53.0 to 97.2μmol/L. Comparison of these methods with ID-LC/MS using patients' samples with elevated bilirubin revealed that the tested methods failed to achieve the bias goal at especially low levels of creatinine. In addition, recovery test using NIST SRM 967a showed that bias in one Jaffe method and two enzymatic methods did not achieve the bias goal at either low or high level of creatinine, indicating they had calibration bias. One enzymatic method failed to achieve all the bias goals in both comparison experiment and recovery test. It is important to understand that both bilirubin interference and calibration traceability to ID-LC/MS should be considered to improve the accuracy of creatinine measurement. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  3. Association of serum total bilirubin with renal outcome in Japanese patients with stages 3-5 chronic kidney disease.

    PubMed

    Sakoh, Teppei; Nakayama, Masaru; Tanaka, Shigeru; Yoshitomi, Ryota; Ura, Yoriko; Nishimoto, Hitomi; Fukui, Akiko; Shikuwa, Yui; Tsuruya, Kazuhiko; Kitazono, Takanari

    2015-09-01

    Serum bilirubin has been reported to be associated with the progression of kidney disease in patients with diabetic nephropathy. Less is known, however, about the relationship between bilirubin and chronic kidney disease (CKD) of other etiologies. This study was designed to clarify whether serum total bilirubin concentration is associated with kidney disease progression in patients with CKD independent of etiology. This prospective observational study enrolled 279 consecutive patients with stages 3-5 CKD. The renal endpoint was the composite of the doubling of serum creatinine or end-stage renal disease requiring dialysis. Patients were divided into three groups by their serum total bilirubin concentrations: ≤0.3 (lowest), 0.4-0.5 (middle), and ≥0.6 (highest) mg/dL. A Cox proportional hazards model was applied to determine the risk factors for poor renal outcome. The median follow-up period was 21months. One-hundred and three patients reached renal end points. After multivariable adjustment, a 0.1mg/dL increase in serum bilirubin was associated negatively with poor renal outcome (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.60-0.87). In addition, after adjustment for confounding factors, including traditional and nontraditional cardiovascular risk factors, the middle (HR 3.14, 95% CI 1.36-8.57) and lowest (HR 4.22, 95% CI 1.81-11.59) bilirubin groups had significantly higher HRs for renal outcome than the highest bilirubin group. Lower serum bilirubin concentration was independently associated with adverse renal outcomes, suggesting that the measurement of serum bilirubin is useful for predicting kidney disease progression in patients with moderate to severe CKD. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Application of phenol red as a marker ligand for bilirubin binding site at subdomain IIA on human serum albumin.

    PubMed

    Sochacka, Jolanta

    2015-10-01

    The drug-bilirubin interaction for all drugs administered especially to infants with hyperbilirubinemia should be evaluated for their ability to displace bilirubin and vice versa. In order to examine whether phenol red (PhRed) can be used as a marker for bilirubin binding site located in subdomain IIA the interaction between PhRed and human serum albumin (HSA) in buffer solution or in normal and pathological sera solutions with different HSA:bilirubin molar ratio was investigated using absorption/absorption difference spectroscopy and molecular docking method. Six sulfonamides representing the binding site in the subdomain IIA and known to influence the binding of bilirubin were used for the PhRed displacement studies. The absorption spectra for PhRed completely bound to HSA showed significant differences in the spectral characteristic relative to the spectral profile of free PhRed. The intensity of the peak originating from the bivalent anionic form of dye was strongly reduced and the maximum peak position was red-shifted by 12 nm. The binding constant (K) of the bivalent anionic form of PhRed, calculated from absorbance data, was 1.61 · 10(4) L mol(-1). The variations of the absorption and absorption difference spectra of PhRed in the presence of HSA-bilirubin complex were indicative of the inhibition of PhRed binding process by bilirubin. Binding of PhRed carried out in the presence of sulfonamides showed that drugs and PhRed have a common site which also involves bilirubin. In agreement with the results of the spectroscopic analysis and molecular docking it was concluded that PhRed may be applied as a marker in the study of the binding of drugs to high-affinity bilirubin binding site.

  5. Looking to the horizon: the role of bilirubin in the development and prevention of age-related chronic diseases.

    PubMed

    Wagner, Karl-Heinz; Wallner, Marlies; Mölzer, Christine; Gazzin, Silvia; Bulmer, Andrew Cameron; Tiribelli, Claudio; Vitek, Libor

    2015-07-01

    Bilirubin, the principal tetrapyrrole, bile pigment and catabolite of haem, is an emerging biomarker of disease resistance, which may be related to several recently documented biological functions. Initially believed to be toxic in infants, the perception of bilirubin has undergone a transformation: it is now considered to be a molecule that may promote health in adults. Data from the last decade demonstrate that mildly elevated serum bilirubin levels are strongly associated with reduced prevalence of chronic diseases, particularly cardiovascular diseases (CVDs), as well as CVD-related mortality and risk factors. Recent data also link bilirubin to other chronic diseases, including cancer and Type 2 diabetes mellitus, and to all-cause mortality. Therefore, there is evidence to suggest that bilirubin is a biomarker for reduced chronic disease prevalence and a predictor of all-cause mortality, which is of important clinical significance. In the present review, detailed information on the association between bilirubin and all-cause mortality, as well as the pathological conditions of CVD, cancer, diabetes and neurodegenerative diseases, is provided. The mechanistic background concerning how bilirubin and its metabolism may influence disease prevention and its clinical relevance is also discussed. Given that the search for novel biomarkers of these diseases, as well as for novel therapeutic modalities, is a key research objective for the near future, bilirubin represents a promising candidate, meeting the criteria of a biomarker, and should be considered more carefully in clinical practice as a molecule that might provide insights into disease resistance. Clearly, however, greater molecular insight is warranted to support and strengthen the conclusion that bilirubin can prevent disease, with future research directions also proposed.

  6. Bilirubin prevents acute DSS-induced colitis by inhibiting leukocyte infiltration and suppressing upregulation of inducible nitric oxide synthase.

    PubMed

    Zucker, Stephen D; Vogel, Megan E; Kindel, Tammy L; Smith, Darcey L H; Idelman, Gila; Avissar, Uri; Kakarlapudi, Ganesh; Masnovi, Michelle E

    2015-11-15

    Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression.

  7. Bilirubin activates transcription of HIF-1α in human proximal tubular cells cultured in the physiologic oxygen content.

    PubMed

    Kim, Sung Gyun; Ahn, Shin-Young; Lee, Eun Seong; Kim, Sejoong; Na, Ki Young; Chae, Dong-Wan; Chin, Ho Jun

    2014-09-01

    The expression of hypoxia-inducible factor (HIF) is influenced by reactive oxygen species (ROS). Effect of bilirubin on HIF-1 expression in proximal tubular cells was investigated under physiological oxygen concentration, which is relative hypoxic condition mimicking oxygen content in the medulla of renal tissue. The human kidney (HK2) cells were cultured in 5% oxygen with or without bilirubin. HIF-1α protein expression was increased by bilirubin treatment at 0.01-0.2 mg/dL concentration. The messenger RNA expression of HIF-1α was increased by 1.69±0.05 folds in the cells cultured with 0.1 mg/dL bilirubin, compared to the control cells. The inhibitors of PI3K/mTOR, PI3K/AKT, and ERK 1/2 pathways did not attenuate increased HIF-1α expression by bilirubin. HIF-1α expression decreased by 10 µM exogenous hydrogen peroxide (H2O2); scavenger of ROS with or without bilirubin in the HK2 cells increased HIF-1α concentration more than that in the cells without bilirubin. Exogenous H2O2 decreased the phosphorylation of P70S6 kinase, which was completely reversed by bilirubin treatment. Knockdown of NOX4 gene by small interfering RNA (siRNA) increased HIF-1α mRNA expression. In coonclusion, bilirubin enhances HIF-1α transcription as well as the up-regulation of HIF-1α protein translation through the attenuation of ROS and subunits of NADPH oxidase.

  8. Gene therapy with bilirubin-UDP-glucuronosyltransferase in the Gunn rat model of Crigler-Najjar syndrome type 1.

    PubMed

    Li, Q; Murphree, S S; Willer, S S; Bolli, R; French, B A

    1998-03-01

    Crigler-Najjar syndrome type 1 (CN type 1) is an autosomal recessive disorder characterized by nonhemolytic jaundice resulting from mutations to the gene encoding bilirubin-UDP-glucuronosyltransferase (UDPGT). The Gunn rat is an accurate animal model of this disease because the bilirubin-UDPGT gene in this strain carries a premature stop codon. The primary objective of this study was to complement this deficiency in vivo using liver-directed gene therapy. The efficiency of adenovirus type 5 (Ad5)-mediated gene transfer to the neonatal rat liver was first assessed by intravenous (i.v.) injection of an Ad5 vector carrying a nuclear-localized LacZ gene. An Ad5 vector expressing the cDNA encoding human bilirubin-UDPGT (Ad5/CMV/hUG-Br1) was then generated and injected i.v. into neonatal Gunn rats. Plasma samples were collected and bilirubin levels were determined at regular intervals. Although the mean level of bilirubin in homozygous Gunn rats 1-2 days after birth was already 14.5-fold higher than that of heterozygous siblings, treatment with Ad5/CMV/hUG-Br1 reduced plasma bilirubin to normal levels within 1 week. Plasma bilirubin in the treated homozygous rats remained normal for 4 weeks before gradually climbing to intermediate levels that were approximately half that of untreated homozygotes by 12 weeks. Administration of Ad5-mediated gene therapy to neonatal Gunn rats effectively complemented the deficiency in bilirubin-UDPGT, resulting in substantial reductions in plasma bilirubin over a 3-month period. The efficacy of Ad5-mediated gene therapy in neonates suggests that this approach might be effective against other hepatic disorders, including autosomal recessive deficiencies in lipid metabolism and vascular homeostasis.

  9. Inducible bilirubin oxidase: A novel function for the mouse cytochrome P450 2A5

    SciTech Connect

    Abu-Bakar, A'edah; Arthur, Dionne Maioha; Aganovic, Simona; Ng, Jack C.; Lang, Matti A.

    2011-11-15

    We have previously shown that bilirubin (BR), a breakdown product of haem, is a strong inhibitor and a high affinity substrate of the mouse cytochrome P450 2A5 (CYP2A5). The antioxidant BR, which is cytotoxic at high concentrations, is potentially useful in cellular protection against oxygen radicals if its intracellular levels can be strictly controlled. The mechanisms that regulate cellular BR levels are still obscure. In this paper we provide preliminary evidence for a novel function of CYP2A5 as hepatic 'BR oxidase'. A high-performance liquid chromatography/electrospray ionisation mass spectrometry screening showed that recombinant yeast microsomes expressing the CYP2A5 oxidise BR to biliverdin, as the main metabolite, and to three other smaller products with m/z values of 301, 315 and 333. The metabolic profile is significantly different from that of chemical oxidation of BR. In chemical oxidation the smaller products were the main metabolites. This suggests that the enzymatic reaction is selective, towards biliverdin production. Bilirubin treatment of primary hepatocytes increased the CYP2A5 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A5 compared to cells treated only with CHX. Collectively, the observations suggest that the CYP2A5 is potentially an inducible 'BR oxidase' where BR may accelerate its own metabolism through stabilization of the CYP2A5 protein. It is possible that this metabolic pathway is potentially part of the machinery controlling intracellular BR levels in transient oxidative stress situations, in which high amounts of BR are produced. -- Highlights: Black-Right-Pointing-Pointer CYP2A5 metabolizes bilirubin to biliverdin and dipyrroles. Black-Right-Pointing-Pointer Bilirubin increased the hepatic CYP2A5 protein and activity levels. Black-Right-Pointing-Pointer Bilirubin does not change the hepatic CYP2A5

  10. Wavelength-dependence of the relative rate constants for the main geometric and structural photoisomerization of bilirubin IX alpha bound to human serum albumin. Demonstration of green light at 510 nm as the most effective wavelength in photochemical changes from (ZZ)-bilirubin IX alpha to (EZ)-cyclobilirubin IX alpha via (EZ)-bilirubin.

    PubMed Central

    Onishi, S; Itoh, S; Isobe, K

    1986-01-01

    The kinetics for the quantitatively important reaction: (Formula: see text) that is, the photochemical interconversion between bilirubin and its geometric and structural photoisomers bound to human serum albumin in aqueous solution when various wavelengths of monochromatic light were used, were assayed by h.p.l.c. In order to clarify the wavelength-dependence of the relative rate constants in the individual steps, a light-source with a half-bandwidth of 10 nm was used at increments of 20 nm, in the range from 410 nm to 550 nm. We describe for the first time studies on the wavelength-dependence of rate constants in geometric and structural photoisomerization reactions in vitro of (ZZ)-bilirubin or (EZ)-bilirubin bound to human serum albumin, especially the relative rate constants of cyclization of (EZ)-bilirubin into (EZ)-cyclobilirubin. Because studies in vitro have demonstrated that the wavelengths from 350 to 450 nm are mutagenic, the results obtained indicated that the safest and ideal light-source for phototherapy is green light of 510 nm, which keeps (ZE)-bilirubin concentrations as low as possible, as shown by a maximal value of k2 at 510 nm and a relatively low value of k1 at 510 nm. This light-source still ensures the substantial absorption of (ZZ)-bilirubin, which is the precursor of (EZ)-bilirubin, the intermediate in (EZ)-cyclobilirubin formation and, furthermore, as shown by the maximal value of k5 and a considerable value of k4 at 510 nm, promotes the cyclization of (EZ)-bilirubin derived from (ZZ)-bilirubin even though k3 at 510 nm also shows a peak value. PMID:3790073

  11. Liquor Bilirubin Levels in Normal Pregnancy: A Reassessment of Early Prediction of Haemolytic Disease

    PubMed Central

    Murray, John; Norrie, D. L.; Ruthven, C. R. J

    1970-01-01

    A comparison was made between chemically and spectrophotometrically determined concentrations of total bile pigment in the liquor amnii. For the period 16 to 26 weeks' gestation the upper limit of normal bile pigment to protein ratio was found to be 0·4. Levels above this would be required as an indication for intrauterine transfusion. In 110 cases of isoimmunization of pregnancy these criteria were applied in the diagnosis of severity of the condition. The ratio of the bile pigment to protein was used rather than a simple bile pigment measurement, and found to be valuable. Nevertheless, it is important to emphasize that fallacious high bilirubin readings may arise by using whatever method, particularly owing to bilirubin and other breakdown products of blood contaminating the liquor. PMID:4991485

  12. Societal impact of bilirubin-induced hearing impairment in resource-limited nations.

    PubMed

    Olusanya, Bolajoko O

    2015-02-01

    Infants with bilirubin-induced neurologic dysfunction (BIND) are characterized by several developmental disabilities including auditory impairments. This paper explores the societal impact of bilirubin-induced auditory impairments, inclusive of hearing impairments and auditory neuropathy spectrum disorders, on these infants, their families, and on the community in resource-limited countries (per capita income of US$6,000 or less). Auditory impairments have substantial emotional, social, and economic impact on the affected infants, their families and communities. The burden is exacerbated by widespread poverty, unfavorable community attitudes towards disabilities, and lack of requisite health, educational, and social services. Curtailing the incidence of avoidable severe hyperbilirubinemia through proactive and effective management of infants at risk or with severe hyperbilirubinemia is necessary at all levels of healthcare delivery. Early detection and intervention for unavoidable auditory impairments should be widely promoted to provide improved developmental trajectories for the affected infants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Influence of bilirubin and other antioxidants on nitrergic relaxation in the pig gastric fundus.

    PubMed

    Colpaert, E E; Lefebvre, R A

    2000-03-01

    1. The influence of several antioxidants (bilirubin, urate, ascorbate, alpha-tocopherol, glutathione (GSH), Cu/Zn superoxide dismutase (SOD) and the manganese SOD mimic EUK-8) on nitrergic relaxations induced by either exogenous nitric oxide (NO; 10(-5) M) or electrical field stimulation (4 Hz; 10 s and 3 min) was studied in the pig gastric fundus. 2. Ascorbate (5x10(-4) M), alpha-tocopherol (4x10(-4) M), SOD (300 - 1000 u ml(-1)) and EUK-8 (3x10(-4) M) did not influence the relaxations to exogenous NO. In the presence of GSH (5x10(-4) M), the short-lasting relaxation to NO became biphasic, potentiated and prolonged. Urate (4x10(-4) M) and bilirubin (2x10(-4) M) also potentiated the relaxant effect of NO. None of the antioxidants influenced the electrically evoked relaxations. 3. 6-Anilino-5,8-quinolinedione (LY83583; 10(-5) M) had no influence on nitrergic nerve stimulation but nearly abolished the relaxant response to exogenous NO. Urate and GSH completely prevented this inhibitory effect, while it was partially reversed by SOD and bilirubin. Ascorbate, alpha-tocopherol and EUK-8 were without effect. 4. Hydroquinone (10(-4) M) did not affect the electrically induced nitrergic relaxations, but markedly reduced NO-induced relaxations. The inhibition of exogenous NO by hydroquinone was completely prevented by urate and GSH. SOD and ascorbate afforded partial protection, while bilirubin, EUK-8 and alpha-tocopherol were ineffective. 5. Hydroxocobalamin (10(-4) M) inhibited relaxations to NO by 50%, but not the electrically induced responses. Full protection versus this inhibitory effect was obtained with urate, GSH and alpha-tocopherol. 6. These results strengthen the hypothesis that several endogenous antioxidant defense mechanisms, enzymatic as well as non-enzymatic, might play a role in the nitrergic neurotransmission process.

  14. Association of Low Serum Concentration of Bilirubin with Increased Risk of Coronary Artery Disease

    DTIC Science & Technology

    1994-01-01

    concentrations were decreased in individuals baseline tracing obtained before the subjects reached with CAD, whereas some of the liver-function enzyme age...Angiographic Data lis, IN). After July 1987, dextran sulfate, Mr 50 000 Summary statistics for the two groups are given in (Ciba Corning, Oberlin, OH), was...low serum bilirubin con- activity or increases in iron stores (9). centrations have been associated with good health, and It remains to be seen

  15. Antioxidant potential of bilirubin-accelerated wound healing in streptozotocin-induced diabetic rats.

    PubMed

    Ram, Mahendra; Singh, Vishakha; Kumar, Dhirendra; Kumawat, Sanjay; Gopalakrishnan, Anu; Lingaraju, Madhu C; Gupta, Priyanka; Tandan, Surendra Kumar; Kumar, Dinesh

    2014-10-01

    Oxidative injury is markedly responsible for wound complications in diabetes mellitus. The biological actions of bilirubin may be relevant to prevent oxidant-mediated cell death, as bilirubin application at a low concentration scavenges reactive oxygen species. Hence, we hypothesized that topical bilirubin application might improve wound healing in diabetic rats. Diabetes was induced in adult male Wistar rats, which were divided into two groups, i.e., diabetic control and diabetic treated. Non-diabetic healthy rats were also taken as healthy control group. Wound area was measured on days 3, 7, 14, and 19 post-wounding. The levels of malondialdehyde (MDA) and reduced glutathione (GSH) and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were estimated in the granulation tissue. There was a significant increase in percent wound closure in healthy control and diabetic treated rats on days 7, 14, and 19, as compared to diabetic control rats on days 7, 14, and 19. There was significant decrease in MDA levels on days 7, 14, and 19 in diabetic treated rats, as compared to diabetic control rats. Levels of GSH were significantly increased on days 3, 7, 14, and 19 in diabetic treated rats, as compared to diabetic control rats. GPx, SOD, and CAT activities were significantly higher on days 3, 7, and 14 in diabetic treated rats, as compared to diabetic control rats. The findings indicate that bilirubin is effective in reducing the oxidant status in wounds of diabetic rats which might have accelerated wound healing in these rats.

  16. Decreased neonatal jaundice readmission rate after implementing hyperbilirubinemia guidelines and universal screening for bilirubin.

    PubMed

    Alkalay, Arie L; Bresee, Catherine J; Simmons, Charles F

    2010-09-01

    Readmission rate for neonatal jaundice approximate 10 per 1000 live births. After applying hyperbilirubinemia guidelines and universal screening for bilirubin in term and near-term newborns, the readmission rate declined significantly from 24 to 3.7 per 1000 live births. Decreased readmission rate for neonatal jaundice may reduce kernicterus rate and health care costs. Further studies are necessary to explore these potential benefits.

  17. Low solubility of unconjugated bilirubin in dimethylsulfoxide – water systems: implications for pKa determinations

    PubMed Central

    2002-01-01

    Background Aqueous pKa values of unconjugated bilirubin are important determinants of its solubility and transport. Published pKa data on an analog, mesobilirubin-XIIIα, studied by 13C-NMR in buffered solutions containing 27 and 64 vol% (C2H3)2SO because of low aqueous solubility of mesobilirubin, were extrapolated to obtain pKa values in water of 4.2 and 4.9. Previous chloroform-water partition data on bilirubin diacid led to higher estimates of its pKa, 8.12 and 8.44, and its aqueous solubility. A thermodynamic analysis, using this solubility and a published solubility in DMSO, suggested that the systems used to measure 13C-NMR shifts were highly supersaturated. This expectation was assessed by measuring the residual concentrations of bilirubin in the supernatants of comparable DMSO-buffer systems, after mild centrifugation to remove microprecipitates. Results Extensive sedimentation was observed from numerous systems, many of which appeared optically clear. The very low supernatant concentrations at the lowest pH values (4.1-5.9) were compatible with the above thermodynamic analysis. Extensive sedimentation and low supernatant concentrations occurred also at pH as high as 7.2. Conclusions The present study strongly supports the validity of the aqueous solubility of bilirubin diacid derived from partition data, and, therefore, the corresponding high pKa values. Many of the mesobilirubin systems in the 13C-NMR studies were probably supersaturated, contained microsuspensions, and were not true solutions. This, and previously documented errors in pH determinations that caused serious errors in pKa values of the many soluble reference acids and mesobilirubin, raise doubts regarding the low pKa estimates for mesobilirubin from the 13C-NMR studies. PMID:12079498

  18. The antioxidant effect of free bilirubin on cumene-hydroperoxide treated human leukocytes.

    PubMed

    Yesilkaya, A; Altinayak, R; Korgun, D K

    2000-07-01

    To examine the antioxidant effect of bilirubin (BR) on leukocyte, we treated leukocytes obtained from healthy subjects with an oxidant and various concentrations of BR. High concentrations of BR decreased thiobarbituric acid reactive substances (TBARS) and catalase activities, increased superoxide dismutase (SOD) activity, but had no effect on glutathione (GSH) concentration. Our results showed that under physiological conditions, BR has an antioxidant effect only in high concentrations.

  19. Interference of Bilirubin in the Determination of Magnesium with Methyl Thymol Blue.

    PubMed

    Maksinovic, Rada; Ketin, Sonja; Biocanin, Rade

    2015-06-01

    Jaundice is a disease named for the yellow color of the skin. This color is the result of elevated levels of bilirubin in the blood serum. In Roma from Krusevac region in the last few years have seen the emergence of jaundice. In 80 of them (40 suffering and 40 from control group) were performed tests of numerous parameters in the laboratories of the Health Center in Krusevac. Magnesium was determined by spectrophotometry with methyl thymol blue, titanium yellow and blue xylidene. Bilirubin was determined by Jandrešek Grofov's method. The results were within the expectations, in addition to magnesium which was determined with methyl thymol blue. In all patients suffering from jaundice concentration of magnesium (0.67 ±0.14 mmol/l) statistically was significantly lower than tested of the control group (0.91± 0.059 mmol/). There is no theoretical data to reduce the concentration of magnesium in serum as a result of jaundice. That's why we determined magnesium both in the control group and in sufferings with two methods as the titanium yellow, and xylidene blew. With these two methods we obtained results that were examined were within normal limits. This has led us to conclude that the determination of bilirubin interferes with magnesium methyl thymol blue.

  20. Bilirubin oxidase from Magnaporthe oryzae: an attractive new enzyme for biotechnological applications

    PubMed Central

    Durand, Fabien; Gounel, Sébastien; Kjaergaard, Christian H.; Solomon, Edward I.

    2013-01-01

    A novel bilirubin oxidase (BOD), from the rice blast fungus Magnaporthe oryzae, has been identified and isolated. The 64-kDa protein containing four coppers was successfully overexpressed in Pichia pastoris and purified to homogeneity in one step. Protein yield is more than 100 mg for 2 L culture, twice that of Myrothecium verrucaria. The kcat/Km ratio for conjugated bilirubin (1,513 mM −1 s−1) is higher than that obtained for the BOD from M. verrucaria expressed in native fungus (980 mM−1 s−1), with the lowest Km measured for any BOD highly desirable for detection of bilirubin in medical samples. In addition, this protein exhibits a half-life for deactivation >300 min at 37 °C, high stability at pH 7, and high tolerance towards urea, making it an ideal candidate for the elaboration of biofuel cells, powering implantable medical devices. Finally, this new BOD is efficient in decolorizing textile dyes such as Remazol brilliant Blue R, making it useful for environmentally friendly industrial applications. PMID:22350257

  1. Bilirubin oxidase from Magnaporthe oryzae: an attractive new enzyme for biotechnological applications.

    PubMed

    Durand, Fabien; Gounel, Sébastien; Kjaergaard, Christian H; Solomon, Edward I; Mano, Nicolas

    2012-12-01

    A novel bilirubin oxidase (BOD), from the rice blast fungus Magnaporthe oryzae, has been identified and isolated. The 64-kDa protein containing four coppers was successfully overexpressed in Pichia pastoris and purified to homogeneity in one step. Protein yield is more than 100 mg for 2 L culture, twice that of Myrothecium verrucaria. The k(cat)/K(m) ratio for conjugated bilirubin (1,513 mM⁻¹ s⁻¹) is higher than that obtained for the BOD from M. verrucaria expressed in native fungus (980 mM⁻¹ s⁻¹), with the lowest K(m) measured for any BOD highly desirable for detection of bilirubin in medical samples. In addition, this protein exhibits a half-life for deactivation >300 min at 37 °C, high stability at pH 7, and high tolerance towards urea, making it an ideal candidate for the elaboration of biofuel cells, powering implantable medical devices. Finally, this new BOD is efficient in decolorizing textile dyes such as Remazol brilliant Blue R, making it useful for environmentally friendly industrial applications.

  2. Delta bilirubin: absorption spectra, molar absorptivity, and reactivity in the diazo reaction.

    PubMed

    Doumas, B T; Wu, T W; Jendrzejczak, B

    1987-06-01

    Delta bilirubin (B delta), isolated from serum, has an absorption maximum near 440 nm and a molar absorptivity of 72,000 L mol-1cm-1 in either Tris HCl (0.1 mol/L, pH 8.5) or phosphate (0.13 mol/L, pH 7.4) buffer. This absorptivity exceeds by approximately 50% and 59%, respectively, that of unconjugated bilirubin in the same buffers. This finding suggests that substantial errors can be incurred in direct spectrophotometry of bilirubins in serum. In the total diazo (TBIL) assay (Clin Chem 1985;31:1779-89), the color yield from B delta increases by 10% as the final diazo concentration is increased from 0.27 to 0.81 mmol/L. In the direct (DBIL) assay, if done in HCl (50 mmol/L), B delta yields approximately 15% more color as the diazo concentration is increased from 0.51 to 1.53 mmol/L, whereas in acetate buffer (0.4 mol/L, pH 4.7) the corresponding color yield is 25% greater. However, the absolute color yield for the reaction in HCl exceeds that in acetate buffer. In both the TBIL and the DBIL assay, B delta reacts slowly, nearly complete reaction requiring 10 min. Thus, B delta may be seriously underestimated in diazo (especially DBIL) methods in which short reaction times (20 s to 1 min) are used.

  3. Interference of Bilirubin in the Determination of Magnesium with Methyl Thymol Blue

    PubMed Central

    Maksinovic, Rada; Ketin, Sonja; Biocanin, Rade

    2015-01-01

    Introduction: Jaundice is a disease named for the yellow color of the skin. This color is the result of elevated levels of bilirubin in the blood serum. In Roma from Krusevac region in the last few years have seen the emergence of jaundice. Material and methods: In 80 of them (40 suffering and 40 from control group) were performed tests of numerous parameters in the laboratories of the Health Center in Krusevac. Magnesium was determined by spectrophotometry with methyl thymol blue, titanium yellow and blue xylidene. Bilirubin was determined by Jandrešek Grofov’s method. Results: The results were within the expectations, in addition to magnesium which was determined with methyl thymol blue. In all patients suffering from jaundice concentration of magnesium (0.67 ±0.14 mmol/l) statistically was significantly lower than tested of the control group (0.91± 0.059 mmol/). There is no theoretical data to reduce the concentration of magnesium in serum as a result of jaundice. That’s why we determined magnesium both in the control group and in sufferings with two methods as the titanium yellow, and xylidene blew. With these two methods we obtained results that were examined were within normal limits. Conclusion: This has led us to conclude that the determination of bilirubin interferes with magnesium methyl thymol blue. PMID:26244045

  4. Point-of-care device for quantification of bilirubin in skin tissue.

    PubMed

    Alla, Suresh K; Huddle, Adam; Butler, Joshua D; Bowman, Peggy S; Clark, Joseph F; Beyette, Fred R

    2011-03-01

    Steady state diffuse reflectance spectroscopy is a nondestructive method for obtaining biochemical and physiological information from skin tissue. In medical conditions such as neonatal jaundice excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. Diffuse reflectance measurement of the skin tissue can provide real time assessment of the progression of a disease or a medical condition. Here we present a noninvasive point-of-care system that utilizes diffuse reflectance spectroscopy to quantifying bilirubin from skin reflectance spectra. The device consists of an optical system integrated with a signal processing algorithm. The device is then used as a platform to study two different spectral databases. The first spectral database is a jaundice animal model in which the jaundice reflectance spectra are synthesized from normal skin. The second spectral database is the spectral measurements collected on human volunteers to quantify the different chromophores and other physical properties of the tissue such as Hematocrit, Hemoglobin, etc. The initial trials from each of these spectral databases have laid the foundation to verify the performance of this bilirubin quantification device.

  5. A spectroscopic study of the wavelength-dependent photoisomerizations of bilirubins bound to human serum albumin

    NASA Astrophysics Data System (ADS)

    Mazzoni, Marina; Agati, Giovanni; Pratesi, Riccardo; Persico, Maurizio

    2005-12-01

    The wavelength-dependent photoisomerizations of the asymmetric bilirubin BR-IXα and of the symmetric bilirubin-IIIα (BR-III) and mesobilirubin-XIIIα (MBR-XIII) bound to human serum albumin (HSA) in aqueous solution were analysed with the help of an exciton coupling model. The modelling was based on the absorption and circular dichroism (CD) spectra (bisignate Cotton effect). Time-dependent density functional theory (TD-DFT) of the free BR-IX molecule suggested the presence of two main bands of exciton coupling character in the blue region of the spectrum, and other weaker bands of charge transfer character at longer wavelengths. These peculiarities were taken into account to fit the photoisomerization quantum yields in the blue-green region as functions of the wavelength, obtaining the bandshape of the exciton coupling bands from the experimental CD spectra. The other excitons were extracted from the decomposition of the band resulting from the difference between the absorption spectrum and the sum (normalized-to-absorption) of the two CD excitons. We expressed photoisomerization quantum yields in terms of the sum of the contributions to photon absorption deriving from all the exciton states normalized to total absorption. For all the reversible photoprocesses of bilirubins and for the irreversible one of BR-IXα in HSA (i.e. lumirubin formation), we give reliable mean values of the individual state excitation probabilities and photoisomerization efficiencies in the pigment protein complex.

  6. Post-test probability for neonatal hyperbilirubinemia based on umbilical cord blood bilirubin, direct antiglobulin test, and ABO compatibility results.

    PubMed

    Peeters, Bart; Geerts, Inge; Van Mullem, Mia; Micalessi, Isabel; Saegeman, Veroniek; Moerman, Jan

    2016-05-01

    Many hospitals opt for early postnatal discharge of newborns with a potential risk of readmission for neonatal hyperbilirubinemia. Assays/algorithms with the possibility to improve prediction of significant neonatal hyperbilirubinemia are needed to optimize screening protocols and safe discharge of neonates. This study investigated the predictive value of umbilical cord blood (UCB) testing for significant hyperbilirubinemia. Neonatal UCB bilirubin, UCB direct antiglobulin test (DAT), and blood group were determined, as well as the maternal blood group and the red blood cell antibody status. Moreover, in newborns with clinically apparent jaundice after visual assessment, plasma total bilirubin (TB) was measured. Clinical factors positively associated with UCB bilirubin were ABO incompatibility, positive DAT, presence of maternal red cell antibodies, alarming visual assessment and significant hyperbilirubinemia in the first 6 days of life. UCB bilirubin performed clinically well with an area under the receiver-operating characteristic curve (AUC) of 0.82 (95 % CI 0.80-0.84). The combined UCB bilirubin, DAT, and blood group analysis outperformed results of these parameters considered separately to detect significant hyperbilirubinemia and correlated exponentially with hyperbilirubinemia post-test probability. Post-test probabilities for neonatal hyperbilirubinemia can be calculated using exponential functions defined by UCB bilirubin, DAT, and ABO compatibility results. • The diagnostic value of the triad umbilical cord blood bilirubin measurement, direct antiglobulin testing and blood group analysis for neonatal hyperbilirubinemia remains unclear in literature. • Currently no guideline recommends screening for hyperbilirubinemia using umbilical cord blood. What is New: • Post-test probability for hyperbilirubinemia correlated exponentially with umbilical cord blood bilirubin in different risk groups defined by direct antiglobulin test and ABO blood group

  7. Effect of Blue Light on the Electronic and Structural Properties of Bilirubin Isomers: Insights into the Photoisomerization and Photooxidation Processes.

    PubMed

    Cardoso, Lucas C; Savedra, Ranylson M L; Silva, Mariana M; Ferreira, Giovana R; Bianchi, Rodrigo F; Siqueira, Melissa F

    2015-08-27

    The central process of neonatal phototherapy by employing blue light has been attributed to the configurational conversion of (4Z,15Z)-bilirubin to (4Z,15E). Indeed, photoisomerization is the early photochemical event during this procedure. However, in this paper, we show that the bilirubin solutions under continuous blue light exposure undergo a photooxidation process. To ascertain the role of this photodegradation in the phototherapy, we evaluated UV–visible absorption spectra obtained from bilirubin solutions in CHCl3, milli-Q water, and physiological saline, as well as FTIR spectroscopy for bilirubin in CHCl3. These analyses also showed that the first 2 h of phototherapy are the most relevant period. In addition, quantum molecular modeling using B3LYP/6-31G(d,p) and ZINDO/S-CIS was performed to evaluate the electronic and structural properties of four bilirubin isomers, showing that the (4Z,15E)-bilirubin isomer is the most polar configuration. Therefore, it can be more soluble in aqueous environments than the other configurations. This clarifies why this is the faster isomer excreted during the phototherapy.

  8. Serum bilirubin levels are lower in overweight asymptomatic middle-aged adults: an early indicator of metabolic syndrome?

    PubMed

    Jenko-Pražnikar, Zala; Petelin, Ana; Jurdana, Mihaela; Žiberna, Lovro

    2013-07-01

    Low levels of bilirubin have recently been associated with obesity, diabetes mellitus, and metabolic syndrome. Here, we hypothesized that serum bilirubin levels might be already altered in overweight asymptomatic middle-aged individuals before full development of the metabolic syndrome. Healthy nonsmoking adults aged 25-49 (64 women and 32 men) participated in this cross-sectional study. All participants who reported stable weight within the last three months underwent standard anthropomorphological measurements of body composition, blood pressure measurements, aerobic and anaerobic capabilities assessment, dietary intake evaluation, and fasting serological measurements of total and direct bilirubin, glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein. Participants were divided into normal-weight and overweight groups. Linear correlation and multiple regression analyses were used to examine the association of serum bilirubin levels with all metabolic syndrome risk factor changes. Serum bilirubin levels were lower in overweight healthy individuals of both sexes, and were negatively associated with abdominal obesity, insulin resistance, fasting glucose, fasting insulin, fasting triglycerides, total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein levels but positively associated with aerobic body capabilities. Our findings suggest that serum bilirubin levels have the potential to be employed as an early biomarker for indicating asymptomatic individuals at increased risk of developing metabolic syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Effect of bilirubin concentration on the risk of diabetic complications: A meta-analysis of epidemiologic studies

    PubMed Central

    Zhu, Bo; Wu, Xiaomei; Bi, Yifei; Yang, Yang

    2017-01-01

    Diabetes can affect many parts of the body and is associated with serious complications. Oxidative stress is a major contributor in the pathogenesis of diabetic complications and bilirubin has been shown to have antioxidant effects. The number of studies on the effect of bilirubin on the risk of diabetic complications has increased, but the results are inconsistent. Thus, we performed a meta-analysis to determine the relationship between bilirubin concentration and the risk of diabetic complications, and to investigate if there was a dose-response relationship. We carried out an extensive search in multiple databases. A fixed or random-effects model was used to calculate the pooled estimates. We conducted a dose-response meta-analysis to analyze the association between these estimates. A total of 132,240 subjects from 27 included studies were analyzed in our meta-analysis. A negative nonlinear association between bilirubin concentration and the risk of diabetic complications was identified (OR: 0.77, 95% CI: 0.73–0.81), with a nonlinear association. We also found that there was a negative association between bilirubin concentration and the risk of diabetic nephropathy, diabetic retinopathy and diabetic neuropathy. The results of our meta-analysis indicate that bilirubin may play a protective role in the occurrence of diabetic complications. PMID:28134328

  10. High serum total bilirubin as a protective factor against hip bone loss in healthy middle-aged men.

    PubMed

    Kim, Beom-Jun; Koh, Jung-Min; Ahn, Seong Hee; Lee, Seung Hun; Kim, Eun Hee; Bae, Sung Jin; Kim, Hong-Kyu; Choe, Jae Won; Kim, Ghi Su

    2013-06-01

    Bilirubin is known to have a physiologic role as an antioxidant that efficiently scavenges peroxyl radicals and suppresses oxidation, and oxidative stress has detrimental effects on bone metabolism. In the present study, we performed a 3-year longitudinal study of healthy middle-aged men, investigating the association between serum total bilirubin concentrations and annualized changes in bone mineral density (BMD). The study enrolled a total of 917 Korean men aged 40 years or older who had undergone comprehensive routine health examinations with an average follow-up interval of 3 years. BMD at proximal femur sites was measured with dual-energy X-ray absorptiometry using the same equipment at baseline and follow-up. The overall mean annualized rates of bone loss at the total femur, femoral neck, and trochanter were -0.25 %/year, -0.34 %/year, and -0.44 %/year, respectively. After adjustment for potential confounders, the rates of bone loss at all proximal femur sites were significantly attenuated in a dose-response fashion across increasing bilirubin concentrations (P = 0.006-0.046). Moreover, compared to subjects in the lowest bilirubin quartile category, those in the highest bilirubin quartile category showed significantly less bone loss at all proximal femur sites after adjustment for confounding factors (P = 0.010-0.048). This study provides the first clinical evidence that serum total bilirubin could be a protective marker against future bone loss, especially in subjects without liver diseases.

  11. Mildly elevated serum total bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons with type 2 diabetes.

    PubMed

    Kawamoto, Ryuichi; Ninomiya, Daisuke; Hasegawa, Yoichi; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori

    2016-01-01

    Diabetes is strongly associated with several mechanisms of tissue damage such as oxidative stress. Serum bilirubin may have a beneficial role in preventing oxidative changes in cardiovascular disease (CVD). Limited information is available on whether serum bilirubin is an independent confounding factor for carotid atherosclerosis among elderly persons with type 2 diabetes. The study subjects were 169 men aged 79 ± 8 (mean ± SD) years and 205 women aged 81 ± 8 years that were enrolled consecutively from patients in the medical department. Carotid intima-media thickness (IMT) and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that serum total bilirubin (β = -0.160) was significantly associated with carotid IMT. Compared to subjects with a serum total bilirubin of tertile-1 (0.13-0.58 mg/dL), the multivariate-adjusted odds ratio (95% confidence interval) of carotid IMT ≥1.0 mm including plaque and carotid plaque was 0.46 (0.23-0.93) and 0.32 (0.17-0.60) in the Tertile-3 group (0.87-1.93 mg/dL), respectively. Next, data were further stratified by gender, age, smoking status, medication and prevalence of CVD. There were no significant differences in serum total bilirubin levels between selected subgroups. Our data demonstrated a negative association between serum total bilirubin and carotid atherosclerosis among elderly persons with type 2 diabetes.

  12. Does corticosteroid treatment cause prolonged recovery and increased total bilirubin level in severe ADAMTS-13-deficient TTP patient?

    PubMed

    Sayiner, Zeynel Abidin; Acik, Didar Yanardag; Yilmaz, Mehmet; Subari, Salih; Mete, Ayse Ozlem; Dai, M Sinan

    2015-10-01

    A 41-year-old female patient complaining of fatigue, headache, mild confusion, and rush on her lower extremities was admitted to our emergency department. Laboratory tests revealed that he had anemia, thrombocytopenia, and increased levels of indirect bilirubin and lactic dehydrogenase (LDH) in blood tests. Direct and indirect Coombs tests were negative, and fragmented erythrocytes were observed in peripheral blood smears. The patient was diagnosed with thrombotic thrombocytopenic purpura (TTP). The best supportive care was provided. Therapeutic plasma exchange (TPE) and 1 mg/kg methylprednisolone treatments were administered. On the 10th day of treatment, LDH level and fragmented red blood cells in peripheral blood smear were decreased, but his direct and indirect bilirubin levels increased despite the fact that he was treated with 1 mg/kg methylprednisolone and TPE. The patient had severe ADAMTS-13 deficiency. After discontinued steroids treatment, his bilirubin level normalized within 4 days. On the 4th day after bilirubin level normalized, vincristine treatment was administered. TPE was also continued. There was no consensus about the optimal schedule for discontinuing plasmapheresis therapy, and also we observed total bilirubin level improvement with discontinued corticosteroid treatment. In this case, corticosteroid treatment was linked with the increase of total bilirubin level in severe ADAMTS-13-deficient TTP patient.

  13. Usefulness of serum bilirubin levels as a biomarker for long-term clinical outcomes after percutaneous coronary intervention.

    PubMed

    Kim, Hyun-Wook; Choi, Dong-Hyun; Lim, Leejin; Lee, Young-Min; Kang, Joon Tae; Chae, Seung Seok; Ki, Young-Jae; Song, Heesang; Koh, Young-Youp

    2015-11-01

    The aim of this study was to evaluate the prognostic value of serum total bilirubin on the development of adverse outcomes after percutaneous coronary intervention (PCI) besides high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B type natriuretic peptide (NT-proBNP). Serum total bilirubin, hs-cTnT, and NT-proBNP were analyzed in 372 patients who underwent PCI. The primary endpoint was cardiac death. There were 21 events of cardiac death during a mean of 25.8 months of follow-up. When the serum total bilirubin cut-off level (median value) was set to 0.58 mg/dL using the receiver operating characteristic curve, the sensitivity was 95.2 % and the specificity was 51.0 % for differentiating between the group with cardiac death and the group without cardiac death. Kaplan-Meier analysis revealed that the lower serum total bilirubin group (<0.58 mg/dL) had a significantly higher cardiac death rate than the higher serum total bilirubin group (≥0.58 mg/dL) (10.4 vs. 0.6 %, log-rank: P = 0.0001). In conclusion, low serum total bilirubin is a predictive marker for cardiac death after PCI.

  14. Bilirubin conjugates in bile of man and rat in the normal state and in liver disease

    PubMed Central

    Fevery, J.; Damme, B. Van; Michiels, R.; Groote, J. De; Heirwegh, K. P. M.

    1972-01-01

    Conjugates of bilirubin were studied in normal bile of man and rat, and in bile of liver patients. In general human bile was obtained by duodenal intubation. In addition T-tube bile was examined in patients operated on for mechanical obstruction. The bile pigment compositions of duodenal and T-tube bile were similar in two patients where comparison was possible. Obstruction of the bile duct in rats was used as an animal model for obstructive jaundice. Diazotized ethyl anthranilate was used for determination of total conjugated bile pigment and for thin-layer chromatography (t.l.c.) analysis of the derived azopigments. The available t.l.c. procedures are versatile and allow rapid and quantitative analysis. A variety of conjugated azopigments can be distinguished. With chloroform, negligible amounts of unconjugated bilirubin are extracted from bile of man. Therefore, the percentage of monoconjugated bile pigments present in the initial bile sample can be calculated from the percentage of azodipyrrole found after diazotization. Normal bile from man and rat yields similar azopigment patterns. The dominant component is azopigment-δ (azodipyrrole β-D-monoglucuronoside). Small amounts of azopigments with complex conjugating structures (γ-azopigments) are present in both cases. Human bile further yields small amounts of azopigments containing xylose or glucose (called azopigments-α2 and -α3, respectively). Monoconjugated bilirubin (estimated from the percentage of azodipyrrole) amounts of 22% of total bile pigments in human bile and to 39% in murine bile. In both, the bulk of bile pigment is bilirubin diglucuronoside. From bile of patients with acquired liver diseases a new azopigment group (β-azopigment) was derived. The γ-azopigment group was increased; the δ-azopigment group (containing azodipyrrole β-D-monoglucuronoside) was decreased. No differentiation was possible between intra- and extrahepatic cholestasis. The percentage of β-azopigment showed a positive

  15. Transient elevation of serum bilirubin (a heme oxygenase-1 metabolite) level in hemorrhagic stroke: bilirubin is a marker of oxidant stress.

    PubMed

    Dohi, K; Mochizuki, Y; Satoh, K; Jimbo, H; Hayashi, M; Toyoda, I; Ikeda, Y; Abe, T; Aruga, T

    2003-01-01

    Bilirubin (Bil) is the end product of heme catabolism. The production of Bil reflects heme oxygenase-1 expression in response to oxidative stress in various diseases. To assess the role of Bil as a marker of oxidative stress in cases of brain damage, we measured serum Bil concentrations in patients with hemorrhagic stroke. Serum levels of total Bil were measured in 20 subarachnoid hemorrhage patients with symptomatic vasospasms and in 23 patients with intracerebral hemorrhage; concentrations were measured every day for 14 consecutive days. Serum Bil levels were significantly elevated in the early phases in both groups. Moreover, transient elevation was observed on the day prior to the observation of clinical manifestations of symptomatic vasospasm after SAH. Bil, known to be a powerful antioxidant, was induced after hemorrhagic stroke, reflecting the intensity of oxidative stress. Plasma Bil concentrations might serve as a useful marker of oxidative stress in hemorrhagic stroke patients.

  16. Bilirubin - blood

    MedlinePlus

    ... Gastroenterology. In: Rennie JM, ed. Rennie and Robsertson's Textbook of Neonatology. 5th ed. Philadelphia, PA: Elsevier; 2012:chap 29. Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, ...

  17. Affinity of human serum albumin for bilirubin varies with albumin concentration and buffer composition: results of a novel ultrafiltration method.

    PubMed

    Weisiger, R A; Ostrow, J D; Koehler, R K; Webster, C C; Mukerjee, P; Pascolo, L; Tiribelli, C

    2001-08-10

    Albumin binding is a crucial determinant of bilirubin clearance in health and bilirubin toxicity in certain disease states. However, prior attempts to measure the affinity of albumin for bilirubin have yielded highly variable results, reflecting both differing conditions and the confounding influence of impurities. We therefore have devised a method based on serial ultrafiltration that successively removes impurities in [(14)C]bilirubin until a stable binding affinity is achieved, and then we used it to assess the effect of albumin concentration and buffer composition on binding. The apparent binding affinity of human serum albumin for [(14)C]bilirubin was strongly dependent on assay conditions, falling from (5.09 +/- 0.24) x 10(7) liters/mol at lower albumin concentrations (15 microm) to (0.54 +/- 0.05) x 10(7) liters/mol at higher albumin concentrations (300 microm). To determine whether radioactive impurities were responsible for this change, we estimated impurities in the stock bilirubin using a novel modeling approach and found them to be 0.11-0.13%. Formation of new impurities during the study and their affinity for albumin were also estimated. After correction for impurities, the binding affinity remained heavily dependent on the albumin concentration (range (5.37 +/- 0.26) x 10(7) liters/mol to (0.65 +/- 0.03) x 10(7) liters/mol). Affinities decreased by about half in the presence of chloride (50 mm). Thus, the affinity of human albumin for bilirubin is not constant, but varies with both albumin concentration and buffer composition. Binding may be considerably less avid at physiological albumin concentrations than previously believed.

  18. Patched Skin Bilirubin Assay to Monitor Neonates Born Extremely Preterm Undergoing Phototherapy.

    PubMed

    De Luca, Daniele; Dell'Orto, Valentina

    2017-09-01

    To verify the reliability and safety of transcutaneous bilirubin (TcB) measurements in patched skin areas in neonates born extremely preterm under phototherapy. Sixty neonates (<30 weeks' gestation) receiving phototherapy were enrolled and TcB was measured via a second-generation transcutaneous bilirubinometer in patched skin areas (of at least 2.5 cm diameter). Total serum bilirubin (TSB), lactate, pH, hemoglobin, and skin temperature were measured within 10 minutes of the TcB assay. Clinicians were blinded to TcB values, and clinical decisions about phototherapy were made with the TSB measurement only. TcB and TSB significantly were correlated (r = 0.84; P <.001), even after adjustment for hemoglobin, pH, lactate, gestational and postnatal age (standardized β = 0.8; P <.001; adjusted R(2) = 0.75), or treatment duration (standardized β = 0.8; P <.001; adjusted R(2) = 0.7). When the Bland-Altman analysis was used, TcB overestimated TSB at high values (mean difference TSB - TcB: -2.8 [2.4] mg/dL). If clinicians used the TcB only, no neonate would have had phototherapy stopped prematurely, and 21 (35%) would have continued phototherapy when it could have been stopped. The correlation between TSB and TcB (measured in patched skin areas) was comparable with that obtained in more mature neonates, and it was not influenced by clinical variables or factors affecting skin bilirubin passage. TcB overestimated TSB, and this may expose infants born preterm to unnecessary phototherapy, although it could spare approximately 65% of TSB assays. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Identification of heme oxygenase-1 stimulators by a convenient ELISA-based bilirubin quantification assay.

    PubMed

    Rücker, Hannelore; Amslinger, Sabine

    2015-01-01

    The upregulation of heme oxygenase-1 (HO-1) has proven to be a useful tool for fighting inflammation. In order to identify new HO-1 inducers, an efficient screening method was developed which can provide new lead structures for drug research. We designed a simple ELISA-based HO-1 enzyme activity assay, which allows for the screening of 12 compounds in parallel in the setting of a 96-well plate. The well-established murine macrophage cell line RAW264.7 is used and only about 26µg of protein from whole cell lysates is needed for the analysis of HO-1 activity. The quantification of HO-1 activity is based on an indirect ELISA using the specific anti-bilirubin antibody 24G7 to quantify directly bilirubin in the whole cell lysate, applying a horseradish peroxidase-tagged antibody together with ortho-phenylenediamine and H2O2 for detection. The bilirubin is produced on the action of HO enzymes by converting their substrate heme to biliverdin and additional recombinant biliverdin reductase together with NADPH at pH 7.4 in buffer. This sensitive assay allows for the detection of 0.57-82pmol bilirubin per sample in whole cell lysates. Twenty-three small molecules, mainly natural products with an α,β-unsaturated carbonyl unit such as polyphenols, including flavonoids and chalcones, terpenes, an isothiocyanate, and the drug oltipraz were tested at typically 6 or 24h incubation with RAW264.7 cells. The activity of known HO-1 inducers was confirmed, while the chalcones cardamonin, flavokawain A, calythropsin, 2',3,4'-trihydroxy-4-methoxychalcone (THMC), and 2',4'-dihydroxy-3,4-dimethoxychalcone (DHDMC) were identified as new potent HO-1 inducers. The highest inductive power after 6h incubation was found at 10µM for DHDMC (6.1-fold), carnosol (3.9-fold), butein (3.1-fold), THMC (2.9-fold), and zerumbone (2.5-fold). Moreover, the time dependence of HO-1 protein production for DHDMC was compared to its enzyme activity, which was further evaluated in the presence of

  20. Genome-wide association of serum bilirubin levels in Korean population.

    PubMed

    Kang, Tae-Wook; Kim, Hee-Jin; Ju, Hyoungseok; Kim, Jeong-Hwan; Jeon, Yeo-Jin; Lee, Han-Chul; Kim, Ka-Kyung; Kim, Jong-Won; Lee, Siwoo; Kim, Jong Yeol; Kim, Seon-Young; Kim, Yong Sung

    2010-09-15

    A large-scale, genome-wide association study was performed to identify genetic variations influencing serum bilirubin levels using 8841 Korean individuals. Significant associations were observed at UGT1A1 (rs11891311, P = 4.78 x 10(-148)) and SLCO1B3 (rs2417940, P = 1.03 x 10(-17)), which are two previously identified loci. The two single-nucleotide polymorphisms (SNPs) were replicated (rs11891311, P = 3.18 x 10(-15)) or marginally significant (rs2417940, P = 8.56 x 10(-4)) in an independent cohort of 1096 individuals. In a conditional analysis adjusted for the top UGT1A1 variant (rs11891311), another variant in UGT1A1 (rs4148323, P = 1.22 x 10(-121)) remained significant; this suggests that in UGT1A1 at least two independent genetic variations influence the bilirubin levels in the Korean population. The protein coding variant rs4148323, which is monomorphic in European-derived populations, may be specifically associated with serum bilirubin levels in Asians (P = 2.56 x 10(-70)). The SLCO1B3 variant (rs2417940, P = 1.67 x 10(-18)) remained significant in a conditional analysis for the top UGT1A1 variant. Interestingly, there were significant differences in the associated variations of SLCO1B3 between Koreans and European-derived populations. While the variant rs2417940 at intron 7 of SLCO1B3 was more significantly associated in Koreans, variants rs17680137 (P = 0.584) and rs2117032 (P = 2.76 x 10(-5)), two of the top-ranked SNPs in European-derived populations, did not reach the genome-wide significance level. Also, variants in SLCO1B1 did not reach genome-wide significance in Koreans. Our result supports the idea that there are considerable ethnic differences in genetic association of bilirubin levels between Koreans and European-derived populations.

  1. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress

    SciTech Connect

    Muhsain, Siti Nur Fadzilah; Lang, Matti A.; Abu-Bakar, A'edah

    2015-01-01

    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200 mg pyrazole/kg/day for 3 days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. - Highlights: • Pyrazole induces oxidative stress in the mouse liver. • Pyrazole-induced oxidative stress induces mitochondrial targeting of key bilirubin regulatory enzymes, HMOX1

  2. Correlation between Bilirubin Glucuronidation and Estradiol-3-Gluronidation in the Presence of Model UDP-Glucuronosyltransferase 1A1 Substrates/Inhibitors

    PubMed Central

    Zhou, Jin; Tracy, Timothy S.

    2011-01-01

    Inhibition of UDP-glucuronosyltransferase (UGT) 1A1-catalyzed bilirubin glucuronidation by drug compounds may potentially be of clinical concern. However, in drug discovery and development settings, bilirubin is less than an ideal in vitro probe for assessing the potential of a chemical entity to inhibit bilirubin glucuronidation. In part, this is due to the propensity of bilirubin to photodegrade and to the instability of its metabolites. To this end, the utility of estradiol-3-glucuronidation as a surrogate in vitro predictor for interactions with bilirubin was evaluated. The glucuronidation kinetics of bilirubin and estradiol were carefully characterized with recombinant UGT1A1 expressed in human embryonic kidney 293 cells. Consistent with previous reports, estradiol-3-glucuronidation displayed sigmoidal kinetics, whereas bilirubin glucuronidation exhibited typical hyperbolic kinetics. The two compounds also mutually inhibited the metabolism of the other. Sixteen UGT1A1 substrates/inhibitors were evaluated as effectors of each reaction. Fourteen compounds inhibited both bilirubin and estradiol glucuronidation. However, two compounds (ethinylestradiol and daidzein) exhibited mixed effects (concentration-dependent activation and inhibition) on estradiol-3-glucuronidation, whereas bilirubin glucuronidation was inhibited by both compounds. In addition, 7-ethyl-10-hydroxycamptothecin, a substrate of UGT1A1 (reported Km = 24 μM) seemed to be a weak inhibitor of bilirubin glucuronidation (IC50 = 356.4 μM) but a partial inhibitor of estradiol-3-glucuronidation. The IC50 values of the inhibitors against estradiol-3-glucuronidation were strongly correlated with IC50 values against bilirubin glucuronidation, resulting in an R2 value of 0.9604 (activator excluded) or 0.8287 (activator included). Thus, estradiol-3-glucuronidation can serve as a good surrogate for predicting inhibition of bilirubin glucuronidation with the caveat that occasionally compounds may demonstrate

  3. The levels of bilirubin may be related to an inflammatory condition in patients with coronary heart disease.

    PubMed

    Greabu, M; Olinescu, R; Kummerow, F A; Crocnan, D O

    2001-01-01

    In agreement with previous reports, we found that the bilirubin level is significantly lower in the blood of patients with coronary heart disease (CHD) than in age and sex matched controls. However, we found that the level of bilirubin in the blood seemed to be an age-dependent phenomenon and closely related to the activation of leukocytes. In 1,000 cardiac catheterised patients from Urbana, USA suffering from CHD, the level of blood bilirubin was found to be lower than in age and sex-matched controls. The same results were obtained on 300 patients with acute ischemia from three hospitals from Bucharest, Romania. The activation of polymorphonuclear leukocytes increased in the catheterised patients, as well in Romanian patients. An activation of leukocytes triggered by a chronic inflammatory process may increase the lysis of erythrocytes. The erythrocytes of patients with 100% stenosis exhibited a higher rate of in vitro lysis in the presence of activated leukocytes and homocysteine. The increased hemolysis may trigger the activation and removal of the resulting bilirubin from blood. Such a mechanism may depend on the liver clearing function. This function was decreased in catheterized patients over 60 years of age, but had accelerated in younger patients. An individual variation in liver function may explain the widespread bilirubin levels in the blood of patients suffering from CHD.

  4. The Relationship between Serum Bilirubin and Elevated Fibrotic Indices among HBV Carriers: A Cross-Sectional Study of a Chinese Population

    PubMed Central

    Du, Min; Zhang, Shanshan; Xiao, Lin; Xu, Yanyan; Liu, Peiyi; Tang, Yuhan; Wei, Sheng; Xing, Mingyou; Miao, Xiaoping; Yao, Ping

    2016-01-01

    The study probed the association between bilirubin and hepatitis B virus (HBV) infection and progression. A cross-sectional analysis of 28,500 middle aged and elderly Chinese participants was performed to analyze the differences of bilirubin in terms of hepatitis B surface antigen (HBsAg) positive or negative and the correlation between bilirubin and severity of hepatic fibrosis estimated by non-invasive indices. Bilirubin was significantly higher in the HBsAg (+) group than the HBsAg (−) group. Higher bilirubin levels were consistently associated with elevated liver fibrosis indices among HBsAg carriers. Compared with quartile 1 of total bilirubin (TBil), the multivariable-adjusted ORs (95% CIs) for elevated fibrosis indices of quartile 4 were 2.24 (95% CIs, 1.57–3.21) estimated by fibrosis 4 score (FIB-4) and 2.22 (95% CIs, 1.60–3.08) estimated by aspartate transaminase to platelet ratio index (APRI). In addition, direct bilirubin (DBil) had a stronger association with elevated liver fibrosis indices than did indirect bilirubin (IBil). Furthermore, the relationship between DBil and elevated fibrosis indices was more robust among participants who were female, overweight or had central fat distribution. These findings suggested that bilirubin levels, especially DBil, were independently associated with an increased risk of increased fibrosis indices. PMID:27941693

  5. Effects of aluminum chloride on serum proteins, bilirubin, and hepatic trace elements in chickens.

    PubMed

    Wang, Ben; Zhu, Yanzhu; Zhang, Hongling; Liu, Liming; Li, Guojiang; Song, Yongli; Li, Yanfei

    2016-09-01

    The aim of this study was to reveal the effects of aluminum chloride (AlCl3) on the hepatic metabolism function and trace elements' distribution. Two hundred healthy male chickens (1 day old) were intraperitoneally administered with AlCl3 (0, 18.31, 27.47, and 36.62 mg kg(-1) day(-1) of Al(3+)) consecutively for 3 days. Then the chickens were allowed to rest for 1 day. The cycle lasted four days. The cycle was repeated 15 times (60 days). The contents of serum total protein (TP), albumin (ALB), total bilirubin (TBI), direct bilirubin (DBI), hepatic aluminum (Al), copper (Cu), iron (Fe), and zinc (Zn) were examined. The results showed that the contents of serum TP and ALB and hepatic Fe and Zn decreased and the contents of serum TBI and DBI and hepatic Al and Cu increased in the chickens with AlCl3 This indicates that chronic administration of AlCl3 impairs the hepatic metabolism function and disorders the hepatic trace elements' distribution. © The Author(s) 2015.

  6. Neonatal bilirubin levels and childhood asthma in the US Collaborative Perinatal Project, 1959-1965.

    PubMed

    Huang, Lisu; Bao, Yixiao; Xu, Zongli; Lei, Xiaoping; Chen, Yan; Zhang, Yongjun; Zhang, Jun

    2013-12-15

    Evidence shows that asthma originates in early life. Studies have found that phototherapy and/or neonatal jaundice may be associated with asthma. We investigated the association between neonatal bilirubin levels and childhood asthma without phototherapy intervention in the Collaborative Perinatal Project, a multicenter prospective cohort study conducted in the United States from 1959 to 1965. A total of 54,795 livebirths were included, and 40,063 children were followed up until 7 years of age or older. Total serum bilirubin (TSB) levels were examined at 48 hours postpartum in newborns with birthweights of 2,250 g or more. Information on asthma and other diseases through age 7 years was summarized and confirmed by a group of pediatricians and child neurologists. Among 28,807 term infants, the overall prevalence of asthma was 5.26%. Risks of asthma increased with both maximum TSB levels and TSB levels at 48 hours postpartum (P for trend < 0.01). Neonatal maximum TSB levels greater than 15 mg/dL were associated with a 61% increase in the risk of childhood asthma (odds ratio = 1.61, 95% confidence interval: 1.04, 2.08) after adjustment for confounders. In this prospective cohort study of infants born at a time when phototherapy was unavailable, neonatal hyperbilirubinemia was associated with an increased risk of childhood asthma.

  7. Photo-isomerization and oxidation of bilirubin in mammals is dependent on albumin binding.

    PubMed

    Goncharova, Iryna; Jašprová, Jana; Vítek, Libor; Urbanová, Marie

    2015-12-01

    The bilirubin (BR) photo-conversion in the human body is a protein-dependent process; an effective photo-isomerization of the potentially neurotoxic Z,Z-BR as well as its oxidation to biliverdin in the antioxidant redox cycle is possible only when BR is bound on serum albumin. We present a novel analytical concept in the study of linear tetrapyrroles metabolic processes based on an in-depth mapping of binding sites in the structure of human serum albumin (HSA). A combination of fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular modeling methods was used for recognition of the binding site for BR, its derivatives (mesobilirubin and bilirubin ditaurate), and the products of the photo-isomerization and oxidation (lumirubin, biliverdin, and xanthobilirubic acid) on HSA. The CD spectra and fluorescent quenching of the Trp-HSA were used to calculate the binding constants. The results of the CD displacement experiments performed with hemin were interpreted together with the findings of molecular docking performed on the pigment-HSA complexes. We estimated that Z,Z-BR and its metabolic products bind on two independent binding sites. Our findings support the existence of a reversible antioxidant redox cycle for BR and explain an additional pathway of the photo-isomerization process (increase of HSA binding capacity; the excess free [unbound] BR can be converted and also bound to HSA).

  8. CYP3A5*3 and bilirubin predict midazolam population pharmacokinetics in Asian cancer patients.

    PubMed

    Seng, Kok-Yong; Hee, Kim-Hor; Soon, Gaik Hong; Sapari, Nur Sabrina; Soong, Richie; Goh, Boon-Cher; Lee, Lawrence Soon-U

    2014-02-01

    We aim to evaluate the influence of covariates, including cytochrome P450 3A (CYP3A) genetic polymorphisms, on the pharmacokinetics of midazolam (MDZ) in Asian cancer patients, using a population pharmacokinetic approach. Pharmacokinetic data were obtained from 24 adult cancer patients who received an intravenous bolus dose of 1 mg MDZ as a CYP3A phenotyping probe, 1-day before starting FOLFIRI chemotherapy. Concentrations of MDZ and its major metabolites, 1'-hydroxymidazolam (1OHM) and 1'-hydroxymidazolam glucuronide (HMG) were measured using liquid chromatography/mass spectrometry. The population pharmacokinetic study was conducted using NONMEM. Demographics, clinical characteristics, and genetic polymorphisms were screened as covariates. A two-compartment model for MDZ and two sequential compartments representing 1OHM and HMG best described the data. The CYP3A5*3 and total bilirubin level significantly influenced MDZ clearance. The population typical MDZ clearance for CYP3A5*3 expressers was 22% lower than non-expressers. Baseline bodyweight was a statistically significant covariate for clearance and distribution volume of 1OHM. Creatinine clearance was positively correlated with HMG clearance. Our data indicate that CYP3A5*3, total bilirubin, bodyweight, and creatinine clearance are important predictors of MDZ and metabolite pharmacokinetics. Further studies in more patients are needed to explore the links between the identified covariates and the disposition of MDZ and its metabolites.

  9. Method for Estimating Bilirubin Isomerization Efficiency in Phototherapy to Treat Neonatal Jaundice

    NASA Astrophysics Data System (ADS)

    Lisenko, S. A.; Kugeiko, M. M.

    2014-11-01

    We propose a method for quantitative assessment of the efficacy of phototherapy to treat neonatal jaundice using the diffuse reflectance spectrum for the newborn's skin, based on the analytical dependence of the measured spectrum on the structural and morphological parameters of the skin, affecting the optical conditions in the medium, and an algorithm for rapid calculation of the bilirubin photoisomerization rate in the skin tissues as a function of the structural and morphological parameters of the skin and the wavelength of the exciting radiation. From the results of a numerical simulation of the process of radiation transport in the skin, we assess the stability of our method to variations in the scattering properties of the skin and the concentrations of its optically active chromophores (melanin, oxyhemoglobin, deoxyhemoglobin). We show that in order to achieve the maximum efficacy of phototherapy, we should use light from the range 484-496 nm. In this case, the intensity of the exciting radiation should be selected individually for each newborn according to the bilirubin photoisomerization rate characteristic for it.

  10. Profile of minocycline neuroprotection in bilirubin-induced auditory system dysfunction.

    PubMed

    Rice, Ann C; Chiou, Victoria L; Zuckoff, Sarah B; Shapiro, Steven M

    2011-01-12

    Excessive hyperbilirubinemia in human neonates can cause permanent dysfunction of the auditory system, as assessed with brainstem auditory evoked potentials (BAEPs). Jaundiced Gunn rat pups (jjs) exhibit similar BAEP abnormalities as hyperbilirubinemic neonates. Sulfadimethoxine (sulfa) administration to jjs, which displaces bilirubin from serum albumin into tissues including brain, exacerbates acute toxicity. Minocycline administered prior to sulfa in jjs protects against BAEP abnormalities. This study evaluates the neuroprotective capabilities of minocycline HCl (50 mg/kg) administered 30 or 120 min after sulfa (200 mg/kg) in 16 days old jjs. BAEPs are recorded at 6 or 24 h post-sulfa. Abnormal BAEP waves exhibit increased latency and decreased amplitude. The sulfa/saline treated jjs exhibited a significantly increased interwave interval between waves I and II (I-II IWI) and significantly decreased amplitudes of waves II and III compared to the saline/saline jjs. The minocycline 30 min post-sulfa (sulfa/mino+30) group was not significantly different from the saline/saline control group, indicating neuroprotection. The minocycline 120 min post-sulfa (sulfa/mino+120) group had a significantly decreased amplitude of wave III at both 6 and 24h. These studies indicate that minocycline has a graded neuroprotective effect when administered after acute bilirubin neurotoxicity.

  11. Amplifying the fluorescence of bilirubin enables the real-time detection of heme oxygenase activity.

    PubMed

    Klemz, Roman; Mashreghi, Mir-Farzin; Spies, Claudia; Volk, Hans-Dieter; Kotsch, Katja

    2009-01-15

    Heme oxygenases (HO) are the rate-limiting enzymes in the degradation of heme to equimolar amounts of antioxidant bile pigments, the signaling molecule carbon monoxide, and ferric iron. The inducible form HO-1 confers protection on cells and tissues that mediates beneficial effects in many diseases. Consequently, measurement of the enzymatic activity is vital in the investigation of the regulatory role of HO. Here we report that the fluorescence characteristics of bilirubin in complex with serum albumin can be used for the real-time detection of HO activity in enzymatic kinetics measurements. We characterized the enzymatic activity of a truncated human HO-1 and measured the HO activity for various cell types and organs, in either the basal naive or the HO-1-induced state. The bilirubin-dependent increase in fluorescence over time monitored by this assay facilitates a very fast, sensitive, and reliable measurement of HO activity. Our approach offers the basis for a highly sensitive high-throughput screening, which provides, inter alia, the opportunity to discover new therapeutic HO-1-inducing agents.

  12. A Thermostable Bilirubin-Oxidizing Enzyme from Activated Sludge Isolated by a Metagenomic Approach

    PubMed Central

    Kimura, Nobutada; Kamagata, Yoichi

    2016-01-01

    A gene coding for a multicopper oxidase (BopA) was identified through the screening of a metagenomic library constructed from wastewater treatment activated sludge. The recombinant BopA protein produced in Escherichia coli exhibited oxidation activity toward 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in the presence of copper, suggesting that BopA is laccase. A bioinformatic analysis of the bopA gene sequence indicated that it has a phylogenetically bacterial origin, possibly derived from a bacterium within the phylum Deinococcus-Thermus. Purified BopA exhibited maximum activity at pH 7.5 with bilirubin as its substrate and was found to be active over a markedly broad pH range from 6 to 11. It also showed notable thermostability; its activity remained intact even after a heat treatment at 90°C for 60 min. This enzyme is a thermostable-bilirubin oxidase that exhibits markedly higher thermostability than that previously reported for laccases. PMID:27885197

  13. Effects of Calcium Ions on Thermodynamic Properties of Mixed Bilirubin/Cholesterol Monolayers

    NASA Astrophysics Data System (ADS)

    Wu, Qiong; Tang, Yu-feng; Li, Ye-min; Xie, An-jian; Shen, Yu-hua; Zhu, Jin-miao; Li, Chuan-hao

    2008-04-01

    The mixed monolayer behavior of bilirubin/cholesterol was studied through surface pressure-area (π-A) isotherms on aqueous solutions containing various concentrations of calcium ions. Based on the data of π-A isotherms, the mean area per molecule, collapse pressure, surface compressibility modulus, excess molecular areas, free energy of mixing, and excess free energy of mixing of the monolayers on different subphases were calculated. The results show an expansion in the structure of the mixed monolayer with Ca2+ in subphase, and non-ideal mixing of the components at the air/water interface is observed with positive deviation from the additivity rule in the excess molecular areas. The miscibility between the components is weakened with the increase of concentration of Ca2+ in subphase. The facts indicate the presence of coordination between Ca2+ and the two components. The mixed monolayer, in which the molar ratio of bilirubin to cholesterol is 3:2, is more stable from a thermodynamic point of view on pure water. But the stable 3:2 stoichiometry complex is destroyed with the increase of the concentration of Ca2+ in subphase. Otherwise, the mixed monolayers have more thermodynamic stability at lower surface pressure on Ca2+ subphase.

  14. A Thermostable Bilirubin-Oxidizing Enzyme from Activated Sludge Isolated by a Metagenomic Approach.

    PubMed

    Kimura, Nobutada; Kamagata, Yoichi

    2016-12-23

    A gene coding for a multicopper oxidase (BopA) was identified through the screening of a metagenomic library constructed from wastewater treatment activated sludge. The recombinant BopA protein produced in Escherichia coli exhibited oxidation activity toward 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in the presence of copper, suggesting that BopA is laccase. A bioinformatic analysis of the bopA gene sequence indicated that it has a phylogenetically bacterial origin, possibly derived from a bacterium within the phylum Deinococcus-Thermus. Purified BopA exhibited maximum activity at pH 7.5 with bilirubin as its substrate and was found to be active over a markedly broad pH range from 6 to 11. It also showed notable thermostability; its activity remained intact even after a heat treatment at 90°C for 60 min. This enzyme is a thermostable-bilirubin oxidase that exhibits markedly higher thermostability than that previously reported for laccases.

  15. Derivatives of 1-naphthyl ethylenediamine dihydrochloride for standardization of direct-bilirubin assays done with the Technicon "SMAC".

    PubMed

    Furda, J; Morgenstern, S; Snyder, L R

    1976-07-01

    The Jendrassik--Groff assay for direct bilirubin was adapted for analysis rates of 150/h on the Technicon "SMAC" continuous-flow analyzer. This requires development of a standard that is compatible with the other 19 channels on this analyzer. N-1-Naphthyl ethylenediamine dihydrochloride has been used for standardization of direct bilirubin assays, but we found it to be unsuitable because values for potassium are falsely elevated when potassium is determined with a valinomycin ion-selective electrode. This interference can be eliminated by alkylating the aliphatic amine group in the standard. The resulting compounds undergo the coupling reaction in the same way as the original compound and function equally well as standards for the direct bilirubin reaction. The only limitation of these analogs is their decreased solubility at physiological pH in some cases. Thus only certain alkyl groups are suitable.

  16. Birth weight, length, head circumference and bilirubin level in Indian newborns in the Sioux Lookout Zone, northwestern Ontario.

    PubMed

    Munroe, M; Shah, C P; Badgley, R; Bain, H W

    1984-09-01

    The norms for birth weight, length, head circumference and bilirubin level for native newborns have not been available. To develop appropriate norms, data were obtained from the charts on all live births in the Sioux Lookout Zone, northwestern Ontario, in 1968-69 and 1974-77. These data were correlated to maternal age and parity as well as sex of the infant. Despite impoverished living conditions, the birth weights of the study population were significantly higher than the Canadian norms; length and head circumference, however, were not significantly different. Over one third of the infants had serum bilirubin levels greater than 12 mg/dL (205 mumol/L). Increased maternal age was associated with increased birth weight and length and a lower bilirubin level.

  17. Evaluation of bilirubin concentration in hemolysed samples, is it really impossible? The altitude-curve cartography approach to interfered assays.

    PubMed

    Brunori, Paola; Masi, Piergiorgio; Faggiani, Luigi; Villani, Luciano; Tronchin, Michele; Galli, Claudio; Laube, Clarissa; Leoni, Antonella; Demi, Maila; La Gioia, Antonio

    2011-04-11

    Neonatal jaundice might lead to severe clinical consequences. Measurement of bilirubin in samples is interfered by hemolysis. Over a method-depending cut-off value of measured hemolysis, bilirubin value is not accepted and a new sample is required for evaluation although this is not always possible, especially with newborns and cachectic oncological patients. When usage of different methods, less prone to interferences, is not feasible an alternative recovery method for analytical significance of rejected data might help clinicians to take appropriate decisions. We studied the effects of hemolysis over total bilirubin measurement, comparing hemolysis-interfered bilirubin measurement with the non-interfered value. Interference curves were extrapolated over a wide range of bilirubin (0-30 mg/mL) and hemolysis (H Index 0-1100). Interference "altitude" curves were calculated and plotted. A bimodal acceptance table was calculated. Non-interfered bilirubin of given samples was calculated, by linear interpolation between the nearest lower and upper interference curves. Rejection of interference-sensitive data from hemolysed samples for every method should be based not upon the interferent concentration but upon a more complex algorithm based upon the concentration-dependent bimodal interaction between the interfered analyte and the measured interferent. The altitude-curve cartography approach to interfered assays may help laboratories to build up their own method-dependent algorithm and to improve the trueness of their data by choosing a cut-off value different from the one (-10% interference) proposed by manufacturers. When re-sampling or an alternative method is not available the altitude-curve cartography approach might also represent an alternative recovery method for analytical significance of rejected data. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Evaluation of the diagnostic value of serum level of total bilirubin in patients with suspected acute appendicitis.

    PubMed

    Motie, Mohammad Reza; Nik, Minoosadat Mousavi; Gharaee, Malihe

    2017-04-01

    Clinical diagnosis of acute appendicitis still remains a problem. Delays in diagnosis of acute appendicitis may cause perforation and septic peritonitis which result in increasing morbidity and mortality. The aim of this study was to determine the sensitivity, specificity and the diagnostic value of total serum bilirubin levels as a predictor of acute appendicitis. In this cross-sectional study, patients who underwent appendectomy with the diagnosis of acute appendicitis from April 2012 to March 2013 at Emam Reza Hospital in Mashhad (Iran) were enrolled. Serum bilirubin-Total and Direct-, were measured. Then based on the final pathologic reports, patients were categorized into five groups of normal appendix, chronic inflammatory changes, acute appendicitis, gangrenous and/or necrotic changes, and perforated appendicitis. Independent sample t-test, ANOVA, and Chi-square test were used for data analysis by SPSS version 16. There were 174 patients studied, (117 male, 57 female) with a mean age of 27.15±0.7 years. All of the patients had rebound tenderness; 75.3% had nausea, 58.6% had anorexia and 21.3% had fever. The histological reports of all patients showed 76.4% acute appendicitis. Analyzing p-values for SGPT, SGOT, WBC was (p=0.903) and differential count was (p=0.959). The study showed no significant difference between the pathological groups. However, there were no significant differences in serum total bilirubin levels between the pathological groups. Total bilirubin showed sensitivity of 48% and specificity of 61% in the diagnosis of acute appendicitis. Total serum bilirubin more than 0.85 mg/dl was the cut-off value with the best performance for diagnosis of appendicitis. Bilirubin levels are reliable, sensitive and specific to diagnosis and a prediction of complicated appendicitis.

  19. Evaluation of the diagnostic value of serum level of total bilirubin in patients with suspected acute appendicitis

    PubMed Central

    Motie, Mohammad Reza; Nik, Minoosadat Mousavi; Gharaee, Malihe

    2017-01-01

    Introduction Clinical diagnosis of acute appendicitis still remains a problem. Delays in diagnosis of acute appendicitis may cause perforation and septic peritonitis which result in increasing morbidity and mortality. The aim of this study was to determine the sensitivity, specificity and the diagnostic value of total serum bilirubin levels as a predictor of acute appendicitis. Methods In this cross-sectional study, patients who underwent appendectomy with the diagnosis of acute appendicitis from April 2012 to March 2013 at Emam Reza Hospital in Mashhad (Iran) were enrolled. Serum bilirubin-Total and Direct-, were measured. Then based on the final pathologic reports, patients were categorized into five groups of normal appendix, chronic inflammatory changes, acute appendicitis, gangrenous and/or necrotic changes, and perforated appendicitis. Independent sample t-test, ANOVA, and Chi-square test were used for data analysis by SPSS version 16. Results There were 174 patients studied, (117 male, 57 female) with a mean age of 27.15±0.7 years. All of the patients had rebound tenderness; 75.3% had nausea, 58.6% had anorexia and 21.3% had fever. The histological reports of all patients showed 76.4% acute appendicitis. Analyzing p-values for SGPT, SGOT, WBC was (p=0.903) and differential count was (p=0.959). The study showed no significant difference between the pathological groups. However, there were no significant differences in serum total bilirubin levels between the pathological groups. Total bilirubin showed sensitivity of 48% and specificity of 61% in the diagnosis of acute appendicitis. Total serum bilirubin more than 0.85 mg/dl was the cut-off value with the best performance for diagnosis of appendicitis. Conclusion Bilirubin levels are reliable, sensitive and specific to diagnosis and a prediction of complicated appendicitis. PMID:28607634

  20. Grasping at ontological straws: overcoming reductionism in the Advaita Vedānta-Neuroscience dialogue.

    PubMed

    Kaplan, Stephen

    2009-01-01

    Contemporary neuropsychology reveals that the parietal lobe contains neurons that are specifically attuned to the act of grasping and this act may be fundamental to the establishment of the phenomenal boundaries between subject and object. Furthermore, alterations to this process, such as the hypoactivation of this region during meditation or the hyperactivation associated with schizophrenia, may eliminate or confuse, respectively, the phenomenal boundaries between subject and object. Traversing disciplines, the Advaita Vedānta school of Hinduism traces some of its key terms for subject and object to the verbal root grah, to grasp. The subject is literally the grasper. Furthermore, the practice of asparśa yoga, the yoga of no-touch, is aimed at stopping, hypoactivating, the grasping process in order to transcend all subject-object boundaries. This paper will argue that while we have not uncovered an identity of thought, we have uncovered a confluence of ideas between these two disciplines. We will see that this confluence of ideas has not pitted the believer against the critic-not forced us into the great reductionism debate that has dominated so much of the interchange between religious studies and the sciences. This case study will illuminate some of the methodological ways around this reductionism battle and also the boundaries of both disciplines for the intellectual benefit of each.

  1. The role of gamma-aminobutyric acid/glycinergic synaptic transmission in mediating bilirubin-induced hyperexcitation in developing auditory neurons.

    PubMed

    Yin, Xin-Lu; Liang, Min; Shi, Hai-Bo; Wang, Lu-Yang; Li, Chun-Yan; Yin, Shan-Kai

    2016-01-05

    Hyperbilirubinemia is a common clinical phenomenon observed in human newborns. A high level of bilirubin can result in severe jaundice and bilirubin encephalopathy. However, the cellular mechanisms underlying bilirubin excitotoxicity are unclear. Our previous studies showed the action of gamma-aminobutyric acid (GABA)/glycine switches from excitatory to inhibitory during development in the ventral cochlear nucleus (VCN), one of the most sensitive auditory nuclei to bilirubin toxicity. In the present study, we investigated the roles of GABAA/glycine receptors in the induction of bilirubin hyperexcitation in early developing neurons. Using the patch clamp technique, GABAA/glycine receptor-mediated spontaneous inhibitory synaptic currents (sIPSCs) were recorded from bushy and stellate cells in acute brainstem slices from young mice (postnatal day 2-6). Bilirubin significantly increased the frequency of sIPSCs, and this effect was prevented by pretreatments of slices with either fast or slow Ca(2+) chelators BAPTA-AM and EGTA-AM suggesting that bilirubin can increase the release of GABA/glycine via Ca(2+)-dependent mechanisms. Using cell-attached recording configuration, we found that antagonists of GABAA and glycine receptors strongly attenuated spontaneous spiking firings in P2-6 neurons but produced opposite effect in P15-19 neurons. Furthermore, these antagonists reversed bilirubin-evoked hyperexcitability in P2-6 neurons, indicating that excitatory action of GABA/glycinergic transmission specifically contribute to bilirubin-induced hyperexcitability in the early stage of development. Our results suggest that bilirubin-induced enhancement of presynaptic release GABA/Glycine via Ca(2+)-dependent mechanisms may play a critical role in mediating neuronal hyperexcitation associated with jaundice, implicating potential new strategies for predicting, preventing, and treating bilirubin neurotoxicity.

  2. Biliary and urinary excretion rates and serum concentration changes of four bilirubin photoproducts in Gunn rats during total darkness and low or high illumination.

    PubMed Central

    Onishi, S; Ogino, T; Yokoyama, T; Isobe, K; Itoh, S; Yamakawa, T; Hashimoto, T

    1984-01-01

    On cycled exposure of Gunn rats to total darkness and low and high illumination, biliary excretion rates of (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin increased up to approx. 10-fold from the mean basal values of 1.2 and 0.2 microgram/h to the mean maximum values of 25.2 and 4.2 micrograms/h respectively, and at the same time those of (EE)-bilirubin and (EE)-cyclobilirubin also increased, but at very much lower rates than those of the first-mentioned two. During the low illumination only (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin appeared in the urine; during the high illumination (EE)-bilirubin and (EE)-cyclobilirubin also appeared, showing a similar excretion pattern to that observed in the bile, but the total urinary excretion rates were lower than the total biliary excretion rates. The serum bilirubin concentrations fell gradually to lower values, accompanied by an increment in (EZ)- and (ZE)-bilirubin, but (EZ)-cyclobilirubin was not detected. It is concluded that during phototherapy the predominant pathway for the removal of bilirubin from the body in the Gunn rat is by biliary excretion of the geometric photoisomers (EZ)- and (ZE)-bilirubin, derived from Z----E isomerization, and the structural photoisomer (EZ)-cyclobilirubin, formed from intramolecular endo-vinyl cyclization. PMID:6477496

  3. Accurate and sensitive high-performance liquid chromatographic method for geometrical and structural photoisomers of bilirubin IX alpha using the relative molar absorptivity values.

    PubMed

    Itoh, S; Isobe, K; Onishi, S

    1999-07-02

    It has been reported that considerable differences exist between the relative molar absorptivity values of the geometrical and structural photoisomers of bilirubin. We have devised an accurate HPLC method for photoisomer quantification based on the following principle: the sum of both the integrated peak areas corrected by each factor for each photoisomer, and the integrated peak area of unchanged (ZZ)-bilirubin [(ZZ)-B] after an anaerobic photoirradiation, should be constant and equal to the integrated peak area of initial (ZZ)-bilirubin [(ZZ)-Bi] before photoirradiation. On this basis, the following equation can be used to determine each factor. [equation: see text] alpha, beta, gamma and delta represent the factors used to correct the integrated peak areas of individual bilirubin photoisomers, and they are arranged in the order of the formula. It was demonstrated that the relative 455 nm molar absorptivity values for (ZZ)-bilirubin and all its geometrical and structural photoisomers, i.e., (ZZ)-bilirubin, (ZE)-bilirubin (EZ)-bilirubin, (EZ)-cyclobilirubin (= lumirubin) and (EE)-cyclobilirubin in the HPLC eluent, are, respectively, 1.0, 0.81 (= alpha), 0.54 (= beta), 0.47 (= gamma) and 0.39 (= delta).

  4. Role of bilirubin as antioxidant in neonatal jaundice and effect of ethanolic extract of sweet lime peel on experimentally induced jaundice in rat.

    PubMed

    Nag, N; Halder, S; Chaudhuri, R; Adhikary, S; Mazumder, S

    2009-02-01

    Bilirubin above a threshold level is toxic to human system and is excreted in urinary and through gastrointestinal tract. The role of bilirubin as antioxidant is debatable. This paper aims at elucidating the role of bilirubin as an antioxidant in neonatal jaundice patients. It is observed that bilirubin up to 6 mg/dl in blood acts as an antioxidant and above 12.5 mg/dl is strongly prooxidant. Phototherapy is the accepted therapeutic management of neonatal jaundice and has been shown to enhance the oxidative stress. Approaches have been taken to formulate a herbal medication which will reduce bilirubin level in the neonates without inducing additional damages. The ethanolic extract of sweet lime peel, administered orally at a dose of 72 microg is found to reduce the oxidative stress in erythrocytes of phenylhydrazine-induced jaundiced rats treated with phototherapy.

  5. Ultrafast deactivation of bilirubin: dark intermediates and two-photon isomerization.

    PubMed

    Carreira-Blanco, Carlos; Singer, Patrick; Diller, Rolf; Luis Pérez Lustres, J

    2016-03-14

    Bilirubin is a neurotoxic product responsible for neonatal jaundice, which is generally treated by phototherapy. The photoreaction involves ultrafast internal conversion via an elusive intermediate and Z-E isomerization with minor yield (less than 3% in solution). The structure of the intermediate remains unclear. Here, the combination of UV-vis and mid-IR ultrafast transient absorption spectroscopy reports a comprehensive picture of the mechanism and provides essential structural information about the intermediate species. Thus, spectral dynamics during the earliest ps unveils a wavepacket travelling from the Franck-Condon region to the crossing point with a dark state. The latter shows a tighter molecular skeleton than the ground state and decays with 15 ps time constant. Remarkably, the relative contribution of a non-decaying component increases linearly with pump energy, suggesting that Z-E isomerization could also be triggered by two-photon excitation. Implications for the photochemistry of protein-bound open tetrapyrroles are discussed.

  6. Bilirubin, formed by activation of heme oxygenase-2, protects neurons against oxidative stress injury

    PubMed Central

    Doré, Sylvain; Takahashi, Masaaki; Ferris, Christopher D.; Hester, Lynda D.; Guastella, Daniel; Snyder, Solomon H.

    1999-01-01

    Heme oxygenase (HO) catalyzes the conversion of heme to carbon monoxide, iron, and biliverdin, which is immediately reduced to bilirubin (BR). Two HO active isozymes exist: HO1, an inducible heat shock protein, and HO2, which is constitutive and highly concentrated in neurons. We demonstrate a neuroprotective role for BR formed from HO2. Neurotoxicity elicited by hydrogen peroxide in hippocampal and cortical neuronal cultures is prevented by the phorbol ester, phorbol 12-myristate 13-acetate (PMA) via stimulation of protein kinase C. We observe phosphorylation of HO2 through the protein kinase C pathway with enhancement of HO2 catalytic activity and accumulation of BR in neuronal cultures. The neuroprotective effects of PMA are prevented by the HO inhibitor tin protoporphyrin IX and in cultures from mice with deletion of HO2 gene. Moreover, BR, an antioxidant, is neuroprotective at nanomolar concentrations. PMID:10051662

  7. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress.

    PubMed

    Muhsain, Siti Nur Fadzilah; Lang, Matti A; Abu-Bakar, A'edah

    2015-01-01

    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200mgpyrazole/kg/day for 3days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  8. Total bilirubin level may be a biomarker of nephropathy in type 2 diabetes mellitus

    PubMed Central

    Zhang, Dan; Zhu, Bo; Zhang, Wei; Wang, Wei; Guo, Dan; Yang, Ligang; Wang, Lu

    2017-01-01

    Abstract Recently, the number of the studies on the relationship between the total bilirubin level (TBL) and diabetic nephropathy (DN) is increasing, but their results were not consistent. Therefore, we performed a meta-analysis to analyze the relationship between TBL and the risk of DN. We searched 5 databases before October 31, 2016, and reviewed the reference list of relevant articles. The fixed or random-effects model was used to pool risk estimates. We conducted the dose–response meta-analysis to evaluate the relationship between TBL and the risk of DN. Our meta-analysis showed that TBL in the DN group was lower than that in diabetes without the kidney disease (NDN) group (standard mean difference [SMD]: −0.63, 95% CI: −0.80, −0.46). The result of each subgroup also showed that TBL in the DN group was lower than that in the NDN group. The result of meta-regression indicated that duration of diabetes mellitus might be the source of heterogeneity. Our meta-analysis also showed that there was a significant negative relationship between TBL and the risk of DN (OR: 0.86, 95%CI: 0.82, 0.90). The results of subgroup analysis were similar to those of SMD; no sources of heterogeneity were detected by meta-regression. Sensitivity analysis indicated that the results were robust. We observed a linear association between TBL and the risk of DN, and there was a negative dose–response association between TBL and the risk of DN. In conclusion, bilirubin may be used as a biomarker of DN. It helps early diagnosis and effective therapeutic strategies on DN. PMID:28072721

  9. The effect of UGT1A1 promoter polymorphism on bilirubin response to hydroxyurea therapy in hemoglobinopathies.

    PubMed

    Italia, Khushnooma Y; Jijina, Farah F; Jain, Dipty; Merchant, Rashid; Nadkarni, Anita H; Mukherjee, Malay; Ghosh, Kanjaksha; Colah, Roshan B

    2010-11-01

    Hydroxyurea is known to reduce ineffective erythropoiesis and thereby hemolysis leading to a reduction in bilirubin levels in patients with hemoglobinopathies. However, the effect of hydroxyurea on hyperbilirubinemia in relation to the UGT1A1 gene promoter polymorphism is not known in Indian patients with different hemoglobinopathies. We studied 112 patients (77 sickle cell anemia, 22 β-thalassemia intermedia and 13 HbE-β-thalassemia) who were on hydroxyurea therapy for 2 years for their response towards hyperbilirubinemia associated with UGT1A1 promoter polymorphism. The patients with (TA)(7)/(TA)(7) repeats had significantly higher serum bilirubin levels than those with (TA)(6)/(TA)(6) repeats in all the groups and the reduction in serum bilirubin after hydroxyurea therapy was still higher among patients with (TA)(7)/(TA)(7) repeats when compared with (TA)(6)/(TA)(6) repeats. Higher bilirubin levels were associated with the (TA)(7)/(TA)(7) sequence however they did not come down to normal levels after hydroxyurea therapy. Copyright © 2010. Published by Elsevier Inc.

  10. Unbound free fatty acids from preterm infants treated with intralipid decouples unbound from total bilirubin potentially making phototherapy ineffective.

    PubMed

    Hegyi, Thomas; Kathiravan, Suganya; Stahl, Gary E; Huber, Andrew H; Kleinfeld, Alan

    2013-01-01

    Extremely low birth weight (ELBW; <1,000 g) infants have poor outcomes, often compromised by bilirubin neurotoxicity. We measured unbound bilirubin (Bf) and unbound free fatty acid (FFAu) levels in 5 ELBW infants in a trial examining the effects of pharmacologic ductal closure on infants treated with Intralipid infusion (3 g/kg/day). The levels for all infants (mean ± SD) were: total serum bilirubin (TSB) 4.6 ± 1.7 mg/dl, FFAu 376 ± 496 nM, and Bf 42 ± 30 nM. Of the 3 infants who died, 2 had TSB <5.9 mg/dl but FFAu >580 nM and Bf >75 nM. Multiple regression revealed a major effect on Bf levels due to FFAu, indicating that Intralipid elevated levels of FFAu and Bf. Indomethacin or ibuprofen reduced Bf levels, most likely by reducing FFAu levels through lipase inhibition. Because displacement of Bf by FFAu decouples Bf from TSB, phototherapy may not reduce the risk of bilirubin or FFAu toxicity in Intralipid-treated ELBW infants.

  11. Inhibition of Human UGT1A1-Mediated Bilirubin Glucuronidation by Polyphenolic Acids Impact Safety of Popular Salvianolic Acid A/B-Containing Drugs and Herbal Products.

    PubMed

    Ma, Guo; Zhang, Ying; Chen, Wenyan; Tang, Zhifang; Xin, Xiaoming; Yang, Ping; Liu, Xiaoqin; Cai, Weimin; Hu, Ming

    2017-09-05

    Bilirubin-related adverse reactions (ADR, e.g., jaundice and hyperbilirubinemia) induced by herbs rich in certain polyphenolic acids are widely reported. However, the causes and the mechanisms underlying these ADR are not well understood. The purpose of this article is to determine the mechanism by which certain polyphenolic acids inhibit UGT1A1-mediated bilirubin glucuronidation, leading to jaundice or hyperbilirubinemia. We investigated in vitro inhibitory effects on bilirubin glucuronidation of salvianolic acid A (SAA), salvianolic acid B (SAB), danshensu (DSS), protocatechuic aldehyde (PA), and rosmarinic acid (RA), as well as two Salvia miltiorrhiza injections (DSI and CDI) rich in polyphenolic acids. The results showed that average formation rates of three bilirubin glucuronides displayed a significant difference (p < 0.05) and the formation of monoglucuronide was favored regardless if an inhibitor was present or not. SAA, SAB, DSI, and CDI, but not DSS, PA, and RA, significantly inhibited human UGT1A1-mediated bilirubin glucuronidation via a mixed-type inhibitory mechanism. Average IC50 values of SAA, SAB, DSI, and CDI-mediated inhibition of bilirubin glucuronidation were bilirubin concentration-dependent, and their values (against total bilirubin glucuronidation) were in the range 0.44 ± 0.02 to 0.86 ± 0.04 μg/mL (for SAA), 4.22 ± 0.30 to 12.50 ± 0.93 μg/mL (for SAB), 9.29 ± 0.76 to 18.82 ± 0.63 μg/mL (for DSI), and 9.18 ± 2.00 to 22.36 ± 1.39 μg/mL (for CDI), respectively. In conclusion, SAA and its analog SAB are the main ingredients responsible for inhibition of bilirubin glucuronidation by DSI and CDI, whose use is associated with many high bilirubin-related ADR.

  12. BILIRUBIN CONCENTRATIONS IN CLINICALLY HEALTHY AND DISEASED CAPTIVE WATERBUCK (KOBUS ELLIPSIPRYMNUS) AT THE SAN DIEGO ZOO SAFARI PARK.

    PubMed

    Sadler, Ryan A; Lamberski, Nadine; Christopher, Mary M

    2016-06-01

    Captive waterbuck ( Kobus ellipsiprymnus ) that appear clinically healthy have been noted to have high serum bilirubin concentrations compared with other ruminants; however, questions remain about the physiologic factors affecting bilirubin concentration and its potential association with underlying disease and icteric serum or mucous membranes. Serum bilirubin concentrations of healthy and diseased waterbuck housed at the San Diego Zoo Safari Park from 1989 to 2012 were retrospectively analyzed to determine any link between icteric serum, total bilirubin concentration (tBili), and disease entities in this species. Total bilirubin and direct (dBili) bilirubin concentrations and the prevalence of icteric serum were compared by subspecies, age group, and health status; associations with complete blood count and biochemical results and clinical diagnosis were assessed. No significant differences were found in tBili or dBili between Ellipsen (n = 32) and Defassa (n = 29) subspecies or in juveniles (n = 22) versus adults (n = 39). Clinically healthy waterbuck (n = 40) had significantly higher tBili (mean ± 2SD, 7.9 ± 1.2 mg/dl; P < 0.001) and dBili (3.7 ± 1.0 mg/dl; P < 0.001) than did diseased waterbuck (n = 21; tBili: 4.9 ± 2.56 mg/dl; dBili: 2.2 ± 0.8 mg/dl). No waterbuck had icteric tissues on physical examination. Twelve (19.7%) waterbuck (six healthy, six diseased) had icteric serum. Few minor correlations were seen between tBili or dBili and clinical, laboratory, or necropsy evidence of disease, though an inverse correlation between dBili and blood glucose was noted. Of the 40 healthy animals, reference intervals were calculated for tBili (5.5-10.3 mg/dl), dBili (1.7-5.7 mg/dl), and indirect bilirubin (2.2-6.2 mg/dl). These results suggest healthy waterbuck have relatively high tBili and dBili compared with related species. Icteric serum may be seen in up to 15% of healthy animals in the absence of icteric tissues.

  13. The diagnostic value of white cell count, C-reactive protein and bilirubin in acute appendicitis and its complications

    PubMed Central

    Parashar, D; Lin, R; Antonowicz, S; Wells, AD; Bajwa, FM; Krijgsman, B

    2013-01-01

    Introduction Inflammatory markers such as white cell count (WCC) and C-reactive protein (CRP) and, more recently, bilirubin have been used as adjuncts in the diagnosis of appendicitis. The aim of this study was to determine the diagnostic accuracy of the above markers in acute and perforated appendicitis as well as their value in excluding the condition. Methods A retrospective analysis of 1,169 appendicectomies was performed. Patients were grouped according to histological examination of appendicectomy specimens (normal appendix = NA, acute appendicitis = AA, perforated appendicitis = PA) and preoperative laboratory test results were correlated. Receiver operating characteristic (ROC) curve area analysis (area under the curve [AUC]) was performed to examine diagnostic accuracy. Results ROC analysis of all laboratory variables showed that no independent variable was diagnostic for AA. Good diagnostic accuracy was seen for AA when all variables were combined (WCC/CRP/bilirubin combined AUC: 0.8173). In PA, the median CRP level was significantly higher than that of AA (158mg/l vs 30mg, p<0.0001). CRP also showed the highest sensitivity (100%) and negative predictive value (100%) for PA. CRP had the highest diagnostic accuracy in PA (AUC: 0.9322) and this was increased when it was combined with WCC (AUC: 0.9388). Bilirubin added no diagnostic value in PA. Normal levels of WCC, CRP and bilirubin could not rule out appendicitis. Conclusions CRP provides the highest diagnostic accuracy for PA. Bilirubin did not provide any discriminatory value for AA and its complications. Normal inflammatory markers cannot exclude appendicitis, which remains a clinical diagnosis. PMID:23827295

  14. NAD+ Attenuates Bilirubin-Induced Hyperexcitation in the Ventral Cochlear Nucleus by Inhibiting Excitatory Neurotransmission and Neuronal Excitability

    PubMed Central

    Liang, Min; Yin, Xin-Lu; Wang, Lu-Yang; Yin, Wei-Hai; Song, Ning-Ying; Shi, Hai-Bo; Li, Chun-Yan; Yin, Shan-Kai

    2017-01-01

    Nicotinamide adenine dinucleotide (NAD+) is an important molecule with extensive biological functions in various cellular processes, including protection against cell injuries. However, little is known regarding the roles of NAD+ in neuronal excitation and excitotoxicity associated with many neurodegenerative disorders and diseases. Using patch-clamp recordings, we studied its potential effects on principal neurons in the ventral cochlear nucleus (VCN), which is particularly vulnerable to bilirubin excitotoxicity. We found that NAD+ effectively decreased the size of evoked excitatory postsynaptic currents (eEPSCs), increased paired-pulse ratio (PPR) and reversed the effect of bilirubin on eEPSCs, implicating its inhibitory effects on the presynaptic release probability (Pr). Moreover, NAD+ not only decreased the basal frequency of miniature EPSCs (mEPSCs), but also reversed bilirubin-induced increases in the frequency of mEPSCs without affecting their amplitude under either condition. Furthermore, we found that NAD+ decreased the frequency of spontaneous firing of VCN neurons as well as bilirubin-induced increases in firing frequency. Whole-cell current-clamp recordings showed that NAD+ could directly decrease the intrinsic excitability of VCN neurons in the presence of synaptic blockers, suggesting NAD+ exerts its actions in both presynaptic and postsynaptic loci. Consistent with these observations, we found that the latency of the first postsynaptic spike triggered by high-frequency train stimulation of presynaptic afferents (i.e., the auditory nerve) was prolonged by NAD+. These results collectively indicate that NAD+ suppresses presynaptic transmitter release and postsynaptic excitability, jointly weakening excitatory neurotransmission. Our findings provide a basis for the exploration of NAD+ for the prevention and treatment of bilirubin encephalopathy and excitotoxicity associated with other neurological disorders. PMID:28217084

  15. UGT1A1∗28 relationship with abnormal total bilirubin levels in chronic hepatitis C patients

    PubMed Central

    de Souza, Marcelo Moreira Tavares; Vaisberg, Victor Van; Abreu, Rodrigo Martins; Ferreira, Aline Siqueira; daSilvaFerreira, Camila; Nasser, Paulo Dominguez; Paschoale, Helena Scavone; Carrilho, Flair José; Ono, Suzane Kioko

    2017-01-01

    Abstract Gilbert syndrome (GS) is a frequent benign clinical condition, marked by intermittent unconjugated hyperbilirubinemia, mostly due to the polymorphism uridine diphosphate-glucuronosyltransferase 1A1∗28 (UGT1A1∗28). Hyperbilirubinemia has been reported in a GS patient undergoing hepatitis C treatment, and other UGT isoforms polymorphisms have been linked to worse outcomes in viral hepatitis. Yet, little is known to GS contributions’ to the liver disease scenario. Our aim was to assess UGT1A1 genotypes’ frequency in chronic hepatitis C (CHC) patients and correlate with total bilirubin (TB). This is a case–control study in a large tertiary medical center. Cases were CHC patients confirmed by hepatitis C virus (HCV)–polymerase chain reaction. Exclusion criteria were hepatitis B virus or human immunodeficiency virus (HIV) coinfection. Control were healthy blood donors. UGT1A1 promoter region gene genotyping was performed, and bilirubin serum levels were available for HCV patients. Genotypes and alleles frequencies were similar in case (n = 585; P = 0.101) and control groups (n = 313; P = 0.795). Total bilirubin increase was noticed according to thymine–adenine repeats in genotypes (P < 0.001), and the TB greater than 1 mg/dL group had more UGT1A1∗28 subjects than in the group with TB values <1 mg/dL (18.3 vs 5.3; P < 0.001). Bilirubin levels are linked to the studied polymorphisms, and this is the first time that these findings are reported in a chronic liver disease sample. Among patients with increased TB levels, the frequency of UGT1A1∗28 is higher than those with normal TB. Personalized care should be considered to GS, regarding either abnormal bilirubin levels or drug metabolism. PMID:28296739

  16. Serum Bilirubin and 6-min Walk Distance as Prognostic Predictors for Inoperable Chronic Thromboembolic Pulmonary Hypertension: A Prospective Cohort Study

    PubMed Central

    Gong, Juan-Ni; Zhai, Zhen-Guo; Yang, Yuan-Hua; Liu, Yan; Gu, Song; Kuang, Tu-Guang; Xie, Wan-Mu; Miao, Ran; Wang, Chen

    2015-01-01

    Background: Inoperable chronic thromboembolic pulmonary hypertension (CTEPH) is a severe clinical syndrome characterized by right cardiac failure and possibly subsequent liver dysfunction. However, whether serum markers of liver dysfunction can predict prognosis in inoperable CTEPH patients has not been determined. Our study aimed to evaluate the potential role of liver function markers (such as serum levels of transaminase, bilirubin, and gamma-glutamyl transpeptidase [GGT]) combined with 6-min walk test in the prediction of prognosis in patients with inoperable CTEPH. Methods: From June 2005 to May 2013, 77 consecutive patients with inoperable CTEPH without confounding co-morbidities were recruited for this prospective cohort study. Baseline clinical characteristics and 6-min walk distance (6MWD) results were collected. Serum biomarkers of liver function, including levels of aspartate aminotransferase, alanine aminotransferase, GGT, uric acid, and serum bilirubin, were also determined at enrollment. All-cause mortality was recorded during the follow-up period. Results: During the follow-up, 22 patients (29%) died. Cox regression analyses demonstrated that increased serum concentration of total bilirubin (hazard ratio [HR] = 7.755, P < 0.001), elevated N-terminal of the prohormone brain natriuretic peptide (HR = 1.001, P = 0.001), decreased 6MWD (HR = 0.990, P < 0.001), increased central venous pressure (HR = 1.074, P = 0.040), and higher pulmonary vascular resistance (HR = 1.001, P = 0.018) were associated with an increased risk of mortality. Serum concentrations of total bilirubin (HR = 4.755, P = 0.007) and 6MWD (HR = 0.994, P = 0.017) were independent prognostic predictors for CTEPH patients. Patients with hyperbilirubinemia (≥23.7 μmol/L) had markedly worse survival than those with normobilirubinemia. Conclusion: Elevated serum bilirubin and decreased 6MWD are potential predictors for poor prognosis in inoperable CTEPH. PMID:26612283

  17. Serum bilirubin levels and risk of type 2 diabetes: results from two independent cohorts in middle-aged and elderly Chinese.

    PubMed

    Wang, Jing; Li, Yaru; Han, Xu; Hu, Hua; Wang, Fei; Li, Xiulou; Yang, Kun; Yuan, Jing; Yao, Ping; Miao, Xiaoping; Wei, Sheng; Wang, Youjie; Cheng, Weihong; Liang, Yuan; Zhang, Xiaomin; Guo, Huan; Yang, Handong; Yuan, Jianmin; Koh, Woon-Puay; Hu, Frank B; Wu, Tangchun; Pan, An; He, Meian

    2017-02-06

    Serum bilirubin is a potent endogenous antioxidant and has been identified as cardiovascular risk in cohort studies, while the relation to type 2 diabetes (T2D) in the elderly remains unclear. We investigated both cross-sectional and prospective associations between serum bilirubin levels and T2D risk in the Dongfeng-Tongji (DFTJ) cohort, and replicated the prospective findings in a nested case-control study (509 cases and 509 controls) within the Singapore Chinese Health Study (SCHS). In the cross-sectional analysis of DFTJ cohort (15,575 participants with 2,532 diabetes cases), serum bilirubin levels (total, direct and indirect) increased in new on-set diabetes and decreased with the diabetic duration. In the longitudinal analysis of DFTJ cohort (772 incident diabetes cases during 4.5 years of follow-up among 12,530 diabetes-free participants at baseline), positive association was found between direct bilirubin and T2D risk comparing extreme quartiles, similar results were observed in the nested case-control study within SCHS. Total and indirect bilirubin levels were not significantly associated with T2D in either cohort. In conclusion, our findings do not support the protective association between serum bilirubin levels and incident T2D in the middle-aged and elderly adults; instead, direct bilirubin levels were associated with increased risk of T2D.

  18. Serum bilirubin levels and risk of type 2 diabetes: results from two independent cohorts in middle-aged and elderly Chinese

    PubMed Central

    Wang, Jing; Li, Yaru; Han, Xu; Hu, Hua; Wang, Fei; Li, Xiulou; Yang, Kun; Yuan, Jing; Yao, Ping; Miao, Xiaoping; Wei, Sheng; Wang, Youjie; Cheng, Weihong; Liang, Yuan; Zhang, Xiaomin; Guo, Huan; Yang, Handong; Yuan, Jianmin; Koh, Woon-Puay; Hu, Frank B.; Wu, Tangchun; Pan, An; He, Meian

    2017-01-01

    Serum bilirubin is a potent endogenous antioxidant and has been identified as cardiovascular risk in cohort studies, while the relation to type 2 diabetes (T2D) in the elderly remains unclear. We investigated both cross-sectional and prospective associations between serum bilirubin levels and T2D risk in the Dongfeng-Tongji (DFTJ) cohort, and replicated the prospective findings in a nested case-control study (509 cases and 509 controls) within the Singapore Chinese Health Study (SCHS). In the cross-sectional analysis of DFTJ cohort (15,575 participants with 2,532 diabetes cases), serum bilirubin levels (total, direct and indirect) increased in new on-set diabetes and decreased with the diabetic duration. In the longitudinal analysis of DFTJ cohort (772 incident diabetes cases during 4.5 years of follow-up among 12,530 diabetes-free participants at baseline), positive association was found between direct bilirubin and T2D risk comparing extreme quartiles, similar results were observed in the nested case-control study within SCHS. Total and indirect bilirubin levels were not significantly associated with T2D in either cohort. In conclusion, our findings do not support the protective association between serum bilirubin levels and incident T2D in the middle-aged and elderly adults; instead, direct bilirubin levels were associated with increased risk of T2D. PMID:28164994

  19. Studies on the genetic linkage of bilirubin and androsterone UDP-glucuronyltransferases by cross-breeding of two mutant rat strains.

    PubMed Central

    Nagai, F; Homma, H; Tanase, H; Matsui, M

    1988-01-01

    Gunn rats, which have defects in bilirubin and 4-nitrophenol UDP-glucuronyltransferases (GT), were crossed with LA Wistar rats with a defect in androsterone GT. The F1 hybrids showed normal GT activities towards androsterone, bilirubin and 4-nitrophenol, demonstrating that Gunn and LA ('low activity') Wistar rats inherit a homozygous dominant trait for androsterone GT and bilirubin GT respectively. The F2 progeny showed four different combinations of bilirubin and androsterone GT activities: defects in both GT activities, a single defect in bilirubin GT activity, a single defect in androsterone GT activity and two normal GT activities. They were segregated in the approximate ratio of 1:3:3:9, which is compatible with Mendel's Principle of Independent Assortment. These results provide evidence that androsterone GT and bilirubin GT are located on different chromosomes. In the F2 generation, defective bilirubin and 4-nitrophenol GT activities were not segregated, indicating that these two mutant genes are closely linked on the same chromosome. PMID:3138978

  20. A Novel Liquid Chromatography Tandem Mass Spectrometry Method for the Estimation of Bilirubin Glucuronides and its Application to In Vitro Enzyme Assays.

    PubMed

    Putluru, Siva P; Matta, Murali K; Ahire, Deepak; Subramanian, Murali; Sinz, Michael; Mandlekar, Sandhya

    2017-01-01

    Bilirubin is a toxic waste product of metabolism, eliminated mainly through UGT1A1 mediated conjugation to mono- and di-glucuronides. Due to the potentially low Km value of bilirubin glucuronidation, the quantitative sensitivity obtained with most UV/visible light detection methods are not sufficient to accurately calculate UGT1A1 enzyme kinetics at low bilirubin concentrations. In addition, bilirubin, as well as its metabolites, are unstable during sample preparation and bioanalysis. This necessitates the need for a rapid, sensitive and robust assay to measure bilirubin glucuronides. A robust LC-MS/MS method was developed to measure low levels of bilirubin glucuronides accurately from in vitro incubations, as well as stabilizing the analytes during sample preparation and analysis. The metabolites were quantified using a qualitative/quantitative approach utilizing UV to MS correction, thereby eliminating the need for synthetic standards. The method was sensitive enough to quantify mono- and di-glucuronides as low as 3 nM from in vitro incubations, and kinetic data was determined for total glucuronide formation. The Km and Vmax values for total bilirubin glucuronide formations were determined to be 0.05 ± 0.01 μM and 181.9 ± 5.3 pmol/min/mg-protein, respectively, in human recombinant UGT1A1, and 0.23 ± 0.05 μM and 875 ± 45 pmol/min/mg protein in human liver microsomes (HLM). We have developed a sensitive LC-MS/MS based method for the quantitation of bilirubin and its glucuronides from in vitro incubations. This method was successfully utilized to determine bilirubin glucuronidation kinetics in HLM and human rUGT1A1. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. Body fat percentage is a major determinant of total bilirubin independently of UGT1A1*28 polymorphism in young obese.

    PubMed

    Belo, Luís; Nascimento, Henrique; Kohlova, Michaela; Bronze-da-Rocha, Elsa; Fernandes, João; Costa, Elísio; Catarino, Cristina; Aires, Luísa; Mansilha, Helena Ferreira; Rocha-Pereira, Petronila; Quintanilha, Alexandre; Rêgo, Carla; Santos-Silva, Alice

    2014-01-01

    Bilirubin has potential antioxidant and anti-inflammatory properties. The UGT1A1*28 polymorphism (TA repeats in the promoter region) is a major determinant of bilirubin levels and recent evidence suggests that raised adiposity may also be a contributing factor. We aimed to study the interaction between UGT1A1 polymorphism, hematological and anthropometric variables with total bilirubin levels in young individuals. 350 obese (mean age of 11.6 years; 52% females) and 79 controls (mean age of 10.5 years; 59% females) were included. Total bilirubin and C-reactive protein (CRP) plasma levels, hemogram, anthropometric data and UGT1A1 polymorphism were determined. In a subgroup of 74 obese and 40 controls body composition was analyzed by dual-energy X-ray absorptiometry. The UGT1A1 genotype frequencies were 49.9%, 42.7% and 7.5% for 6/6, 6/7 and 7/7 genotypes, respectively. Patients with 7/7 genotype presented the highest total bilirubin levels, followed by 6/7 and 6/6 genotypes. Compared to controls, obese patients presented higher erythrocyte count, hematocrit, hemoglobin and CRP levels, but no differences in bilirubin or in UGT1A1 genotype distribution. Body fat percentage was inversely correlated with bilirubin in obese patients but not in controls. This inverse association was observed either in 6/7 or 6/6 genotype obese patients. UGT1A1 polymorphism and body fat percentage were the main factors affecting bilirubin levels within obese patients (linear regression analysis). In obese children and adolescents, body fat composition and UGT1A1 polymorphism are independent determinants of total bilirubin levels. Obese individuals with 6/6 UGT1A1 genotype and higher body fat mass may benefit from a closer clinical follow-up.

  2. Evaluation of genetic effect of NOS3 and G×E interaction on the variability of serum bilirubin in a Han Chinese population.

    PubMed

    Yao, Yingshui; Fang, Zhengmei; Yang, Song; Zhao, Hailong; Chen, Yanchun; Jin, Yuelong; Zhao, Xianghai; Zhu, Lijun; Tian, Yuanrui; Shen, Chong

    2017-08-08

    Bilirubin was shown to be related to the generation and functional exertion of endothelial nitric oxide synthase (eNOS) whilst the genetic effect of NOS3 on bilirubin variability was rarely reported. Herein we assessed the associations of three single nucleotide polymorphisms (SNPs) of NOS3 (rs4496877, rs1808593, and rs3918186) with bilirubin elevation in 2077 adults. The results showed that rs1808593 was significantly associated with bilirubin elevation, and odds ratios (ORs) of dominant model for the elevation of total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IDBIL) were 0.837, 0.821 and 0.754, respectively (P < 0.05 for all). Stratification analysis indicated that rs3918186 was significantly associated with the elevation of TBIL and IDBIL in the males, and ORs of dominant model were 1.505 and 1.440 with P < 0.05 for all. In the smoking group, significant associations of rs4496877, rs1808593, and rs3918186 with TBIL elevation were observed, and ORs of dominant model were 1.739, 0.758 and 1.626 (P < 0.05 for all). rs4496877 and rs3918186 were both associated with TBIL elevation in the drinking group, and ORs were 1.557 and 1.769 with P < 0.05 for all. In the ≥55 year-old group, rs4496877 and rs1808593 were significantly associated with DBIL and IDBIL elevations, and ORs were 1.340 and 0.790 (P < 0.05). Meanwhile, rs4496877, rs1808593, rs3918186, smoking, and drinking were shown to have a notable interaction effects on the TBIL elevation. Our findings supported that NOS3 harbors the genetic susceptibility to the bilirubin elevation. Age, gender, smoking, and drinking could be involved in the genetic modification of NOS3 on the bilirubin variability. Copyright © 2017. Published by Elsevier Inc.

  3. Body Fat Percentage Is a Major Determinant of Total Bilirubin Independently of UGT1A1*28 Polymorphism in Young Obese

    PubMed Central

    Kohlova, Michaela; Bronze-da-Rocha, Elsa; Fernandes, João; Costa, Elísio; Catarino, Cristina; Aires, Luísa; Mansilha, Helena Ferreira; Rocha-Pereira, Petronila; Quintanilha, Alexandre; Rêgo, Carla; Santos-Silva, Alice

    2014-01-01

    Objectives Bilirubin has potential antioxidant and anti-inflammatory properties. The UGT1A1*28 polymorphism (TA repeats in the promoter region) is a major determinant of bilirubin levels and recent evidence suggests that raised adiposity may also be a contributing factor. We aimed to study the interaction between UGT1A1 polymorphism, hematological and anthropometric variables with total bilirubin levels in young individuals. Methods 350 obese (mean age of 11.6 years; 52% females) and 79 controls (mean age of 10.5 years; 59% females) were included. Total bilirubin and C-reactive protein (CRP) plasma levels, hemogram, anthropometric data and UGT1A1 polymorphism were determined. In a subgroup of 74 obese and 40 controls body composition was analyzed by dual-energy X-ray absorptiometry. Results The UGT1A1 genotype frequencies were 49.9%, 42.7% and 7.5% for 6/6, 6/7 and 7/7 genotypes, respectively. Patients with 7/7 genotype presented the highest total bilirubin levels, followed by 6/7 and 6/6 genotypes. Compared to controls, obese patients presented higher erythrocyte count, hematocrit, hemoglobin and CRP levels, but no differences in bilirubin or in UGT1A1 genotype distribution. Body fat percentage was inversely correlated with bilirubin in obese patients but not in controls. This inverse association was observed either in 6/7 or 6/6 genotype obese patients. UGT1A1 polymorphism and body fat percentage were the main factors affecting bilirubin levels within obese patients (linear regression analysis). Conclusion In obese children and adolescents, body fat composition and UGT1A1 polymorphism are independent determinants of total bilirubin levels. Obese individuals with 6/6 UGT1A1 genotype and higher body fat mass may benefit from a closer clinical follow-up. PMID:24901842

  4. On the acid dissociation constants of bilirubin and biliverdin. pKa values from 13C NMR spectroscopy.

    PubMed

    Lightner, D A; Holmes, D L; McDonagh, A F

    1996-02-02

    Biliverdin and bilirubin are naturally-occurring tetrapyrrolic bile pigments containing two propionic acid side chains. These side chains, and their propensity for ionization, are critical in the biological disposition of the pigments. Surprisingly, accurate dissociation constants for the propionic acid groups of biliverdin are unknown, and a wide range of values, extending over some 4 orders of magnitude, has been suggested for the Ka values of the propionic acid groups of bilirubin in aqueous solutions. Recently, pKa values of 6.7-9.3 have been reported for bilirubin--values much greater than the value of approximately 5 typical of propionic acid groups. These curiously high values, currently being used to explain the biological transport and metabolism of bilirubin and related compounds, have been attributed to intramolecular hydrogen bonding. We have determined the pKa values of 99% 13C-enriched (13CO2H) [8(3),12(3)-13C2]mesobilirubin-XIII, alpha, the corresponding biliverdin, and several monopropionic model compounds by 13C NMR spectroscopy. This technique allows direct observation and quantitative measurement of the carboxylic acid and carboxylate anion carbon signals. Analysis of the variation of carboxyl 13C NMR chemical shift with pH gave rubin pKa values of 4.2 and 4.9 and verdin pKa values of 3.9 and 5.3 in aqueous buffers containing only a very small quantity (0.086 mol fraction) of dimethyl sulfoxide. When extrapolated to water, the pKa values are essentially unchanged. The data provide the first experimentally-determined pKa values for a biliverdin. They indicate that intramolecular hydrogen bonding has little effect on the acid dissociation of bilirubin and suggest that the equilibrium acidity of the bilirubin carboxylic acid groups is not abnormally high but similar to the thermodynamic acidity found in other carboxylic acids, as originally suggested by Overbeek et al. (Overbeek, J. T. G., Vink, C. L. J., and Deenstra, H. (1955) Recl. Trav. Chim

  5. An hour-specific nomogram for transcutaneous bilirubin values in term and late preterm Hispanic neonates.

    PubMed

    Engle, William D; Lai, Susanna; Ahmad, Naveed; Manning, M Denise; Jackson, Gregory L

    2009-06-01

    We sought to determine percentile values for hour-specific transcutaneous bilirubin (TcB) measurements in Hispanic neonates during the first 72 hours of age. Neonates with gestational age >or= 35 weeks and body weight >or= 2100 g were included. All neonates were screened with JM-103 TcB measurements at a minimum of every 24 hours by nursing personnel, and only TcB values obtained in Hispanic neonates with postnatal ages of 10 to 74 hours were analyzed. The 5th, 25th, 50th, 75th, and 95th percentile curves were determined. These data were compared with a previously published TcB nomogram predominantly composed of white, non-Hispanic neonates. A total of 3284 TcB values were measured in 2005 neonates. A nomogram was constructed for this exclusively Hispanic population, identifying the 5th, 25th, 50th, 75th, and 95th percentile curves. The 95th percentile values at 24, 48, and 72 hours were 7.6, 11.0, and 12.4 mg/dL, respectively. The comparison between our results and those of the previously published study indicated that small but consistent differences between the two study populations were apparent, with the Hispanic neonates having significantly higher TcB values at the majority of time points analyzed. These observations were made despite a higher proportion of neonates >or= 40 weeks' gestation ( p < 0.001) and a lower proportion exclusively breast-fed ( p < 0.001) in the Hispanic population versus those in the previous study. Although higher bilirubin levels for certain populations are well documented, such differences in Hispanic neonates have not been confirmed. A TcB nomogram for Hispanic neonates is presented as a tool that will aid the clinician in the management of jaundice for this population. Compared with the previous study, this report indicates that although differences were relatively small, significantly higher TcB values were observed in the Hispanic population.

  6. Bilirubin and amyloid-beta peptide induce cytochrome c release through mitochondrial membrane permeabilization.

    PubMed Central

    Rodrigues, C. M.; Solá, S.; Silva, R.; Brites, D.

    2000-01-01

    BACKGROUND: The pathogenesis of bilirubin encephalopathy and Alzheimer's disease appears to result from accumulation of unconjugated bilirubin (UCB) and amyloid-beta (Abeta) peptide, respectively, which may cause apoptosis. Permeabilization of the mitochondrial membrane, with release of intermembrane proteins, has been strongly implicated in cell death. Inhibition of the mitochondrial permeability is one pathway by which ursodeoxycholate (UDC) and tauroursodeoxycholate (TUDC) protect against apoptosis in hepatic and nonhepatic cells. In this study, we further characterize UCB- and Abeta-induced cytotoxicty in isolated neural cells, and investigate membrane perturbation during incubation of isolated mitochondria with both agents. In addition, we evaluate whether the anti-apoptotic drugs UDC and TUDC prevent any changes from occurring. MATERIALS AND METHODS: Primary rat neuron and astrocyte cultures were incubated with UCB or Abeta peptide, either alone or in the presence of UDC. Apoptosis was assessed by DNA fragmentation and nuclear morphological changes. Isolated mitochondria were treated with each toxic, either alone or in combination with UDC, TUDC, or cyclosporine A. Mitochondrial swelling was measured spectrophotometrically and cytochrome c protein levels determined by Western blot. RESULTS: Incubation of neural cells with both UCB and Abeta induced apoptosis (p < 0.01). Coincubation with UDC reduced apoptosis by > 50% (p < 0.05). Both toxins caused membrane permeabilization in isolated mitochondria (p < 0.001); whereas, pretreatment with UDC was protective (p < 0.05). TUDC was even more effective at preventing matrix swelling mediated by Abeta (p < 0.01). UDC and TUDC markedly reduced cytochrome c release associated with mitochondrial permeabilization induced by UCB and Abeta, respectively (p < 0.05). Moreover, cyclosporine A significantly inhibited mitochondrial swelling and cytochrome c efflux mediated by UCB (p < 0.05). CONCLUSION: UCB and Abeta peptide

  7. Effects of statin treatments and polymorphisms in UGT1A1 and SLCO1B1 on serum bilirubin levels in Chinese patients with hypercholesterolaemia.

    PubMed

    Hu, Miao; Tomlinson, Brian

    2012-08-01

    In vitro and animal studies showed that statins could increase bilirubin levels by activation of haem oxygenase-1, whereas the effect of statins on serum bilirubin levels in humans remains controversial. The organic anion transporting polypeptide 1B1 (OATP1B1, gene SLCO1B1) and UDP-glucuronosyltransferase 1A1 (UGT1A1) play an important role in the disposition of bilirubin. This study investigated 1) whether common polymorphisms in UGT1A1 and SLCO1B1 influence bilirubin levels; 2) whether statin treatments affect bilirubin levels; and 3) whether the polymorphisms examined influence the drug effect. Associations between common polymorphisms in UGT1A1 and SLCO1B1 and the serum bilirubin levels on no lipid-lowering treatment were analyzed in 379 Chinese patients with hypercholesterolaemia. Effects of simvastatin 40 mg daily and rosuvastatin 10 mg daily on the bilirubin levels were compared in 236 subjects with good compliance to both statins. The UGT1A1 polymorphisms associated with reduced enzyme activity were significantly associated with increased baseline bilirubin levels. The bilirubin levels were increased from a geometric mean (95% CI) of 10.9 (10.3-11.4) μmol/L at baseline to 11.6 (11.1-12.0) μmol/L with rosuvastatin and 12.5 (11.9-13.0) μmol/L with simvastatin and the increase was greater with simvastatin (P < 0.001). There was no relationship between polymorphisms in UGT1A1 or SLCO1B1 and changes in bilirubin levels with the two statins. This study showed that the polymorphisms in UGT1A1, but not SLCO1B1, were associated with serum bilirubin levels in Chinese patients. Statins increased bilirubin levels and this effect was independent of the polymorphisms in UGT1A1 and SLCO1B1. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Breast milk jaundice: an in vitro study of the effect of free fatty acids on the bilirubin-serum albumin complex.

    PubMed

    Yong, F C; Cheah, S S

    1977-08-01

    Oleic and palmitic acids at concentrations above 1.1 mg percent (40 micrometer) are capable of displacing bilirubin from the serum albumin-bilirubin conjugates. The release of bilirubin is also demonstrated by thin layer gel chromatography. Since both oleate and palmitate constitute the major fatty acids in breast milk, the results may indicate that the development of jaundice in breast-fed infants could result at least in part from elevated levels of free fatty acids present in the blood serum of these neonates.

  9. Training healthcare personnel for mass-casualty incidents in a virtual emergency department: VED II.

    PubMed

    Heinrichs, Wm Leroy; Youngblood, Patricia; Harter, Phillip; Kusumoto, Laura; Dev, Parvati

    2010-01-01

    Training emergency personnel on the clinical management of a mass-casualty incident (MCI) with prior chemical, biological, radioactive, nuclear, or explosives (CBRNE) -exposed patients is a component of hospital preparedness procedures. The objective of this research was to determine whether a Virtual Emergency Department (VED), designed after the Stanford University Medical Center's Emergency Department (ED) and populated with 10 virtual patient victims who suffered from a dirty bomb blast (radiological) and 10 who suffered from exposure to a nerve toxin (chemical), is an effective clinical environment for training ED physicians and nurses for such MCIs. Ten physicians with an average of four years of post-training experience, and 12 nurses with an average of 9.5 years of post-graduate experience at Stanford University Medical Center and San Mateo County Medical Center participated in this IRB-approved study. All individuals were provided electronic information about the clinical features of patients exposed to a nerve toxin or radioactive blast before the study date and an orientation to the "game" interface, including an opportunity to practice using it immediately prior to the study. An exit questionnaire was conducted using a Likert Scale test instrument. Among these 22 trainees, two-thirds of whom had prior Code Triage (multiple casualty incident) training, and one-half had prior CBRNE training, about two-thirds felt immersed in the virtual world much or all of the time. Prior to the training, only four trainees (18%) were confident about managing CBRNE MCIs. After the training, 19 (86%) felt either "confident" or "very confident", with 13 (59%) attributing this change to practicing in the virtual ED. Twenty-one (95%) of the trainees reported that the scenarios were useful for improving healthcare team skills training, the primary objective for creating them. Eighteen trainees (82%) believed that the cases also were instructive in learning about clinical

  10. Decolorization and biodegradation of remazol brilliant blue R by bilirubin oxidase.

    PubMed

    Liu, Youxun; Huang, Juan; Zhang, Xiaoyu

    2009-12-01

    The dye-decolorizing potential of bilirubin oxidase (BOX) was demonstrated for an anthraquinone dye, remazol brilliant blue R (RBBR). The dye was decolorized 40% within 4 h by the BOX alone, whereas it was more efficient in the presence of 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), showing 91.5% decolorization within 25 min. The effects of operational parameters on decolorization were examined. The results showed that the decolorization efficiency decreased with increasing RBBR concentration, and a marked inhibition effect was exhibited when the dye concentrations were above 100 mg l(-1). The optimum temperature for enzymatic decolorization was 40 degrees C. BOX showed efficient decolorization of the dye with a wide pH range of 5-8.5. The maximum decolorization activity occurred at pH 8 with ABTS and at pH 5 without ABTS. Analysis of RBBR ultraviolet and visible (UV-VIS) spectra after BOX treatment indicated that the decolorization of RBBR was due to biodegradation. Our results suggested that ABTS can serve as an electron mediator to facilitate the oxidation of RBBR, and the BOX-ABTS mediator-involved dye decolorization mechanism was similar to that of laccase. Operation over a wide range of pH and efficient decolorization suggested that the BOX can be used to decolorize synthetic dyes from effluents, especially for anthraquinonic dyes.

  11. Bromophenol blue binding to mammalian albumins and displacement of albumin-bound bilirubin.

    PubMed

    Kim, B Boon; Abdul Kadir, H; Tayyab, S

    2008-10-15

    Interaction of bromophenol blue (BPB) with serum albumins from different mammalian species, namely, human (HSA), bovine (BSA), goat (GSA), sheep (SSA), rabbit (RbSA), porcine (PSA) and dog (DSA) was studied using absorption and absorption difference spectroscopy. BPB-albumin complexes showed significant differences in the spectral characteristics, i.e., extent of bathochromic shift and hypochromism relative to the spectral features of free BPB. Absorption difference spectra of these complexes also showed variations in the position of maxima and absorption difference (deltaAbs.) values. Absorption difference spectra of different bilirubin (BR)-albumin complexes showed a significant blue shift accompanied by decrease in deltaAbs. values in presence of BPB which were indicative of the displacement of bound BR from its binding site in BR-albumin complexes. These changes in the difference spectral characteristics of BR-albumin complexes were more marked at higher BPB concentration. However, the extent of these changes was different for different BR-albumin complexes. Taken together, all these results suggest that BPB partially shares BR binding site on albumin and different mammalian albumins show differences in the microenvironment of the BR/BPB binding site.

  12. Analysis of binding ability of two tetramethylpyridylporphyrins to albumin and its complex with bilirubin

    NASA Astrophysics Data System (ADS)

    Solomonov, Alexey V.; Shipitsyna, Maria K.; Vashurin, Arthur S.; Rumyantsev, Evgeniy V.; Timin, Alexander S.; Ivanov, Sergey P.

    2016-11-01

    An interaction between 5,10,15,20-tetrakis-(N-methyl-x-pyridyl)porphyrins, x = 2; 4 (TMPyPs) with bovine serum albumin (BSA) and its bilirubin (BR) complex was investigated by UV-Viz and fluorescence spectroscopy under imitated physiological conditions involving molecular docking studies. The parameters of forming intermolecular complexes (binding constants, quenching rate constants, quenching sphere radius etc.) were determined. It was showed that the interaction between proteins and TMPyPs occurs via static quenching of protein fluorescence and has predominantly hydrophobic and electrostatic character. It was revealed that obtained complexes are relatively stable, but in the case of TMPyP4 binding with proteins occurs better than TMPyP2. Nevertheless, both TMPyPs have better binding ability with free protein compared to BRBSA at the same time. The influence of TMPyPs on the conformational changes in protein molecules was studied using synchronous fluorescence spectroscopy. It was found that there is no competition of BR with TMPyPs for binging sites on protein molecule and BR displacement does not occur. Molecular docking calculations have showed that TMPyPs can bind with albumin via tryptophan residue in the hydrophilic binding site of protein molecule but it is not one possible interaction way.

  13. Prognostic significance of increased serum bilirubin levels coincident with cardiac decompensation in chronic heart failure.

    PubMed

    Shinagawa, Hisahito; Inomata, Takayuki; Koitabashi, Toshimi; Nakano, Hironari; Takeuchi, Ichiro; Naruke, Takashi; Ohsaka, Tsutomu; Nishii, Mototsugu; Takehana, Hitoshi; Izumi, Tohru

    2008-03-01

    The aim of this study was to analyze the relationship between abnormal liver function tests (LFTs) coincident with heart failure (HF) exacerbation and subsequent long-term outcome in patients with chronic HF. The study population consisted of 183 consecutive patients admitted for HF exacerbation with left ventricular ejection fraction < or =40%. Cox proportional hazard analysis revealed that serum total bilirubin (T-Bil) levels on admission (hazard ratio 1.896, p<0.001, 95% confidence interval 1.323-2.717), but not T-Bil at discharge or other LFTs, was an independent predictor of subsequent cardiac events after hospital discharge (cardiac death or readmission for HF exacerbation) The cardiac-event-free rates significantly decreased according to increasing tertiles of T-Bil stratified by the level of 0.7 and 1.2 mg/dl (p<0.001). T-Bil on admission had significant correlations with simultaneously-measured central venous pressure (CVP) (r=0.42, p<0.01) and cardiac index (CI) (r= -0.50, p<0.01). The patients demonstrating high CVP together with low CI showed significantly increased T-Bil compared with any other group. Increased T-Bil coincident with cardiac decompensation predicts a worse long-term prognosis of CHF, presumably through the potential liability to both congestion and tissue hypoperfusion simultaneously when HF deteriorates.

  14. Cross-Sectional and Longitudinal Associations between Serum Bilirubin and Prediabetes in a Health Screening Population.

    PubMed

    Oda, Eiji

    2016-06-01

    Longitudinal associations between total bilirubin (TB) and prediabetes have not been reported. This study investigated cross-sectional and longitudinal associations between TB and prediabetes. Cross-sectional associations between TB and prediabetes were investigated in 3681 nondiabetic subjects. Longitudinal associations between TB and prediabetes over 6 years were investigated in 2149 subjects who were normoglycemic at baseline. Prediabetes was defined as fasting plasma glucose (FPG) levels of ≥5.6 mmol/L or glycated hemoglobin levels of ≥5.7% excluding diabetes. The prevalence of prediabetes was 25.4%, and the cumulative incidence of prediabetes during 6 years was 25.5% in a Japanese health screening population. Prevalent prediabetes was significantly associated with the quintiles of TB in nonsmoking men (trend, p<0.001) and women (trend, p=0.012), but not in smoking men (trend, p=0.689). Incident prediabetes was not significantly associated with the quintiles of TB, while it was positively associated with 1 standard deviation increase in TB in nonsmoking men (hazard ratio [95% confidence interval]; 1.21 [1.07 to 1.37], p=0.002). TB levels were significantly inversely associated with prevalent prediabetes in nonsmokers, but not in smokers, whereas an inverse association between TB levels and incident prediabetes seemed to be unlikely. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  15. Characterization of erythrosine B binding to bovine serum albumin and bilirubin displacement.

    PubMed

    Mathavan, Vinodaran M K; Boh, Boon Kim; Tayyab, Saad

    2009-08-01

    The interaction of crythrosine B (ErB), a commonly used dye for coloring foods and drinks, with bovine scrum albumin (BSA) was investigated both in the absence and presence of bilirubin (BR) using absorption and absorption difference spectroscopy. ErB binding to BSA was reflected from a significant red shift of 11 nm in the absorption maximum of ErB (527 nm) with the change in absorbance at lamdamax. Analysis of absorption difference spectroscopic titration results of BSA with increasing concentrations of ErB3 using Benesi-Hildebrand equation gave the association constant, K as 6.9 x 10(4) M(-1). BR displacing action of ErB was revealed by a significant blue shift in the absorption maximum, accompanied by a decrease in absorbance difference at lamdamax in the difference spectrum of BR-BSA complex upon addition of increasing concentrations of ErB. This was further substantiated by fluorescence spectroscopy, as addition of increasing concentrations of ErB to BR-BSA complex caused a significant decrease in fluoresccnce at 510 nm. The results suggest that ErB binds to a site in the vicinity of BR binding site on BSA. Therefore, intake of ErB may increase the risk of hyperbilirubinemia in the healthy subjects.

  16. Lack of utility of measuring serum bilirubin concentration in distinguishing perforation status of pediatric appendicitis.

    PubMed

    Bonadio, William; Bruno, Santina; Attaway, David; Dharmar, Logesh; Tam, Derek; Homel, Peter

    2017-06-01

    Pediatric appendicitis is a common, potentially serious condition. Determining perforation status is crucial to planning effective management. Determine the efficacy of serum total bilirubin concentration [STBC] in distinguishing perforation status in children with appendicitis. Retrospective review of 257 cases of appendicitis who received abdominal CT scan and measurement of STBC. There were 109 with perforation vs 148 without perforation. Although elevated STBC was significantly more common in those with [36%] vs without perforation [22%], the mean difference in elevated values between groups [0.1mg/dL] was clinically insignificant. Higher degrees of hyperbilirubinemia [>2mg/dL] were rarely encountered [5%]. Predictive values for elevated STBC in distinguishing perforation outcome were imprecise [sensitivity 38.5%, specificity 78.4%, PPV 56.8%, NPV 63.4%]. ROC curve analysis of multiple clinical and other laboratory factors for predicting perforation status was unenhanced by adding the STBC variable. Specific analysis of those with perforated appendicitis and percutaneously-drained intra-abdominal abscess which was culture-positive for Escherichia coli showed an identical rate of STBC elevation compared to all with perforation. The routine measurement of STBC does not accurately distinguish perforation status in children with appendicitis, nor discern infecting organism in those with perforation and intra-abdominal abscess. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Alteration in bilirubin excretion in individuals chronically exposed to arsenic in Mexico.

    PubMed

    Hernández-Zavala, A; Del Razo, L M; Aguilar, C; García-Vargas, G G; Borja, V H; Cebrián, M E

    1998-10-15

    We have studied hepatic function in individuals chronically exposed to arsenic (As) via drinking water in Region Lagunera, Mexico. We studied 51 individuals living in three villages exposed to As in water. Nazareno (0.014 mgAs/l), Santa Ana (0.1 mgAs/l) and Benito Juárez (0.3 mgAs/l). We determined the serum activity of aspartate aminotransferase (SAT) and alanine aminotransferase (ALT) as indicators of hepatocellular injury and that of gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) as indicators of cholestasic injury. Serum bilirubin was used as an indicator of organic conjugated anion transport. Total proteins, albumin and globulin fraction in serum were used as indicators of biosynthetic liver capacity. The main findings of this study were the predominantly conjugated hyperbilirubinemia and increased serum ALP activity which were related to the concentration of total arsenic (TAs) in urine, suggesting the presence of cholestasis in As-exposed individuals. No significant changes were observed in the other parameters studied.

  18. Bilirubin oxidation end products directly alter K+ channels important in the regulation of vascular tone.

    PubMed

    Hou, Shangwei; Xu, Rong; Clark, Joseph F; Wurster, William L; Heinemann, Stefan H; Hoshi, Toshinori

    2011-01-01

    The exact etiology of delayed cerebral vasospasm following cerebral hemorrhage is not clear, but a family of compounds termed 'bilirubin oxidation end products (BOXes)' derived from heme has been implicated. As proper regulation of vascular smooth muscle tone involves large-conductance Ca(2+)- and voltage-dependent Slo1 K(+) (BK, maxiK, K(Ca)1.1) channels, we examined whether BOXes altered functional properties of the channel. Electrophysiological measurements of Slo1 channels heterologously expressed in a human cell line and of native mouse BK channels in isolated cerebral myocytes showed that BOXes markedly diminished open probability. Biophysically, BOXes specifically stabilized the conformations of the channel with its ion conduction gate closed. The results of chemical amino-acid modifications and molecular mutagenesis together suggest that two specific lysine residues in the structural element linking the transmembrane ion-permeation domain to the carboxyl cytosolic domain of the Slo1 channel are critical in determining the sensitivity of the channel to BOXes. Inhibition of Slo1 BK channels by BOXes may contribute to the development of delayed cerebral vasospasm following brain hemorrhage.

  19. Bilirubin oxidation end products directly alter K+ channels important in the regulation of vascular tone

    PubMed Central

    Hou, Shangwei; Xu, Rong; Clark, Joseph F; Wurster, William L; Heinemann, Stefan H; Hoshi, Toshinori

    2011-01-01

    The exact etiology of delayed cerebral vasospasm following cerebral hemorrhage is not clear, but a family of compounds termed ‘bilirubin oxidation end products (BOXes)' derived from heme has been implicated. As proper regulation of vascular smooth muscle tone involves large-conductance Ca2+- and voltage-dependent Slo1 K+ (BK, maxiK, KCa1.1) channels, we examined whether BOXes altered functional properties of the channel. Electrophysiological measurements of Slo1 channels heterologously expressed in a human cell line and of native mouse BK channels in isolated cerebral myocytes showed that BOXes markedly diminished open probability. Biophysically, BOXes specifically stabilized the conformations of the channel with its ion conduction gate closed. The results of chemical amino-acid modifications and molecular mutagenesis together suggest that two specific lysine residues in the structural element linking the transmembrane ion-permeation domain to the carboxyl cytosolic domain of the Slo1 channel are critical in determining the sensitivity of the channel to BOXes. Inhibition of Slo1 BK channels by BOXes may contribute to the development of delayed cerebral vasospasm following brain hemorrhage. PMID:20424637

  20. Differential impact of serum total bilirubin level on cerebral atherosclerosis and cerebral small vessel disease

    PubMed Central

    Kim, Jonguk; Yoon, Seung-Jae; Woo, Min-Hee; Kim, Sang-Heum; Kim, Nam-Keun; Kim, Jinkwon; Kim, OK-Joon; Oh, Seung-Hun

    2017-01-01

    Background A low serum total bilirubin (T-bil) level is associated with an increased risk of atherosclerosis. However, the differential impact of the serum T-bil level on cerebral atherosclerosis and cerebral small vessel disease (SVD) is still unclear. Methods We evaluated serum T-bil levels from 1,128 neurologically healthy subjects. Indices of cerebral atherosclerosis (extracranial arterial stenosis [ECAS] and intracranial arterial stenosis [ICAS]), and indices of SVD (silent lacunar infarct [SLI], and moderate-to-severe white matter hyperintensities [msWMH]) were evaluated by the use of brain magnetic resonance imaging (MRI) and MR angiography. Results In logistic regression analysis after adjusting for confounding variables, subjects within middle T-bil (odds ratio [OR]: 0.63; 95% CI: 0.41–0.97) and high T-bil tertiles (OR: 0.54; 95% CI: 0.33–0.86) showed a lower prevalence of ECAS than those in a low T-bil tertile. Although subjects with a high T-bil tertile had a lower prevalence of ICAS than those with a low T-bil tertile, the statistical significance was marginal after adjusting for confounding variables. There were no significant differences in the proportions of subjects with SLI and msWMH across serum T-bil tertile groups. Conclusions The serum T-bil level is negatively associated with cerebral atherosclerosis, especially extracranial atherosclerosis, but not with SVD. PMID:28319156

  1. Excessive bilirubin elevation in a patient with hereditary spherocytosis and intrahepatic cholestasis.

    PubMed

    Wree, A; Canbay, A; Müller-Beissenhirtz, H; Dechêne, A; Gerken, G; Dührsen, U; Lammert, F; Nückel, H

    2011-08-01

    Hereditary spherocytosis is a common hemolytic anemia with an estimated incidence of 1 / 2500 births. It is caused by a molecular defect in one or more of the proteins of the red blood cell cytoskeleton. Mutations in the ABCB11 gene, encoding the bile salt export pump, can entail progressive familial intrahepatic cholestasis and benign recurred intrahepatic cholestasis. A 18 year old Turkish patient with hereditary spherocytosis was admitted to hospital with pruritus and severe jaundice. Ultrasound examination presented stones in gallbladder and bile duct. After endoscopic retrograde cholangiography with extraction of small bile duct stones abdominal pain resolved and liver enzymes normalized within a few days, but bilirubin and bile acids remained highly elevated. Liver biopsy revealed a severe canalicular cholestasis. Genetic analysis showed the compound heterozygous variants ABCB11 A 444V and 3084A > G. Treatment with ursodesoxycholic acid and intermittent therapy with prednisone reduced pruritus and jaundice with concomitant improvement of blood test. Here we report the first case of a patient with combined hereditary spherocytosis and compound heterozygous ABCB11 gene variants predisposing to intrahepatic cholestasis. Therefore, patients with hemolytic disorders should be investigated for bile acid transporter diseases in case of hyperbilirubinemia and severe cholestasis.

  2. Rethinking the immune properties of bilirubin in viral hepatitis: from bench to bedside

    PubMed Central

    Corral-Jara, Karla F; Trujillo-Ochoa, Jorge L; Realpe, Mauricio; Panduro, Arturo; Roman, Sonia; Fierro, Nora A

    2015-01-01

    Communication between the immune system and metabolic components can be exemplified by the process of heme catabolism. The immunomodulatory functions of the enzymes, substrates and active products related to catabolism of the heme group have been extensively studied. Bilirubin (BR), the final breakdown product of heme, is primarily considered to be a toxic waste product but has recently been considered to be an immunomodulatory metabolite. Through mechanisms that include intracellular signaling and transcriptional control, BR affects those immune cell functions that regulate cell proliferation, differentiation and apoptosis. During the pathogenesis of viral hepatitis, the heme degradation pathway is disrupted, resulting in changes to normal BR concentrations. These alterations have been previously studied mainly as a consequence of the infection. However, little is known about the potential immunomodulatory role played by BR in the development of infectious hepatocellular diseases. Differences in BR levels in the context of viral hepatitis are likely to provide important insights into the metabolite-mediated mechanisms controlling the immune responses underlying both the long-term persistence of hepatitis C virus (HCV) infection and the resolution of hepatitis A virus (HAV) infection during the acute phase. In this review, the cross-talk between heme catabolism and immune function is described in detail. Special emphasis is given to discoveries that hold promise for identifying immunologic features of metabolic products in the resolution of viral diseases. PMID:26719800

  3. Lysozyme and bilirubin bind to ACE and regulate its conformation and shedding

    PubMed Central

    Danilov, Sergei M.; Lünsdorf, Heinrich; Akinbi, Henry T.; Nesterovitch, Andrew B.; Epshtein, Yuliya; Letsiou, Eleftheria; Kryukova, Olga V.; Piegeler, Tobias; Golukhova, Elena Z.; Schwartz, David E.; Dull, Randal O.; Minshall, Richard D.; Kost, Olga A.; Garcia, Joe G. N.

    2016-01-01

    Angiotensin I-converting enzyme (ACE) hydrolyzes numerous peptides and is a critical participant in blood pressure regulation and vascular remodeling. Elevated tissue ACE levels are associated with increased risk for cardiovascular and respiratory disorders. Blood ACE concentrations are determined by proteolytic cleavage of ACE from the endothelial cell surface, a process that remains incompletely understood. In this study, we identified a novel ACE gene mutation (Arg532Trp substitution in the N domain of somatic ACE) that increases blood ACE activity 7-fold and interrogated the mechanism by which this mutation significantly increases blood ACE levels. We hypothesized that this ACE mutation disrupts the binding site for blood components which may stabilize ACE conformation and diminish ACE shedding. We identified the ACE-binding protein in the blood as lysozyme and also a Low Molecular Weight (LMW) ACE effector, bilirubin, which act in concert to regulate ACE conformation and thereby influence ACE shedding. These results provide mechanistic insight into the elevated blood level of ACE observed in patients on ACE inhibitor therapy and elevated blood lysozyme and ACE levels in sarcoidosis patients. PMID:27734897

  4. Rethinking the immune properties of bilirubin in viral hepatitis: from bench to bedside.

    PubMed

    Corral-Jara, Karla F; Trujillo-Ochoa, Jorge L; Realpe, Mauricio; Panduro, Arturo; Roman, Sonia; Fierro, Nora A

    2015-12-01

    Communication between the immune system and metabolic components can be exemplified by the process of heme catabolism. The immunomodulatory functions of the enzymes, substrates and active products related to catabolism of the heme group have been extensively studied. Bilirubin (BR), the final breakdown product of heme, is primarily considered to be a toxic waste product but has recently been considered to be an immunomodulatory metabolite. Through mechanisms that include intracellular signaling and transcriptional control, BR affects those immune cell functions that regulate cell proliferation, differentiation and apoptosis. During the pathogenesis of viral hepatitis, the heme degradation pathway is disrupted, resulting in changes to normal BR concentrations. These alterations have been previously studied mainly as a consequence of the infection. However, little is known about the potential immunomodulatory role played by BR in the development of infectious hepatocellular diseases. Differences in BR levels in the context of viral hepatitis are likely to provide important insights into the metabolite-mediated mechanisms controlling the immune responses underlying both the long-term persistence of hepatitis C virus (HCV) infection and the resolution of hepatitis A virus (HAV) infection during the acute phase. In this review, the cross-talk between heme catabolism and immune function is described in detail. Special emphasis is given to discoveries that hold promise for identifying immunologic features of metabolic products in the resolution of viral diseases.

  5. Studies on behaviors of dipalmitoylposphatidylcholine and bilirubin in mixed monolayer at the air/water interface

    NASA Astrophysics Data System (ADS)

    Shen, Yuhua; Tang, Yufeng; Xie, Anjian; Zhu, Jinmiao; Li, Shikuo; Zhang, Yong

    2006-06-01

    Mixed monolayers of dipalmitoylposphatidylcholine (DPPC) and bilirubin (BR) were prepared on different subphases. The properties of DPPC/BR monolayer, such as collapse pressure ( πcoll), limiting area per molecule ( Alim), surface compressibility modulus, free energy (Δ Gmix) and excess free energy (Δ Gex), were investigated based on the analysis of the surface pressure-area isotherms on pure water. The results showed that DPPC and BR were miscible and formed non-ideal mixed monolayers at the air/water interface. With the molar fraction of BR ( XBR) increasing, the LE-LC coexistence region of DPPC monolayer was eliminated gradually. The DPPC/BR complex (M D-B) of 1:2 stoichiometry formed as a result of the strong hydrogen bonds between the polar groups of DPPC and BR. The studies of effects of pH values and calcium ions in subphase on the DPPC/BR monolayers showed that the mixed monolayer became expanded on alkali aqueous solution and on 1 mmol/L CaCl 2 aqueous solution. The orientation of DPPC and BR at air/water interface was also discussed.

  6. Bilirubin Oxidase from Bacillus pumilus: A promising enzyme for the elaboration of efficient cathodes in Biofuel cells

    PubMed Central

    Durand, Fabien; Kjaergaard, Christian Hauge; Suraniti, Emmanuel; Gounel, Sébastien; Hadt, Ryan G.; Solomon, Edward I; Mano, Nicolas

    2013-01-01

    A CotA Multicopper Oxidase (MCO) from Bacillus pumilus, previously identified as a laccase, has been studied and characterized as a new bacterial Bilirubin Oxidase (BOD). The 59kDa protein containing four coppers, was successfully over-expressed in Escherichia coli and purified to homogeneity in one step. This 509 amino-acid enzyme, having 67% and 26% sequence identity with CotA from Bacillus subtilis and BOD from Myrothecium verrucaria, respectively, shows higher turnover activity towards bilirubin compared to other bacterial MCOs. The current density for O2 reduction, when immobilized in a redox hydrogel, is only 12% smaller than the current obtained with Trachyderma tsunodae BOD. Under continuous electrocatalysis, an electrode modified with the new BOD is more stable, and has a higher tolerance towards NaCl, than a T. tsunodae BOD modified electrode. This makes BOD from B. pumilus an attractive new candidate for application in biofuel cells and biosensors. PMID:22410485

  7. Dexamethasone increases UDP-glucuronyltransferase activity towards bilirubin, oestradiol and testosterone in foetal liver from rhesus monkey during late gestation.

    PubMed Central

    Leakey, J E; Althaus, Z R; Bailey, J R; Slikker, W

    1985-01-01

    We previously showed that in perinatal rhesus monkeys hepatic UDP-glucuronyltransferase activities appear to develop differentially in two clusters, analogous to those of the rat. We demonstrate here that hepatic UDP-glucuronyltransferase activities differ between the rat and the rhesus monkey in their response to glucocorticoids. Treatment of pregnant rhesus monkeys with dexamethasone during late gestation increases UDP-glucuronyltransferase activities towards bilirubin, oestradiol and testosterone in the foetal-liver microsomal fraction to 25, 4 and 4 times their low control values respectively. Analogous dexamethasone treatment in rat fails to increase these activities significantly in the foetal liver. These findings suggest that maternal glucocorticoid therapy in late gestation could greatly increase the newborn primate's capacity to glucuronidate bilirubin. PMID:3919703

  8. Prognostic significance of pretreatment serum levels of albumin, LDH and total bilirubin in patients with non-metastatic breast cancer.

    PubMed

    Liu, Xiaoan; Meng, Qing H; Ye, Yuanqing; Hildebrandt, Michelle A T; Gu, Jian; Wu, Xifeng

    2015-02-01

    Liver function tests (LFTs) have been reported as independent predictors of non-liver disease-related morbidity and mortality in general population and cancer patients. In this study, we evaluated the relationship between pretreatment serum LFTs and overall survival (OS) in non-metastatic Caucasian breast cancer patients. Seven LFTs, including albumin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase (LDH), total bilirubin and total protein, were measured in pretreatment serum from 2425 female Caucasian patients with newly diagnosed, histologically confirmed non-metastatic invasive breast cancer. Multivariate Cox model was used to estimate hazard ratio (HR) and 95% confidence interval (CI) for the association of individual LFTs with 5-year OS while adjusting for age, smoking status, pathological characteristics and treatment regimen. We found that serum albumin, LDH and total bilirubin were significantly associated with 5-year OS in multivariate Cox analyses. Patients with higher albumin level exhibited 45% reduced risk of death (HR = 0.55, 95% CI: 0.40-0.75) compared with those with lower albumin level. Patients with higher total bilirubin level had a nearly 40% reduction in the risk of death (HR = 0.62, 95% CI: 0.45-0.85) and patients with higher LDH levels had a 1.42-fold increased risk of death (HR = 1.42, 95% CI: 1.08-1.88). Furthermore, cumulative analysis showed a significant dose-response trend of significantly increasing risk of death with increasing number of unfavorable LFT levels. Our result highlighted the potential of using pretreatment serum levels of albumin, LDH and total bilirubin as prognostic factors for OS in patients with non-metastatic breast cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Studies on preparing and adsorption property of grafting terpolymer microbeads of PEI-GMA/AM/MBA for bilirubin.

    PubMed

    Gao, Baojiao; Lei, Haibo; Jiang, Liding; Zhu, Yong

    2007-06-15

    Crosslinking copolymer microbeads with a diameter range of 100-150 microm were synthesized by suspension copolymerization of glycidyl methacrylate (GMA), acrylamide (AM) and N,N'-methylene bisacrylamide (MBA). Subsequently, polyethyleneimine (PEI) was grafted on the surfaces of the terpolymer microbeads GMA/AM/MBA via the ring-opening reaction of the epoxy groups, and the grafting microbeads PEI-GMA/AM/MBA were prepared. In this paper, the adsorption property of the grafting microbeads for bilirubin was mainly investigated, and the effects of various factors, such as pH value, ionic strength and grafting degree of PEI on the surface of grafting microbeads and the adsorption capacity of the grafting microbeads for bilirubin were examined. The batch adsorption experiment results show that by right of the action of grafted polyamine macromolecules PEI, the grafting microbeads PEI-GMA/AM/MBA have quite strong adsorption ability for bilirubin; the isotherm adsorption conforms to Freundlich equation. The pH value of the medium affects the adsorption capacity greatly, As in the nearly neutral solutions with pH 6, the grafting microbeads have the strongest adsorption ability for bilirubin, whereas in acidic and basic solutions their adsorption ability is weak. The ionic strength hardly affects the adsorption ability of the grafting microbeads. The grafting degree of PEI on the surfaces of the grafting microbeads also has a great effect on the adsorption capacity, and higher the grafting degree of PEI on the surface of the microbead PEI-GMA/AM/MBA, the stronger is the adsorption ability of the microbeads.

  10. Inverse association between serum total bilirubin levels and diabetic peripheral neuropathy in patients with type 2 diabetes.

    PubMed

    Kim, Eun Sook; Lee, Sung Won; Mo, Eun Young; Moon, Sung Dae; Han, Je Ho

    2015-11-01

    Several studies have suggested that bilirubin, a potent innate antioxidant, plays a protective role against cardiovascular and microvascular disease. This study investigated the association between serum concentrations of total bilirubin (TB) and the presence of diabetic peripheral neuropathy (DPN) in Korean diabetic patients. This cross-sectional study involved 1207 patients aged more than 30 years with type 2 diabetes. DPN was assessed according to clinical symptoms and physical examinations using Michigan Neuropathy Screening Instrument examination score, 10-g monofilament sensation, and current perception threshold. The subjects were stratified into gender-specific tertiles based on TB values, and the relationship between the TB values and DPN was analyzed. Compared with patients within the lowest TB tertile, those with higher TB levels consisted of patients with shorter duration of diabetes, lower HbA1c, better renal function, and less autonomic neuropathy, retinopathy, and albuminuria. Serum TB levels were inversely associated with DPN. In multivariate analysis for the development of DPN after adjusting for potential confounding factors including retinopathy, albuminuria, and autonomic neuropathy, the TB levels were inversely associated with the presence of DPN, both as a continuous variable [odds ratio (OR) per log standard deviation (SD) 0.79; 95% confidence interval (CI) 0.65-0.97; P = 0.022] and when categorized in tertiles (the highest vs. the lowest tertile; OR 0.63; 95% CI 0.40-0.99; P = 0.046). Low serum bilirubin levels are significantly associated with DPN, independently of classic risk factors and other microvascular complications. Further investigation is necessary to determine whether serum bilirubin has a prognostic significance on DPN.

  11. Total bilirubin level in relation to excipients in parenteral morphine sulfate administered to seriously ill newborn infants.

    PubMed

    Lesko, S M; Mitchell, A A

    1994-10-01

    We examined exposure to excipients in different morphine sulfate preparations in relation to maximum total bilirubin level during the first 5 days of life among 155 infants admitted to a newborn intensive care unit. Sixty-six (43%), 47 (30%), and 42 (27%) newborns were exposed to chlorobutanol, phenol and neither excipient, respectively. Mean maximum total bilirubin in the first 5 days of life among newborns not exposed to chlorobutanol or phenol was 10.8 mg/dL (184 mumol/L). After adjusting for birthweight, race, sex, and use of phototherapy, the maximum total bilirubin level among newborns exposed to phenol was 1.4 mg/dL (24 mumol/L) higher than the maximum level among newborns exposed to neither excipient (P < 0.05); the corresponding difference associated with chlorobutanol exposure was 1.6 mg/dL (27 mumol/L) (P < 0.02). Further adjustment for potential confounding by the major risk factors for hyperbilirubinaemia did not materially change the results. While unconfirmed, these findings support the growing concern that excipients added to parenteral medications may not be 'inactive' as is often assumed, and that the safety of such exposures in seriously ill newborn infants needs to be studied further.

  12. Involvement of ABC transporters in chemosensitivity of human renal cell carcinoma, and regulation of MRP2 expression by conjugated bilirubin.

    PubMed

    Nomura, Masaaki; Matsunami, Toshio; Kobayashi, Kayoko; Uchibayashi, Tadao; Koshida, Kiyoshi; Tanaka, Motohiro; Namiki, Mikio; Mizuhara, Yasuharu; Akiba, Tetsuo; Yokogawa, Koichi; Moritani, Shuzo; Miyamoto, Ken-Ichi

    2005-01-01

    In this study, the involvement of ATP-binding cassette (ABC) transporters in in vitro chemosensitivity of surgically removed human renal cell carcinomas was investigated. The relative expression levels of transporter mRNAs in the renal tumors from 13 patients were similar to those in the surrounding normal kidney tissues. Five renal cell carcinomas cultured successfully in vitro for 14 days showed significantly decreased expression of multi-drug resistance-associated proteins 2 and 6 (MRP2 and MRP6) mRNAs. In vitro chemosensitivity testing of the same specimens using the collagen-gel matrix assay indicated that some anticancer drugs were effective, especially cisplatin, which is an MRP2 substrate. MRP2 mRNA expression in renal carcinoma was significantly increased when cells were cultured in the presence of conjugated bilirubin. In an established renal proximal tubule epithelial cell line (RPTEC), conjugated bilirubin increased MRP2 expression at the mRNA and protein levels, and decreased the cisplatin sensitivity of the cells. These results indicate that MRP2 expression in renal cell carcinoma may be regulated by conjugated bilirubin in the body and decreased during in vitro culture. Thus, the effectiveness of anticancer drugs selected on the basis of in vitro chemosensitivity testing of clinical cancers may be overestimated.

  13. Research Advances. Image Pinpoints All 5 Million Atoms in Viral Coat; Bilirubin, "Animals-Only" Pigment, Found in Plants; New Evidence Shows Humans Make Salicylic Acid

    NASA Astrophysics Data System (ADS)

    King, Angela G.

    2009-08-01

    Recent "firsts" in chemical research: image of a viral capsid pinpointing 5 million atoms; isolation and identification of an "animal" pigment, bilirubin, from a plant source; evidence that humans make salicylic acid.

  14. Influence of Clinical Status on the Association Between Plasma Total and Unbound Bilirubin and Death or Adverse Neurodevelopmental Outcomes in Extremely Low Birth Weight Infants

    PubMed Central

    Oh, William; Stevenson, David K.; Tyson, Jon E.; Morris, Brenda H.; Ahlfors, Charles E.; Bender, G. Jesse; Wong, Ronald J.; Perritt, Rebecca; Vohr, Betty R.; Van Meurs, Krista P.; Vreman, Hendrik J.; Das, Abhik; Phelps, Dale L.; O’Shea, T. Michael; Higgins, Rosemary D.

    2010-01-01

    Objectives To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18–22 months corrected age in extremely low birth weight infants. Method Total plasma biirubin and unbound biirubin were measured in 1,101 extremely low birth weight infants at 5±1 day of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18–22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow-up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. Results Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow-up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow-up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. Conclusions In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma and unbound bilirubin and death or adverse neurodevelopmental outcomes at 18–22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants. PMID:20105142

  15. First Observation Of The Wavelength-Dependent Photoproduction Of The 4E,15Z Configurational Isomer Of Bilirubin Bound To Human Serum Albumin

    NASA Astrophysics Data System (ADS)

    Mc Donagh, Antony F.; Agati, Giovanni; Fusi, Franco; Pratesi, R.

    1987-07-01

    The photochemistry of bilirubin (BR) is of considerable interest because of its importance in the treatment of neonatal jaundice with visible light phototherapy. Patients are irradiated with blue, white or green fluorescent lamps to induce conversion of the unexcretable and toxic bilirubin to more polar, water-soluble and easily excreted photoproducts. The molecular mechanisms responsible for the phototherapeutic action of light on jaundiced babies have not jet been completely elucidated.

  16. Human serum albumin-stabilized gold nanoclusters act as an electron transfer bridge supporting specific electrocatalysis of bilirubin useful for biosensing applications.

    PubMed

    Santhosh, Mallesh; Chinnadayyala, Somasekhar R; Singh, Naveen K; Goswami, Pranab

    2016-10-01

    Human serum albumin (HSA)-stabilized Au18 nanoclusters (AuNCs) were synthesized and chemically immobilized on an Indium tin oxide (ITO) plate. The assembly process was characterized by advanced electrochemical and spectroscopic techniques. The bare ITO electrode generated three irreversible oxidation peaks, whereas the HSA-AuNC-modified electrode produced a pair of redox peaks for bilirubin at a formal potential of 0.27V (vs. Ag/AgCl). However, the native HSA protein immobilized on the ITO electrode failed to produce any redox peak for bilirubin. The results indicate that the AuNCs present in HSA act as electron transfer bridge between bilirubin and the ITO plate. Docking studies of AuNC with HSA revealed that the best docked structure of the nanocluster is located around the vicinity of the bilirubin binding site, with an orientation that allows specific oxidation. When the HSA-AuNC-modified electrode was employed for the detection of bilirubin using chronoamperometry at 0.3V (vs. Ag/AgCl), a steady-state current response against bilirubin in the range of 0.2μM to 7μM, with a sensitivity of 0.34μAμM(-1) and limit of detection of 86.32nM at S/N 3, was obtained. The bioelectrode was successfully applied to measure the bilirubin content in spiked serum samples. The results indicate the feasibility of using HSA-AuNC as a biorecognition element for the detection of serum bilirubin levels using an electrochemical technique.

  17. Selective and sensitive detection of free bilirubin in blood serum using human serum albumin stabilized gold nanoclusters as fluorometric and colorimetric probe.

    PubMed

    Santhosh, Mallesh; Chinnadayyala, Somasekhar R; Kakoti, Ankana; Goswami, Pranab

    2014-09-15

    We report here a fluorescence quenching based non-enzymatic method for sensitive and reliable detection of free bilirubin in blood serum samples using human serum albumin (HSA) stabilized gold nanoclusters (HSA-AuNCs) as fluorescent probe. The fluorescence of the nanoclusters was strongly quenched by bilirubin in a concentration dependent manner by virtue of the inherent specific interaction between bilirubin and HSA. A strong binding constant of 0.55×10(6) L mole(-1) between the HSA-AuNC and bilirubin was discerned. The nano clusters each with size ~1.0 nm (in diameter) and a core of Au18 were homogeneously distributed in HSA molecules as revealed from the respective high resolution transmission electron microscopic and mass spectroscopic studies. The fluorescence quenching phenomena which obeyed a simple static quenching mechanism, was utilized for interference free detection of bilirubin with minimum detection limit (DL) of 248±12 nM (S/N=3). The fluorescence response of HSA-AuNCs against bilirubin was practically unaltered over a wide pH (6-9) and temperature (25-50 °C) range. Additionally, peroxidase-like catalytic activity of these nanoclusters was exploited for colorimetric detection of bilirubin in serum sample with a DL of 200±19 nM by following the decrease in absorbance (at λ440 nm) of the reaction and its rate constant (Kp) of 2.57±0.63 mL μg(-1) min(-1). Both these fluorometric and colorimetric methods have been successfully used for detection of free bilirubin in blood serum samples.

  18. Impairment of enzymatic antioxidant defenses is associated with bilirubin-induced neuronal cell death in the cerebellum of Ugt1 KO mice

    PubMed Central

    Bortolussi, G; Codarin, E; Antoniali, G; Vascotto, C; Vodret, S; Arena, S; Cesaratto, L; Scaloni, A; Tell, G; Muro, A F

    2015-01-01

    Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced encephalopathy and eventually death by kernicterus. Despite extensive studies, the molecular and cellular mechanisms of bilirubin toxicity are still poorly defined. To fill this gap, we investigated the molecular processes underlying neuronal injury in a mouse model of severe neonatal jaundice, which develops hyperbilirubinemia as a consequence of a null mutation in the Ugt1 gene. These mutant mice show cerebellar abnormalities and hypoplasia, neuronal cell death and die shortly after birth because of bilirubin neurotoxicity. To identify protein changes associated with bilirubin-induced cell death, we performed proteomic analysis of cerebella from Ugt1 mutant and wild-type mice. Proteomic data pointed-out to oxidoreductase activities or antioxidant processes as important intracellular mechanisms altered during bilirubin-induced neurotoxicity. In particular, they revealed that down-representation of DJ-1, superoxide dismutase, peroxiredoxins 2 and 6 was associated with hyperbilirubinemia in the cerebellum of mutant mice. Interestingly, the reduction in protein levels seems to result from post-translational mechanisms because we did not detect significant quantitative differences in the corresponding mRNAs. We also observed an increase in neuro-specific enolase 2 both in the cerebellum and in the serum of mutant mice, supporting its potential use as a biomarker of bilirubin-induced neurological damage. In conclusion, our data show that different protective mechanisms fail to contrast oxidative burst in bilirubin-affected brain regions, ultimately leading to neurodegeneration. PMID:25950469

  19. Thymoquinone, an active constituent of Nigella sativa seeds, binds with bilirubin and protects mice from hyperbilirubinemia and cyclophosphamide-induced hepatotoxicity.

    PubMed

    Laskar, Amaj A; Khan, Masood A; Rahmani, Arshad H; Fatima, Sana; Younus, Hina

    2016-08-01

    Some reports indicate that thymoquinone (TQ), the main constituent of Nigella sativa seeds, is hepatoprotective. The aim of this study was to determine whether TQ is able to bind directly to bilirubin, and whether TQ or liposomal formulation of TQ (Lip-TQ) can reduce cyclophosphamide (CYP)-induced liver toxicity, serum bilirubin level in mice. The binding of TQ with bilirubin was studied by UV-VIS, fluorescence and Near-UV CD spectroscopy. Inhibition of binding of bilirubin to erythrocytes by TQ was also examined. To increase the in vivo efficacy, Lip-TQ was prepared and used against CYP-induced toxicity. The protective role of TQ or Lip-TQ against CYP-induced toxicity was assessed by determining the liver function parameters, the levels of superoxide dismutase (SOD) and catalase (CAT), and histological studies. It was found that TQ binds to bilirubin and significantly inhibits the binding of bilirubin to erythrocytes. Lip-TQ (10 mg/kg) significantly reduced the levels of aspartate transaminase (AST) from 254 ± 48 to 66 ± 18 IU/L (P < 0.001), alanine transaminase (ALT) from 142 ± 28 to 47.8 ± 16 IU/L (P < 0.05) and serum bilirubin from 2.8 ± 0.50 to 1.24 ± 0.30 mg/dl (P < 0.05). Treatment with Lip-TQ reduced the CYP-induced inflammation and hemorrhage in liver tissues. Moreover, treatment with free or Lip-TQ protected the activity of SOD and CAT in CYP-injected mice. Therefore, TQ can reduce the level of bilirubin in systemic circulation in disease conditions that lead to hyperbilirubinemia and liver toxicity and hence may be used as a supplement in the treatment of liver ailments.

  20. Impairment of enzymatic antioxidant defenses is associated with bilirubin-induced neuronal cell death in the cerebellum of Ugt1 KO mice.

    PubMed

    Bortolussi, G; Codarin, E; Antoniali, G; Vascotto, C; Vodret, S; Arena, S; Cesaratto, L; Scaloni, A; Tell, G; Muro, A F

    2015-05-07

    Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced encephalopathy and eventually death by kernicterus. Despite extensive studies, the molecular and cellular mechanisms of bilirubin toxicity are still poorly defined. To fill this gap, we investigated the molecular processes underlying neuronal injury in a mouse model of severe neonatal jaundice, which develops hyperbilirubinemia as a consequence of a null mutation in the Ugt1 gene. These mutant mice show cerebellar abnormalities and hypoplasia, neuronal cell death and die shortly after birth because of bilirubin neurotoxicity. To identify protein changes associated with bilirubin-induced cell death, we performed proteomic analysis of cerebella from Ugt1 mutant and wild-type mice. Proteomic data pointed-out to oxidoreductase activities or antioxidant processes as important intracellular mechanisms altered during bilirubin-induced neurotoxicity. In particular, they revealed that down-representation of DJ-1, superoxide dismutase, peroxiredoxins 2 and 6 was associated with hyperbilirubinemia in the cerebellum of mutant mice. Interestingly, the reduction in protein levels seems to result from post-translational mechanisms because we did not detect significant quantitative differences in the corresponding mRNAs. We also observed an increase in neuro-specific enolase 2 both in the cerebellum and in the serum of mutant mice, supporting its potential use as a biomarker of bilirubin-induced neurological damage. In conclusion, our data show that different protective mechanisms fail to contrast oxidative burst in bilirubin-affected brain regions, ultimately leading to neurodegeneration.

  1. Did exclusive breast-feeding and early discharge lead to excessive bilirubin levels in newborns in Antigua and Barbuda?

    PubMed

    Martin, T C; Shea, M; Alexander, D; Bradbury, L; Lovell-Roberts, L; Francis, V

    2002-06-01

    Hyperbilirubinaemia is a common neonatal problem worldwide and is the leading cause of admission to the Special Care Nursery in Antigua and Barbuda. In 1990, the Innocenti Declaration in support of breast-feeding led to the adoption of the Baby-Friendly Hospital Initiative in many countries of the Caribbean, including Antigua and Barbuda. Comparing 1989 to the years 1992 to 1994, the Special Care Nursery at Holberton Hospital experienced a 40% increase in newborns admitted with hyperbilirubinaemia (peak total bilirubin > 12 mg/dl or 205 mumol/l). A retrospective review of Special Care Nursery and Maternity Ward records was undertaken to determine the incidence and aetiology of hyperbilirubinaemia from 1992 to 1994. There were 3721 infants born in Antigua and Barbuda in those years, 98% of Afro-Caribbean or mixed ancestry. The overall incidence of peak total bilirubin over 12 mg/dl (205 mumol/l) was 12.5% (466/3721), not inconsistent with the reported incidence of 8 to 20% in other countries. However, the incidence of higher levels of hyperbilirubinaemia in Antigua and Barbuda exceeded those reported for other countries. In Antigua and Barbuda, total bilirubin of 15 mg/dl (255 mumol/l) or higher was found in 263 of 3721 infants (7.1%) compared to 5.9% in India and 2% of breast-fed infants in the United States of America (USA). Total bilirubin of 20 mg/dl (340 mumol/l) or higher was seen in 91 of 3721 infants (2.5%) exceeding reported prevalence in the USA for both African-American and Caucasian infants (1%) and equal to the reported prevalence in Asian infants (2%). The possible aetiologies of hyperbilirubinaemia in neonates with total bilirubin 18 mg/dl (306 mumol/l) or higher in our patients were investigated. Medical records of 134 of 156 (86%) infants having this level of hyperbilirubinaemia were available for review. The possible reason for hyperbilirubinaemia was ABO incompatibility in 4/134 (3%), Rh incompatibility in 1/134 (1%), prematurity in 12/134 (9

  2. Ameliorative Effect of Vanillic Acid on Serum Bilirubin, Chronotropic and Dromotropic Properties in the Cholestasis-Induced Model Rats

    PubMed Central

    Atefipour, Narges; Dianat, Mahin; Badavi, Mohammad; Sarkaki, Alireza

    2016-01-01

    Introduction The liver modulates several important roles, such as metabolism and liver cirrhosis, which have several cardiovascular problems. Due to preservative role of antioxidant agents in cardiovascular disease, consequently, many of them are applied as medicinal plants in traditional medicine. Vanillic acid (VA), as an antioxidant agent, has a principal preservative role on some diseases. In this study, the effect of vanillic acid was examined on heart rate (as chronotropic property), P-R interval (as dromotropic property), and serum bilirubin in cholestasis-induced model rats. Methods In this study, 32 male Sprague-Dawley rats weighing 200–250 g were allocated into four groups, and each group contained eight rats as follows: Control (normal saline, 1 ml/kg, gavage, daily for 4 weeks), cirrhotic (normal saline, 1 ml/kg, gavage, daily for 4 weeks), vanillic acid (10 mg/kg, gavage, daily for 4 weeks), cirrhotic treated with vanillic acid (10 mg/kg, gavage, daily for 4 weeks). Chronic biliary cirrhosis was induced in cirrhotic groups by four weeks Bile Duct Ligation (BDL). At the first day and four weeks after surgery, the animals were anesthetized, electrocardiograms were recorded (lead II), and chronotropic and dromotropic properties (HR and PR interval) were investigated. At the end of experimental duration, the animals were anesthetized, and blood samples were taken to measure serum bilirubin. The results were analyzed using t-test and one-way ANOVA by SPSS software, version 22. Results After induced of BDL, the results presented that laboratory parameter (bilirubin) in the cirrhotic group significantly increased compared to the control group. The P-R interval was reduced in the cirrhotic group compared to the control group, and there was no significant difference between heart rate in all groups. Bilirubin were reduced in cirrhotic groups treated with vanillic acid (VA) compared to cirrhotic group and also administration of VA in the cirrhotic treated with

  3. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    SciTech Connect

    Song, Shasha; Wang, Shuang; Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin; Zhu, Daling

    2013-08-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway.

  4. Bilirubin-induced neural impairment: a special focus on myelination, age-related windows of susceptibility and associated co-morbidities.

    PubMed

    Brites, Dora; Fernandes, Adelaide

    2015-02-01

    Bilirubin-induced neurologic dysfunction (BIND) and classical kernicterus are clinical manifestations of moderate to severe hyperbilirubinemia whenever bilirubin levels exceed the capacity of the brain defensive mechanisms in preventing its entrance and cytotoxicity. In such circumstances and depending on the associated co-morbidities, bilirubin accumulation may lead to short- or long-term neurodevelopmental disabilities, which may include deficits in auditory, cognitive, and motor processing. Neuronal cell death, astrocytic reactivity, and microglia activation are part of the bilirubin-induced pathogenesis. Less understood is how abnormal growth and maturation of oligodendrocytes may impact on brain development, affecting the formation of myelin tracts. Based on in-vitro and in-vivo models, as well as in clinical cases presented here, we propose the existence of impaired myelination by bilirubin with long-term sequelae, mainly in pre-term infants. Sensitive time-windows are highlighted and centered on the different developmental-dependent impairments determined by bilirubin, and the influence of sepsis and hypoxia is reviewed.

  5. Adjusting CA19-9 values to predict malignancy in obstructive jaundice: Influence of bilirubin and C-reactive protein

    PubMed Central

    La Greca, Gaetano; Sofia, Maria; Lombardo, Rosario; Latteri, Saverio; Ricotta, Agostino; Puleo, Stefano; Russello, Domenico

    2012-01-01

    AIM: To find a possible relationship between inflammation and CA19-9 tumor marker by analyzing data from patients with benign jaundice (BJ) and malignant jaundice (MJ). METHODS: All patients admitted for obstructive jaundice, in the period 2005-2009, were prospectively enrolled in the study, obtaining a total of 102 patients. On admission, all patients underwent complete standard blood test examinations including C-reactive protein (CRP), bilirubin, CA19-9. Patients were considered eligible for the study when they presented obstructive jaundice confirmed by instrumental examinations and increased serum bilirubin levels (total bilirubin > 2.0 mg/dL). The standard cut-off level for CA19-9 was 32 U/mL, whereas for CRP this was 1.5 mg/L. The CA19-9 level was adjusted by dividing it by the value of serum bilirubin or by the CRP value. The patients were divided into 2 groups, MJ and BJ, and after the adjustment a comparison between the 2 groups of patients was performed. Sensitivity, specificity and positive predictive values were calculated before and after the adjustment. RESULTS: Of the 102 patients, 51 were affected by BJ and 51 by MJ. Pathologic CA19-9 levels were found in 71.7% of the patients. In the group of 51 BJ patients there were 29 (56.9%) males and 22 (43.1%) females with a median age of 66 years (range 24-96 years), whereas in the MJ group there were 24 (47%) males and 27 (53%) females, with a mean age of 70 years (range 30-92 years). Pathologic CA19-9 serum level was found in 82.3% of MJ. CRP levels were pathologic in 66.6% of the patients with BJ and in 49% with MJ. Bilirubin and CA19-9 average levels were significantly higher in MJ compared with BJ (P = 0.000 and P = 0.02), while the CRP level was significantly higher in BJ (P = 0.000). Considering a CA19-9 cut-off level of 32 U/mL, 82.3% in the MJ group and 54.9% in the BJ group were positive for CA19-9 (P = 0.002). A CA19-9 cut-off of 100 U/mL increases the difference between the two groups: 35.3% in

  6. Modification of biliary tree permeability in rats treated with a manganese-bilirubin combination

    SciTech Connect

    Ayotte, P.; Plaa, G.L.

    1986-06-30

    Previous studies in this laboratory demonstrated incorporation of manganese (Mn) and bilirubin (BR) in rat liver bile canalicular membrane (BCM) following a cholestatic regimen composed sequentially of Mn plus BR. The present study investigates biliary tree permeability using segmented retrograde intrabiliary injection (SRII) with (/sup 3/H)mannitol and (3H)inulin as marker substances. Male Sprague-Dawley rats were given the following iv: (a) Mn (high and low dose), (b) BR, (c) sulfobromophthalein (BSP), (d) Mn-BSP-BR, (e) MnBR. Results obtained with mannitol showed a approximately 63% decrease (p less than 0.05) in marker recovery following administration of MnBR combination. While BSP alone had no effect on mannitol recovery, BSP abolished the MnBR response when administered in the Mn-BSP-BR sequence. With inulin, Mn (high dose), MnBR, and Mn-BSP-BR all produced a approximately 45% decrease (p less than 0.05) in recovery, while BSP or BR alone caused a approximately 25% decrease (p less than 0.05). Mn (low dose) was without effect. These results and others obtained when the time pattern of the MnBR treatment was modified suggest: (1) MnBR treatment increases biliary tree permeability by altering both BCM and the junctional complex; (2) BCM alteration is probably the more critical event, since BSP, which protects against MnBR cholestasis, protected against the MnBR-induced change in mannitol recovery, but exerted no effect on inulin recovery.

  7. The Negative Relationship between Bilirubin Level and Diabetic Retinopathy: A Meta-Analysis

    PubMed Central

    Wu, Xiaomei; Ning, Kang; Jiang, Feng; Zhang, Lu

    2016-01-01

    Objectives Findings on the relationship between total bilirubin level (TBL) and diabetic retinopathy (DR) are inconsistent. Thus, we carried out a meta-analysis to investigate the relationship between TBL and the risk of DR. Methods Relevant studies were selected from six databases up to 31 May 2016 using a search strategy. The relevant data were extracted from the included studies according to the inclusion and exclusion criteria, and the mean value with standard errors or odds ratio (OR) with 95% confidence intervals (CIs) were calculated. We compared TBL in patients with DR with that in patients with diabetes but without retinopathy (NDR), and analyzed the dose-response relationship between TBL and the risk of DR. Results Twenty-four studies were selected in this meta-analysis. Twenty studies were included to calculate the pooled SMD, and the results showed that TBL in the DR group was lower than that in the NDR group (SMD: –0.52, 95% CI: –0.67, –0.38). Nine studies were included to calculate the pooled ORs, and the results showed that there was a significant negative relationship between TBL and the risk of DR (OR: 0.19, 95% CI: 0.14, 0.25). Six studies were included to investigate the dose-response relationship between TBL and the risk of DR, and we found a nonlinear relationship between TBL and the risk of DR. The results of our meta-analysis were found to be reliable using subgroup and sensitivity analyses. Conclusions The results of our meta-analysis indicate that higher TBL may be protective against DR in subjects with diabetes, and TBL could be used as a biomarker to predict the risk of DR. PMID:27571522

  8. Handgrip Strength Is Positively Associated with Mildly Elevated Serum Bilirubin Levels among Community-Dwelling Adults.

    PubMed

    Kawamoto, Ryuichi; Ninomiya, Daisuke; Kumagi, Teru

    2016-11-01

    Handgrip strength (HGS) is a useful measure of health-related quality of life and general muscle strength. Serum total bilirubin (T-B) may present potential beneficial effects in preventing oxidative changes which are associated with a risk of metabolic syndrome and the development of cardiovascular disease. Limited information is available regarding whether HGS is an independent confounding factor for serum T-B. The study participants were 214 men aged 71 ± 8 (mean ± standard deviation) years and 302 women aged 71 ± 7 years that were enrolled consecutively from among paticipants aged ≥ 50 years through an annual check-up process. We evaluated the relationship between serum T-B and confounding factors within each sex. HGS related significantly with serum T-B in both men (r = 0.156, p = 0.023) and women (r = 0.173, p = 0.003). Multiple linear regression analysis showed that in men, HGS (β = 0.173) as well as smoking status (β = -0.147), exercise habit (β = 0.138), low-density lipoprotein cholesterol (β = 0.146), and hemoglobin A1c (HbA1c) (β = -0.198) were significantly and independently associated with serum T-B. In women, HGS (β = 0.159) as well as smoking status (β = -0.116), high-density lipoprotein cholesterol (β = 0.159), and HbA1c (β = -0.161) were significantly and independently associated with serum T-B. Multivariate-adjusted serum T-B levels were significantly lower in subjects with the lowest HGS level in both sexes. Increased HGS is strongly associated with increased serum T-B, independent of confounding factors in both sexes.

  9. Mutual structural effect of bilirubin and model membranes by vibrational circular dichroism.

    PubMed

    Novotná, Pavlína; Goncharova, Iryna; Urbanová, Marie

    2014-03-01

    In this study, vibrational circular dichroism (VCD) spectroscopy was employed for the first time to study the bilirubin (BR) interaction with model membranes and models for membrane proteins. An enantioselective interaction of BR with zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and sphingomyelin (SPM) liposomes was observed by VCD and electronic circular dichroism (ECD) complemented by absorption and fluorescence spectroscopy. The M-form of BR was preferentially recognized in the BR/DMPC system at concentration above 1×10(-4)M, for lower concentrations the P-form of BR was recognized by the DMPC liposomes. The VCD spectra also showed that the SPM liposomes, which represent the main component of nerve cell membrane, were significantly more disturbed by the presence of BR than the DMPC liposomes-a stable association with a strong VCD signal was observed providing the explanations for the supposed BR neurotoxicity. The effect of time and pH on the BR/DMPC or SPM liposome systems was shown to be essential while the effect of temperature in the range of 15-70°C was negligible demonstrating the surprisingly high temperature stability of BR when interacting with the studied membranes. The influence of a membrane protein was tested on a model consisting of poly-l-arginine (PLAG) bound in the α-helical form to the surface of 1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol) liposomes and sodium dodecyl sulfate micelles. VCD and also ECD spectra showed that a variety of BR diastereoisomers interacted with PLAG in such systems. In a system of PLAG with micelles composed of sodium dodecyl sulfate, the M-form of bound BR was observed. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Heme Degradation by Heme Oxygenase Protects Mitochondria but Induces ER Stress via Formed Bilirubin.

    PubMed

    Müllebner, Andrea; Moldzio, Rudolf; Redl, Heinz; Kozlov, Andrey V; Duvigneau, J Catharina

    2015-04-30

    Heme oxygenase (HO), in conjunction with biliverdin reductase, degrades heme to carbon monoxide, ferrous iron and bilirubin (BR); the latter is a potent antioxidant. The induced isoform HO-1 has evoked intense research interest, especially because it manifests anti-inflammatory and anti-apoptotic effects relieving acute cell stress. The mechanisms by which HO mediates the described effects are not completely clear. However, the degradation of heme, a strong pro-oxidant, and the generation of BR are considered to play key roles. The aim of this study was to determine the effects of BR on vital functions of hepatocytes focusing on mitochondria and the endoplasmic reticulum (ER). The affinity of BR to proteins is a known challenge for its exact quantification. We consider two major consequences of this affinity, namely possible analytical errors in the determination of HO activity, and biological effects of BR due to direct interaction with protein function. In order to overcome analytical bias we applied a polynomial correction accounting for the loss of BR due to its adsorption to proteins. To identify potential intracellular targets of BR we used an in vitro approach involving hepatocytes and isolated mitochondria. After verification that the hepatocytes possess HO activity at a similar level as liver tissue by using our improved post-extraction spectroscopic assay, we elucidated the effects of increased HO activity and the formed BR on mitochondrial function and the ER stress response. Our data show that BR may compromise cellular metabolism and proliferation via induction of ER stress. ER and mitochondria respond differently to elevated levels of BR and HO-activity. Mitochondria are susceptible to hemin, but active HO protects them against hemin-induced toxicity. BR at slightly elevated levels induces a stress response at the ER, resulting in a decreased proliferative and metabolic activity of hepatocytes. However, the proteins that are targeted by BR still have

  11. Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue).

    PubMed

    Ebbesen, Finn; Madsen, Poul H; Vandborg, Pernille K; Jakobsen, Lasse H; Trydal, Torleif; Vreman, Hendrik J

    2016-10-01

    Phototherapy using blue light is the treatment of choice worldwide for neonatal hyperbilirubinemia. However, treatment with turquoise light may be a desirable alternative. Therefore, the aim of this randomized, controlled study was to compare the bilirubin isomer distribution in serum of jaundiced neonates after 24 h of therapy with narrow-band (LED) light centered at 497 nm (turquoise) vs. 459 nm (blue), of essentially equal irradiance. Eighty-three neonates (≥33 wk gestational age) with uncomplicated hyperbilirubinemia were included in the study. Forty neonates were exposed to light centered at 497 nm and 43 infants with light centered at 459 nm. Irradiances were 5.2 × 10(15) and 5.1 × 10(15) photons/cm(2)/s, respectively. After 24 h of treatment no significant differences in serum concentrations of total bilirubin isomers and Z,Z-bilirubin were observed between the 2 groups. Interestingly, concentrations of Z,E-bilirubin, and thus also total bilirubin isomers formed during therapy, were highest for infants receiving light centered at 459 nm, while the concentration of E,Z-bilirubin was highest for those receiving light centered at 497 nm. No significant difference was found between concentrations of E,Z-lumirubin. Therapy with LED light centered at 497 nm vs. 459 nm, applied with equal irradiance on the infants, resulted in a different distribution of bilirubin isomers in serum.

  12. The ability of bilirubin in identifying smokers with higher risk of lung cancer: a large cohort study in conjunction with global metabolomic profiling.

    PubMed

    Wen, Chi-Pang; Zhang, Fanmao; Liang, Dong; Wen, Christopher; Gu, Jian; Skinner, Heath; Chow, Wong-Ho; Ye, Yuanqing; Pu, Xia; Hildebrandt, Michelle A T; Huang, Maosheng; Chen, Chien-Hua; Hsiung, Chao Agnes; Tsai, Min Kuang; Tsao, Chwen Keng; Lippman, Scott M; Wu, Xifeng

    2015-01-01

    We aimed to identify serum metabolites as potential valuable biomarkers for lung cancer and to improve risk stratification in smokers. We performed global metabolomic profiling followed by targeted validation of individual metabolites in a case-control design of 386 lung cancer cases and 193 matched controls. We then validated bilirubin, which consistently showed significant differential levels in cases and controls, as a risk marker for lung cancer incidence and mortality in a large prospective cohort composed of 425,660 participants. Through global metabolomic profiling and following targeted validation, bilirubin levels consistently showed a statistically significant difference among healthy controls and lung cancer cases. In the prospective cohort, the inverse association was only seen in male smokers, regardless of smoking pack-years and intensity. Compared with male smokers in the highest bilirubin group (>1 mg/dL), those in the lowest bilirubin group (<0.75 mg/dL) had 55% and 66% increase in risks of lung cancer incidence and mortality, respectively. For every 0.1 mg/dL decrease of bilirubin, the risks for lung cancer incidence and mortality increased by 5% and 6% in male smokers, respectively (both P < 0.001). There was a significant interaction between low serum bilirubin level and smoking on lung cancer risk (Pinteraction = 0.001). Low levels of serum bilirubin are associated with higher risks of lung cancer incidence and mortality in male smokers and can be used to identify higher risk smokers for lung cancer. ©2014 American Association for Cancer Research.

  13. The ability of bilirubin in identifying smokers with higher risk of lung cancer: a large cohort study in conjunction with global metabolomic profiling

    PubMed Central

    Wen, Chi-Pang; Zhang, Fanmao; Liang, Dong; Wen, Christopher; Gu, Jian; Skinner, Heath; Chow, Wong-Ho; Ye, Yuanqing; Pu, Xia; Hildebrandt, Michelle A.T.; Huang, Maosheng; Chen, Chien-Hua; Hsiung, Chao Agnes; Tsai, Min Kuang; Tsao, Chwen Keng; Lippman, Scott M.; Wu, Xifeng

    2014-01-01

    Purpose We aimed to identify serum metabolites as potential valuable biomarkers for lung cancer and to improve risk stratification in smokers. Experimental Design We performed global metabolomic profiling followed by targeted validation of individual metabolites in a case-control design of 386 lung cancer cases and 193 matched controls. We then validated bilirubin, which consistently showed significant differential levels in cases and controls, as a risk marker for lung cancer incidence and mortality in a large prospective cohort comprised of 425,660 participants. Results Through global metabolomic profiling and following targeted validation, bilirubin levels consistently showed a statistically significant difference among healthy controls and lung cancer cases. In the prospective cohort, the inverse association was only seen in male smokers, regardless of smoking pack-years and intensity. Compared with male smokers in the highest bilirubin group (>1 mg/dL), those in the lowest bilirubin group (<0.75 mg/dL) had 55% and 66% increase in risks of lung cancer incidence and mortality, respectively. For every 0.1 mg/dL decrease of bilirubin, the risks for lung cancer incidence and mortality increased by 5% and 6% in male smokers, respectively (both P < 0.001). There was a significant interaction between low serum bilirubin level and smoking on lung cancer risk (P for interaction = 0.001). Conclusion Low levels of serum bilirubin are associated with higher risks of lung cancer incidence and mortality in male smokers and can be used to identify higher risk smokers for lung cancer. PMID:25336700

  14. Total Serum Bilirubin within Three Months of Hepatoportoenterostomy Predicts Short-term Outcomes in Biliary Atresia

    PubMed Central

    Shneider, Benjamin L.; Magee, John C.; Karpen, Saul J.; Rand, Elizabeth B.; Narkewicz, Michael R.; Bass, Lee M.; Schwarz, Kathleen; Whitington, Peter F.; Bezerra, Jorge A.; Kerkar, Nanda; Haber, Barbara; Rosenthal, Philip; Turmelle, Yumirle P.; Molleston, Jean P.; Murray, Karen F.; Ng, Vicky L.; Wang, Kasper S.; Romero, Rene; Squires, Robert H.; Arnon, Ronen; Sherker, Averell H.; Moore, Jeffrey; Ye, Wen; Sokol, Ronald J.

    2015-01-01

    Objectives To prospectively assess the value of serum total bilirubin (TB) within 3 months of hepatoportoenterostomy (HPE) in infants with biliary atresia (BA) as a biomarker predictive of clinical sequelae of liver disease in the first two years of life. Study design Infants with BA undergoing HPE between June 2004-January 2011 were enrolled in a prospective, multicenter study. Complications were monitored until 2 years of age or the earliest of liver transplant (LT), death, or study withdrawal. TB below 2 mg/dL (34.2 μM) at any time in the first 3 months (TB<2.0, all others = TB≥2) after HPE was examined as a biomarker, using Kaplan-Meier survival and logistic regression. Results Fifty percent (68/137) of infants had TB<2.0 in the first 3 months after HPE. Transplant-free survival at 2 years was significantly higher in the TB<2.0 group vs. TB≥2 (86% vs. 20%, p<0.0001). Infants with TB≥2 had diminished weight gain (p<0.0001), greater probability of developing ascites (OR 6.4, 95% CI 2.9–14.1, p<0.0001), hypoalbuminemia (OR 7.6, 95% CI 3.2–17.7, p< 0.0001), coagulopathy (OR 10.8, 95% CI 3.1–38.2, p=0.0002), LT (OR 12.4, 95% CI 5.3–28.7, p<0.0001), or LT or death (OR 16.8, 95% CI 7.2–39.2, p<0.0001). Conclusions Infants whose TB does not fall below 2.0 mg/dL within 3 months of HPE were at high risk for early disease progression, suggesting they should be considered for LT in a timely fashion. Interventions increasing the likelihood of achieving TB <2.0 mg/dL within 3 months of HPE may enhance early outcomes. PMID:26725209

  15. Cytochrome P450 2A5 and bilirubin: Mechanisms of gene regulation and cytoprotection

    SciTech Connect

    Kim, Sangsoo Daniel; Antenos, Monica; Squires, E. James; Kirby, Gordon M.

    2013-07-15

    Bilirubin (BR) has recently been identified as the first endogenous substrate for cytochrome P450 2A5 (CYP2A5) and it has been suggested that CYP2A5 plays a major role in BR clearance as an alternative mechanism to BR conjugation by uridine-diphosphate glucuronyltransferase 1A1. This study investigated the mechanisms of Cyp2a5 gene regulation by BR and the cytoprotective role of CYP2A5 in BR hepatotoxicity. BR induced CYP2A5 expression at the mRNA and protein levels in a dose-dependent manner in primary mouse hepatocytes. BR treatment also caused nuclear translocation of Nuclear factor-E2 p45-related factor 2 (Nrf2) in hepatocytes. In reporter assays, BR treatment of primary hepatocytes transfected with a Cyp2a5 promoter-luciferase reporter construct resulted in a 2-fold induction of Cyp2a5 reporter activity. Furthermore, cotransfection of the hepatocytes with a Nrf2 expression vector without BR treatment resulted in an increase in Cyp2a5 reporter activity of approximately 2-fold and BR treatment of Nrf2 cotransfectants further increased reporter activity by 4-fold. In addition, site-directed mutation of the ARE in the reporter construct completely abolished both the BR- and Nrf2-mediated increases in reporter activity. The cytoprotective role of CYP2A5 against BR-mediated apoptosis was also examined in Hepa 1–6 cells that lack endogenous CYP2A5. Transient overexpression of CYP2A5 partially blocked BR-induced caspase-3 cleavage in Hepa 1–6 cells. Furthermore, in vitro degradation of BR was increased by microsomes from Hepa 1–6 cells overexpressing CYP2A5 compared to control cells transfected with an empty vector. Collectively, these results suggest that Nrf2-mediated CYP2A5 transactivation in response to BR may provide an additional mechanism for adaptive cytoprotection against BR hepatotoxicity. - Highlights: • The mechanism of Cyp2a5 gene regulation by BR was investigated. • The cytoprotective role of CYP2A5 in BR hepatotoxicity was determined. • BR

  16. Umbilical cord bilirubin as a predictor of neonatal jaundice: a retrospective cohort study.

    PubMed

    Jones, Kelsey D J; Grossman, S E; Kumaranayakam, Dharshini; Rao, Arati; Fegan, Greg; Aladangady, Narendra

    2017-09-20

    Hyperbilirubinaemia is a major cause of neonatal morbidity. Early identification of those infants most at risk might allow the development of targeted primary preventative therapy and follow-up. The objective of this study was to assess whether arterial umbilical cord bilirubin (aUCB) level at delivery predicts the development of neonatal jaundice in term deliveries. Retrospective analysis of hospital biochemistry records identified term deliveries with recorded aUCB. Infant medical records were reviewed to identify those who developed neonatal hyperbilirubinaemia (requiring treatment according to UK NICE guidelines) with/without a positive direct antiglobulin test (DAT). Of 1411 term deliveries with a clearly recorded aUCB, 30 infants developed clinically-significant jaundice (2.7%), of whom 8 were DAT + ve (0.6%) mostly due to ABO incompatibility. aUCB strongly predicted the development of DAT + ve jaundice (area under the ROC curve = 0.996), as well as all-cause jaundice (area under the ROC curve = 0.74). However, this effect was critically dependent on maternal blood group. Amongst infants at risk of ABO incompatibility (maternal blood groups O + ve/O-ve, 39.7%) the predictive value of aUCB for all cause jaundice was strengthened (area under the ROC curve = 0.88). Amongst those not at risk (defined maternal blood group not O + ve/O-ve, 51.0%) it disappeared completely (area under the ROC curve = 0.46). A cutoff of 35 μmol/l for mothers with blood group O + ve/O-ve increased the pre-test probability for all-cause jaundice of 4% to a post-test probability of 30%. For infants of mothers with blood group O, aUCB predicts development of neonatal jaundice. There was no evident utility for infants of mothers with other blood groups. Estimation of aUCB should be considered as a strategy for early identification of those at risk of neonatal haemolytic jaundice.

  17. Breast Milk Jaundice: Effect of 3α 20β-pregnanediol on Bilirubin Conjugation by Human Liver

    PubMed Central

    Adlard, B. P. F.; Lathe, G. H.

    1970-01-01

    The effect of 3α,20β-pregnanediol and other steroids on bilirubin conjugation was examined using liver tissue from human and four other species. Neither 3α,20β-pregnanediol nor 3α,20β-pregnanediol inhibited conjugation by human liver slices or by solubilized human liver microsomes. 3α,20β-pregnanediol is unlikely to be the inhibitor causing breast milk jaundice. Oestriol inhibited conjugation by human liver slices. A comparison of species indicated that the response of the human liver slice system to steroids resembles that of the rabbit and guinea-pig rather than the rat or mouse. PMID:4246186

  18. Endogenously elevated bilirubin modulates kidney function and protects from circulating oxidative stress in a rat model of adenine-induced kidney failure.

    PubMed

    Boon, Ai-Ching; Lam, Alfred K; Gopalan, Vinod; Benzie, Iris F; Briskey, David; Coombes, Jeff S; Fassett, Robert G; Bulmer, Andrew C

    2015-10-26

    Mildly elevated bilirubin is associated with a reduction in the presence and progression of chronic kidney disease and related mortality, which may be attributed to bilirubin's antioxidant properties. This study investigated whether endogenously elevated bilirubin would protect against adenine-induced kidney damage in male hyperbilirubinaemic Gunn rats and littermate controls. Animals were orally administered adenine or methylcellulose solvent (vehicle) daily for 10 days and were then monitored for 28 days. Serum and urine were assessed throughout the protocol for parameters of kidney function and antioxidant/oxidative stress status and kidneys were harvested for histological examination upon completion of the study. Adenine-treated animals experienced weight-loss, polyuria and polydipsia; however, these effects were significantly attenuated in adenine-treated Gunn rats. No difference in the presence of dihydroadenine crystals, lymphocytic infiltration and fibrosis were noted in Gunn rat kidneys versus controls. However, plasma protein carbonyl and F2-isoprostane concentrations were significantly decreased in Gunn rats versus controls, with no change in urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine or kidney tissue F2-isoprostane concentrations. These data indicated that endogenously elevated bilirubin specifically protects from systemic oxidative stress in the vascular compartment. These data may help to clarify the protective relationship between bilirubin, kidney function and cardiovascular mortality in clinical investigations.

  19. Population-based pediatric reference intervals for HbA1c, bilirubin, albumin, CRP, myoglobin and serum enzymes.

    PubMed

    Rödöö, Peo; Ridefelt, Peter; Aldrimer, Mattias; Niklasson, Frank; Gustafsson, Jan; Hellberg, Dan

    2013-08-01

    Many previous studies on reference intervals are hampered by the inclusion of only hospital-based populations of children and adolescents. This study included 694 children, evenly distributed from 6 months to 18 years of age. They were recruited as volunteers at child care units and schools. All subjects were apparently healthy. A questionnaire on diseases and medications was filled out by parents and by the older children. Alanine aminotransferase (ALT), albumin, aspartate aminotransferase (AST), bilirubin, conjugated bilirubin, C-reactive protein (CRP), creatine kinase (CK), Gamma-glutamyltransferase (GGT), HbA1c (mono S and IFCC calibrations), lactate dehydrogenase (LD), myoglobin and panceratic amylase were analyzed on Abbott Architect ci8200, and for HbA1c on Tosoh G7 and a mono S-system. Age- and gender-related 2.5th and 97.5th percentiles were estimated. For some analytes the differences to comparable studies were substantial. The study gives age- and gender-specific pediatric reference intervals, measured with modern methods for a number of important analytes. The results emphasize the importance to evaluate pediatric reference intervals in different populations and ethnic groups including only healthy subjects.

  20. The study on clinical value of the detection about serum and Unconjugated Bilirubin in diagnosis of neonatal jaundice.

    PubMed

    Wang, Guangzhou; Wang, Jiefei; Huang, Nannan; Yu, Fengqin

    2016-01-01

    In this paper, the clinical value of the detection about serum and unconjugated bilirubin (UCB) in neonatal jaundice was studied to found an effective and rapid method for diagnose of neonatal jaundice. ALB (Serum Albumin), total serum bilirubin (TSB) and UCB were detected by ELISA method among the 100 cases with neonatal jaundice selected for the study. The values of ALB, UCB and TSB in moderate jaundice patients were (42.83±3.87) g/L, (287.35±44.38) μm/L, (304.16±43.40) μm/L, respectively; as for the severe jaundice patients, the values were (38.41±4.82) g/L, (354.38±48.75) μm/L, (375.20±47.51) μm/L. The results showed significant differences with the p< 0.05 between moderate and severe jaundice patients. The level of ALB, UCB, TSB in hemolytic jaundice, obstructive jaundice and jaundice caused by other infections also had significant differences, and the difference was statistically significant (p<0.05). The detection of ALB and UCB provides a useful method for the diagnosis and assessment of neonatal jaundice.

  1. Bilirubin as an antioxidant in micelles and lipid bilayers: its contribution to the total antioxidant capacity of human blood plasma.

    PubMed

    MacLean, Patricia D; Drake, Emily C; Ross, L; Barclay, C

    2007-08-15

    The antioxidant capacities, antioxidant activities, k(inh), and stoichiometric factors, n, of water-soluble derivatives of bilirubin (BR), BR-human serum albumin (BR-HSA), and BR-ditaurate disodium conjugate (BRC) were determined in aqueous/lipid dispersions of sodium dodecyl sulfate (SDS) micelles/methyl linoleate and in bilayers of dilinoleoylphosphatidylcholine (DLPC) during initiation by water-soluble azo-bis-amidinopropane dihydrochloride (ABAP). The inhibition rate constants for BRC and BR-HSA were similar in micelles (k(inh) approximately 1.3 x 10(4) M(-1) s(-1)), where n approximately 2, whereas the k(inh) for BR-HSA dropped by (1/2) in bilayers. The dimethyl ester of bilirubin (BRDE) gave a k(inh) only one-tenth that of the vitamin E analog, pentamethylhydroxychroman (PMHC) in SDS micelles/methyl linoleate when initiated by lipid-soluble azo-bis-2,4-dimethylvaleronitrile (DMVN). Biliverdin hydrochloride (BVHCl) was NOT an effective peroxyl radical-trapping agent in the micellar phase during initiation by ABAP or DMVN containing methyl linoleate but it inhibited oxygen uptake in the aqueous phase. Both BRC and BR-HSA extended the total radical antioxidant parameter (TRAP) of human blood plasma and their contribution to TRAP was in the range of 5-10% of the natural TRAP of blood plasma, depending on the BR content determined in the blood plasma.

  2. Effect of heparin dose and infusion rate on lipid clearance and bilirubin binding in premature infants receiving intravenous fat emulsions.

    PubMed

    Spear, M L; Stahl, G E; Hamosh, M; McNelis, W G; Richardson, L L; Spence, V; Polin, R A; Pereira, G R; Hamosh, P

    1988-01-01

    The effect of heparin dose and infusion rate on plasma lipids, lipases, and unbound bilirubin was investigated in 22 premature infants with physiologic jaundice. Infants were randomly assigned to receive low or high intravenous doses (24 vs 137.3 U/day) of heparin. Each patient then received 2 g/kg/day of 10% Intralipid on 2 successive days: one day during a 15-hour period and the other day over 24 hours, with the order assigned randomly. The results demonstrate a significantly greater change in serum-free fatty acids in infants receiving the high heparin dose during the 15-hour lipid infusion period. Lipoprotein lipase activity rose more with the high heparin dose and equally at either infusion rate. We conclude that lipid infusions of 2 g/kg/day with low heparin dosage infused over 24 hours resulted in less elevation in serum-free fatty acids. There were no adverse effects on unbound bilirubin at either infusion rate or heparin dosage.

  3. Bilirubin Oxidase from Myrothecium verrucaria Physically Absorbed on Graphite Electrodes. Insights into the Alternative Resting Form and the Sources of Activity Loss.

    PubMed

    Tasca, Federico; Farias, Diego; Castro, Carmen; Acuna-Rougier, Cristina; Antiochia, Riccarda

    2015-01-01

    The oxygen reduction reaction is one of the most important chemical processes in energy converting systems and living organisms. Mediator-less, direct electro-catalytic reduction of oxygen to water was achieved on spectrographite electrodes modified by physical adsorption of bilirubin oxidases from Myrothecium verrucaria. The existence of an alternative resting form of the enzyme is validated. The effect on the catalytic cycle of temperature, pH and the presence of halogens in the buffer was investigated. Previous results on the electrochemistry of bilirubin oxidase and on the impact of the presence of halogens are reviewed and reinterpreted.

  4. Levels of alkaline phosphatase and bilirubin are surrogate end points of outcomes of patients with primary biliary cirrhosis: an international follow-up study.

    PubMed

    Lammers, Willem J; van Buuren, Henk R; Hirschfield, Gideon M; Janssen, Harry L A; Invernizzi, Pietro; Mason, Andrew L; Ponsioen, Cyriel Y; Floreani, Annarosa; Corpechot, Christophe; Mayo, Marlyn J; Battezzati, Pier M; Parés, Albert; Nevens, Frederik; Burroughs, Andrew K; Kowdley, Kris V; Trivedi, Palak J; Kumagi, Teru; Cheung, Angela; Lleo, Ana; Imam, Mohamad H; Boonstra, Kirsten; Cazzagon, Nora; Franceschet, Irene; Poupon, Raoul; Caballeria, Llorenç; Pieri, Giulia; Kanwar, Pushpjeet S; Lindor, Keith D; Hansen, Bettina E

    2014-12-01

    Noninvasive surrogate end points of long-term outcomes of patients with primary biliary cirrhosis (PBC) are needed to monitor disease progression and evaluate potential treatments. We performed a meta-analysis of individual patient data from cohort studies to evaluate whether patients' levels of alkaline phosphatase and bilirubin correlate with their outcomes and can be used as surrogate end points. We performed a meta-analysis of data from 4845 patients included in 15 North American and European long-term follow-up cohort studies. Levels of alkaline phosphatase and bilirubin were analyzed in different settings and subpopulations at different time points relative to the clinical end point (liver transplantation or death). Of the 4845 patients, 1118 reached a clinical end point. The median follow-up period was 7.3 years; 77% survived for 10 years after study enrollment. Levels of alkaline phosphatase and bilirubin measured at study enrollment (baseline) and each year for 5 years were strongly associated with clinical outcomes (lower levels were associated with longer transplant-free survival). At 1 year after study enrollment, levels of alkaline phosphatase that were 2.0 times the upper limit of normal (ULN) best predicted patient outcome (C statistic, 0.71) but not significantly better than other thresholds. Of patients with alkaline phosphatase levels ≤ 2.0 times the ULN, 84% survived for 10 years compared with 62% of those with levels >2.0 times the ULN (P < .0001). Absolute levels of alkaline phosphatase 1 year after study enrollment predicted patient outcomes better than percentage change in level. One year after study enrollment, a bilirubin level 1.0 times the ULN best predicted patient transplant-free survival (C statistic, 0.79). Of patients with bilirubin levels ≤ 1.0 times the ULN, 86% survived for 10 years after study enrollment compared with 41% of those with levels >1.0 times the ULN (P < .0001). Combining levels of alkaline phosphatase and

  5. Bilirubin Oxidase from Myrothecium verrucaria Physically Absorbed on Graphite Electrodes. Insights into the Alternative Resting Form and the Sources of Activity Loss

    PubMed Central

    Tasca, Federico; Farias, Diego; Castro, Carmen; Acuna-Rougier, Cristina; Antiochia, Riccarda

    2015-01-01

    The oxygen reduction reaction is one of the most important chemical processes in energy converting systems and living organisms. Mediator-less, direct electro-catalytic reduction of oxygen to water was achieved on spectrographite electrodes modified by physical adsorption of bilirubin oxidases from Myrothecium verrucaria. The existence of an alternative resting form of the enzyme is validated. The effect on the catalytic cycle of temperature, pH and the presence of halogens in the buffer was investigated. Previous results on the electrochemistry of bilirubin oxidase and on the impact of the presence of halogens are reviewed and reinterpreted. PMID:26196288

  6. Determination of free bilirubin and its binding capacity by HSA using a microfluidic chip-capillary electrophoresis device with a multi-segment circular-ferrofluid-driven micromixing injection.

    PubMed

    Sun, Hui; Nie, Zhou; Fung, Ying Sing

    2010-09-01

    A PMMA microfluidic chip-CE device with a multi-segment circular-ferrofluid-driven micromixing injector has been developed for the determination of free bilirubin and its binding capacity by HSA at equilibrium. The design of the device and its fabrication by a low cost CO(2) laser are discussed for intended applications. Under optimized conditions, the total binding capacity of HSA for bilirubin was determined as 16.3±1.4 mg/l00 mL human serum (n=3) and residual binding capacity for bilirubin 9.8 mg/100 mL (n=3) in normal infants. To assess risk of hyperbilirubinemia, free bilirubin and residual binding capacity by HSA provide a better indicator than total bilirubin, as neonates with impaired bilirubin binding capacity could be detected. In addition, residual binding capacity provides an advanced indicator to predict the onset of hyperbilirubinemia before the appearance of free bilirubin. HSA down to 94 nL is used in each titration and a full assay of four titrations takes up 376 nL HSA, sufficient for newborns with HSA in microliter range. The device has shown capable to provide adequate margin of protection to detect an early rising level of bilirubin and impaired binding capacity prior to the onset of jaundice condition.

  7. Correlation Between C-reactive Protein and Non-enzymatic Antioxidants (Albumin, Ferritin, Uric Acid and Bilirubin) in Hemodialysis Patients.

    PubMed

    Beciragic, Amela; Resic, Halima; Prohic, Nejra; Karamehic, Jasenko; Smajlovic, Ajdin; Masnic, Fahrudin; Ajanovic, Selma; Coric, Aida

    2015-04-01

    Increased levels of C-Reactive Protein are found in 30-60% on hemodialysis patients and it is closely associated with the progression of atherosclerosis, cardiovascular morbidity and mortality. Non enzymatic antioxidants are antioxidants which primarily retain potentially dangerous ions of iron and copper in their inactive form and thereby prevent its participation in the production of free radicals. The aim of the study was to examine the relationship of CRP and non enzymatic antioxidants (albumin, ferritin, uric acid and bilirubin) i.e. examine the importance of CRP as a serum biomarker in assessing the condition of inflammation and its relationship to antioxidant protection in patients on hemodialysis. The study was cross-sectional, clinical, comparative and descriptive. The study involved 100 patients (non diabetic) on chronic hemodialysis. The control group consisted of 50 subjects without subjective and objective indicators of chronic renal disease. In all patients, the concentration of CRP as well as concentrations of non enzymatic antioxidants were determined. In the group of hemodialysis patients 60% were men and 40% women. The average age of hemodialysis patients was 54.13 ± 11.8 years and the average age of the control group 41.72 ± 9.8 years. The average duration of hemodialysis treatment was 91.42 ± 76.2 months. In the group of hemodialysis patients statistically significant, negative linear correlation was determined between the concentration of CRP in and albumin concentration (rho = -0.251, p = 0.012) as well as negative, statistics insignificant, linear correlation between serum CRP and the concentration of uric acid (r = -0.077, p = 0.448). Furthermore, the positive, linear correlation was determined between serum CRP and ferritin (r = 0.159, p = 0.114) and positive linear correlation between CRP and total serum bilirubin (r = 0.121, p = 0.230). In the control group was determined a statistically significant, positive, linear correlation

  8. Bilirubin-induced inflammatory response, glutamate release, and cell death in rat cortical astrocytes are enhanced in younger cells.

    PubMed

    Falcão, Ana S; Fernandes, Adelaide; Brito, Maria A; Silva, Rui F M; Brites, Dora

    2005-11-01

    Unconjugated bilirubin (UCB) encephalopathy is a predominantly early life condition resulting from the impairment of several cellular functions in the brain of severely jaundiced infants. However, only few data exist on the age-dependent effects of UCB and their association with increased vulnerability of premature newborns, particularly in a sepsis condition. We investigated cell death, glutamate efflux, and inflammatory cytokine dynamics after exposure of astrocytes at different stages of differentiation to clinically relevant concentrations of UCB and/or lipopolysaccharide (LPS). Younger astrocytes were more prone to UCB-induced cell death, glutamate efflux, and inflammatory response than older ones. Furthermore, in immature cells, LPS exacerbated UCB effects, such as cell death by necrosis. These findings provide a basis for the increased susceptibility of premature newborns to UCB deleterious effects, namely when associated with sepsis, and underline how crucial the course of cell maturation can be to UCB encephalopathy during moderate to severe neonatal jaundice.

  9. Bilirubin scavenges chloramines and inhibits myeloperoxidase-induced protein/lipid oxidation in physiologically relevant hyperbilirubinemic serum.

    PubMed

    Boon, A C; Hawkins, C L; Coombes, J S; Wagner, K H; Bulmer, A C

    2015-09-01

    Hypochlorous acid (HOCl), an oxidant produced by myeloperoxidase (MPO), induces protein and lipid oxidation, which is implicated in the pathogenesis of atherosclerosis. Individuals with mildly elevated bilirubin concentrations (i.e., Gilbert syndrome; GS) are protected from atherosclerosis, cardiovascular disease, and related mortality. We aimed to investigate whether exogenous/endogenous unconjugated bilirubin (UCB), at physiological concentrations, can protect proteins/lipids from oxidation induced by reagent and enzymatically generated HOCl. Serum/plasma samples supplemented with exogenous UCB (≤250µM) were assessed for their susceptibility to HOCl and MPO/H2O2/Cl(-) oxidation, by measuring chloramine, protein carbonyl, and malondialdehyde (MDA) formation. Serum/plasma samples from hyperbilirubinemic Gunn rats and humans with GS were also exposed to MPO/H2O2/Cl(-) to: (1) validate in vitro data and (2) determine the relevance of endogenously elevated UCB in preventing protein and lipid oxidation. Exogenous UCB dose-dependently (P<0.05) inhibited HOCl and MPO/H2O2/Cl(-)-induced chloramine formation. Albumin-bound UCB efficiently and specifically (3.9-125µM; P<0.05) scavenged taurine, glycine, and N-α-acetyllysine chloramines. These results were translated into Gunn rat and GS serum/plasma, which showed significantly (P<0.01) reduced chloramine formation after MPO-induced oxidation. Protein carbonyl and MDA formation was also reduced after MPO oxidation in plasma supplemented with UCB (P<0.05; 25 and 50µM, respectively). Significant inhibition of protein and lipid oxidation was demonstrated within the physiological range of UCB, providing a hypothetical link to protection from atherosclerosis in hyperbilirubinemic individuals. These data demonstrate a novel and physiologically relevant mechanism whereby UCB could inhibit protein and lipid modification by quenching chloramines induced by MPO-induced HOCl. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Independent Analysis of Albumin-Bilirubin Grade in a 765-Patient Cohort Treated with Transarterial Locoregional Therapy for Hepatocellular Carcinoma.

    PubMed

    Hickey, Ryan; Mouli, Samdeep; Kulik, Laura; Desai, Kush; Thornburg, Bartley; Ganger, Daniel; Baker, Talia; Abecassis, Michael; Ralph Kallini, Joseph; Gabr, Ahmed; Gates, Vanessa L; Benson Iii, Al B; Lewandowski, Robert J; Salem, Riad

    2016-06-01

    To assess validity of albumin-bilirubin (ALBI) grade as a predictor of survival in patients undergoing transarterial embolization for hepatocellular carcinoma. Baseline albumin and bilirubin values of 765 consecutive patients treated with conventional transarterial chemoembolization or yttrium-90 ((90)Y) radioembolization at a single institution were used to determine liver function according to ALBI grade. Survival outcomes were stratified by ALBI grade using Kaplan-Meier and stratified by Child-Pugh (C-P) class and Barcelona Clinic Liver Cancer (BCLC) stage. Discriminatory ability was assessed by C-index. For 428 patients receiving (90)Y radioembolization, ALBI grade yielded distinct survival curves (P < .001). When stratified by C-P class and BCLC stage, ALBI grade revealed different survival outcomes for C-P B (P = .001), BCLC A (P < .001), BCLC B (P = .001), and BCLC C (P < .001). When substratified by BCLC stage, ALBI grade was a better discriminator of survival than C-P class (C-index 0.792, 0.763, respectively). For 337 patients receiving transarterial chemoembolization, ALBI grade yielded distinct survival curves (P < .001). When stratified by C-P class and BCLC stage, ALBI grade provided distinct survival curves for C-P B (P = .02), BCLC B (P = .001), and BCLC C (P = .02). When substratified by BCLC stage, ALBI grade was a better discriminator of survival than C-P class (C-index 0.739, 0.735, respectively). ALBI grade outperforms C-P class at discriminating survival in patients receiving transarterial chemoembolization or (90)Y radioembolization. ALBI grade is also valuable in patients with moderate liver dysfunction and BCLC B disease. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

  11. Higher plasma bilirubin predicts veno-occlusive disease in early childhood undergoing hematopoietic stem cell transplantation with cyclosporine

    PubMed Central

    Kim, Kwi Suk; Moon, Aree; Kang, Hyoung Jin; Shin, Hee Young; Choi, Young Hee; Kim, Hyang Sook; Kim, Sang Geon

    2016-01-01

    AIM: To analyze the association between plasma bilirubin levels and veno-occlusive disease (VOD) in non-adult patients undergoing hematopoietic stem cell transplantation (HSCT) during cyclosporine therapy. METHODS: A total of 123 patients taking cyclosporine were evaluated using an electronic medical system at the Seoul National University Children’s Hospital from the years 2004 through 2011. Patients were grouped by age and analyzed for incidence and type of adverse drug reactions (ADRs) including VOD. RESULTS: The HSCT patients were divided into three age groups: G#1 ≥ 18; 9 ≤ G#2 ≤ 17; and G#3 ≤ 8 years of age). The majority of transplant donor types were cord blood transplantations. Most prevalent ADRs represented acute graft-vs-host disease (aGVHD) and VOD. Although the incidences of aGVHD did not vary among the groups, the higher frequency ratios of VOD in G#3 suggested that an age of 8 or younger is a risk factor for developing VOD in HSCT patients. After cyclosporine therapy, the trough plasma concentrations of cyclosporine were lower in G#3 than in G#1, indicative of its increased clearance. Moreover, in G#3 only, a maximal total bilirubin level (BILmax) of ≥ 1.4 mg/dL correlated with VOD incidence after cyclosporine therapy. CONCLUSION: HSCT patients 8 years of age or younger are more at risk for developing VOD, diagnosed as hyperbilirubinemia, tender hepatomegaly, and ascites/weight gain after cyclosporine therapy, which may be represented by a criterion of plasma BILmax being ≥ 1.4 mg/dL, suggestive of more sensitive VOD indication in this age group. PMID:27358786

  12. Bilirubin calculi crushing by laser irradiation at a molecular oscillating region wavelength based on infrared absorption spectrum analysis using a free-electron laser: an experimental study.

    PubMed

    Watanabe, M; Kajiwara, H; Awazu, K; Aizawa, K

    2001-01-01

    We investigated a new laser technique of crushing bilirubin calculi, our aim being to crush calculi in isolation using a minimally invasive procedure. Infrared absorption spectrum analysis of the bilirubin calculi was conducted, revealing maximum absorption spectrum at a wavelength of the C=O stretching vibration of ester binding that exists within the molecular structure of bilirubin calcium. As an experiment to crush calculi using the free-electron laser, we set the laser at the effective irradiation wavelength of ester binding, and conducted noncontact irradiation of the bilirubin calculi. The calculi began to slowly ablate until the irradiated site had been completely obliterated after 20s of irradiation. Moreover, absorption spectrum analysis of the irradiated site, from a comparison of absorption peak ratios, revealed that absorption peak intensities decreased over time at the absorption wavelength of ester binding. These findings suggest that irradiation of molecular oscillating region wavelengths peculiar to calculi based on infrared absorption spectrum analysis results in the gradual crushing of calculi in isolation by breaking down their molecular structure.

  13. Endogenously elevated bilirubin modulates kidney function and protects from circulating oxidative stress in a rat model of adenine-induced kidney failure

    PubMed Central

    Boon, Ai-Ching; Lam, Alfred K.; Gopalan, Vinod; Benzie, Iris F.; Briskey, David; Coombes, Jeff S.; Fassett, Robert G.; Bulmer, Andrew C.

    2015-01-01

    Mildly elevated bilirubin is associated with a reduction in the presence and progression of chronic kidney disease and related mortality, which may be attributed to bilirubin’s antioxidant properties. This study investigated whether endogenously elevated bilirubin would protect against adenine-induced kidney damage in male hyperbilirubinaemic Gunn rats and littermate controls. Animals were orally administered adenine or methylcellulose solvent (vehicle) daily for 10 days and were then monitored for 28 days. Serum and urine were assessed throughout the protocol for parameters of kidney function and antioxidant/oxidative stress status and kidneys were harvested for histological examination upon completion of the study. Adenine-treated animals experienced weight-loss, polyuria and polydipsia; however, these effects were significantly attenuated in adenine-treated Gunn rats. No difference in the presence of dihydroadenine crystals, lymphocytic infiltration and fibrosis were noted in Gunn rat kidneys versus controls. However, plasma protein carbonyl and F2-isoprostane concentrations were significantly decreased in Gunn rats versus controls, with no change in urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine or kidney tissue F2-isoprostane concentrations. These data indicated that endogenously elevated bilirubin specifically protects from systemic oxidative stress in the vascular compartment. These data may help to clarify the protective relationship between bilirubin, kidney function and cardiovascular mortality in clinical investigations. PMID:26498893

  14. Conjugated bilirubin affects cytokine profiles in hepatitis A virus infection by modulating function of signal transducer and activator of transcription factors

    PubMed Central

    Castro-García, Flor P; Corral-Jara, Karla F; Escobedo-Melendez, Griselda; Sandoval-Hernandez, Monserrat A; Rosenstein, Yvonne; Roman, Sonia; Panduro, Arturo; Fierro, Nora A

    2014-01-01

    Hepatitis A virus (HAV) infection is the major cause of acute liver failure in paediatric patients. The clinical spectrum of infection is variable, and liver injury is determined by altered hepatic enzyme function and bilirubin concentration. We recently reported differences in cytokine profiles between distinct HAV-induced clinical courses, and bilirubin has been recognized as a potential immune-modulator. However, how bilirubin may affect cytokine profiles underlying the variability in the course of infection has not been determined. Herein, we used a transcription factor (TF) binding site identification approach to retrospectively analyse cytokine expression in HAV-infected children and to predict the entire set of TFs associated with the expression of specific cytokine profiles. The results suggested that modulation of the activity of signal transducers and activators of transcription proteins (STATs) may play a central role during HAV infection. This led us to compare the degree of STAT phosphorylation in peripheral blood lymphoid cells (PBLCs) from paediatric patients with distinct levels of conjugated bilirubin (CB). Low CB levels in sera were associated with increased STAT-1 and STAT-5 phosphorylation. A positive correlation was observed between the serum interleukin-6 (IL-6) content and CB values, whereas higher levels of CB correlated with reduced serum IL-8 values and with a reduction in the proportion of PBLCs positive for STAT-5 phosphorylation. When CB was used to stimulate patients’ PBLCs in vitro, the levels of IL-6 and tumour necrosis factor-α were increased. The data showed that bilirubin plays a role in STAT function and affects cytokine profile expression during HAV infection. PMID:24943111

  15. Developmental Onset of Bilirubin-induced Neurotoxicity Involves Toll-like Receptor 2-dependent Signaling in Humanized UDP-glucuronosyltransferase1 Mice*

    PubMed Central

    Yueh, Mei-Fei; Chen, Shujuan; Nguyen, Nghia; Tukey, Robert H.

    2014-01-01

    Biological and signaling events that connect developmentally induced hyperbilirubinemia to bilirubin-induced neurological dysfunction (BIND) and CNS toxicity in humans are poorly understood. In mammals, UDP-glucuronosyltransferase 1A1 (UGT1A1) is the sole enzyme responsible for bilirubin glucuronidation, a rate-limiting step necessary for bilirubin metabolism and clearance. Humanized mice that express the entire UGT1 locus (hUGT1) and the UGT1A1 gene, develop neonatal hyperbilirubinemia, with 8–10% of hUGT1 mice succumbing to CNS damage, a phenotype that is presented by uncontrollable seizures. We demonstrate that neuroinflammation and reactive gliosis are prominent features of bilirubin brain toxicity, and a disturbed redox status resulting from activation of NADPH oxidase is an important contributing mechanism found in BIND. Using knock-out mice and primary brain cells, we connect a key pattern recognition receptor, Toll-like receptor 2 (TLR2), to hyperbilirubinemia-induced signaling. We illustrate a requirement for TLR2 signaling in regulating gliosis, proinflammatory mediators, and oxidative stress when neonatal mice encounter severe hyperbilirubinemia. TLR2-mediated gliosis strongly correlates with pronounced neuroinflammation in the CNS with up-regulation of TNFα, IL-1β, and IL-6, creating a pro-inflammatory CNS environment. Gene expression and immunohistochemistry staining show that hUGT1/Tlr2−/− mice fail to activate glial cells, proinflammatory cytokines, and stress response genes. In addition, bilirubin-induced apoptosis was significantly enhanced by blocking TLR2 signaling indicating its anti-apoptotic property. Consequently, a higher neonatal death rate (57.1%) in hUGT1/Tlr2−/− mice was observed when compared with hUGT1 mice (8.7%). These results suggest that TLR2 signaling and microglia neuroinflammation are linked to a repair and/or protection mode against BIND. PMID:24403077

  16. Conjugated bilirubin affects cytokine profiles in hepatitis A virus infection by modulating function of signal transducer and activator of transcription factors.

    PubMed

    Castro-García, Flor P; Corral-Jara, Karla F; Escobedo-Melendez, Griselda; Sandoval-Hernandez, Monserrat A; Rosenstein, Yvonne; Roman, Sonia; Panduro, Arturo; Fierro, Nora A

    2014-12-01

    Hepatitis A virus (HAV) infection is the major cause of acute liver failure in paediatric patients. The clinical spectrum of infection is variable, and liver injury is determined by altered hepatic enzyme function and bilirubin concentration. We recently reported differences in cytokine profiles between distinct HAV-induced clinical courses, and bilirubin has been recognized as a potential immune-modulator. However, how bilirubin may affect cytokine profiles underlying the variability in the course of infection has not been determined. Herein, we used a transcription factor (TF) binding site identification approach to retrospectively analyse cytokine expression in HAV-infected children and to predict the entire set of TFs associated with the expression of specific cytokine profiles. The results suggested that modulation of the activity of signal transducers and activators of transcription proteins (STATs) may play a central role during HAV infection. This led us to compare the degree of STAT phosphorylation in peripheral blood lymphoid cells (PBLCs) from paediatric patients with distinct levels of conjugated bilirubin (CB). Low CB levels in sera were associated with increased STAT-1 and STAT-5 phosphorylation. A positive correlation was observed between the serum interleukin-6 (IL-6) content and CB values, whereas higher levels of CB correlated with reduced serum IL-8 values and with a reduction in the proportion of PBLCs positive for STAT-5 phosphorylation. When CB was used to stimulate patients' PBLCs in vitro, the levels of IL-6 and tumour necrosis factor-α were increased. The data showed that bilirubin plays a role in STAT function and affects cytokine profile expression during HAV infection. © 2014 John Wiley & Sons Ltd.

  17. Serum alkaline phosphatase and bilirubin are early surrogate markers for ischemic cholangiopathy and graft failure in liver transplantation from donation after circulatory death.

    PubMed

    Halldorson, J B; Rayhill, S; Bakthavatsalam, R; Montenovo, M; Dick, A; Perkins, J; Reyes, J

    2015-03-01

    Liver transplantation with the use of donation after circulatory death (DCD) is associated with ischemic cholangiopathy (IC) often leading to graft loss. We hypothesized that serial postoperative analysis of alkaline phosphatase and bilirubin might identify patients who would later on develop ischemic cholangiopathy and/or graft loss, allowing early recognition and potentially retransplantation. The University of Washington DCD experience totals 89 DCD liver transplantations performed from 2003 to 2011 with Kaplan-Meier estimated 5-year patient and graft survival rates of 81.6% and 75.6%, respectively; 84/89 patients transplanted with DCD livers lived ≥ 60 days after transplantation and were analyzed. Serum bilirubin and alkaline phosphatase levels at 1 week, 2 week, 1 month, and 2 months after transplantation were analyzed. Two-month serum bilirubin and alkaline phosphatase proved to have the strongest associations with development of IC and graft failure. Two-month alkaline phosphatase of <100 U/L had a negative predictive value of 97% for development of IC. Two-month alkaline phosphatase demonstrated an inflection starting at >300 U/L strongly associated with development of IC (P < .0001). Serum bilirubin at 2 months was most strongly associated with graft failure within the 1st year with a strong inflection point at 2.5 mg/dL (P = .0001). All jaundiced recipients at 60 days after transplantation (bilirubin >2.5 mg/dL) developed graft failure within the 1st year (P < .0001). Use of these early surrogate markers could facilitate prioritization and early retransplantation for DCD liver recipients with allografts destined for failure.

  18. Predictive Value of Total Serum Bilirubin within 6 Hour of Birth for the Development of Hyperbilirubinemia After 72 hours of Birth

    PubMed Central

    Vanaki, Raghavendra; Badakali, Ashok V.; Pol, Ramesh R; Yelamali, Bhuvaneshwari

    2016-01-01

    Introduction Neonatal jaundice is benign and no intervention might be required, but jaundice can be associated with an underlying disease condition, which therefore warrants accurate and unbiased estimation of bilirubin. Total Serum Bilirubin (TSB) measurements (at discharge between 18 hours and 72 hours) can be used to predict the chances of developing severe hyperbilirubinemia. Materials and Methods The present hospital-based prospective study was undertaken to determine the predictive value of serum bilirubin before 6 hours of life for subsequent hyperbilirubinemia in healthy term neonates. One hundred and fifty healthy term newborns delivered during January 2013–December 2013 at Hanagal Shri Kumareshwara Hospital and Research Centre, S. Nijalingappa Medical College, Bagalkot Karnataka, India, were included in the study. Serum bilirubin levels were estimated twice, first, within 6 hours of life and second, after 72 hours of life. Bilirubin values were plotted on previously published nomograms. Sensitivity, specificity of the test was established. Results A measure of TSB levels (within 6 hours of life) across the study population, showed that maximum number of infants (70/150) had TSB level between 4.1 and 5.5 mg/dL and 16 infants had TSB level >5.6 mg/dL. The TSB levels (after 72 hours of life) showed that maximum newborns (83/150) had TSB levels between 12.8 and 15.3 mg/dL and 9 infants had TSB levels between 7.7 and 10.2mg/dL. Eighteen infants developed hyperbilirubinemia. Newborns with TSB value of >4.95mg/dL within 6hours of life had developed significant hyperbilirubinemia after 72 hours of life with sensitivity of 100% and specificity of 89% (p=0.0001), which was highly statistically significant. Conclusion A TSB level of >5 mg/dL within 6 hours of birth would serve as a predictor for risk of subsequent hyperbilirubinemia in the near future. PMID:27790538

  19. Modification of continuous venovenous hemodiafiltration with single-pass albumin dialysate allows for removal of serum bilirubin.

    PubMed

    Chawla, Lakhmir S; Georgescu, Florin; Abell, Bruce; Seneff, Michael G; Kimmel, Paul L

    2005-03-01

    A 53-year-old woman was admitted to the hospital with ischemic colitis and underwent a subtotal colectomy. She developed acute renal failure, severe hyperbilirubinemia, and intense pruritus resistant to medical treatment. Extracorporeal albumin dialysis using a Molecular Adsorbent Recirculating System (MARS; Gambro Co, Lund, Sweden) has been used to treat liver failure and reduce total serum bilirubin (SB) levels. A trial of extracorporeal albumin dialysis with continuous renal replacement therapy (RRT) was instituted to achieve net removal of SB. A 25% albumin solution was mixed with conventional dialysate to yield a dialysate concentration of 1.85% or 5.0% albumin. The patient underwent 2 continuous RRT sessions using extracorporeal albumin dialysis (1.85% and 5.0% albumin dialysate). Pretreatment and posttreatment SB levels were determined, and total bilirubin concentration (TB) also was measured in each of the collection bags during conventional and albumin dialysis. Pretreatment and posttreatment SB levels were 50.4 mg/dL (862 micromol/L) and 39.0 mg/dL (667 micromol/L) with 1.85% albumin dialysate and 47.1 mg/dL (805 micromol/L) and 39.7 mg/dL (679 micromol/L) with 5.0% albumin dialysate, respectively. The collected dialysate TB level was 0.3 mg/dL (5 micromol/L) during nonalbumin RRT and increased to 1.37 +/- 0.06 mg/dL (23 +/- 1 micromol/L) with 1.85% albumin dialysis. The collected dialysate fluid TB level was 0.3 mg/dL (5 micromol/L) during the nonalbumin RRT and increased to 1.38 +/- 0.15 mg/dL (24 +/- 3 micromol/L) during 5.0% albumin RRT. Single-pass albumin dialysis with continuous RRT cleared SB better than standard continuous RRT. Single-pass albumin dialysis with continuous RRT is feasible and may be a viable alternative in centers that do not have access to MARS therapy. This modality merits additional evaluation for its efficacy in clearing albumin-bound serum toxins.

  20. Increasing the catalytic activity of Bilirubin oxidase from Bacillus pumilus: Importance of host strain and chaperones proteins.

    PubMed

    Gounel, Sébastien; Rouhana, Jad; Stines-Chaumeil, Claire; Cadet, Marine; Mano, Nicolas

    2016-07-20

    Aggregation of recombinant proteins into inclusion bodies (IBs) is the main problem of the expression of multicopper oxidase in Escherichia coli. It is usually attributed to inefficient folding of proteins due to the lack of copper and/or unavailability of chaperone proteins. The general strategies reported to overcome this issue have been focused on increasing the intracellular copper concentration. Here we report a complementary method to optimize the expression in E. coli of a promising Bilirubin oxidase (BOD) isolated from Bacillus pumilus. First, as this BOD has a disulfide bridge, we switched E.coli strain from BL21 (DE3) to Origami B (DE3), known to promote the formation of disulfide bridges in the bacterial cytoplasm. In a second step, we investigate the effect of co-expression of chaperone proteins on the protein production and specific activity. Our strategy allowed increasing the final amount of enzyme by 858% and its catalytic rate constant by 83%. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Heat and drying time modulate the O2 reduction current of modified glassy carbon electrodes with bilirubin oxidases.

    PubMed

    Suraniti, Emmanuel; Abintou, Margot; Durand, Fabien; Mano, Nicolas

    2012-12-01

    Here we show that the magnitude of the O(2) reduction current of cathodes based on Bilirubin oxidases (BOD) immobilized into a redox hydrogel strongly depends on the drying conditions such as the curing time and temperature of drying as well as the thermostability of the BOD. To illustrate this effect, we performed experiments with two different BODs: one labile BOD from Trachyderma tsunodae and one highly thermostable BOD from Bacillus pumilus with different preparation protocols. The balance between the kinetics of formation of the hydrogel and the enzyme stability leads to optimal drying conditions of 2h at 25°C for both types of BODs when the most widespread protocol uses 18 hours at ambient temperature. For drying times longer than two hours, the catalytic current decreases because of the instability of T. tsunodae. Finally the optimal conditions for BOD from T. tsunodae lead to a faster preparation of electrodes than with the protocol currently in use (2h vs. 18h) and catalytic currents for oxygen reduction 100% higher (1040μA/cm(2) vs. 517μA/cm(2)).

  2. Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

    PubMed Central

    Bora, Tanujjal; Lakshman, Karthik Kunjali; Sarkar, Soumik; Makhal, Abhinandan; Sardar, Samim; Pal, Samir Kumar

    2013-01-01

    Summary In recent years, nanotechnology has gained significant interest for applications in the medical field. In this regard, a utilization of the ZnO nanoparticles for the efficient degradation of bilirubin (BR) through photocatalysis was explored. BR is a water insoluble byproduct of the heme catabolism that can cause jaundice when its excretion is impaired. The photocatalytic degradation of BR activated by ZnO nanoparticles through a non-radiative energy transfer pathway can be influenced by the surface defect-states (mainly the oxygen vacancies) of the catalyst nanoparticles. These were modulated by applying a simple annealing in an oxygen-rich atmosphere. The mechanism of the energy transfer process between the ZnO nanoparticles and the BR molecules adsorbed at the surface was studied by using steady-state and picosecond-resolved fluorescence spectroscopy. A correlation of photocatalytic degradation and time-correlated single photon counting studies revealed that the defect-engineered ZnO nanoparticles that were obtained through post-annealing treatments led to an efficient decomposition of BR molecules that was enabled by Förster resonance energy transfer. PMID:24367739

  3. Preoperative levels of bilirubin or creatinine adjusted by age can predict their reversibility after implantation of left ventricular assist device.

    PubMed

    Imamura, Teruhiko; Kinugawa, Koichiro; Shiga, Taro; Endo, Miyoko; Kato, Naoko; Inaba, Toshiro; Maki, Hisataka; Hatano, Masaru; Yao, Atsushi; Nishimura, Takashi; Hirata, Yasunobu; Kyo, Shunei; Ono, Minoru; Nagai, Ryozo

    2013-01-01

    It is often difficult to predict reversibility of liver or renal function after left ventricular assist device (LVAD) implantation in patients with stage D heart failure. Data were obtained for 69 patients who had received a LVAD (18 continuous-flow, 51 pulsatile). Persistent hepatic or renal dysfunction was defined as levels of total bilirubin (TB) or creatinine (Cre) >1.5mg/dl at 6 months after LVAD implantation. TB score or Cre score was calculated: 0.15 × age+1.1 × (preoperative TB) or 0.2 × age+3.6 × (preoperative Cre), in which coefficients were determined on the basis of odds ratios for persistent hepatic or renal dysfunction, respectively. Receiver-operating characteristics analyses showed good predictabilities for persistent end-organ dysfunction (area under curve: 0.794 for TB score and 0.839 for Cre score). High-risk strata of TB score (>11.0 points) or Cre score (>14.1 points) were associated with persistently higher levels of TB or Cre (TB, 1.32 ± 0.51; Cre, 1.23 ± 0.41 mg/dl; both P<0.001 vs. low-risk strata). Reversibility of end-organ function with LVAD implantation can be well predicted by our new risk scoring system that consists of the preoperative TB or Cre level adjusted by the patient's age. The scoring system would be beneficial, especially in considering the indication of a bridge to candidacy.

  4. Total Serum Bilirubin Predicts Fat-Soluble Vitamin Deficiency Better Than Serum Bile Acids in Infants with Biliary Atresia

    PubMed Central

    Venkat, Veena L.; Shneider, Benjamin L.; Magee, John C.; Turmelle, Yumirle; Arnon, Ronen; Bezerra, Jorge A.; Hertel, Paula M.; Karpen, Saul J; Kerkar, Nanda; Loomes, Kathleen M.; Molleston, Jean; Murray, Karen F.; Ng, Vicky L.; Raghunathan, Trivellore; Rosenthal, Philip; Schwartz, Kathleen; Sherker, Averell H.; Sokol, Ronald J.; Teckman, Jeffrey; Wang, Kasper; Whitington, Peter F.; Heubi, James E.

    2014-01-01

    Objective Fat soluble vitamin (FSV) deficiency is a well-recognized consequence of cholestatic liver disease and reduced intestinal intraluminal bile acids. We hypothesized that serum bile acids (SBA) would predict biochemical FSV deficiency better than serum total bilirubin level (TB) in infants with biliary atresia. Methods Infants enrolled in the Trial of Corticosteroid Therapy in Infants with Biliary Atresia (START) after hepatoportoenterostomy were the subjects of this investigation. Infants received standardized FSV supplementation and monitoring of TB, SBA and vitamin levels at 1, 3 and 6 months. A logistic regression model was used with the binary indicator variable insufficient/sufficient as the outcome variable. Linear and non-parametric correlations were made between specific vitamin measurement levels and either TB or SBA. Results The degree of correlation for any particular vitamin at a specific time point was higher with TB than SBA (higher for TB in 31 circumstances versus 3 circumstances for SBA). Receiver operating characteristic (ROC) shows that TB performed better than SBA (AUC 0.998 vs. 0.821). Including both TB and SBA did not perform better than TB alone (AUC 0.998). Conclusion We found that TB was a better predictor of FSV deficiency than SBA in infants with biliary atresia. The role of SBA as a surrogate marker of FSV deficiency in other cholestatic liver diseases, such as PFIC, alpha-one antitrypsin deficiency and Alagille syndrome where the pathophysiology is dominated by intrahepatic cholestasis, warrants further study. PMID:25419594

  5. Research Update: Facile synthesis of CoFe2O4 nano-hollow spheres for efficient bilirubin adsorption

    NASA Astrophysics Data System (ADS)

    Rakshit, Rupali; Pal, Monalisa; Chaudhuri, Arka; Mandal, Madhuri; Mandal, Kalyan

    2015-11-01

    Herein, we report an unprecedented bilirubin (BR) adsorption efficiency of CoFe2O4 (CFO) nanostructures in contrast to the commercially available activated carbon and resin which are generally used for haemoperfusion and haemodialysis. We have synthesized CFO nanoparticles of diameter 100 nm and a series of nano-hollow spheres of diameter 100, 160, 250, and 350 nm using a simple template free solvothermal technique through proper variation of reaction time and capping agent, oleylamine (OLA), respectively, and carried out SiO2 coating by employing Stöber method. The comparative BR adsorption study of CFO and SiO2 coated CFO nanostructures indicates that apart from porosity and hollow configuration of nanostructures, the electrostatic affinity between anionic carboxyl group of BR and cationic amine group of OLA plays a significant role in adsorbing BR. Finally, we demonstrate that the BR adsorption capacity of the nanostructures can be tailored by varying the morphology as well as size of the nanostructures. We believe that our developed magnetic nanostructures could be considered as a potential material towards therapeutic applications against hyperbilirubinemia.

  6. The albumin-bilirubin grade improves hepatic reserve estimation post-sorafenib failure: implications for drug development.

    PubMed

    Pinato, D J; Yen, C; Bettinger, D; Ramaswami, R; Arizumi, T; Ward, C; Pirisi, M; Burlone, M E; Thimme, R; Kudo, M; Sharma, R

    2017-03-01

    Drug development in hepatocellular carcinoma (HCC) is limited by disease heterogeneity, with hepatic reserve being a major source of variation in survival outcomes. The albumin-bilirubin (ALBI) grade is a validated index of liver function in patients with HCC. To test the accuracy of the ALBI grade in predicting post-sorafenib overall survival (PSOS) in patients who permanently discontinued treatment. From a prospectively maintained international database of 447 consecutive referrals, we derived 386 eligible patients treated with sorafenib within Barcelona Clinic Liver Cancer C stage (62%), 75% of whom were of Child class A at initiation. Clinical variables at sorafenib discontinuation were analysed for their impact on post-sorafenib overall survival using uni- and multivariable analyses. Median post-sorafenib overall survival of the 386 eligible patients was 3.4 months and median sorafenib duration was 2.9 months, with commonest causes of cessation being disease progression (68%) and toxicity (24%). At discontinuation, 92 patients (24%) progressed to terminal stage, due to worsening Child class to C in 40 (10%). Median post-sorafenib overall survival in patients eligible for second-line therapies (n = 294) was 17.5, 7.5 and 1.9 months according respectively to ALBI grade 1, 2 and 3 (P < 0.001). The ALBI grade at sorafenib discontinuation identifies a subset of patients with prolonged stability of hepatic reserve and superior survival. This may allow improved patient selection for second-line therapies in advanced HCC. © 2017 John Wiley & Sons Ltd.

  7. The effect of premature and delayed birth on the development of UDP-glucuronosyltransferase activities towards bilirubin, morphine and testosterone in the rat.

    PubMed Central

    Campbell, M T; Wishart, G J

    1980-01-01

    In the rat, UDP-glucuronosyltransferase activities towards bilirubin, morphine and testosterone increase markedly after normal or premature birth. This rapid development is superimposed upon a much slower maturation of activity which occurs in utero during the last 2 days of normal gestation and gestation when birth is delayed. Development of all three activities is similar under these different conditions, suggesting a common developmenpal regulatory mechanism. PMID:6769435

  8. Veno-occlusive disease of the liver in the absence of elevation in bilirubin in pediatric patients after hematopoietic stem cell transplantation.

    PubMed

    Myers, Kasiani C; Dandoy, Christopher; El-Bietar, Javier; Davies, Stella M; Jodele, Sonata

    2015-02-01

    Veno-occlusive disease (VOD) of the liver is a well-described and significant complication of hematopoietic stem cell transplantation (HSCT), with limited successful therapeutic options in severe cases. Prompt diagnosis and initiation of treatment is crucial to restrict the extent of disease. However, a subset of patients may not meet all current diagnostic criteria at presentation, and waiting for these to be met may delay therapy. We retrospectively reviewed 794 HSCT patients treated at our institution between 2003 and 2013, identifying 17 (2.1%) who developed VOD. Of these, 5 (29%) were noted to have an absence of elevated bilirubin at the time of VOD diagnosis and reversal of portal venous flow on ultrasound. Median total and conjugated bilirubin at VOD diagnosis were 1.0 and 0.2 mg/dL, respectively. All 5 patients were subsequently diagnosed with multiorgan failure associated with VOD, including 1 with encephalopathy. Four were treated with intravenous high-dose methylprednisolone (500 mg/m(2) per dose every 12 hours for 6 doses). One patient received defibrotide therapy in addition to steroids and another supportive care alone. VOD resolved in 4 of 5 patients, with median time to resolution of VOD, defined as recovery of all organ function and normalization of bilirubin and portal venous flow, of 8 days. Two patients died later from progressive primary disease and chronic graft-versus-host disease, respectively. We conclude that a high index of suspicion for VOD should be maintained in patients despite lack of bilirubin elevation in the presence of other diagnostic criteria such as hepatomegaly, abdominal pain, ascites, or weight gain. Early ultrasound evaluation in these patients may lead to more timely diagnosis and therapeutic interventions. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  9. Cruciferous vegetable feeding alters UGT1A1 activity: diet- and genotype-dependent changes in serum bilirubin in a controlled feeding trial1

    PubMed Central

    Navarro, Sandi L.; Peterson, Sabrina; Chen, Chu; Makar, Karen W.; Schwarz, Yvonne; King, Irena B; Li, Shuying S.; Li, Lin; Kestin, Mark; Lampe, Johanna W.

    2009-01-01

    Chemoprevention by isothiocyanates from cruciferous vegetables occurs partly through up-regulation of phase-II conjugating enzymes, such as UDP-glucuronosyl-transferases (UGT). UGT1A1 glucuronidates bilirubin, estrogens, and several dietary carcinogens. The UGT1A1*28 polymorphism reduces transcription compared to the wild-type, resulting in decreased enzyme activity. Isothiocyanates are metabolized by glutathione-S-transferases (GST); variants may alter isothiocyanate clearance, such that response to crucifers may vary by genotype. We evaluated, in a randomized, controlled, cross-over feeding trial in humans (n=70), 3 test diets, (single- and double-“dose” cruciferous and cruciferous plus apiaceous) compared to a fruit-and-vegetable-free basal diet. We measured serum bilirubin concentrations on days 0, 7, 11 and 14 of each 2-week feeding period to monitor UGT1A1 activity, and determined effects of UGT1A1*28 and GSTM1/GSTT1-null variants on response. Aggregate bilirubin response to all vegetable-containing diets was statistically significantly lower compared to the basal diet (p<0.03 for all). Within each UGT1A1 genotype, lower bilirubin concentrations were seen in: *1/*1 in both single and double-dose cruciferous diets compared to basal (p<0.03 for both); *1/*28 in double-dose cruciferous and cruciferous plus apiaceous compared to basal, and cruciferous plus apiaceous compared to single-dose cruciferous (p<0.02 for all); and *28/*28 in all vegetable-containing diets compared to basal (p<0.02 for all). Evaluation of the effects of diet stratified by GST genotype revealed some statistically significant genotypic differences however, the magnitude was similar and not statistically significant between genotypes. These results may have implications for altering carcinogen metabolism through dietary intervention, particularly among UGT1A1*28/*28 individuals. PMID:19336732

  10. Bilirubin oxidase from Myrothecium verrucaria: X-ray determination of the complete crystal structure and a rational surface modification for enhanced electrocatalytic O2 reduction.

    PubMed

    Cracknell, James A; McNamara, Thomas P; Lowe, Edward D; Blanford, Christopher F

    2011-07-07

    The blue multi-copper oxidase bilirubin oxidase (BOx) from the ascomycete plant pathogen Myrothecium verrucaria (Mv) efficiently catalyses the oxidation of bilirubin to biliverdin, with the concomitant reduction of O(2) to water, a reaction of considerable interest for low-temperature bio-fuel cell applications. We have solved the complete X-ray determined structure of Mv BOx at 2.4 Å resolution, using molecular replacement with the Spore Coat Protein A (CotA) enzyme from Bacillus subtilis (PDB code 1GSK) as a template. The structure reveals an unusual environment around the blue type 1 copper (T1 Cu) that includes two non-coordinating hydrophilic amino acids, asparagine and threonine. The presence of a long, narrow and hydrophilic pocket near the T1 Cu suggests that structure of the substrate-binding site is dynamically determined in vivo. We show that the interaction between the binding pocket of Mv BOx and its highly conjugated natural organic substrate, bilirubin, can be used to stabilise the enzyme on a pyrolytic graphite electrode, more than doubling its electrocatalytic activity relative to the current obtained by simple adsorption of the protein to the carbon surface.

  11. A needle extraction utilizing a molecularly imprinted-sol-gel xerogel for on-line microextraction of the lung cancer biomarker bilirubin from plasma and urine samples.

    PubMed

    Moein, Mohammad Mahdi; Jabbar, Dunia; Colmsjö, Anders; Abdel-Rehim, Mohamed

    2014-10-31

    In the present work, a needle trap utilizing a molecularly imprinted sol-gel xerogel was prepared for the on-line microextraction of bilirubin from plasma and urine samples. Each prepared needle could be used for approximately one hundred extractions before it was discarded. Imprinted and non-imprinted sol-gel xerogel were applied for the extraction of bilirubin from plasma and urine samples. The produced molecularly imprinted sol-gel xerogel polymer showed high binding capacity and fast adsorption/desorption kinetics for bilirubin in plasma and urine samples. The adsorption capacity of molecularly imprinted sol-gel xerogel polymer was approximately 60% higher than that of non-imprinted polymer. The effect of the conditioning, washing and elution solvents, pH, extraction time, adsorption capacity and imprinting factor were investigated. The limit of detection and the lower limit of quantification were set to 1.6 and 5nmolL(-1), respectively using plasma or urine samples. The standard calibration curves were obtained within the concentration range of 5-1000nmolL(-1) in both plasma and urine samples. The coefficients of determination values (R(2)) were ≥0.998 for all runs. The extraction recovery was approximately 80% for BR in the human plasma and urine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Study on dioxygen reduction by mutational modifications of the hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase

    SciTech Connect

    Morishita, Hirotoshi; Kurita, Daisuke; Kataoka, Kunishige; Sakurai, Takeshi

    2014-07-18

    Highlights: • Proton transport pathway in bilirubin oxidase was mutated. • Two intermediates in the dioxygen reduction steps were trapped and characterized. • A specific glutamate for dioxygen reduction by multicopper oxidases was identified. - Abstract: The hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase is constructed with Glu463 and water molecules to transport protons for the four-electron reduction of dioxygen. Substitutions of Glu463 with Gln or Ala were attributed to virtually complete loss or significant reduction in enzymatic activities due to an inhibition of the proton transfer steps to dioxygen. The single turnover reaction of the Glu463Gln mutant afforded the highly magnetically interacted intermediate II (native intermediate) with a broad g = 1.96 electron paramagnetic resonance signal detectable at cryogenic temperatures. Reactions of the double mutants, Cys457Ser/Glu463Gln and Cys457Ser/Glu463Ala afforded the intermediate I (peroxide intermediate) because the type I copper center to donate the fourth electron to dioxygen was vacant in addition to the interference of proton transport due to the mutation at Glu463. The intermediate I gave no electron paramagnetic resonance signal, but the type II copper signal became detectable with the decay of the intermediate I. Structural and functional similarities between multicopper oxidases are discussed based on the present mutation at Glu463 in bilirubin oxidase.

  13. X-ray analysis of bilirubin oxidase from Myrothecium verrucaria at 2.3 Å resolution using a twinned crystal

    PubMed Central

    Mizutani, Kimihiko; Toyoda, Mayuko; Sagara, Kenta; Takahashi, Nobuyuki; Sato, Atsuko; Kamitaka, Yuji; Tsujimura, Seiya; Nakanishi, Yuji; Sugiura, Toshiyuki; Yamaguchi, Shotaro; Kano, Kenji; Mikami, Bunzo

    2010-01-01

    Bilirubin oxidase (BOD), a multicopper oxidase found in Myrothecium verrucaria, catalyzes the oxidation of bilirubin to biliverdin. Oxygen is the electron acceptor and is reduced to water. BOD is used for diagnostic analysis of bilirubin in serum and has attracted considerable attention as an enzymatic catalyst for the cathode of biofuel cells that work under neutral conditions. Here, the crystal structure of BOD is reported for the first time. Blue bipyramid-shaped crystals of BOD obtained in 2-methyl-2,4-pentanediol (MPD) and ammonium sulfate solution were merohedrally twinned in space group P63. Structure determination was achieved by the single anomalous diffraction (SAD) method using the anomalous diffraction of Cu atoms and synchrotron radiation and twin refinement was performed in the resolution range 33–2.3 Å. The overall organization of BOD is almost the same as that of other multicopper oxidases: the protein is folded into three domains and a total of four copper-binding sites are found in domains 1 and 3. Although the four copper-binding sites were almost identical to those of other multicopper oxidases, the hydrophilic Asn residue (at the same position as a hydrophobic residue such as Leu in other multicopper oxidases) very close to the type I copper might contribute to the characteristically high redox potential of BOD. PMID:20606269

  14. Bilirubin inhibits the up-regulation of inducible nitric oxide synthase by scavenging reactive oxygen species generated by the toll-like receptor 4-dependent activation of NADPH oxidase.

    PubMed

    Idelman, Gila; Smith, Darcey L H; Zucker, Stephen D

    2015-08-01

    It has been previously shown that bilirubin prevents the up-regulation of inducible nitric oxide synthase (iNOS) in response to LPS. The present study examines whether this effect is exerted through modulation of Toll-Like Receptor-4 (TLR4) signaling. LPS-stimulated iNOS and NADPH oxidase (Nox) activity in RAW 264.7 murine macrophages was assessed by measuring cellular nitrate and superoxide ( [Formula: see text] ) production, respectively. The generation of both nitrate and [Formula: see text] in response to LPS was suppressed by TLR4 inhibitors, indicating that activation of iNOS and Nox is TLR4-dependent. While treatment with superoxide dismutase (SOD) and bilirubin effectively abolished LPS-mediated [Formula: see text] production, hydrogen peroxide and nitrate release were inhibited by bilirubin and PEG-catalase, but not SOD, supporting that iNOS activation is primarily dependent upon intracellular H2O2. LPS treatment increased nuclear translocation of the redox-sensitive transcription factor Hypoxia Inducible Factor-1α (HIF-1α), an effect that was abolished by bilirubin. Cells transfected with murine iNOS reporter constructs in which the HIF-1α-specific hypoxia response element was disrupted exhibited a blunted response to LPS, supporting that HIF-1α mediates Nox-dependent iNOS expression. Bilirubin, but not SOD, blocked the cellular production of interferon-β, while interleukin-6 production remained unaffected. These data support that bilirubin inhibits the TLR4-mediated up-regulation of iNOS by preventing activation of HIF-1α through scavenging of Nox-derived reactive oxygen species. Bilirubin also suppresses interferon-β release via a ROS-independent mechanism. These findings characterize potential mechanisms for the anti-inflammatory effects of bilirubin.

  15. Relationship between plasma bilirubin level and oxidative stress markers in HIV-infected patients on atazanavir- vs. efavirenz-based antiretroviral therapy.

    PubMed

    Estrada, V; Monge, S; Gómez-Garre, M D; Sobrino, P; Masiá, M; Berenguer, J; Portilla, J; Viladés, C; Martínez, E; Blanco, J R

    2016-10-01

    Chronic oxidative stress (OS) may play a role in cardiovascular disease in HIV-infected patients, and increased bilirubin levels may have a beneficial role in counteracting OS. Atazanavir (ATV) inhibits UDP-glucuronosyl-transferase 1A1 (UGT1A1), thus increasing unconjugated bilirubin levels. We aimed to compare changes in OS markers in patients on ATV/ritonavir (ATV/r)- vs. efavirenz (EFV)-based first-line antiretroviral therapy (ART). A multicentre, prospective cohort study of HIV-infected patients who started first-line ART with either ATV/r or EFV was conducted. Lipoprotein-associated phospholipase A2 (Lp-PLA2), myeloperoxidase (MPO) and oxidized low-density lipoprotein (oxLDL) were measured for 145 patients in samples obtained at baseline and after at least 9 months of ART during which the initial regimen was maintained and the patient was virologically suppressed. The change in OS markers was modelled using multiple linear regressions adjusting for baseline values and confounders. After adjustment for baseline variables, patients on ATV/r had a significantly greater decrease in Lp-PLA2 [estimated difference -16.3; 95% confidence interval (CI) -31.4, -1.25; P = 0.03] and a significantly smaller increase in OxLDL (estimated difference -21.8; 95% CI -38.0, -5.6; P < 0.01) relative to those on EFV, whereas changes in MPO were not significantly different (estimated difference 1.2; 95% CI -14.3, 16.7; P = 0.88). Adjusted changes in bilirubin were significantly greater for the ATV/r group than for the EFV group (estimated difference 1.33 mg/dL; 95% CI 1.03, 1.52 mg/dL; P < 0.01). Changes in bilirubin and changes in OS markers were significantly correlated. When compared with EFV, ATV/r-based therapy was associated with lower levels of oxidative stress biomarkers, which was in part attributable to increased bilirubin levels. © 2016 British HIV Association.

  16. Influence of Phosphatidylcholine and Calcium on Self-Association and Bile Salt Mixed Micellar Binding of the Natural Bile Pigment, Bilirubin Ditaurate.

    PubMed

    Neubrand, Michael W; Carey, Martin C; Laue, Thomas M

    2015-11-17

    Recently [Neubrand, M. W., et al. (2015) Biochemistry 54, 1542-1557], we determined a concentration-dependent monomer-dimer-tetramer equilibrium in aqueous bilirubin ditaurate (BDT) solutions and explored the nature of high-affinity binding of BDT monomers with monomers and micelles of the common taurine-conjugated bile salts (BS). We now investigate, employing complementary physicochemical methods, including fluorescence emission spectrophotometry and quasi-elastic light scattering spectroscopy, the influence of phosphatidylcholine (PC), the predominant phospholipid of bile and calcium, the major divalent biliary cation, on these self-interactions and heterointeractions. We have used short-chain, lyso and long-chain PC species as models and contrasted our results with those of parallel studies employing unconjugated bilirubin (UCB) as the fully charged dianion. Both bile pigments interacted with the zwitterionic headgroup of short-chain lecithins, forming water-soluble (BDT) and insoluble ion-pair complexes (UCB), respectively. Upon micelle formation, BDT monomers apparently remained at the headgroup mantle of short-chain PCs, but the ion pairs with UCB became internalized within the micelle's hydrophobic core. BDT interacted with the headgroups of unilamellar egg yolk (EY) PC vesicles; however, with the simultaneous addition of CaCl2, a reversible aggregation took place, but not vesicle fusion. With mixed EYPC/BS micelles, BDT became bound to the hydrophilic surface (as with simple BS micelles), and in turn, both BDT and BS bound calcium, but not other divalent cations. The calcium complexation of BDT and BS was enhanced strongly with increases in micellar EYPC, suggesting calcium-mediated cross-bridging of hydrophilic headgroups at the micelle's surface. Therefore, the physicochemical binding of BDT to BS in an artificial bile medium is influenced not only by BS species and concentration but also by long-chain PCs and calcium ions that exert a specific rather

  17. Bilirubin UDP-Glucuronosyltransferase 1A1 (UGT1A1) Gene Promoter Polymorphisms and HPRT, Glycophorin A, and Micronuclei Mutant Frequencies in Human Blood

    SciTech Connect

    Grant, D; Hall, I J; Eastmond, D; Jones, I M; Bell, D A

    2004-10-06

    A dinucleotide repeat polymorphism (5-, 6-, 7-, or 8-TA units) has been identified within the promoter region of UDP-glucuronosyltransferase 1A1 gene (UGT1A1). The 7-TA repeat allele has been associated with elevated serum bilirubin levels that cause a mild hyperbilirubinemia (Gilbert's syndrome). Studies suggest that promoter transcriptional activity of UGT1A1 is inversely related to the number of TA repeats and that unconjugated bilirubin concentration increases directly with the number of TA repeat elements. Because bilirubin is a known antioxidant, we hypothesized that UGT1A1 repeats associated with higher bilirubin may be protective against oxidative damage. We examined the effect of UGT1A1 genotype on somatic mutant frequency in the hypoxanthine-guanine phosphoribosyl-transferase (HPRT) gene in human lymphocytes and the glycophorin A (GPA) gene of red blood cells (both N0, NN mutants), and the frequency of lymphocyte micronuclei (both kinetochore (K) positive or micronuclei K negative) in 101 healthy smoking and nonsmoking individuals. As hypothesized, genotypes containing 7-TA and 8-TA displayed marginally lower GPA{_}NN mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). In contrast, our analysis showed that lower expressing UGT1A1 alleles (7-TA and 8-TA) were associated with modestly increased HPRT mutation frequency (p<0.05) while the same low expression genotypes were not significantly associated with micronuclei frequencies (K-positive or K-negative) when compared to high expression genotypes (5-TA and 6-TA). We found weak evidence that UGT1A1 genotypes containing 7-TA and 8-TA were associated with increased GPA{_}N0 mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). These data suggest that UGT1A1 genotype may modulate somatic mutation of some types, in some cell lineages, by a mechanism not involving bilirubin antioxidant activity. More detailed studies examining UGT1A1 promoter variation, oxidant/antioxidant balance and genetic

  18. Application of poly[oxyethylene(dimethylimino)propyl-(dimethylimino)ethylene] as enzyme stabilizer for bilirubin oxidase immobilized electrode.

    PubMed

    Katano, Hajime; Uematsu, Kohei; Hibi, Takao; Ikeda, Tokuji; Tsukatani, Toshihide

    2009-09-01

    It has been shown that polyammonium cations comprising quaternary ammonium and hydrophilic groups such as amide and hydroxyl groups stabilize a redox enzyme bilirubin oxidase (BOD). The BOD catalyzes the reaction: 4[Fe(CN)6]4- + 4H+ + O2 --> 4[Fe(CN)6]3- + 2H2O, and has been a promising enzyme for use as a cathode catalyst in biofuel cells. In this study, the stabilizing effect of poly[oxyethylene(dimethylimino)propyl(dimethylimino)ethylene] (PA1) on BOD has been investigated. The sample solution containing BOD and the PA1 salt was kept at a given temperature, and the loss of the enzymatic activity was detected after given stored times. The activity decreased exponentially with stored time so that the first-order rate-constant of inactivation was determined. The inactivation rate-constant lowered with increasing the concentration of the PA1 salt, suggesting that BOD was stabilized by the association with the PA1 cation. The PA1 cation may act like a protective colloid or decrease the local disorder of BOD by its wrapping. A membrane-covered electrode containing BOD, PA1, and [Fe(CN)6](4-/3-) in the internal solution phase was examined in air-saturated aqueous solution. The electrode gave a well-defined current-potential curve with a steady state limiting current due to the PA1-[Fe(CN)6](4-/3-) polyion complex-mediated bioelectrocatalytic current for the reduction of O2. The decreasing of the steady state limiting current became slower in the presence of the PA1 salt, indicating again the stabilizing effect of PA1 cation on BOD.

  19. Anti-cancer effects of blue-green alga Spirulina platensis, a natural source of bilirubin-like tetrapyrrolic compounds.

    PubMed

    Koníčková, Renata; Vaňková, Kateřina; Vaníková, Jana; Váňová, Kateřina; Muchová, Lucie; Subhanová, Iva; Zadinová, Marie; Zelenka, Jaroslav; Dvořák, Aleš; Kolář, Michal; Strnad, Hynek; Rimpelová, Silvie; Ruml, Tomáš; J Wong, Ronald; Vítek, Libor

    2014-01-01

    Spirulina platensis is a blue-green alga used as a dietary supplement because of its hypocholesterolemic properties. Among other bioactive substances, it is also rich in tetrapyrrolic compounds closely related to bilirubin molecule, a potent antioxidant and anti-proliferative agent. The aim of our study was to evaluate possible anticancer effects of S. platensis and S. platensis-derived tetrapyrroles using an experimental model of pancreatic cancer. The anti-proliferative effects of S. platensis and its tetrapyrrolic components [phycocyanobilin (PCB) and chlorophyllin, a surrogate molecule for chlorophyll A] were tested on several human pancreatic cancer cell lines and xenotransplanted nude mice. The effects of experimental therapeutics on mitochondrial reactive oxygen species (ROS) production and glutathione redox status were also evaluated. Compared to untreated cells, experimental therapeutics significantly decreased proliferation of human pancreatic cancer cell lines in vitro in a dose-dependent manner (from 0.16 g•L-1 [S. platensis], 60 μM [PCB], and 125 μM [chlorophyllin], p<0.05). The anti-proliferative effects of S. platensis were also shown in vivo, where inhibition of pancreatic cancer growth was evidenced since the third day of treatment (p < 0.05). All tested compounds decreased generation of mitochondrial ROS and glutathione redox status (p = 0.0006; 0.016; and 0.006 for S. platensis, PCB, and chlorophyllin, respectively). In conclusion, S. platensis and its tetrapyrrolic components substantially decreased the proliferation of experimental pancreatic cancer. These data support a chemopreventive role of this edible alga. Furthermore, it seems that dietary supplementation with this alga might enhance systemic pool of tetrapyrroles, known to be higher in subjects with Gilbert syndrome.

  20. Assessment of the Albumin-Bilirubin (ALBI) Grade as a Prognostic Indicator for Hepatocellular Carcinoma Patients Treated With Radioembolization.

    PubMed

    Gui, Bin; Weiner, Ashley A; Nosher, John; Lu, Shou-En; Foltz, Gretchen M; Hasan, Omar; Kim, Seung K; Gendel, Vyacheslav; Mani, Naganathan B; Carpizo, Darren R; Saad, Nael E; Kennedy, Timothy J; Zuckerman, Darryl A; Olsen, Jeffrey R; Parikh, Parag J; Jabbour, Salma K

    2017-04-17

    As the utility of Child-Pugh (C-P) class is limited by the subjectivity of ascites and encephalopathy, we evaluated a previously established objective method, the albumin-bilirubin (ALBI) grade, as a prognosticator for yttrium-90 radioembolization (RE) treatment for patients with hepatocellular carcinoma (HCC). A total of 117 patients who received RE for HCC from 2 academic centers were reviewed and stratified by ALBI grade, C-P class, and Barcelona Clinic Liver Cancer stage. The overall survival (OS) according to these 3 criteria was evaluated by Kaplan-Meier survival analysis. The utilities of C-P class and ALBI grade as prognostic indicators were compared using the log-rank test. Multivariate Cox regression analysis was performed to identify additional predictive factors. Patients with ALBI grade 1 (n=49) had superior OS than those with ALBI grade 2 (n=65) (P=0.01). Meanwhile, no significant difference was observed in OS between C-P class A (n=100) and C-P class B (n=14) (P=0.11). For C-P class A patients, the ALBI grade (1 vs. 2) was able to stratify 2 clear and nonoverlapping subgroups with differing OS curves (P=0.03). Multivariate Cox regression test identified alanine transaminase, Barcelona Clinic Liver Cancer stage, and ALBI grade as the strongest prognostic factors for OS (P<0.10). ALBI grade as a prognosticator has demonstrated clear survival discrimination that is superior to C-P class among HCC patients treated with RE, particularly within the subgroup of C-P class A patients. ALBI grade is useful for clinicians to make decisions as to whether RE should be recommended to patients with HCC.

  1. The pH dependence of the cathodic peak potential of the active sites in bilirubin oxidase.

    PubMed

    Filip, Jaroslav; Tkac, Jan

    2014-04-01

    This is the first study showing pH dependence of three distinct redox sites within bilirubin oxidase (BOD) adsorbed on a nanocomposite modified electrode. The 1st redox centre with the highest redox potential Ec(1st)=404 mV vs. Ag/AgCl (614 mV vs. NHE at pH7.0) exhibited pH dependence with a slope -dEc(1st)/dpH=66(±3) mV under a non-turnover process. The 2nd redox centre with a potential Ec(2nd)=228 mV vs. Ag/AgCl (438 mV vs. NHE at pH7.0) was not dependent on pH in the absence and presence of O2. Finally, the 3rd redox site with a redox potential Ec(3rd)=92 mV vs. Ag/AgCl (302 mV vs. NHE at pH7.0) exhibited pH dependence for a cathodic process with -dEc(3rd)/dpH=70(±6) mV and for anodic process with -dEa(3rd)/dpH=73(±2) mV, respectively. Moreover, two break points for dependence of Ec(1st) or Ec(3rd) on pH were observed for the 1st (T1) site and the 3rd site assigned to involvement of two acidic amino acids (Asp105 and Glu463). A diagram of a potential difference between cathodic peaks of BOD as a dependence on pH is shown. The results obtained can be of interest for construction of biofuel cells based on BOD such as for generation of a low level of electricity from body fluids.

  2. Exposure to Lipopolysaccharide and/or Unconjugated Bilirubin Impair the Integrity and Function of Brain Microvascular Endothelial Cells

    PubMed Central

    Cardoso, Filipa L.; Kittel, Ágnes; Veszelka, Szilvia; Palmela, Inês; Tóth, Andrea; Brites, Dora; Deli, Mária A.; Brito, Maria A.

    2012-01-01

    Background Sepsis and jaundice are common conditions in newborns that can lead to brain damage. Though lipopolysaccharide (LPS) is known to alter the integrity of the blood-brain barrier (BBB), little is known on the effects of unconjugated bilirubin (UCB) and even less on the joint effects of UCB and LPS on brain microvascular endothelial cells (BMEC). Methodology/Principal Findings Monolayers of primary rat BMEC were treated with 1 µg/ml LPS and/or 50 µM UCB, in the presence of 100 µM human serum albumin, for 4 or 24 h. Co-cultures of BMEC with astroglial cells, a more complex BBB model, were used in selected experiments. LPS led to apoptosis and UCB induced both apoptotic and necrotic-like cell death. LPS and UCB led to inhibition of P-glycoprotein and activation of matrix metalloproteinases-2 and -9 in mono-cultures. Transmission electron microscopy evidenced apoptotic bodies, as well as damaged mitochondria and rough endoplasmic reticulum in BMEC by either insult. Shorter cell contacts and increased caveolae-like invaginations were noticeable in LPS-treated cells and loss of intercellular junctions was observed upon treatment with UCB. Both compounds triggered impairment of endothelial permeability and transendothelial electrical resistance both in mono- and co-cultures. The functional changes were confirmed by alterations in immunostaining for junctional proteins β-catenin, ZO-1 and claudin-5. Enlargement of intercellular spaces, and redistribution of junctional proteins were found in BMEC after exposure to LPS and UCB. Conclusions LPS and/or UCB exert direct toxic effects on BMEC, with distinct temporal profiles and mechanisms of action. Therefore, the impairment of brain endothelial integrity upon exposure to these neurotoxins may favor their access to the brain, thus increasing the risk of injury and requiring adequate clinical management of sepsis and jaundice in the neonatal period. PMID:22586454

  3. Modelling Aṣṭādhyāyī: An Approach Based on the Methodology of Ancillary Disciplines (Vedāṅga)

    NASA Astrophysics Data System (ADS)

    Mishra, Anand

    This article proposes a general model based on the common methodological approach of the ancillary disciplines (Vedāṅga) associated with the Vedas taking examples from Śikṣā, Chandas, Vyākaraṇa and Prātiśā khya texts. It develops and elaborates this model further to represent the contents and processes of Aṣṭādhyāyī. Certain key features are added to my earlier modelling of Pāṇinian system of Sanskrit grammar. This includes broader coverage of the Pāṇinian meta-language, mechanism for automatic application of rules and positioning the grammatical system within the procedural complexes of ancillary disciplines.

  4. Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer

    PubMed Central

    Bortolussi, Giulia; Zentilin, Lorena; Baj, Gabriele; Giraudi, Pablo; Bellarosa, Cristina; Giacca, Mauro; Tiribelli, Claudio; Muro, Andrés F.

    2012-01-01

    Crigler-Najjar type I (CNI) syndrome is a recessively inherited disorder characterized by severe unconjugated hyperbilirubinemia caused by uridine diphosphoglucuronosyltransferase 1A1 (UGT1A1) deficiency. The disease is lethal due to bilirubin-induced neurological damage unless phototherapy is applied from birth. However, treatment becomes less effective during growth, and liver transplantation is required. To investigate the pathophysiology of the disease and therapeutic approaches in mice, we generated a mouse model by introducing a premature stop codon in the UGT1a1 gene, which results in an inactive enzyme. Homozygous mutant mice developed severe jaundice soon after birth and died within 11 d, showing significant cerebellar alterations. To rescue neonatal lethality, newborns were injected with a single dose of adeno-associated viral vector 9 (AAV9) expressing the human UGT1A1. Gene therapy treatment completely rescued all AAV-treated mutant mice, accompanied by lower plasma bilirubin levels and normal brain histology and motor coordination. Our mouse model of CNI reproduces genetic and phenotypic features of the human disease. We have shown, for the first time, the full recovery of the lethal effects of neonatal hyperbilirubinemia. We believe that, besides gene-addition-based therapies, our mice could represent a very useful model to develop and test novel technologies based on gene correction by homologous recombination.—Bortolussi, G., Zentilin, L., Baj, G., Giraudi, P., Bellarosa, C., Giacca, M., Tiribelli, C., Muro, A. F. Rescue of bilirubin-induced neonatal lethality in a mouse model of Crigler-Najjar syndrome type I by AAV9-mediated gene transfer. PMID:22094718

  5. Prevalence of Hypoalbuminemia and Elevated Bilirubin/Albumin Ratios in a Large Cohort of Infants in the Neonatal Intensive Care Unit.

    PubMed

    Watchko, Jon F; Spitzer, Alan R; Clark, Reese H

    2017-09-01

    To provide descriptive data on serum albumin levels and the bilirubin to albumin (B/A) ratio in neonates admitted to the neonatal intensive care unit, assess the effect of gestational and chronological age on serum albumin and the B/A ratio, and evaluate the association between extreme values and mortality. Using a retrospective cohort design, we queried the Pediatrix clinical data warehouse for all infants born between 23 and 41 weeks of gestation from 1997 to 2014 who had a report of both a serum albumin and total serum bilirubin (TSB) level on the same day between birth and 14 days of life. There were 382 190 paired albumin and bilirubin levels across 164 401 neonates (15% of the 1 072 682 infants in the clinical data warehouse). Both gestational age and postnatal age were independent factors that influenced the values for serum albumin, TSB, and B/A ratio (ANOVA; P < .0001). TSB and B/A ratios values above birth weight-specific thresholds for exchange transfusions were uncommon (<6% of infants). Hypoalbuminemia (<2.5 mg/dL) was common (29% of infants). Neonates with serum albumin levels <2.5 g/dL or with B/A ratio levels exceeding exchange thresholds were at higher risk of death compared with infants who did not exceed these levels. This association was independent of other risk factors (estimated gestational age, birth weight, sex, and the presence of a major anomaly). Both gestational age and postnatal age influence TSB, albumin, and B/A ratios; hypoalbuminemia and extreme B/A ratios are associated with an increased risk of death. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Pretreatment direct bilirubin and total cholesterol are significant predictors of overall survival in advanced non-small-cell lung cancer patients with EGFR mutations.

    PubMed

    Zhang, Yanwei; Xu, Jianlin; Lou, Yuqing; Hu, Song; Yu, Keke; Li, Rong; Zhang, Xueyan; Jin, Bo; Han, Baohui

    2017-04-01

    This study was designed to examine the prediction of pretreatment circulating bilirubin and cholesterol for overall survival in 459 advanced non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations. Circulating total bilirubin, direct bilirubin (DB), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were measured at baseline. The mean age (standard deviation) of all study patients was 58.7 (10.5) years, and 42.9% of them was males. Ever smokers accounted for 27.0% and lung adenocarcinoma for 90.4%. The median follow-up time and survival time were 29.5 and 34.9 months, respectively. Patients with higher DB had a 1.68-fold increased risk of death compared with patients with lower DB (hazard ratio [HR] = 1.68, 95% confidence interval [CI]: 1.22-2.30, p = 0.001), while patients with higher TC were at a 63% reduced risk of death compared with patients with lower TC (HR = 0.37, 95% CI: 0.20-0.67, p = 0.001). As for HDL-C, patients with higher levels had the risk of death reduced by 46% (HR = 0.54, 95% CI: 0.29-1.00, p = 0.049) compared with patients with lower levels. After the Bonferroni correction, only DB and TC were significantly associated with NSCLC survival. Our findings demonstrate for the first time that pretreatment DB was identified as a significant risk factor, yet TC as a protective factor, for overall survival in NSCLC patients with EGFR mutations.

  7. The Bilirubin Albumin Ratio in the Management of Hyperbilirubinemia in Preterm Infants to Improve Neurodevelopmental Outcome: A Randomized Controlled Trial – BARTrial

    PubMed Central

    van Imhoff, Deirdre E.; Bos, Arend F.; Lopriore, Enrico; Offringa, Martin; Ruiter, Selma A. J.; van Braeckel, Koen N. J. A.; Krabbe, Paul F. M.; Quik, Elise H.; van Toledo-Eppinga, Letty; Nuytemans, Debbie H. G. M.; van Wassenaer-Leemhuis, Aleid G.; Benders, Manon J. N.; Korbeeck-van Hof, Karen K. M.; van Lingen, Richard A.; Groot Jebbink, Liesbeth J. M.; Liem, Djien; Mansvelt, Petri; Buijs, Jan; Govaert, Paul; van Vliet, Ineke; Mulder, Twan L. M.; Wolfs, Cecile; Fetter, Willem P. F.; Laarman, Celeste

    2014-01-01

    Background and Objective High bilirubin/albumin (B/A) ratios increase the risk of bilirubin neurotoxicity. The B/A ratio may be a valuable measure, in addition to the total serum bilirubin (TSB), in the management of hyperbilirubinemia. We aimed to assess whether the additional use of B/A ratios in the management of hyperbilirubinemia in preterm infants improved neurodevelopmental outcome. Methods In a prospective, randomized controlled trial, 615 preterm infants of 32 weeks' gestation or less were randomly assigned to treatment based on either B/A ratio and TSB thresholds (consensus-based), whichever threshold was crossed first, or on the TSB thresholds only. The primary outcome was neurodevelopment at 18 to 24 months' corrected age as assessed with the Bayley Scales of Infant Development III by investigators unaware of treatment allocation. Secondary outcomes included complications of preterm birth and death. Results Composite motor (100±13 vs. 101±12) and cognitive (101±12 vs. 101±11) scores did not differ between the B/A ratio and TSB groups. Demographic characteristics, maximal TSB levels, B/A ratios, and other secondary outcomes were similar. The rates of death and/or severe neurodevelopmental impairment for the B/A ratio versus TSB groups were 15.4% versus 15.5% (P = 1.0) and 2.8% versus 1.4% (P = 0.62) for birth weights ≤1000 g and 1.8% versus 5.8% (P = 0.03) and 4.1% versus 2.0% (P = 0.26) for birth weights of >1000 g. Conclusions The additional use of B/A ratio in the management of hyperbilirubinemia in preterm infants did not improve their neurodevelopmental outcome. Trial Registration Controlled-Trials.com ISRCTN74465643 PMID:24927259

  8. Electrochemical pretreatment of amino-carbon nanotubes on graphene support as a novel platform for bilirubin oxidase with improved bioelectrocatalytic activity towards oxygen reduction.

    PubMed

    Navaee, Aso; Salimi, Abdollah; Jafari, Fereydoon

    2015-03-23

    The electrochemical conditioning of amino-carbon nanotubes (CNTs) on a graphene support in an alkaline solution is used to produce -NHOH as hydrophilic functional groups for the efficient immobilization of bilirubin oxidase enzyme. The application of the immobilized enzyme for the direct electrocatalytic reduction of O2 is investigated. The onset potential of 0.81 V versus NHE and peak current density of 2.3 mA cm(-2) for rotating modified electrode at 1250 rpm, indicate improved biocatalytic activity of the proposed system for O2 reduction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Evaluation of new oxidation methods for the measurement of bilirubin on the aeroset clinical chemistry analyzer and comparison with methods on the Hitachi 717.

    PubMed

    Sturm, Ernhard; Albrecht-Groos, Ragnhild; Seyfarth, Michael

    2002-01-01

    We evaluated analytical and performance quality of the new oxidation methods for direct and total bilirubin on the Abbott Aeroset clinical chemistry analyzer. Within-day imprecisions for Abbott Aeroset assays ranged from 0.7 to 2.9% and between-day imprecisions from 2.1 to 7.3%. Inaccuracies as compared with the control "target values" for the Jendrassik-Gróf method showed deviations of -18.2 to +4.2%. Limits of detection were determined and showed very low values of < or = 0.25 micromol/l and dilution linearities were confirmed up to > 300 micromol/l. A method comparison for 100 patient samples with established Jendrassik-Gróf and DPD methods on the Roche Hitachi 717 showed good linearities between the investigated methods (r > or = 0.995). Due to slopes that ranged from 0.829 to 0.950, reference ranges for the oxidation methods differ slightly from those of established Roche Jendrassik-Gróf methods, but results can be adapted by the introduction of converting factors. In conclusion, the oxidation bilirubin assays revealed convincing analytical and performance qualities for medical needs that were similar or even better than for established methods. Application of the oxidation methods on the Aeroset clinical chemistry analyzer also improves laboratory efficiency by increasing throughput, speed of obtaining results and lowered sample and reagent volumes compared to established methods.

  10. Simple and sensitive method for the quantification of total bilirubin in human serum using 3-methyl-2-benzothiazolinone hydrazone hydrochloride as a chromogenic probe

    NASA Astrophysics Data System (ADS)

    Nagaraja, Padmarajaiah; Avinash, Krishnegowda; Shivakumar, Anantharaman; Dinesh, Rangappa; Shrestha, Ashwinee Kumar

    2010-11-01

    We here describe a new spectrophotometric method for measuring total bilirubin in serum. The method is based on the cleavage of bilirubin giving formaldehyde which further reacts with diazotized 3-methyl-2-benzothiazolinone hydrazone hydrochloride giving blue colored solution with maximum absorbance at 630 nm. Sensitivity of the developed method was compared with Jendrassik-Grof assay procedure and its applicability has been tested with human serum samples. Good correlation was attained between both methods giving slope of 0.994, intercept 0.015, and R2 = 0.997. Beers law obeyed in the range of 0.068-17.2 μM with good linearity, absorbance y = 0.044 Cbil + 0.003. Relative standard deviation was 0.006872, within day precision ranged 0.3-1.2% and day-to-day precision ranged 1-6%. Recovery of the method varied from 97 to 102%. The proposed method has higher sensitivity with less interference. The obtained product was extracted and was spectrally characterized for structural confirmation with FT-IR, 1H NMR.

  11. Breast milk jaundice: in vitro inhibition of rat liver bilirubin-uridine diphosphate glucuronyltransferase activity and Z protein-bromosulfophthalein binding by human breast milk.

    PubMed

    Foliot, A; Ploussard, J P; Housset, E; Christoforov

    1976-06-01

    Twenty-four samples of breast milk from nine mothers of infants suffering from breast milk jaundice were studied. Eight samples of milk from mothers of nonjaundiced infants, along with five formula milks enriched with polyunsaturated fatty acids, served as controls. Milks from mothers with jaundiced infants had no inhibitory effect when assayed immediately after thawing. However, after these milk samples were stores at 4 degrees, they strongly inhibited bilirubin conjugation (80.3% inhibition of uridine diphosphate glucuronyltransferase (UDPGT) activity) and bromosulfophthalein (BSP) binding to cytoplasmic Z protein (dye binding inhibited 82.1%). There was no effect on BSP binding to Y protein (see Table 1). Heating the milk to 56 degrees modified the results in the following manner; when the milk was heated immediately after thawing, no inhibitory effect was seen, even after storage for 96 hr. On the other hand, when the milk was first stored at 96 hr and then heated, it had the same inhibitory effects as the milks which were stored without heating. The present study shows that pathologic breast milk will inhibit BSP-Z protein binding only when stored under conditions that also cause the appearance of the capacity to inhibit bilirubin conjugation in vitro, as well as causing the liberation of nonesterified fatty acids. Thus, the appearance of this inhibitory capacity in vitro seems linked to the lipolytic activity particular to pathologic milks.

  12. Correlations between periparturient serum concentrations of non-esterified fatty acids, beta-hydroxybutyric acid, bilirubin, and urea and the occurrence of clinical and subclinical postpartum bovine endometritis

    PubMed Central

    2010-01-01

    Background Postpartum endometritis in cattle is a multifactorial disease with high economic impact. Both, clinical endometritis (CE) and subclinical endometritis (SCE) result in decreased reproductive performance. Results from in vitro studies led to the implication that non-esterified fatty acids (NEFA), beta-hydroxybutyric acid (BHBA), bilirubin, and urea could be used as predictors for endometritis in veterinary practice. In this field study, we set out to establish optimal predictor cut points of these metabolic parameters for the detection of CE and SCE. Serum samples were collected one week prior to parturition (wk -1), in the first week postpartum (wk +1) and between 28 and 35 days postpartum (wk +5) from 209 Holstein-Friesian cows. At wk +5, all cows were examined for signs of CE and SCE. Results Higher concentrations of urea at wk +1 were associated with increased odds of CE (OR = 1.7, P = 0.04) in primiparous (PP) cows. A predictor cut point of 3.9 mmol/L (sensitivity: 61%, specificity: 70%) was determined. In multiparous (MP) cows, the logistic regression model revealed that higher concentrations of NEFA at wk -1 were associated with increased odds of CE and SCE (healthy vs. CE: OR = 9.1, P = 0.05; healthy vs. SCE: OR = 12.1, P = 0.04). A predictor cut point of 0.3 mmol/L (sensitivity: 38%, specificity: 87% and sensitivity: 35%, specificity: 89%, respectively) was determined. Increasing concentrations of urea at wk +5 were associated with decreased odds of CE (healthy vs. CE: OR = 0.6, P = 0.01; SCE vs. CE: OR = 0.5, P = 0.03). A predictor cut point of 3.8 mmol/L (sensitivity: 52%, specificity: 81%) was determined. For BHBA and bilirubin relationships with CE or SCE were not detected. Conclusions The corresponding combinations of sensitivity and specificity of the determined predictor cut points were not satisfactory for practical use. Thus, the analysed parameters, i.e. NEFA, BHBA, bilirubin, and urea, at the chosen time points, i.e. at wk -1, at wk +1

  13. Correction of patient results for Beckman Coulter LX-20 assays affected by interference due to hemoglobin, bilirubin or lipids: a practical approach.

    PubMed

    Vermeer, Henricus J; Steen, Gerard; Naus, André J M; Goevaerts, Berrie; Agricola, Pauline T; Schoenmakers, Christian H H

    2007-01-01

    The influence of interference by hemolysis, icterus and lipemia on the results of routine chemistries may lead to wrong interpretations. On Synchron LX-20 instruments (Beckman Coulter) serum or plasma indices can be used as reliable semi-quantitative measures of the magnitude of such interference. In an article recently published in this journal, we presented the results of a multicenter study carried out in Dutch hospitals in which we determined cutoff indices for analytes above which analytically significant interference exists. Clinically significant interference cutoff indices were also derived for these analytes. In this article, we describe the handling of patient samples with clinically significant interference by hemolysis, icterus or lipemia. We investigated several possible approaches for correction of the result: dilution of the interference; mathematical correction in the case of hemolysis; treatment with ferrocyanide to destroy bilirubin; and removal of lipids in lipemic patient samples. We concluded, that mathematical correction of potassium or lactate dehydrogenase results in hemolytic samples can only be carried out if intravascular hemolysis is ruled out. Hemoglobin quantification in serial patient samples, combined with measurement of haptoglobin, represents a useful tool to rule out in vivo hemolysis. We derived an algorithm for this situation. We do not simply recommend mathematical correction, unless it is clinically acceptable. We present formulas for potassium and lactate dehydrogenase: corrected potassium=measured potassium-(hemolytic index increment x 0.14); corrected lactate dehydrogenase=measured lactate dehydrogenase-(hemolytic index increment x 75). The dilution studies indicated that dilution is only applicable for bilirubin, C-reactive protein and iron. The results of treatment with ferrocyanide were poor, and we do not recommend this method. Removal of lipids using high-speed centrifugation or LipoClear (StatSpin Inc.), a non

  14. A multimedia CD-ROM tool to improve student understanding of bile salts and bilirubin metabolism: evaluation of its use in a medical hybrid PBL course.

    PubMed

    Azer, Samy A

    2005-03-01

    Over the last 35 years our understanding of bile salts, bilirubin metabolism, and hepatobiliary transport has progressively increased. From 1965 to the end of 2002, 3,610 articles and review papers have been published on hepatobiliary and enterocyte transport of bile salts. However, there is a lack of information in the content of current textbooks about hepatobiliary physiology, bile salt transporters, bile formation, mechanisms underlying cholestasis, and drug-induced liver injury. The use of an integrated multimedia program on the liver covering these gaps in textbooks may be useful to student learning. This study aims to 1) assess student views on a multimedia CD-ROM ("The Liver") integrating basic and clinical sciences related to the liver, bile salts, and bilirubin metabolism, 2) assess the usefulness of problem-based learning (PBL) cases included in the multimedia CD-ROM, and 3) assess student learning before and after use of the multimedia CD-ROM. A total of 106 first-year medical students (27 with and 79 without a prior university degree) at the University of Melbourne participated in this study. Students were tested on the liver, bile salts, and bilirubin metabolism before and after using the multimedia CD-ROM. After completing the multimedia CD-ROM, each student filled out a 5-point Likert scale questionnaire evaluating the features of the program and its usefulness to their learning. Results show that the aims of the package were clear to participants, the contents were logically organized and clear, the key concepts were easy to identify, the contents were pitched to an appropriate level, and the package was interactive and encouraged participants to reflect on their learning. Students also agreed that the assessment tools used in the program and the feedback provided were meaningful and helpful to their learning. No differences were found when responses were compared on the basis of academic background, gender, citizenship, or first language of

  15. Bilirubin nomograms for identification of neonatal hyperbilirubinemia in healthy term and late-preterm infants: a systematic review and meta-analysis.

    PubMed

    Yu, Zhang-Bin; Han, Shu-Ping; Chen, Chao

    2014-08-01

    Hyperbilirubinemia occurs in most healthy term and late-preterm infants, and must be monitored to identify those who might develop severe hyperbilirubinemia. Total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) nomograms have been developed and validated to identify neonatal hyperbilirubinemia. This study aimed to review previously published studies and compare the TcB nomograms with the TSB nomogram, and to determine if the former has the same predictive value for significant hyperbilirubinemia as TSB nomogram does. A predefined search strategy and inclusion criteria were set up. We selected studies assessing the predictive ability of TSB/TcB nomograms to identify significant hyperbilirubinemia in healthy term and late-preterm infants. Two independent reviewers assessed the quality and extracted the data from the included studies. Meta-Disc 1.4 analysis software was used to calculate the pooled sensitivity, specificity, and positive likelihood ratio of TcB/TSB nomograms. A pooled summary of the receiver operating characteristic of the TcB/TSB nomograms was created. After screening 187 publications from electronic database searches and reference lists of eligible articles, we included 14 studies in the systematic review and meta-analysis. Eleven studies were of medium methodological quality. The remaining three studies were of low methodological quality. Seven studies evaluated the TcB nomograms, and seven studies assessed TSB nomograms. There were no differences between the predictive abilities of the TSB and TcB nomograms (the pooled area under curve was 0.819 vs. 0.817). This study showed that TcB nomograms had the same predictive value as TSB nomograms, both of which could be used to identify subsequent significant hyperbilirubinemia. But this result should be interpreted cautiously because some methodological limitations of these included studies were identified in this review.

  16. Predictive value of cord blood bilirubins for hyperbilirubinemia in neonates at risk for maternal-fetal blood group incompatibility and hemolytic disease of the newborn

    PubMed Central

    Calkins, Kara L.; Roy, Devika; Molchan, Lauren; Bradley, Lyndsey; Grogan, Tristan; Elashoff, David; Walker, Valencia P.

    2015-01-01

    Objective To determine the predictive ability of cord blood bilirubin (CBB) for hyperbilirubinemia in a population at risk for maternal-fetal blood group incompatibility and hemolytic disease of the newborn. Study Design This is a single center retrospective case-control study. Cases received phototherapy; controls did not. Cases were matched 1:3 to controls by gender and treating physician. Inclusion criteria included: ≥ 35 weeks gestation, CBB, and one or more total serum bilirubin (TSB) concentrations. The primary outcome was CBB. Secondary outcomes were a TSB > 75th percentile, length of stay, and neonatal intensive care unit admission. The prognostic ability of CBB for phototherapy and TSB > 75th percentile was assessed using area under the receiver operating characteristic (ROC) curve. Logistic regression analyses were performed to determine predictors for phototherapy and TSB > 75th percentile. Result When compared to controls (n=142), cases (n=54) were more likely to have a positive Coombs’ test (82% vs. 41%, p<0.001) and TSB > 75th percentile (85% vs. 21%, p<0.001). When compared to controls, cases had a higher mean (±SD) CBB (2.5±0.5 vs. 1.8±0.4 mg/dL, p<0.001). The area under the ROC curve (±SEM) for CBB for phototherapy and TSB >75th percentile was 0.87±0.03 (p<0.001, 95% CI 0.82,0.93) and 0.87±0.03 (p<0.001, 95% CI 0.82,0.92), respectively. Conclusion In this study, the mean CBB concentration was higher in neonates who received phototherapy compared to those who did not. CBB concentrations may help predict severe hyperbilirubinemia and phototherapy in a population at risk for hemolytic disease of the newborn. PMID:26518407

  17. Cerebrospinal fluid total protein cannot reliably distinguish true subarachnoid haemorrhage from other causes of raised cerebrospinal fluid net bilirubin and net oxyhaemoglobin absorbances.

    PubMed

    Birch, Katherine; Burrows, Gillian; Cruickshank, Anne; Egner, William; Holbrook, Ian; Lewis, Emma; McNeilly, Jane; Patel, Dina; Worthington, Viki

    2014-11-01

    In cerebrospinal fluid (CSF) spectrophotometry, if the net bilirubin absorbance (NBA) and net oxyhaemoglobin absorbance (NOA) are both raised with a visible oxyhaemoglobin peak, the revised national guidelines for analysis of CSF bilirubin advise interpreting the results as 'Consistent with subarachnoid haemorrhage (SAH)' regardless of the CSF total protein concentration of the specimen. We wanted to study the range of CSF total protein concentrations found in confirmed SAH to establish if the CSF total protein value can give further guidance on the likelihood of SAH. Consecutive cases from five different hospital sites were included if the CSF NBA was greater than 0.007 AU and the NOA was greater than 0.02 AU with a visible oxyhaemoglobin peak. For the cases identified, the laboratory information management system and patient records were interrogated to identify the total protein concentration of the CSF specimen and whether SAH had ultimately been confirmed or excluded by other methods and supporting evidence. Results from 132 patients were included. The CSF total protein range in confirmed SAH was 0.23-3.08 g/L with a median concentration of 0.7 g/L (n = 51). In the SAH excluded group, the CSF total protein range was 0.43-29 g/L with a median concentration of 1.9 g/L (n = 81). Although confirmed SAH was not associated with the very highest concentrations of CSF total protein, a definite CSF protein cut-off concentration above which SAH could reliably be excluded cannot be recommended. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  18. Serum Total Bilirubin, not Cholelithiasis, is Influenced by UGT1A1 Polymorphism, Alpha Thalassemia and βs Haplotype: First Report on Comparison between Arab-Indian and African βs Genes

    PubMed Central

    Alkindi, Said Y.; Pathare, Anil; Al Zadjali, Shoaib; Panjwani, Vinodhkumar; Wasim, Fauzia; Khan, Hammad; Chopra, Pradeep; Krishnamoorthy, Rajagopal; Alkindi, Salam

    2015-01-01

    Background We explored the potential relationship between steady state serum bilirubin levels and the incidence of cholelithiasis in the context of UGT1A1 gene A(TA)nTAA promoter polymorphism in Omani sickle cell anemia (SCA) patients, homozygotes for African (Benin and Bantu) and Arab-Indian βS haplotypes, but sharing the same microgeographical environment and comparable life style factors. Methods 136 SCA patients were retrospectively studied in whom imaging data including abdominal CT scan, MRI or Ultrasonography were routinely available. Available data on the mean steady state hematological/biochemical parameters (n=136), βs haplotypes(n=136), α globin gene status (n=105) and UGT1A1 genotypes (n=133) were reviewed from the respective medical records. Results The mean serum total bilirubin level was significantly higher in the homozygous UGT1A1(AT)7 group as compared to UGT1A1(AT)6 group. Thus, not cholelithiasis but total serum bilirubin was influenced by UGT1A1 polymorphism in this SCA cohort. Conclusion As observed in other population groups, the UGT1A1 (AT)7 homozygosity was significantly associated with raised serum total bilirubin level, but the prevalence of gallstones in the Omani SCA patients was not associated with α thalassaemia, UGT1A1 polymorphism, or βs haplotypes. PMID:26543529

  19. Desferrioxamine dehydrogenates bilirubin in two stages, leading to a 1:1 red-coloured adduct. Characterization of the products by high-performance liquid chromatography/electrospray ionization mass spectrometry.

    PubMed

    De Matteis, Francesco; Lord, Gwyn A

    2008-12-01

    We have used open-chain tetrapyrroles, such as bilirubin, as molecular probes to investigate the pro-oxidant activity of desferrioxamine (DES) and its modulation by Trolox. On exposure to Fe-EDTA/H2O2, bilirubin and mesobilirubin underwent bleaching. When DES was present, bleaching was prevented and both rubins were converted into green-coloured derivatives and then into red pigments. Trolox added with DES inhibited the colour changes induced by DES. The oxidative products were resolved from their parent compounds by high-performance liquid chromatography (HPLC) and studied by electrospray ionization mass spectrometry and by UV/visible spectroscopy. The green products were identified as biliverdin or mesobiliverdin; the red pigments as the 1:1 molar adduct of DES with biliverdin or mesobiliverdin, less two hydrogens in both cases. It is concluded that DES exercises its oxidative activity through nitroxyl oxidizing radicals capable of efficient hydrogen abstraction, dehydrogenating either rubin to the corresponding verdin. A diradical derivative of DES (bearing two nitroxyl radicals in the same molecule) may be involved in the oxidation of verdins to red pigments, through concerted dehydrogenation and adduct formation. These results shed further light on the redox properties of bilirubin, DES and Trolox, and their interactions. They provide further evidence of the pro-oxidant activity of DES and suggest a more general biological significance, as rapid removal of bilirubin by bleaching or dehydrogenation may have pharmacological/toxicological implications in severe jaundice. Copyright 2008 John Wiley & Sons, Ltd.

  20. Co-administration of α-lipoic acid and glutathione is associated with no significant changes in serum bilirubin, alkaline phosphatase or γ-glutamyltranspeptidase levels during the treatment of neuroborreliosis with intravenous ceftriaxone.

    PubMed

    Puri, Basant K; Hakkarainen-Smith, Jaana S; Derham, Anne; Monro, Jean A

    2015-09-01

    While pharmacotherapy with intravenous ceftriaxone, a third-generation cephalosporin, is a potential treatment of Lyme neuroborreliosis, there is concern that it can cause the formation of biliary sludge, leading to hepatobiliary complications such as biliary colic, jaundice and cholelithiasis, which are reflected in changes in serum levels of bilirubin and markers of cholestatic liver injury (alkaline phosphatase and γ-glutamyltranspeptidase). It has been suggested that the naturally occurring substances α-lipoic acid and glutathione may be helpful in preventing hepatic disease. α-Lipoic acid exhibits antioxidant, anti-inflammatory and anti-apoptotic activities in the liver, while glutathione serves as a sulfhydryl buffer. The aim of this study was to determine whether co-administration of α-lipoic acid and glutathione is associated with significant changes in serum levels of bilirubin, alkaline phosphatase and γ-glutamyltranspeptidase during the treatment of Lyme neuroborreliosis with long-term intravenous ceftriaxone. Serum levels of bilirubin, alkaline phosphatase and γ-glutamyltranspeptidase were measured in 42 serologically positive Lyme neuroborreliosis patients before and after long-term treatment with intravenous ceftriaxone (2-4 g daily) with co-administration of oral/intravenous α-lipoic acid (600 mg daily) and glutathione (100 mg orally or 0.6-2.4 g intravenously daily). None of the patients developed biliary colic and there were no significant changes in serum bilirubin, alkaline phosphatase or γ-glutamyltranspeptidase levels over the course of the intravenous ceftriaxone treatment (mean length 75.0 days). Co-administration of α-lipoic acid and glutathione is associated with no significant changes in serum bilirubin, alkaline phosphatase or γ-glutamyltranspeptidase levels during the treatment of neuroborreliosis with intravenous ceftriaxone.

  1. Circulating cell-free DNA, telomere length and bilirubin in the Vienna Active Ageing Study: exploratory analysis of a randomized, controlled trial

    PubMed Central

    Tosevska, Anela; Franzke, Bernhard; Hofmann, Marlene; Vierheilig, Immina; Schober-Halper, Barbara; Oesen, Stefan; Neubauer, Oliver; Wessner, Barbara; Wagner, Karl-Heinz

    2016-01-01

    Telomere length (TL) in blood cells is widely used in human studies as a molecular marker of ageing. Circulating cell-free DNA (cfDNA) as well as unconjugated bilirubin (UCB) are dynamic blood constituents whose involvement in age-associated diseases is largely unexplored. To our knowledge, there are no published studies integrating all three parameters, especially in individuals of advanced age. Here we present a secondary analysis from the Vienna Active Aging Study (VAAS), a randomized controlled intervention trial in institutionalized elderly individuals (n = 101). Using an exploratory approach we combine three blood-based molecular markers (TL, UCB and cfDNA) with a range of primary and secondary outcomes from the intervention. We further look at the changes occurring in these parameters after 6-month resistance exercise training with or without supplementation. A correlation between UCB and TL was evident at baseline (p < 0.05), and both were associated with increased chromosomal anomalies such as nucleoplasmatic bridges and nuclear buds (p < 0.05). Of the three main markers explored in this paper, only cfDNA decreased significantly (p < 0.05) after 6-month training and dietary intervention. No clear relationship could be established between cfDNA and either UCB or TL. The trial was registered at ClinicalTrials.gov (NCT01775111). PMID:27905522

  2. Integration of Platinum Group Metal-Free Catalysts and Bilirubin Oxidase into a Hybrid Material for Oxygen Reduction: Interplay of Chemistry and Morphology.

    PubMed

    Rojas-Carbonell, Santiago; Babanova, Sofia; Serov, Alexey; Artyushkova, Kateryna; Workman, Michael J; Santoro, Carlo; Mirabal, Alex; Calabrese Barton, Scott; Atanassov, Plamen

    2017-04-10

    Catalytic activity toward the oxygen reduction reaction (ORR) of platinum group metal-free (PGM-free) electrocatalysts integrated with an enzyme (bilirubin oxidase, BOx) in neutral media was studied. The effects of chemical and morphological characteristics of PGM-free materials on the enzyme enhancement of the overall ORR kinetics was investigated. The surface chemistry of the PGM-free catalyst was studied using X-ray Photoelectron Spectroscopy. Catalyst surface morphology was characterized using two independent methods: length-scale specific image analysis and nitrogen adsorption. Good agreement of macroscopic and microscopic morphological properties was found. Enhancement of ORR activity by the enzyme is influenced by chemistry and surface morphology of the catalyst itself. Catalysts with a higher nitrogen content, specifically pyridinic moieties, showed the greatest enhancement. Furthermore, catalysts with a higher fraction of surface roughness in the range of 3-5 nm exhibited greater performance enhancement than catalysts lacking features of this size. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Biofuel cells based on direct enzyme-electrode contacts using PQQ-dependent glucose dehydrogenase/bilirubin oxidase and modified carbon nanotube materials.

    PubMed

    Scherbahn, V; Putze, M T; Dietzel, B; Heinlein, T; Schneider, J J; Lisdat, F

    2014-11-15

    Two types of carbon nanotube electrodes (1) buckypaper (BP) and (2) vertically aligned carbon nanotubes (vaCNT) have been used for elaboration of glucose/O2 enzymatic fuel cells exploiting direct electron transfer. For the anode pyrroloquinoline quinone dependent glucose dehydrogenase ((PQQ)GDH) has been immobilized on [poly(3-aminobenzoic acid-co-2-methoxyaniline-5-sulfonic acid), PABMSA]-modified electrodes. For the cathode bilirubin oxidase (BOD) has been immobilized on PQQ-modified electrodes. PABMSA and PQQ act as promoter for enzyme bioelectrocatalysis. The voltammetric characterization of each electrode shows current densities in the range of 0.7-1.3 mA/cm(2). The BP-based fuel cell exhibits maximal power density of about 107 µW/cm(2) (at 490 mV). The vaCNT-based fuel cell achieves a maximal power density of 122 µW/cm(2) (at 540 mV). Even after three days and several runs of load a power density over 110 µW/cm(2) is retained with the second system (10mM glucose). Due to a better power exhibition and an enhanced stability of the vaCNT-based fuel cells they have been studied in human serum samples and a maximal power density of 41 µW/cm(2) (390 mV) can be achieved. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Validation of transcutaneous bilirubin nomogram for identifying neonatal hyperbilirubinemia in healthy Chinese term and late-preterm infants: a multicenter study.

    PubMed

    Yu, Zhangbin; Han, Shuping; Wu, Jinxia; Li, Mingxia; Wang, Huaiyan; Wang, Jimei; Liu, Jiebo; Pan, Xinnian; Yang, Jie; Chen, Chao

    2014-01-01

    to prospectively validate a previously constructed transcutaneous bilirubin (TcB) nomogram for identifying severe hyperbilirubinemia in healthy Chinese term and late-preterm infants. this was a multicenter study that included 9,174 healthy term and late-preterm infants in eight hospitals of China. TcB measurements were performed using a JM-103 bilirubinometer. TcB values were plotted on a previously developed TcB nomogram, to identify the predictive ability for subsequent significant hyperbilirubinemia. in the present study, 972 neonates (10.6%) developed significant hyperbilirubinemia. The 40(th) percentile of the nomogram could identify all neonates who were at risk of significant hyperbilirubinemia, but with a low positive predictive value (PPV) (18.9%). Of the 453 neonates above the 95(th) percentile, 275 subsequently developed significant hyperbilirubinemia, with a high PPV (60.7%), but with low sensitivity (28.3%). The 75(th) percentile was highly specific (81.9%) and moderately sensitive (79.8%). The area under the curve (AUC) for the TcB nomogram was 0.875. this study validated the previously developed TcB nomogram, which could be used to predict subsequent significant hyperbilirubinemia in healthy Chinese term and late-preterm infants. However, combining TcB nomogram and clinical risk factors could improve the predictive accuracy for severe hyperbilirubinemia, which was not assessed in the study. Further studies are necessary to confirm this combination. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  5. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation.

    PubMed

    Berman, Marvin D; Carey, Martin C

    2015-01-01

    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. Copyright © 2015 the American Physiological Society.

  6. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation

    PubMed Central

    Berman, Marvin D.

    2014-01-01

    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. PMID:25359538

  7. The location of the high- and low-affinity bilirubin-binding sites on serum albumin: ligand-competition analysis investigated by circular dichroism.

    PubMed

    Goncharova, Iryna; Orlov, Sergey; Urbanová, Marie

    2013-01-01

    The locations of three bilirubin (BR)-binding sites with different affinities were identified as subdomains IB, IIA and IIIA for five mammalian serum albumins (SAs): human (HSA), bovine (BSA), rat, (RSA), rabbit (RbSA) and sheep (SSA). The stereoselectivity of a high-affinity BR-binding site was identified in the BR/SA=1/1 system by circular dichroism (CD) spectroscopy, the sites with low affinity to BR were analyzed using difference CD. Site-specific ligand-competition experiments with ibuprofen (marker for subdomain IIIA) and hemin (marker for subdomain IB) did not reveal any changes for the BR/SA=1/1 system and showed a decrease of the bound BR at BR/SA=3/1. Both sites were identified as sites with low affinity to BR. The correlation between stereoselectivity and the arrangement of Arg-Lys residues indicated similarity between the BR-binding sites in subdomain IIIA for all of the SAs studied. Subdomain IB in HSA, BSA, SSA and RbSA has P-stereoselectivity while in RSA it has M-selectivity toward BR. A ligand-competition experiment with gossypol shows a decrease of the CD signal of bound BR for the BR/SA=1/1 system as well as for BR/SA=3/1. Subdomain IIA was assigned as a high-affinity BR-binding site. The P-stereoselectivity of this site in HSA (and RSA, RbSA) was caused by the right-hand localization of charged residues R257/R218-R222, whereas the left-hand orientation of R257/R218-R199 led to the M-stereoselectivity of the primary binding site in BSA (and SSA).

  8. Estimation of indocyanine green elimination rate constant k and retention rate at 15 min using patient age, weight, bilirubin, and albumin.

    PubMed

    Kim, Ga Yeong; Bae, Kyun Seop; Noh, Gyu Jeong; Min, Won Ki

    2009-01-01

    We sought to estimate the indocyanine green (ICG) clearance (Cl), the elimination rate constant (k), and the retention rate at 15 min (R (15)) using patient-specific covariates only. We analyzed plasma ICG concentration data at 5, 10, and 15 min after intravenous injection of 0.5 mg/kg of ICG and 17 kinds of patient-specific covariates in 1,276 patients using NONMEM (GloboMax LLC, Ellicott City, MD) for population pharmacokinetic modeling. The population models designed were externally validated on another dataset of 1,629 patients. The population typical value (TV) of Cl (Cl (TV)) and TV of volume of distribution (Vd (TV)) were modeled as: Cl (TV) (mL/min) = 117 x age (year)(-0.119) x body weight (kg)(0.348) x total bilirubin (mg/dL)(-0.226) x albumin (g/dL)(0.327). Vd (TV) (L) = 0.415 x body weight (kg)(0.596) x albumin (g/dL)(-0.292). ICG concentration at zero time (C (0)) and 15 min (C (15)) for R (15) (C (15)/C (0) x 100) were derived from following equations. C (0) = dose/Vd (TV) and C (15) = C (0)e(-k t ) where t = 15 min and k = Cl (TV)/Vd (TV). [corrected] Median percent prediction error and absolute prediction error in the estimated values were 18.0% and 25.6% for Cl; 6.1% and 16.5% for k; and -7.0% and 33.1% for R (15). The predictive performance of ICG k was better than those of ICG Cl and R (15).

  9. Mayo Genome Consortia: A Genotype-Phenotype Resource for Genome-Wide Association Studies With an Application to the Analysis of Circulating Bilirubin Levels

    PubMed Central

    Bielinski, Suzette J.; Chai, High Seng; Pathak, Jyotishman; Talwalkar, Jayant A.; Limburg, Paul J.; Gullerud, Rachel E.; Sicotte, Hugues; Klee, Eric W.; Ross, Jason L.; Kocher, Jean-Pierre A.; Kullo, Iftikhar J.; Heit, John A.; Petersen, Gloria M.; de Andrade, Mariza; Chute, Christopher G.

    2011-01-01

    OBJECTIVE: To create a cohort for cost-effective genetic research, the Mayo Genome Consortia (MayoGC) has been assembled with participants from research studies across Mayo Clinic with high-throughput genetic data and electronic medical record (EMR) data for phenotype extraction. PARTICIPANTS AND METHODS: Eligible participants include those who gave general research consent in the contributing studies to share high-throughput genotyping data with other investigators. Herein, we describe the design of the MayoGC, including the current participating cohorts, expansion efforts, data processing, and study management and organization. A genome-wide association study to identify genetic variants associated with total bilirubin levels was conducted to test the genetic research capability of the MayoGC. RESULTS: Genome-wide significant results were observed on 2q37 (top single nucleotide polymorphism, rs4148325; P=5.0 × 10–62) and 12p12 (top single nucleotide polymorphism, rs4363657; P=5.1 × 10–8) corresponding to a gene cluster of uridine 5′-diphospho-glucuronosyltransferases (the UGT1A cluster) and solute carrier organic anion transporter family, member 1B1 (SLCO1B1), respectively. CONCLUSION: Genome-wide association studies have identified genetic variants associated with numerous phenotypes but have been historically limited by inadequate sample size due to costly genotyping and phenotyping. Large consortia with harmonized genotype data have been assembled to attain sufficient statistical power, but phenotyping remains a rate-limiting factor in gene discovery research efforts. The EMR consists of an abundance of phenotype data that can be extracted in a relatively quick and systematic manner. The MayoGC provides a model of a unique collaborative effort in the environment of a common EMR for the investigation of genetic determinants of diseases. PMID:21646302

  10. Membraneless enzymatic ethanol/O2 fuel cell: Transitioning from an air-breathing Pt-based cathode to a bilirubin oxidase-based biocathode

    NASA Astrophysics Data System (ADS)

    Aquino Neto, Sidney; Milton, Ross D.; Hickey, David P.; De Andrade, Adalgisa R.; Minteer, Shelley D.

    2016-08-01

    The bioelectrooxidation of ethanol was investigated in a fully enzymatic membraneless ethanol/O2 biofuel cell assembly using hybrid bioanodes containing multi-walled carbon nanotube (MWCNT)-decorated gold metallic nanoparticles with either a pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) enzyme or a nicotinamide adenine dinucleotide (NAD+)-dependent ADH enzyme. The biofuel cell anode was prepared with the PQQ-dependent enzyme and designed using either a direct electron transfer (DET) architecture or via a mediated electron transfer (MET) configuration through a redox polymer, 1,1‧-dimethylferrocene-modified linear polyethyleneimine (FcMe2-C3-LPEI). In the case of the bioanode containing the NAD+-dependent enzyme, only the mediated electron transfer mechanism was employed using an electropolymerized methylene green film to regenerate the NAD+ cofactor. Regardless of the enzyme being employed at the anode, a bilirubin oxidase-based biocathode prepared within a DET architecture afforded efficient electrocatalytic oxygen reduction in an ethanol/O2 biofuel cell. The power curves showed that DET-based bioanodes via the PQQ-dependent ADH still lack high current densities, whereas the MET architecture furnished maximum power density values as high as 226 ± 21 μW cm-2. Considering the complete membraneless enzymatic biofuel cell with the NAD+-dependent ADH-based bioanode, power densities as high as 111 ± 14 μW cm-2 were obtained. This shows the advantage of PQQ-dependent ADH for membraneless ethanol/O2 biofuel cell applications.

  11. Review: Bilirubin pKa studies: new models and theories indicate high pKa values in water, dimethylformamide and DMSO.

    PubMed

    Mukerjee, Pasupati; Ostrow, J Donald

    2010-01-01

    Correct aqueous pKa values of unconjugated bilirubin (UCB), a poorly-soluble, unstable substance, are essential for understanding its functions. Our prior solvent partition studies, of unlabeled and [14C] UCB, indicated pKa values above 8.0. These high values were attributed to effects of internal H-bonding in UCB. Many earlier and subsequent studies have reported lower pKa values, some even below 5.0, which are often used to describe the behavior of UCB. We here review 18 published studies that assessed aqueous pKa values of UCB, critically evaluating their methodologies in relation to essential preconditions for valid pKa measurements (short-duration experiments with purified UCB below saturation and accounting for self-association of UCB). These re-assessments identified major deficiencies that invalidate the results of all but our partition studies. New theoretical modeling of UCB titrations shows remarkable, unexpected effects of self-association, yielding falsely low pKa estimates, and provides some rationalization of the titration anomalies. The titration behavior reported for a soluble thioether conjugate of UCB at high aqueous concentrations is shown to be highly anomalous. Theoretical re-interpretations of data in DMSO and dimethylformamide show that those indirectly-derived aqueous pKa values are unacceptable, and indicate new, high average pKa values for UCB in non-aqueous media (>11 in DMSO and, probably, >10 in dimethylformamide). No reliable aqueous pKa values of UCB are available for comparison with our partition-derived results. A companion paper shows that only the high pKa values can explain the pH-dependence of UCB binding to phospholipids, cyclodextrins, and alkyl-glycoside and bile salt micelles.

  12. Exome-Wide Association Study Identifies New Low-Frequency and Rare UGT1A1 Coding Variants and UGT1A6 Coding Variants Influencing Serum Bilirubin in Elderly Subjects: A Strobe Compliant Article.

    PubMed

    Oussalah, Abderrahim; Bosco, Paolo; Anello, Guido; Spada, Rosario; Guéant-Rodriguez, Rosa-Maria; Chery, Céline; Rouyer, Pierre; Josse, Thomas; Romano, Antonino; Elia, Maurizzio; Bronowicki, Jean-Pierre; Guéant, Jean-Louis

    2015-06-01

    Genome-wide association studies (GWASs) have identified loci contributing to total serum bilirubin level. However, no exome-wide approaches have been performed to address this question. Using exome-wide approach, we assessed the influence of protein-coding variants on unconjugated, conjugated, and total serum bilirubin levels in a well-characterized cohort of 773 ambulatory elderly subjects from Italy. Coding variants were replicated in 227 elderly subjects from the same area. We identified 4 missense rare (minor allele frequency, MAF < 0.5%) and low-frequency (MAF, 0.5%-5%) coding variants located in the first exon of the UGT1A1 gene, which encodes for the substrate-binding domain (rs4148323 [MAF = 0.06%; p.Gly71Arg], rs144398951 [MAF = 0.06%; p.Ile215Val], rs35003977 [MAF = 0.78%; p.Val225Gly], and rs57307513 [MAF = 0.06%; p.Ser250Pro]). These variants were in strong linkage disequilibrium with 3 intronic UGT1A1 variants (rs887829, rs4148325, rs6742078), which were significantly associated with total bilirubin level (P = 2.34 × 10(-34), P = 7.02 × 10(-34), and P = 8.27 × 10(-34)), as well as unconjugated, and conjugated bilirubin levels. We also identified UGT1A6 variants in association with total (rs6759892, p.Ser7Ala, P = 1.98 × 10(-26); rs2070959, p.Thr181Ala, P = 2.87 × 10(-27); and rs1105879, p.Arg184Ser, P = 3.27 × 10(-29)), unconjugated, and conjugated bilirubin levels. All UGT1A1 intronic variants (rs887829, rs6742078, and rs4148325) and UGT1A6 coding variants (rs6759892, rs2070959, and rs1105879) were significantly associated with gallstone-related cholecystectomy risk. The UGT1A6 variant rs2070959 (p.Thr181Ala) was associated with the highest risk of gallstone-related cholecystectomy (OR, 4.58; 95% CI, 1.58-13.28; P = 3.21 × 10(-3)). Using an exome-wide approach we identified coding variants on UGT1A1 and UGT1A6 genes in association with serum bilirubin level and

  13. Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

    PubMed Central

    Kapitulnik, Jaime; Benaim, Clara; Sasson, Shlomo

    2012-01-01

    Unconjugated bilirubin (UCB) is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS). High glucose levels (hyperglycemia) generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB). In the current study we show that UCB (1–40 μM) induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM) levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langerhans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM) glucose levels. While UCB (0.1–40 μM) did not alter ROS production in cells exposed to normal glucose, relatively low (“physiological”) UCB concentrations (0.1–5 μM) attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20–40 μM) increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic

  14. Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions.

    PubMed

    Kapitulnik, Jaime; Benaim, Clara; Sasson, Shlomo

    2012-01-01

    Unconjugated bilirubin (UCB) is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS). High glucose levels (hyperglycemia) generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB). In the current study we show that UCB (1-40 μM) induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM) levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langerhans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM) glucose levels. While UCB (0.1-40 μM) did not alter ROS production in cells exposed to normal glucose, relatively low ("physiological") UCB concentrations (0.1-5 μM) attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20-40 μM) increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

  15. Point mutations at the type I Cu ligands, Cys457 and Met467, and at the putative proton donor, Asp105, in Myrothecium verrucaria bilirubin oxidase and reactions with dioxygen.

    PubMed

    Kataoka, Kunishige; Kitagawa, Rieko; Inoue, Megumi; Naruse, Daisaku; Sakurai, Takeshi; Huang, Hong-wei

    2005-05-10

    The type I Cu site in the Cys457Ser mutant of Myrothecium verrucaria bilirubin oxidase was vacant, but the trinuclear center composed of a type II Cu and a pair of type III Cu's was fully occupied by three Cu ions. Cys457Ser could react with dioxygen, affording reaction intermediate I with absorption maxima at 340, 470, and 675 nm. This intermediate corresponds to that obtained from laccase, whose type I Cu is cupric and type II and III Cu's are cuprous [Zoppellaro, G., Sakurai, T., and Huang, H. (2001) J. Biochem. 129, 949-953] or whose type I Cu is substituted with Hg [Palmer, A. E., Lee, S. K., and Solomon, E. I. (2001) J. Am. Chem. Soc. 123, 6591-6599]. Another type I Cu mutant, Met467Gln, with modified spectroscopic properties and redox potential, afforded reaction intermediate II with absorption maxima at 355 and 450 nm. This intermediate corresponds to that obtained during the reaction of laccase [Sundaram, U. M., Zhang, H. H., Hedman, B., Hodgson, K. O., and Solomon, E. I. (1997) J. Am. Chem. Soc. 119, 12525-12540; Huang, H., Zoppellaro, G., and Sakurai, T. (1999) J. Biol. Chem. 274, 32718-32724]. According to a three-dimensional model of bilirubin oxidase, Asp105 is positioned near the trinuclear center. Asp105Glu and Asp105Ala exhibited 46 and 7.5% bilirubin oxidase activity compared to the wild-type enzyme, respectively, indicating that Asp105 conserved in all multi-copper oxidases donates a proton to reaction intermediates I and II. In addition, this amino acid might be involved in the formation of the trinuclear center and in the binding of dioxygen based on the difficulties in incorporating four Cu ions