Theoretical modeling of the absorption spectrum of aqueous riboflavin

Science.gov (United States)

Zanetti-Polzi, Laura; Aschi, Massimiliano; Daidone, Isabella; Amadei, Andrea

2017-02-01

In this study we report the modeling of the absorption spectrum of riboflavin in water using a hybrid quantum/classical mechanical approach, the MD-PMM methodology. By means of MD-PMM calculations, with which the effect of riboflavin internal motions and of solvent interactions on the spectroscopic properties can be explicitly taken into account, we obtain an absorption spectrum in very good agreement with the experimental spectrum. In particular, the calculated peak maxima show a consistent improvement with respect to previous computational approaches. Moreover, the calculations show that the interaction with the environment may cause a relevant recombination of the gas-phase electronic states.

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

NARCIS (Netherlands)

Hulzebos, Christian V.; Dijk, Peter H.

2014-01-01

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)

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

Science.gov (United States)

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.

Bilirubin glucuronidation by intact Gunn rat fibroblasts expressing bilirubin UDP-glucuronosyltransferase

NARCIS (Netherlands)

Seppen, J.; Tada, K.; Hellwig, S.; Bakker, C. T.; Prasad, V. R.; Roy Chowdhury, N.; Roy Chowdhury, J.; Bosma, P. J.; Oude Elferink, R. P.

1996-01-01

Crigler-Najjar (CN) disease is an inherited disorder of bilirubin metabolism. The disease is caused by a deficiency of the hepatic enzyme bilirubin UDP-glucuronosyltransferase (B-UGT). Patients with CN disease have high serum levels of the toxic compound, unconjugated bilirubin. The only defect in

Comparison of Transcutaneous Bilirubin Measurement With Total Serum Bilirubin Levels in Preterm Neonates Receiving Phototherapy.

Science.gov (United States)

Pendse, Amruta; Jasani, Bonny; Nanavati, Ruchi; Kabra, Nandkishor

2017-08-15

To compare transcutaneous bilirubin with total serum bilirubin in preterm neonates after initiation of phototherapy. Jaundice was assessed in 30 preterm neonates with transcutaneous bilirubin and total serum bilirubin before initiation of phototherapy and at 12 hr after initiation of phototherapy. A photo-occlusive patch was applied over the sternum. Transcutaneous bilirubin has a good correlation with total serum bilirubin after initiation of phototherapy. (r=0.918, Pbilirubin at 28-32 weeks of gestation (r = 0.97) was better correlated with total serum bilirubin than those at 32-37 weeks (r =0.88). The correlation was better for neonates 72 hours of age (r = 0.82). Transcutaneous bilirubin correlates significantly with total serum bilirubin at the patched sternal site after initiation of phototherapy in preterm neonates.

Bilirubin and atherosclerotic diseases.

Science.gov (United States)

Vítek, L

2017-04-05

Bilirubin is the final product of heme catabolism in the systemic circulation. For decades, increased serum/plasma bilirubin levels were considered an ominous sign of an underlying liver disease. However, data from recent years convincingly suggest that mildly elevated bilirubin concentrations are associated with protection against various oxidative stress-mediated diseases, atherosclerotic conditions being the most clinically relevant. Although scarce data on beneficial effects of bilirubin had been published also in the past, it took until 1994 when the first clinical study demonstrated an increased risk of coronary heart disease in subjects with low serum bilirubin levels, and bilirubin was found to be a risk factor for atherosclerotic diseases independent of standard risk factors. Consistent with these results, we proved in our own studies, that subjects with mild elevation of serum levels of unconjugated bilirubin (benign hyperbilirubinemia, Gilbert syndrome) have much lower prevalence/incidence of coronary heart as well as peripheral vascular disease. We have also demonstrated that this association is even more general, with serum bilirubin being a biomarker of numerous other diseases, often associated with increased risk of atherosclerosis. In addition, very recent data have demonstrated biological pathways modulated by bilirubin, which are responsible for observed strong clinical associations.

Inherited Disorders of Bilirubin Clearance

Science.gov (United States)

Memon, Naureen; Weinberger, Barry I; Hegyi, Thomas; Aleksunes, Lauren M

2016-01-01

Inherited disorders of hyperbilirubinemia may be caused by increased bilirubin production or decreased bilirubin clearance. Reduced hepatic bilirubin clearance can be due to defective 1) unconjugated bilirubin uptake and intrahepatic storage, 2) conjugation of glucuronic acid to bilirubin (e.g. Gilbert syndrome, Crigler-Najjar syndrome, Lucey-Driscoll syndrome, breast milk jaundice), 3) bilirubin excretion into bile (Dubin-Johnson syndrome), or 4) conjugated bilirubin re-uptake (Rotor syndrome). In this review, the molecular mechanisms and clinical manifestations of these conditions are described, as well as current approaches to diagnosis and therapy. PMID:26595536

Observing broad-absorption line quasars with Spectrum-Rontgen-Gamma

DEFF Research Database (Denmark)

Singh, K.P.; Schnopper, H.W.; Westergaard, Niels Jørgen Stenfeldt

1998-01-01

Broad-absorption line quasars are found to have extremely weak soft X-ray emission when compared with other optically selected quasars. In the only example of PHL 5200 for which a detailed X-ray spectrum has been obtained with ASCA, strong absorption in the source appears to be responsible...

The Biological Effects of Bilirubin Photoisomers

Science.gov (United States)

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

Visible absorption spectrum of the CH3CO radical.

Science.gov (United States)

Rajakumar, B; Flad, Jonathan E; Gierczak, Tomasz; Ravishankara, A R; Burkholder, James B

2007-09-20

The visible absorption spectrum of the acetyl radical, CH(3)CO, was measured between 490 and 660 nm at 298 K using cavity ring-down spectroscopy. Gas-phase CH(3)CO radicals were produced using several methods including: (1) 248 nm pulsed laser photolysis of acetone (CH(3)C(O)CH(3)), methyl ethyl ketone (MEK, CH(3)C(O)CH(2)CH(3)), and biacetyl (CH(3)C(O)C(O)CH(3)), (2) Cl + CH(3)C(O)H --> CH(3)C(O) + HCl with Cl atoms produced via pulsed laser photolysis or in a discharge flow tube, and (3) OH + CH(3)C(O)H --> CH(3)CO + H(2)O with two different pulsed laser photolysis sources of OH radicals. The CH(3)CO absorption spectrum was assigned on the basis of the consistency of the spectra obtained from the different CH(3)CO sources and agreement of the measured rate coefficients for the reaction of the absorbing species with O(2) and O(3) with literature values for the CH(3)CO + O(2) + M and CH(3)CO + O(3) reactions. The CH(3)CO absorption spectrum between 490 and 660 nm has a broad peak centered near 535 nm and shows no discernible structure. The absorption cross section of CH(3)CO at 532 nm was measured to be (1.1 +/- 0.2) x 10(-19) cm(2) molecule(-1) (base e).

Inapplicability of small-polaron model for the explanation of infrared absorption spectrum in acetanilide.

Science.gov (United States)

Zeković, Slobodan; Ivić, Zoran

2009-01-01

The applicability of small-polaron model for the interpretation of infrared absorption spectrum in acetanilide has been critically reexamined. It is shown that the energy difference between the normal and anomalous peak, calculated by means of small-polaron theory, displays pronounced temperature dependence which is in drastic contradiction with experiment. It is demonstrated that self-trapped states, which are recently suggested to explain theoretically the experimental absorption spectrum in protein, cannot cause the appearance of the peaks in absorption spectrum for acetanilide.

Early predictive value of cord blood bilirubin and dynamic monitoring of transcutaneous bilirubin for hyperbilirubinemia of newborns

Directory of Open Access Journals (Sweden)

Haishan Guan

2017-12-01

Conclusions: The increase of cord blood bilirubin effectively predict the occurrence of neonatal hyperbilirubinemia. There is a good correlation between levels of transcutaneous bilirubin and serum bilirubin. Moreover, combined detection of transcutaneous bilirubin and cord blood bilirubin can significantly improve the prediction accuracy of hyperbilirubinemia.

Broad-spectrum enhanced absorption of graphene-molybdenum disulfide photovoltaic cells in metal-mirror microcavity

Science.gov (United States)

Jiang-Tao, Liu; Yun-Kai, Cao; Hong, Tong; Dai-Qiang, Wang; Zhen-Hua, Wu

2018-04-01

The optical absorption of graphene-molybdenum disulfide photovoltaic cells (GM-PVc) in wedge-shaped metal-mirror microcavities (w-MMCs) combined with a spectrum-splitting structure was studied. Results showed that the combination of spectrum-splitting structure and w-MMC can enable the light absorption of GM-PVcs to reach about 65% in the broad spectrum. The influence of processing errors on the absorption of GM-PVcs in w-MMCs was 3-14 times lower than that of GM-PVcs in wedge photonic crystal microcavities. The light absorption of GM-PVcs reached 60% in the broad spectrum, even with the processing errors. The proposed structure is easy to implement and may have potentially important applications in the development of ultra-thin and high-efficiency solar cells and optoelectronic devices.

Ab initio calculation of the electronic absorption spectrum of liquid water

International Nuclear Information System (INIS)

Martiniano, Hugo F. M. C.; Galamba, Nuno; Cabral, Benedito J. Costa

2014-01-01

The electronic absorption spectrum of liquid water was investigated by coupling a one-body energy decomposition scheme to configurations generated by classical and Born-Oppenheimer Molecular Dynamics (BOMD). A Frenkel exciton Hamiltonian formalism was adopted and the excitation energies in the liquid phase were calculated with the equation of motion coupled cluster with single and double excitations method. Molecular dynamics configurations were generated by different approaches. Classical MD were carried out with the TIP4P-Ew and AMOEBA force fields. The BLYP and BLYP-D3 exchange-correlation functionals were used in BOMD. Theoretical and experimental results for the electronic absorption spectrum of liquid water are in good agreement. Emphasis is placed on the relationship between the structure of liquid water predicted by the different models and the electronic absorption spectrum. The theoretical gas to liquid phase blue-shift of the peak positions of the electronic absorption spectrum is in good agreement with experiment. The overall shift is determined by a competition between the O–H stretching of the water monomer in liquid water that leads to a red-shift and polarization effects that induce a blue-shift. The results illustrate the importance of coupling many-body energy decomposition schemes to molecular dynamics configurations to carry out ab initio calculations of the electronic properties in liquid phase

Usefulness of the bilirubin/albumin ratio for predicting bilirubin-induced neurotoxicity in premature infants

NARCIS (Netherlands)

Hulzebos, C. V.; van Imhoff, D. E.; Bos, A. F.; Ahlfors, C. E.; Verkade, H. J.; Dijk, P. H.

Unconjugated hyperbilirubinaemia occurs in almost all premature infants and is potentially neurotoxic. Treatment is based on total serum bilirubin (TSB), but treatment thresholds are not evidence based. Free bilirubin (Bf) - that is, not bound to albumin, seems a better parameter for bilirubin

Binding of bilirubin and its structural analogues to hepatic microsomal bilirubin UDP glucuronyltransferase

International Nuclear Information System (INIS)

Vanstapel, F.; Blanckaert, N.

1987-01-01

Hepatic glucuronidation of the asymmetrical natural bilirubin molecule results in formation of two different positional isomers, bilirubin C-8 monoglucuronide and bilirubin C-12 monoglucuronide. In view of the existence of multiple isoforms of UDPglucuronyltransferase, which is the microsomal enzyme system responsible for bilirubin esterification, the authors performed kinetic analysis of microsomal glucuronidation of bilirubin and a number of its structural congeners to determine whether synthesis of the two monoglucuronide isomers involved two distinct substrate-binding sites or reflected two different modes of binding to a single catalytic site. Both isomers were found in all tested species (man, rat, guinea pig, sheep), but there were marked species differences in the C-8/C-12 ratio of monoglucuronide found in bile or formed by liver microsomes. Correspondence between in vivo and in vitro results for such regioselectivity of glucuronidation was excellent in each species. On the basis of these results of kinetic analysis of bilirubin esterification at variable pigment substrate concentrations and inhibition studies with alternative substrates, the authors postulate that both natural monoglucuronide isomers are synthesized at a single binding site. Possible mechanisms responsible for the markedly regioselective esterification of bilirubin by rat and sheep liver were investigated by study of glucuronidation of selected structural analgoues of the pigment. Collectively, their findings suggest that the molecular from(s) of bilirubin able to engage in catalytically effective binding to UDPglucuronyltransferase does (do) not correspond with intramolecularly hydrogen-bonded conformers and that the nature of the β-substituents of the outer pyrromethenone rings is a key determinant of glucuronidation rate

Biology of Bilirubin Photoisomers.

Science.gov (United States)

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Bilirubin present in diverse angiosperms.

Science.gov (United States)

Pirone, Cary; Johnson, Jodie V; Quirke, J Martin E; Priestap, Horacio A; Lee, David

2010-01-01

Bilirubin is an orange-yellow tetrapyrrole produced from the breakdown of heme by mammals and some other vertebrates. Plants, algae and cyanobacteria synthesize molecules similar to bilirubin, including the protein-bound bilins and phytochromobilin which harvest or sense light. Recently, we discovered bilirubin in the arils of Strelitzia nicolai, the White Bird of Paradise Tree, which was the first example of this molecule in a higher plant. Subsequently, we identified bilirubin in both the arils and the flowers of Strelitzia reginae, the Bird of Paradise Flower. In the arils of both species, bilirubin is present as the primary pigment, and thus functions to produce colour. Previously, no tetrapyrroles were known to generate display colour in plants. We were therefore interested in determining whether bilirubin is broadly distributed in the plant kingdom and whether it contributes to colour in other species. In this paper, we use HPLC/UV and HPLC/UV/electrospray ionization-tandem mass spectrometry (HPLC/UV/ESI-MS/MS) to search for bilirubin in 10 species across diverse angiosperm lineages. Bilirubin was present in eight species from the orders Zingiberales, Arecales and Myrtales, but only contributed to colour in species within the Strelitziaceae. The wide distribution of bilirubin in angiosperms indicates the need to re-assess some metabolic details of an important and universal biosynthetic pathway in plants, and further explore its evolutionary history and function. Although colour production was limited to the Strelitziaceae in this study, further sampling may indicate otherwise.

Newborn Bilirubin Screening for Preventing Severe Hyperbilirubinemia and Bilirubin Encephalopathy: A Rapid Review.

Science.gov (United States)

Bhardwaj, Kalpana; Locke, Tiffany; Biringer, Anne; Booth, Allyson; Darling, Elizabeth K; Dougan, Shelley; Harrison, Jane; Hill, Stephen; Johnson, Ana; Makin, Susan; Potter, Beth; Lacaze-Masmonteil, Thierry; Little, Julian

2017-01-01

According to the 2004 American Academy of Pediatrics guideline on the management of hyperbilirubinemia, every newborn should be assessed for the risk of developing severe hyperbilirubinemia with the help of predischarge total serum bilirubin or transcutaneous bilirubin measurements and/or assessments of clinical risk factors. The aim of this rapid review is 1) to review the evidence for 1) predicting and preventing severe hyperbilirubinemia and bilirubin encephalopathy, 2) determining the efficacy of home/community treatments (home phototherapy) in the prevention of severe hyperbilirubinemia, and 3) non-invasive/transcutaneous methods for estimating serum bilirubin level. In this rapid review, studies were identified through the Medline database. The main outcomes of interest were severe hyperbilirubinemia and encephalopathy. A subset of articles was double screened and all articles were critically appraised using the SIGN and AMSTAR checklists. This review investigated if systems approach is likely to reduce the occurrence of severe hyperbilirubinemia. Fifty-two studies met the inclusion criteria. Included studies assessed the association between bilirubin measurement early in neonatal life and the subsequent development of severe hyperbilirubinemia and chronic bilirubin encephalopathy/kernicterus. It was observed that, highest priority should be given to (i) universal bilirubin screening programs; (ii) implementation of community and midwife practice; (iii) outreach to communities for education of prospective parents; and (iv) development of clinical pathways to monitor, evaluate and track infants with severe hyperbilirubinemia. We found substantial observational evidence that severe hyperbilirubinemia can be accurately predicted and prevented through universal bilirubin screening. So far, there is no evidence of any harm. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Electronic absorption spectrum of copper-doped magnesium potassium phosphate hexahydrate

Science.gov (United States)

Rao, S. N.; Sivaprasad, P.; Reddy, Y. P.; Rao, P. S.

1992-04-01

The optical absorption and EPR spectra of magnesium potassium phosphate hexahydrate (MPPH) doped with copper ions are recorded both at room and liquid nitrogen temperatures. The spectrum is characteristic of Cu2+ in tetragonal symmetry. The spin-Hamiltonian parameters and molecular orbital coefficients are evaluated. A correlation between EPR and optical absorption studies is drawn.

Cobinding of bilirubin and laurate to human serum albumin: spectroscopic characterization of stoichiometric complexes

DEFF Research Database (Denmark)

Honoré, B; Sato, H; Brodersen, R

1988-01-01

Light absorption and CD spectra of bound bilirubin and albumin fluorescence spectra have been recorded from mixtures containing albumin, A, bilirubin, B, and laurate, L, in Tris-NaCl buffer at pH 8.2, 25 degrees C. Concentrations of the corresponding stoichiometric complexes, ABiLj, for i = 0....../3 and j = 0/3, have been calculated from previously determined stoichiometric cobinding constants (H. Sato et al. (1988) Arch. Biochem. Biophys. 260, 811-821). Spectral data of the complexes have finally been found by iterative computer fitting using the principle of several acceptable solutions (R...

Photoacoustic microscopy of bilirubin in tissue phantoms

Science.gov (United States)

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.

[Signal analysis and spectrum distortion correction for tunable diode laser absorption spectroscopy system].

Science.gov (United States)

Bao, Wei-Yi; Zhu, Yong; Chen, Jun; Chen, Jun-Qing; Liang, Bo

2011-04-01

In the present paper, the signal of a tunable diode laser absorption spectroscopy (TDLAS) trace gas sensing system, which has a wavelength modulation with a wide range of modulation amplitudes, is studied based on Fourier analysis method. Theory explanation of spectrum distortion induced by laser intensity amplitude modulation is given. In order to rectify the spectrum distortion, a method of synchronous amplitude modulation suppression by a variable optical attenuator is proposed. To validate the method, an experimental setup is designed. Absorption spectrum measurement experiments on CO2 gas were carried out. The results show that the residual laser intensity modulation amplitude of the experimental system is reduced to -0.1% of its original value and the spectrum distortion improvement is 92% with the synchronous amplitude modulation suppression. The modulation amplitude of laser intensity can be effectively reduced and the spectrum distortion can be well corrected by using the given correction method and system. By using a variable optical attenuator in the TDLAS (tunable diode laser absorption spectroscopy) system, the dynamic range requirements of photoelectric detector, digital to analog converter, filters and other aspects of the TDLAS system are reduced. This spectrum distortion correction method can be used for online trace gas analyzing in process industry.

Bilirubin Binding Capacity in the Preterm Neonate.

Science.gov (United States)

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Bilirubin Binding to PPARα Inhibits Lipid Accumulation

Science.gov (United States)

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

Absorption spectrum of DNA for wavelengths greater than 300 nm

International Nuclear Information System (INIS)

Sutherland, J.C.; Griffin, K.P.

1981-01-01

Although DNA absorption at wavelengths greater than 300 nm is much weaker than that at shorter wavelengths, this absorption seems to be responsible for much of the biological damage caused by solar radiation of wavelengths less than 320 nm. Accurate measurement of the absorption spectrum of DNA above 300 nm is complicated by turbidity characteristic of concentrated solutions of DNA. We have measured the absorption spectra of DNA from calf thymus, Clostridium perfringens, Escherichia coli, Micrococcus luteus, salmon testis, and human placenta using procedures which separate optical density due to true absorption from that due to turbidity. Above 300 nm, the relative absorption of DNA increases as a function of guanine-cytosine content, presumably because the absorption of guanine is much greater than the absorption of adenine at these wavelengths. This result suggests that the photophysical processes which follow absorption of a long-wavelength photon may, on the average, differ from those induced by shorter-wavelength photons. It may also explain the lower quantum yield for the killing of cells by wavelengths above 300 nm compared to that by shorter wavelengths

The synthesis of 13C-bilirubin and its use in the validation of bilirubin kinetic studies in rats

International Nuclear Information System (INIS)

Sturrock, E.D.

1994-04-01

The total synthesis of [10- 13 C] bilirubin IXα], the principal waste product of haem degradation, is described. Site specific labelling was accomplished by the Vilsmeier formulation of one of the dipyrrolic fragments using [1- 13 C] dimethylformamide. The penultimate dehydrohalogenation reaction was complicated by a competing elimination reaction which yielded a bridged biliverdin derivative. The base catalysed reaction affords a novel [10- 13 C]-8,12-bis(2-methoxycarbonylethyl)-7,13,17-trimethyl-2,18-propano-3-vinylbilin-1,19(21H,24H)-dione in which the 2 and 18 positions of the macrocycle are bridged with a propano tether, the structure has been established using single crystal X-ray and 1 H nuclear Overhauser effect studies. [ 14 C]bilirubin was prepared, bio synthetically, using [ 14 C]aminolevulinic acid. Bilirubin kinetics in 4 rats were measured by the analysis of the plasma disappearance of [ 14 C]bilirubin in a two-compartment model. The plasma half-life of the first and second exponentials were 1.97 and 32.8 minutes respectively. The data were used to determine model independent parameters k 12 , k 21 , and k 20 . In the proposed model, plasma unconjugated bilirubin exchanges with a hepatic unconjugated bilirubin pool. Bilirubin is eliminated from the system via the proposed hepatic pool. These studies provide an analysis of the kinetics of unconjugated bilirubin in rates and are intended to serve as a reference point for studies using a stable isotope of bilirubin. The plasma disappearance of [10- 13 C]bilirubin IXα in three rats was studied using mass spectrometry to measure the bilirubin δ 13 C. Validation of the experimental procedure in terms of range and reproducibility of the detection method was carried out. The half lives of the initial and terminal exponentials were 2.27±2.5 and 22.8±12.9 minutes. Despite the large 95% confidence limits calculated for these clearance curves they serve as an important foundation for future bilirubin kinetic

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Studies on bile acid and bilirubin in liver diseases Part 2. Clinical significance of serum bilirubin sulfate in various liver diseases

OpenAIRE

石川, 泰祐

1980-01-01

The clinical significance of serum bilirubin sulfate, one of the direct bilirubin, was evaluated in various liver diseases with over 2 mg/dl of serum bilirubin concentration. The diagnosis included 25 cases of acute hepatitis, 8 cases of chronic hepatitis, 8 cases of liver cirrhosis and 16 cases of liver cirrhosis with hepatoma. Bilirubin sulfate was fractioned by Yonei's solvent partition method. The clinical significance of bilirubin sulfate was assessed by comparison of bilirubin sulfate w...

Bilirubin-Induced Neurotoxicity in the Preterm Neonate.

Science.gov (United States)

Watchko, Jon F

2016-06-01

Bilirubin-induced neurotoxicity in preterm neonates remains a clinical concern. Multiple cellular and molecular cascades likely underlie bilirubin-induced neuronal injury, including plasma membrane perturbations, excitotoxicity, neuroinflammation, oxidative stress, and cell cycle arrest. Preterm newborns are particularly vulnerable secondary to central nervous system immaturity and concurrent adverse clinical conditions that may potentiate bilirubin toxicity. Acute bilirubin encephalopathy in preterm neonates may be subtle and manifest primarily as recurrent symptomatic apneic events. Low-bilirubin kernicterus continues to be reported in preterm neonates, and although multifactorial in nature, is often associated with marked hypoalbuminemia. Copyright © 2016 Elsevier Inc. All rights reserved.

Serum Bilirubin Concentrations in Patients With Takayasu Arteritis.

Science.gov (United States)

Peng, You-Fan; Deng, Yi-Bin

2017-06-01

- Bilirubin has strong anti-inflammatory and antioxidative stress action. Progression of inflammation involving arteries is a crucial activator in pathogenesis of Takayasu arteritis (TA). - To investigate the relationship between serum bilirubin and TA. - Our study involved 115 consecutive TA patients. Patients with active-phase disease were followed and received prednisone therapy. - Lower concentrations of serum bilirubin were detected in TA patients compared with healthy subjects (0.6 ± 0.31 versus 0.7 ± 0.22 mg/dL, P = .02). Serum bilirubin concentrations in active TA patients were lower than those in inactive patients (0.5 ± 0.20 versus 0.8 ± 0.32 mg/dL, P bilirubin correlated positively with total protein (r = 0.193, P = .04) and negatively with C-reactive protein and erythrocyte sedimentation rate (r = -0.213, P = .03, and r = -0.532, P bilirubin was associated with a 1.10 times increase in the odds for TA compared with the controls (odds ratio = 0.913, 95% CI, 0.856-0.974; P = .006). Serum bilirubin was correlated with erythrocyte sedimentation rate (β = -0.170, P bilirubin in predicting active TA patients was 0.802. Serum bilirubin levels were found to be significantly increased after prednisone treatment (0.5 ± 0.20 versus 0.7 ± 0.15 mg/dL, P = .002). - Lower serum bilirubin levels are associated with TA, and serum bilirubin may be influenced by prednisone therapy in active TA patients. Serum bilirubin levels in TA patients correlate negatively with erythrocyte sedimentation rate.

Determination of mixture valence plutonium and multicomponent by computer resolution analysis of absorption spectrum (UV/VIS/NIR) (CRAAS)

International Nuclear Information System (INIS)

Zhuang Weixin; Ye Guoan; Huang Lifeng; Sun Hongfang; Zhao Yanju

1996-09-01

A spectrophotometry has been developed which can directly determine a multi-component sample by spectrophotometry without any chemical separation. CRAAS (Computer Resolution Analysis of Absorption Spectrum) has been reported. It is different from the previous spectrophotometry depending on only one or several special absorption peak. The CRAAS deals with the whole region of absorption spectrum by mathematical statistics. So CRAAS has higher accuracy, stronger power and very high resolution. The trouble comes from overlap of different spectrum in each other has been solved because CRAAS depends on the whole spectrum. As long as two spectra have different shape, their concentrations can be determined even their special absorption peaks are seriously overlapped. The accuracy is about +-5%. (2 refs., 7 figs., 8 tabs.)

On the nature of solvatochromic effect: The riboflavin absorption spectrum as a case study

Science.gov (United States)

Daidone, Isabella; Amadei, Andrea; Aschi, Massimiliano; Zanetti-Polzi, Laura

2018-03-01

We present here the calculation of the absorption spectrum of riboflavin in acetonitrile and dimethyl sulfoxide using a hybrid quantum/classical approach, namely the perturbed matrix method, based on quantum mechanical calculations and molecular dynamics simulations. The calculated spectra are compared to the absorption spectrum of riboflavin previously calculated in water and to the experimental spectra obtained in all three solvents. The experimentally observed variations in the absorption spectra upon change of the solvent environment are well reproduced by the calculated spectra. In addition, the nature of the excited states of riboflavin interacting with different solvents is investigated, showing that environment effects determine a recombination of the gas-phase electronic states and that such a recombination is strongly affected by the polarity of the solvent inducing significant changes in the absorption spectra.

Functionalized SBA-15 materials for bilirubin adsorption

Science.gov (United States)

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.

Absorption spectrum of a V-type three-level atom driven by a coherent field

International Nuclear Information System (INIS)

Dong Po; Tang, S.H.

2002-01-01

We examine the absorption of a weak probe beam by a laser driven V-type atom with a pair of closely lying excited levels, where both the driving and probe lasers interact simultaneously with the two transitions. The effects of quantum interference among decay channels on the absorption spectra are also investigated. We introduce dipole moments in the dressed-state representation and the Hamiltonian in terms of the dressed states describing the interaction between the probe and the atom. In the degenerate case, features similar to that of a driven two-level atomic system are found due to some dark transitions in the spontaneous emission and the fact that the probe beam only detects certain transitions. In the nondegenerate case, the absorption spectrum is strongly influenced by the degree of quantum interference, resulting in different line shapes for emission peaks, absorption peaks, and dispersionlike profiles. The effect of probe polarization on the absorption spectrum is also investigated

[Effects of LED spectrum combinations on the absorption of mineral elements of hydroponic lettuce].

Science.gov (United States)

Chen, Xiao-Li; Guo, Wen-Zhong; Xue, Xu-Zhang; Mmanake Beauty, Morewane

2014-05-01

Lettuce (Lactuca sativa) was hydroponically cultured in a completely enclosed plant factory, in which spectrum proportion-adjustable LED panels were used as sole light source for plant growth. Absorption and content of eleven mineral elements such as K, P, Ca, Mg, Na, Fe, Mn, Zn, Cu, B and Mo in Lactuca sativa under different spectral component conditions were studied by ICP -AES technology. The results showed that: (1) Single or combined spectrums corresponding to the absorbing peaks of chlorophyll a and b (450, 660 nm) could enhance the absorbing ability of roots especially for mineral elements Na, Fe, Mn, Cu and Mo, the single red spectrum had the most significant promoting effect under which contents of those four elements were respectively 7. 8, 4. 2, 4. 0 and 3. 7 times more than that under FL; (2) Absorption of K and B was the highest under FL which was 10. 309 mg g-1 and 32. 6 microg g-1 while the values decreased significantly under single or combined spectrum of red and blue; (3) Plants grown under single blue spectrum had the lowest absorption of Ca and Mg which respectively decreased by 35% and 33% than FL; (4) Lettuce grown under the spectrum combination of 30% blue and 70% red had the highest accumulations of biomass while those grown under 20% blue and 80% red had the highest accumulations of the following seven elements Ca, Mg, Na, Fe, Mn, Zn and B. The results provided theoretical basis for adjusting nutrient solution formula and selecting light spectrum of hydroponic lettuce.

H i Absorption in the Steep-Spectrum Superluminal Quasar 3C 216.

Science.gov (United States)

Pihlström; Vermeulen; Taylor; Conway

1999-11-01

The search for H i absorption in strong compact steep-spectrum sources is a natural way to probe the neutral gas contents in young radio sources. In turn, this may provide information about the evolution of powerful radio sources. The recently improved capabilities of the Westerbork Synthesis Radio Telescope have made it possible to detect a 0.31% (19 mJy) deep neutral atomic hydrogen absorption line associated with the steep-spectrum superluminal quasar 3C 216. The redshift (z=0.67) of the source shifts the frequency of the 21 cm line down to the ultra-high-frequency (UHF) band (850 MHz). The exact location of the H i-absorbing gas remains to be determined by spectral line VLBI observations at 850 MHz. We cannot exclude that the gas might be extended on galactic scales, but we think it is more likely to be located in the central kiloparsec. Constraints from the lack of X-ray absorption probably rule out obscuration of the core region, and we argue that the most plausible site for the H i absorption is in the jet-cloud interaction observed in this source.

The effect of gamma-radiation on bilirubin

International Nuclear Information System (INIS)

Iqbal, M.S.; Shad, M.A.; Akhtar, M.I.

2001-01-01

The effect of gamma-radiations on bilirubin, in vitro, has been studied. It was found that gamma-radiation causes oxidation of bilirubin to biliverdine as one of the products. The likely implication of this effect in transformation of bilirubin to excretable products, in vino, in case of jaundice is discussed. (author)

Hepatic conversion of bilirubin monoglucuronide to diglucuronide in uridine diphosphate-glucuronyl transferase-deficient man and rat by bilirubin glucuronoside glucuronosyltransferase

NARCIS (Netherlands)

Chowdhury, J. R.; Jansen, P. L.; Fischberg, E. B.; Daniller, A.; Arias, I. M.

1978-01-01

The microsomal enzyme uridine diphosphate (UDP) glucuronate glucuronyltransferase (E.C. 2.4.1.17) catalyzes formation of bilirubin mono-glucuronide from bilirubin and UDPglucuronic acid. Bilirubin glucuronoside glucuronosyltransferase (E.C. 2.4.1.95), an enzyme concentrated in plasma

Does bilirubin protect against developing diabetes mellitus?

Science.gov (United States)

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Bilirubin bound to cells does not form photoisomers

International Nuclear Information System (INIS)

Christensen, T.; Kinn, G.

1993-01-01

Cultured cells from one human and one murine cell line were incubated with bilirubin by different methods that allowed bilirubin to be bound to cells. The cells were irradiated with visible light of different wavelengths. Bilirubin bound to human serum albumin was also irradiated with light. After irradiation, bilirubin and its photoisomers were extracted and analyzed by HPLC. No photoisomers were found in samples of irradiated cells, while the types and amounts of photoisomers that were expected from the literature were found in samples of irradiated bilirubin/albumin mixtures. It is concluded that the formation of therapeutically active photoisomers during phototherapy most probably does not take place in skin cells, but most likely in bilirubin bound to albumin in the vessels or in the interstitial space. 16 refs., 2 figs

Bilirubin Blood Test: MedlinePlus Lab Test Information

Science.gov (United States)

... this page: https://medlineplus.gov/labtests/bilirubinbloodtest.html Bilirubin Blood Test To use the sharing features on this page, please enable JavaScript. What is a Bilirubin Blood Test? A bilirubin blood test measures the ...

Towards bilirubin imprinted poly(methacrylic acid-co-ethylene glycol dimethylacrylate) for the specific binding of α-bilirubin

International Nuclear Information System (INIS)

Syu, M.-J.; Deng, J.-H.; Nian, Y.-M.

2004-01-01

With α-bilirubin as a molecular template, polymerization of methacrylic acid (MAA) was carried out with the aid of the initiator 2,2-azobisisobutyronitrile (AIBN) and the cross-linking agent ethylene glycol dimethylacrylate (EGDMA). Bulk polymerization was successfully carried out so that poly(methacrylic acid-co-ethylene glycol dimethylacrylate) (poly(MAA-EGDMA)) imprinted with α-bilirubin was first developed. UV irradiation polymerization and heated polymerization methods were compared. Effect of different ratios of monomer to EGDMA during the polymerization was also discussed. Proper solvent for better desorption of α-bilirubin from the imprinted poly(MAA-EGDMA) was investigated. In addition, SEM photos were provided for observing the differences between the surfaces of the imprinted poly(MAA-EGDMA) before and after extraction. The corresponding binding results of α-bilirubin imprinted poly(MAA-EGDMA) and non-imprinted poly(MAA-EGDMA) both after extraction were compared. How the pH values during extraction stage affected the binding capacities of the imprinted polymer as well as non-imprinted polymer were also discussed. Similar study and comparison were made for different binding pH values. Different compounds of similar molecular weight were used to show the specific binding of the imprinted polymer for bilirubin. The results further confirmed the successful binding as well as specificity of the imprinted poly(MAA-EGDMA) for α-bilirubin

Serum bilirubin and the risk of rheumatoid arthritis.

Science.gov (United States)

Juping, Du; Yuan, Yuan; Shiyong, Chen; Jun, Li; Xiuxiu, Zhou; Haijian, Ying; Jianfeng, Shi; Bo, Shen

2017-11-01

Oxidative stress and immune imbalance play an important role in the pathogenesis of rheumatoid arthritis (RA). Bilirubin is a powerful antioxidant and also regarded as immunomodulator. Increased evidence shows that bilirubin should be a protective factor for autoimmune disease. However, the relationship between bilirubin and RA remain unclear. We analyzed serum bilirubin levels and other laboratory and clinical data in 130 RA patients (35 patients without any complications), 81 osteoarthritis (OA) patients and 96 healthy controls. Binary logistic regression adjusted by age and gender revealed that the levels of serum total, indirect bilirubin were significantly lower in RA patients, when compared with healthy controls (P=.015, OR=0.767, 95% CI=0.619-0.951; P=.010, OR=0.664, 95% CI=0.487-0.906, respectively) or OA patients (P=.000, OR=0.763, 95% CI=0.661-0.882; P=.000, OR=0.656, 95% CI=0.532-0.808, respectively). A reduced trend of levels of bilirubin has been detected along with increased disease activity, despite with no significance (P>.05). Spearman rank test further demonstrated that IgG and ESR were negative associated with total, indirect bilirubin, and albumin, prealbumin, APOA, HDL-C were positively associated with bilirubin. In conclusion, the levels of serum bilirubins were decreased in RA, and decreased levels could be associated with IgG, albumin and inflammatory marker ESR. © 2017 Wiley Periodicals, Inc.

Animal pigment bilirubin discovered in plants.

Science.gov (United States)

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.

Supramolecular Complexes Formed in Systems Bile Salt-Bilirubin-Silica

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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 (B Total ), which is currently used to guide clinical care; the bilirubin binding capacity (BBC); and the concentration of non-albumin bound or free bilirubin (B Free ). The fourth component is the bilirubin-albumin equilibrium dissociation constant, K D , which is calculated from B Total , BBC, and B Free 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 B Total ) are needed to expedite the clinical use of bilirubin binding. At any B Total , the B Free and the relative risk of bilirubin neurotoxicity increase as the K D /BBC ratio increases (ie, bilirubin binding worsens). Comparing the K D /BBC ratio of newborns with B Total of concern with that typical for the population helps determine whether the risk of bilirubin neurotoxicity varies significantly from the inherent risk at that B Total Furthermore, the bilirubin binding panel individualizes care because it helps to determine how aggressive intervention should be at any B Total , irrespective of whether it is above or below established B Total guidelines. The bilirubin binding panel may reduce anxiety, costs, unnecessary treatment, and the likelihood of undetected bilirubin neurotoxicity. Copyright © 2016 by the American Academy of Pediatrics.

Bilirubin and Stroke Risk Using a Mendelian Randomization Design.

Science.gov (United States)

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) (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.

Bilirubin and its oxidation products damage brain white matter

Science.gov (United States)

Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

2014-01-01

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

Influence of skin optical losses on configurational photoisomerization of bilirubin during phototherapy

International Nuclear Information System (INIS)

Pratesi, R.; Cecchi, G.

1984-01-01

Kubelka-Munk theory of radiation transfer in turbid media is applied to determine the influence of skin optical losses on the efficiency of phototherapy of neonatal hyperbilirubinemia. By using a multilayer model of the skin and a rate equation analysis of bilirubin photoisomerization, the photon absorption rates of birilubin and of its configurational photoisomers and, in turn, the photoequilibrium concentrations and rise time are calculated for spectrally Gaussian light sources and fluorescent lamps used in phototherapy

Quantitation of bilirubin conjugates with high-performance liquid chromatography in patients with low total serum bilirubin levels

NARCIS (Netherlands)

Jansen, P. L.; Cuypers, H. T.; Peters, W. H.

1984-01-01

Bilirubin mono- and diconjugates were determined by alkaline methanolysis and high-performance liquid chromatography (HPLC) in serum from patients with metastatic liver disease and liver cirrhosis. Conjugates could be detected and quantitated at normal or low total bilirubin levels. Comparison with

Bilirubin adsorption on nanocrystalline titania films

International Nuclear Information System (INIS)

Yang Zhengpeng; Si Shihui; Fung Yingsing

2007-01-01

Bilirubin produced from hemoglobin metabolism and normally conjugated with albumin is a kind of lipophilic endotoxin, and can cause various diseases when its concentration is high. Bilirubin adsorption on the nanocrystalline TiO 2 films was investigated using quartz crystal microbalance, UV-vis and IR techniques, and factors affecting its adsorption such as pH, bilirubin concentration, solution ionic strength, temperature and thickness of TiO 2 films were discussed. The amount of adsorption and parameters for the adsorption kinetics were estimated from the frequency measurements of quartz crystal microbalance. A fresh surface of the nanocrystalline TiO 2 films could be photochemically regenerated because holes and hydroxyl radicals were generated by irradiating the nanocrystalline TiO 2 films with UV light, which could oxidize and decompose organic materials, and the nanocrystalline TiO 2 films can be easily regenerated when it is used as adsorbent for the removal of bilirubin

Cells, bilirubin and light: formation of bilirubin photoproducts and cellular damage at defined wavelengths

International Nuclear Information System (INIS)

Christensen, T.; Kinn, G.; Granli, T.; Amundsen, I.

1994-01-01

Cultured cells from one human and one murine cell line were treated with bilirubin and irradiated with visible light of different wavelengths, either from phototherapy lamps or from a Xenon/Mercury lamp equipped with a monochromator. Bilirubin bound to human serum albumin was also irradiated with light. After irradiation, the bilirubin and its photoisomers were extracted with High Pressure Liquid Chromatography. The formation of single strand breaks in the DNA of treated cells was studied using a fluorescence marker. Cytotoxicity in the mouse skin cell line was measured by loss of the ability to form visible colonies in vitro. Green light exposure favours the production of lumirubin, while blue light causes more DNA damage and cytotoxicity. Green light may be more efficient and safer than shorter wavelength exposure when treating jaundiced newborns with phototherapy. 27 refs., 6 figs

A microscopic evaluation of collagen-bilirubin interactions: in vitro surface phenomenon.

Science.gov (United States)

Usharani, N; Jayakumar, G C; Rao, J R; Chandrasekaran, B; Nair, B U

2014-02-01

This study is carried out to understand the morphology variations of collagen I matrices influenced by bilirubin. The characteristics of bilirubin interaction with collagen ascertained using various techniques like XRD, CLSM, fluorescence, SEM and AFM. These techniques are used to understand the distribution, expression and colocalization patterns of collagen-bilirubin complexes. The present investigation mimic the in vivo mechanisms created during the disorder condition like jaundice. Fluorescence technique elucidates the crucial role played by bilirubin deposition and interaction during collagen organization. Influence of bilirubin during collagen fibrillogenesis and banding patterns are clearly visualize using SEM. As a result, collagen-bilirubin complex provides different reconstructed patterns because of the influence of bilirubin concentration. Selectivity, specificity and spatial organization of collagen-bilirubin are determined through AFM imaging. Consequently, it is observed that the morphology and quantity of the bilirubin binding to collagen varied by the concentrations and the adsorption rate in protein solutions. Microscopic studies of collagen-bilirubin interaction confirms that bilirubin influence the fibrillogenesis and alter the rate of collagen organization depending on the bilirubin concentration. This knowledge helps to develop a novel drug to inhibit the interface point of interaction between collagen and bilirubin. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

Trans-Cutaneous Bilirubinometery versus Serum Bilirubin in Neonatal Jaundice.

Science.gov (United States)

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.

Comparison of serum bilirubin estimation with transcutaneous bilirubinometry in neonates

International Nuclear Information System (INIS)

Waqar, T.; Ahmad, Z.; Ali, A.

2010-01-01

Objective: To assess usefulness of Minolta Air shield transcutaneous bilirubinometer by comparing bilirubin values obtained by transcutaneous jaundice meter with serum bilirubin estimation. Design: Analytical cross sectional study. Place and duration: NICU Military Hospital Rawalpindi Pakistan Jun 2002 to May 2005. Subjects and Methods: One hundred and fifty neonates admitted to NICU because of visible jaundice were included in the study. Serum was sent to laboratory for total bilirubin estimation. At the same time bilirubin was also checked by a Jaundice Meter. Data was tabulated and t-test applied to compare the two values. Results: One hundred and fifty paired estimations were performed. The transcutaneous bilirubin values ranged from 8.0 mg/dl to 20.4 mg/dl. While serum bilirubin by jaundice meter values ranged between 5.3 mg/dl and 26.0 mg/dl. A Scatter diagram was plotted. It showed a correlation coefficient of 0.78. Conclusion: Bilirubin values obtained by transcutaneous bilirubin meter were not significantly different from laboratory values thus proving the fact that transcutaneous bilirubinometer is a useful device to measure bilirubin. (author)

Spectral matching research for light-emitting diode-based neonatal jaundice therapeutic device light source

Science.gov (United States)

Gan, Ruting; Guo, Zhenning; Lin, Jieben

2015-09-01

To decrease the risk of bilirubin encephalopathy and minimize the need for exchange transfusions, we report a novel design for light source of light-emitting diode (LED)-based neonatal jaundice therapeutic device (NJTD). The bilirubin absorption spectrum in vivo was regarded as target. Based on spectral constructing theory, we used commercially available LEDs with different peak wavelengths and full width at half maximum as matching light sources. Simple genetic algorithm was first proposed as the spectral matching method. The required LEDs number at each peak wavelength was calculated, and then, the commercial light source sample model of the device was fabricated to confirm the spectral matching technology. In addition, the corresponding spectrum was measured and the effect was analyzed finally. The results showed that fitted spectrum was very similar to the target spectrum with 98.86 % matching degree, and the actual device model has a spectrum close to the target with 96.02 % matching degree. With higher fitting degree and efficiency, this matching algorithm is very suitable for light source matching technology of LED-based spectral distribution, and bilirubin absorption spectrum in vivo will be auspicious candidate for the target spectrum of new LED-based NJTD light source.

Subwavelength atom localization via amplitude and phase control of the absorption spectrum

OpenAIRE

Sahrai, Mostafa; Tajalli, Habib; Kapale, Kishore T.; Zubairy, M. Suhail

2005-01-01

We propose a scheme for subwavelength localization of an atom conditioned upon the absorption of a weak probe field at a particular frequency. Manipulating atom-field interaction on a certain transition by applying drive fields on nearby coupled transitions leads to interesting effects in the absorption spectrum of the weak probe field. We exploit this fact and employ a four-level system with three driving fields and a weak probe field, where one of the drive fields is a standing-wave field o...

Patterning of graphite nanocones for broadband solar spectrum absorption

Directory of Open Access Journals (Sweden)

Yaoran Sun

2015-06-01

Full Text Available We experimentally demonstrate a broadband vis-NIR absorber consisting of 300-400 nm nanocone structures on highly oriented pyrolytic graphite. The nanocone structures are fabricated through simple nanoparticle lithography process and analyzed with three-dimensional finite-difference time-domain methods. The measured absorption reaches an average level of above 95% over almost the entire solar spectrum and agrees well with the simulation. Our simple process offers a promising material for solar-thermal devices.

Tunable ultranarrow spectrum selective absorption in a graphene monolayer at terahertz frequency

Science.gov (United States)

Wu, Jun

2016-06-01

Complete absorption in a graphene monolayer at terahertz frequency through the critical coupling effect is investigated. It is achieved by sandwiching the graphene monolayer between a dielectric grating and a Bragg grating. The designed graphene absorber exhibits near-unity absorption at resonance but with an ultranarrow spectrum and antenna-like response, which is attributed to the combined effects of guided mode resonance with dielectric grating and the photonic band gap with Bragg grating. In addition to numerical simulation, the electric field distributions are also illustrated to provide a physical understanding of the perfect absorption effect. Furthermore, the absorption performance can be tuned by only changing the Fermi level of graphene, which is beneficial for real application. It is believed that this study may be useful for designing next-generation graphene-based optoelectronic devices.

Thermodynamic studies of bilirubin/cholesterol mixtures at the air/water interface

International Nuclear Information System (INIS)

Xie Anjian; Shen Yuhua; Xia Bing; Chen Hongbo; Ouyang Jianming

2005-01-01

Mixed monolayers of cholesterol and bilirubin spread at the air/water interface were used as model systems to examine the cholesterol effect on bilirubin. Miscibility and interactions between cholesterol and bilirubin were studied based on the analysis of the surface pressure-molecular area isotherms. From the isotherm data differentiated with respect to area, the condensing effect of cholesterol on the mixed monolayers could be observed distinctly. By studying surface compressibility modulus of bilirubin/cholesterol binary system vs. molecule area, we show that the liquid expanded-condensed phase transition (LE-C) of bilirubin was eliminated by cholesterol. In monolayers, bilirubin and cholesterol were found to be miscible at low surface pressure and immiscible at high surface pressure by studying the excess molecular areas of bilirubin/cholesterol system vs. mole fraction of bilirubin. The results from excess free energy of bilirubin/cholesterol system vs. mole fraction of bilirubin (X BR ) show that the maximum negative value of ΔG exc appeared at X BR =0.6, which indicates the formation of a bilirubin/cholesterol complex (M B-C ) of 3:2 stoichiometry as a result of the strong hydrogen bond between the polar groups of cholesterol and bilirubin and the self-assembly characteristics of cholesterol

The Relationship Between Dynamics and Structure in the Far Infrared Absorption Spectrum of Liquid Water

Energy Technology Data Exchange (ETDEWEB)

Woods, K.

2005-01-14

Using an intense source of far-infrared radiation, the absorption spectrum of liquid water is measured at a temperature ranging from 269 to 323 K. In the infrared spectrum we observe modes that are related to the local structure of liquid water. Here we present a FIR measured spectrum that is sensitive to the low frequency (< 100cm{sup -1}) microscopic details that exist in liquid water.

Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules

International Nuclear Information System (INIS)

Crawford, J.M.; Gollan, J.L.

1988-01-01

Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer [ 14 C]bilirubin-[ 3 H]bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous [ 14 C]bilirubin monoglucuronide-[ 3 H]bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism

Study of MRI characteristics of newborn bilirubin encephalopathy

International Nuclear Information System (INIS)

Wu Wulin; Wang Xiaoyi; Liao Weihua; Liu Fan; Zhang Ping

2008-01-01

Objective: To explore routine magnetic resonance imaging characteristics of newborn bilirubin encephalopathy (NBE). Methods: MRI features and clinical data of 17 patients with Newborn bilirubin encephalopathy were retrospectively analyzed, globus pallidus (GP)and subthalamic signal intensity was evaluated. The increase of GP signal intensity and serum total bilirubin peak value were analyzed using pearson correlation analysis. Serum total bilirubin peak value between patients with high signal in the subthalamic nuclei on T 1 WI and patients without high signal in the subthalamic nuclei were compared statistically. Results: The main MRI presentation in the NBE group was abnormally increased signal intensity in the GP on T 1 WI, which was not apparent on T 2 WI. One patient showed abnormal high signal intensity in the posteromedial part of GP. Nine patients had high signal in the subthalamic nuclei on T 1 WI and normal signal on T 2 WI. Four patients showed high signal in the brainstem with sparing of dorsal pontine. The increase in value of GP signal intensity was 249.0-423.8 in 12 patients and their serum total bilirubin peak values were 366.0-983.3 μmol/L. A positive correlation was found between increase of GP signal intensity and serum total bilirubin peak value. The serum total bilirubin level of abnormal subthalamic group and normal subthalamic group were 660.7±192.4 μmol/L and 513.3±107.51 μmol/L respectively. The difference between the two groups was not statistically significant (t=1.914, P>0.05). Conclusion: The routine MRI has some characteristics and is useful in the diagnosis of newborn bilirubin encephalopathy. (authors)

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

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bilirubin (total or direct) test system. 862.1110... Systems § 862.1110 Bilirubin (total or direct) test system. (a) Identification. A bilirubin (total or direct) test system is a device intended to measure the levels of bilirubin (total or direct) in plasma...

Extreme Bilirubin Levels as a Causal Risk Factor for Symptomatic Gallstone Disease

DEFF Research Database (Denmark)

Stender, Stefan; Frikke-Schmidt, Ruth; Nordestgaard, Børge G

2013-01-01

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.......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....

Anti-Genotoxic Potential of Bilirubin In Vivo

DEFF Research Database (Denmark)

Wallner, Marlies; Antl, Nadja; Rittmannsberger, Barbara

2013-01-01

The bile pigment bilirubin is a known antioxidant and is associated with protection from cancer and cardiovascular disease (CVD) when present in too strong concentrations. Unconjugated bilirubin (UCB) might also possess anti-genotoxic potential by preventing oxidative damage to DNA. Moderately...... elevated bilirubin levels are found in individuals with Gilbert syndrome and more severe in the hyperbilirubinemic Gunn rat model. This study was therefore aimed to assess the levels of oxidative damage to DNA in Gilbert syndrome subjects and Gunn rats compared to matched controls. Seventy-six individuals...

beta-Glucuronidase-resistant bilirubin glucuronide isomers in cholestatic liver disease--determination of bilirubin metabolites in serum by means of high-pressure liquid chromatography

NARCIS (Netherlands)

Jansen, P. L.

1981-01-01

"Direct reacting bilirubin" in serum of patients with cholestatic liver disease and in serum of bile duct-ligated rats consists of a complex mixture of bilirubin metabolites. These metabolites were studied by means of high-pressure liquid chromatography. Bilirubin glucuronides in normal bile are

HI absorption in 3C 49 and 3C 268.3 - Probing the environment of compact steep spectrum and GHz peaked spectrum sources

NARCIS (Netherlands)

Labiano, A; Vermeulen, RC; Barthel, PD; O'Dea, CP; Gallimore, JF; Baum, S; de Vries, W

Aims. Localize and study the redshifted 21 cm H I absorption known to occur in the subgalactic sized compact steep spectrum galaxies 3C 49 and 3C 268.3. Methods. We carried out European VLBI Network UHF hand spectral line observations. Results. We have detected H I absorption towards the western

Enzymatic conversion of bilirubin monoglucuronide to diglucuronide by rat liver plasma membranes

NARCIS (Netherlands)

Jansen, P. L.; Chowdhury, J. R.; Fischberg, E. B.; Arias, I. M.

1977-01-01

Formation of bilirubin monoglucuronide from unconjugated bilirubin requires a microsomal enzyme, UDP-glucuronate glucuronyltransferase (EC 2.4.1.17). Conversion of bilirubin monoglucuronide to bilirubin diglucuronide, the major bilirubin conjugate in bile, was studied in subcellular fractions of rat

Conjugated Bilirubin Triggers Anemia by Inducing Erythrocyte Death

Science.gov (United States)

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

Modeling the absorption spectrum of the permanganate ion in vacuum and in aqueous solution

DEFF Research Database (Denmark)

Olsen, Jógvan Magnus Haugaard; Hedegård, Erik Donovan

2017-01-01

The absorption spectrum of the MnO4(-) ion has been a test-bed for quantum-chemical methods over the last decades. Its correct description requires highly-correlated multiconfigurational methods, which are incompatible with the inclusion of finite-temperature and solvent effects due to their high...... by employing the polarizable embedding (PE) model combined with a range-separated complete active space short-range density functional theory method (CAS-srDFT). Finite-temperature effects are taken into account by averaging over structures obtained from ab initio molecular dynamics simulations. The explicit...... treatment of finite-temperature and solvent effects facilitates the interpretation of the bands in the low-energy region of the MnO4(-) absorption spectrum, whose assignment has been elusive....

UDP-glucuronyltransferase-catalyzed deconjugation of bilirubin monoglucuronide

NARCIS (Netherlands)

Cuypers, H. T.; ter Haar, E. M.; Jansen, P. L.

1984-01-01

Bilirubin monoglucuronide is rapidly deconjugated when incubated with UDP and rat liver microsomal preparations at pH 5.1. The following evidence was found that this reaction is catalyzed by UDP-glucuronyltransferase: (i) unconjugated bilirubin and UDP-glucuronic acid were identified as the reaction

Development of bilirubin metabolism and transport in the neonate.

Science.gov (United States)

Gartner, L M

1977-01-01

Comprehensive physiologic study of the developmental processes of bilirubin metabolism and transport reveal a complex interaction of various steps. Phase I Physiologic Jaundice results from the simultaneous increase in bilirubin load presented to the liver and decrease in bilirubin conjugating capacity. Phase II appears to result from a mild decrease in hepatic uptake capacity, coupled with the continuing increase in bilirubin load. Since these results are based upon studies of newborn rhesus monkeys, confirmatory studies in human neonates are required. Perhaps the most challenging aspect of these observations relates to the concept of a developmentally determined delicate imbalance between two functions. It is unlikely that pharmacologic agents could radically alter a single function. Therefore, it is perhaps more realistic to think that drug treatments which only slightly alter two functions simultaneously but in the appropriate directions could more effectively reduce the risk of toxicity. Thus, a mild increase in bilirubin conjugation coupled with a small but significant decrease in bilirubin load could markedly alleviate the severity of physiologic jaundice.

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

Science.gov (United States)

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. Copyright © 2014 Elsevier Inc. All rights reserved.

Acute Alcohol Consumption Elevates Serum Bilirubin, an Endogenous Antioxidant

Science.gov (United States)

O’Malley, Stephanie S.; Gueorguieva, Ralitza; Wu, Ran; Jatlow, Peter I.

2015-01-01

Background Moderate alcohol consumption has been associated with both negative and favorable effects on health. The mechanisms responsible for reported favorable effects remain unclear. Higher (not necessarily elevated) concentrations of serum bilirubin, an antioxidant, have also been associated with reduced risk of cardiovascular disease and all-cause mortality. This study tests the hypothesis that single dose alcohol consumption elevates bilirubin providing a potential link between these observations. Methods 18 healthy individuals (8 cigarette smokers) were administered alcohol, calibrated to achieve blood concentrations of 20, 80 and 120 mg/dL, in random order in 3 laboratory sessions separated by a week. Each session was preceded by and followed by 5–7 days of alcohol abstinence. Serum bilirubin was measured at 7:45 am prior to drinking, at 2 pm, and at 7:45 the next morning. Mixed effects regression models compared baseline and 24 hr. post-drinking bilirubin concentrations. Results Total serum bilirubin (sum of indirect and direct) concentration increased significantly after drinking from baseline to 24 hours in non-smokers (from Mean=0.38, SD=0.24 to Mean=0.51 SD=0.30, F(1, 32.2) =24.24, pbilirubin concentration and the ratio of indirect (unconjugated) to direct (conjugated) bilirubin also increased significantly. Conclusions Alcohol consumption leads to increases in serum bilirubin in nonsmokers. Considering the antioxidant properties of bilirubin, our findings suggest one possible mechanism for the reported association between alcohol consumption and reduced risk of some disorders that could be tested in future longitudinal studies. PMID:25707709

Continuous optical measurement system of hemolysis during a photosensitization reaction using absorption spectrum

Science.gov (United States)

Hamada, R.; Ogawa, E.; Arai, T.

2018-02-01

To investigate hemolysis phenomena during a photosensitization reaction with the reaction condition continuously and simultaneously for a safety assessment of hemolysis side effect, we constructed an optical system to measure blood sample absorption spectrum during the reaction. Hemolysis degree might be under estimated in general evaluation methods because there is a constant oxygen pressure assumption in spite of oxygen depression take place. By investigating hemoglobin oxidation and oxygen desorption dynamics obtained from the contribution of the visible absorption spectrum and multiple regression analysis, both the hemolysis phenomena and its oxygen environment might be obtained with time. A 664 nm wavelength laser beam for the reaction excitation and 475-650 nm light beam for measuring the absorbance spectrum were arranged perpendicularly crossing. A quartz glass cuvette with 1×10 mm in dimensions for the spectrum measurement was located at this crossing point. A red blood cells suspension medium was arranged with low hematocrit containing 30 μg/ml talaporfin sodium. This medium was irradiated up to 40 J/cm2 . The met-hemoglobin, oxygenatedhemoglobin, and deoxygenated-hemoglobin concentrations were calculated by a multiple regression analysis from the measured spectra. We confirmed the met-hemoglobin concentration increased and oxygen saturation decreased with the irradiation time, which seems to indicate the hemolysis progression and oxygen consumption, respectively. By using our measuring system, the hemolysis progression seems to be obtained with oxygen environment information.

Prognostic significance of serum bilirubin in stroke

International Nuclear Information System (INIS)

Arslan, A.; Ismail, M.; Khan, F.; Khan, A.; Khattak, M.B.; Anwar, M.J.

2011-01-01

Background: Oxidative injury is an important cause of the neurologic lesion in stroke. Serum bilirubin is considered a natural antioxidant that may affect the prognosis of stroke. The purpose of this study was to evaluate the prognostic significance of bilirubin in stroke patients. Methods: A prospective cross-sectional study was conducted in Medical Units of Khyber Teaching Hospital, Peshawar. Inpatients admitted with acute attack of stroke were included in this study. Data regarding serum bilirubin and concurrent cerebrovascular risk factors were collected. National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to analyse stroke's severity and functional outcomes, respectively. Results: Hypertension, diabetes mellitus and heart diseases were the most common risk factors. Patients were divided into 3 groups on the basis of serum bilirubin, i.e., =0.6 mg/dl (Group-1), 0.7-0.9 mg/dl (Group-2), and =1.0 mg/dl (Group-3). The mean pre-hospitalisation NIHSS score for Groups 1, 2 and 3 was 5.62, 11.66 and 25.33, respectively; and post-hospitalisation score was 0.875, 3.76 and 16.26, respectively. The pre-hospitalisation mRS score was 4 for Group-1, 4.52 for Group-2 and 4.93 for Group-3; while post-hospitalisation Mrs Score was 1.50, 2.38 and 4.26, respectively. Average serum bilirubin level was significantly higher in patients with poor outcomes as compared with good outcomes (p<0.01). Conclusions: This study suggests that higher serum bilirubin levels were associated with increased stroke severity, longer hospitalisation and poor prognosis. (author)

Exciton absorption spectrum of thin Ag sub 2 ZnI sub 4

CERN Document Server

Yunakova, O N; Kovalenko, E N

2002-01-01

In Ag sub 2 ZnI sub 4 compound thin films one investigated into the electron spectrum of absorption within 3-6 eV photon energy range. The boundary of interband absorption is determined to correspond to the direct permitted transitions with E sub g = 3.7 eV forbidden gap width. A strong exciton band at E = 3.625 eV (80 K) GAMMA half width temperature run of which within 80-390 K range is governed by exciton-phonon interaction typical for quasi-single-dimensional excitons, is adjacent to the absorption boundary. At T <= 390 K one observes a bend in E(T) and GAMMA(T) dependences associated with generation of the Frenkel defects and followed by transfer of Ag ions to the interstices and vacancies of the compound crystalline lattice

CFCI3 (CFC-11): UV Absorption Spectrum Temperature Dependence Measurements and the Impact on Atmospheric Lifetime and Uncertainty

Science.gov (United States)

Mcgillen, Max R.; Fleming, Eric L.; Jackman, Charles H.; Burkholder, James B.

2014-01-01

CFCl3 (CFC-11) is both an atmospheric ozone-depleting and potent greenhouse gas that is removed primarily via stratospheric UV photolysis. Uncertainty in the temperature dependence of its UV absorption spectrum is a significant contributing factor to the overall uncertainty in its global lifetime and, thus, model calculations of stratospheric ozone recovery and climate change. In this work, the CFC-11 UV absorption spectrum was measured over a range of wavelength (184.95 - 230 nm) and temperature (216 - 296 K). We report a spectrum temperature dependence that is less than currently recommended for use in atmospheric models. The impact on its atmospheric lifetime was quantified using a 2-D model and the spectrum parameterization developed in this work. The obtained global annually averaged lifetime was 58.1 +- 0.7 years (2 sigma uncertainty due solely to the spectrum uncertainty). The lifetime is slightly reduced and the uncertainty significantly reduced from that obtained using current spectrum recommendations

Membrane Transporters for Bilirubin and Its Conjugates: A Systematic Review

Directory of Open Access Journals (Sweden)

Jovana Čvorović

2017-12-01

Full Text Available Background: Bilirubin is a highly-hydrophobic tetrapyrrole which binds to plasma albumin. It is conjugated in the liver to glucuronic acid, and the water-soluble glucuronides are excreted in urine and bile. The membrane transporters of bilirubin diglucuronide are well-known. Still undefined are however the transporters performing the uptake of bilirubin from the blood into the liver, a process known to be fast and not rate-limited. The biological importance of this process may be appraised by considering that in normal adults 200–300 mg of bilirubin are produced daily, as a result of the physiologic turnover of hemoglobin and cellular cytochromes. Nevertheless, research in this field has yielded controversial and contradicting results. We have undertaken a systematic review of the literature, believing in its utility to improve the existing knowledge and promote further advancements.Methods: We have sourced the PubMed database until 30 June 2017 by applying 5 sequential searches. Screening and eligibility criteria were applied to retain research articles reporting results obtained by using bilirubin molecules in membrane transport assays in vitro or by assessing serum bilirubin levels in in vivo experiments.Results: We have identified 311 articles, retaining 44, reporting data on experimental models having 6 incremental increases of complexity (isolated proteins, membrane vesicles, cells, organ fragments, in vivo rodents, and human studies, demonstrating the function of 19 membrane transporters, encoded by either SLCO or ABC genes. Three other bilirubin transporters have no gene, though one, i.e., bilitranslocase, is annotated in the Transporter Classification Database.Conclusions: This is the first review that has systematically examined the membrane transporters for bilirubin and its conjugates. Paradoxically, the remarkable advancements in the field of membrane transport of bilirubin have pointed to the elusive mechanism(s enabling

Reduced total serum bilirubin levels are associated with ulcerative colitis.

Directory of Open Access Journals (Sweden)

Kathleen M Schieffer

Full Text Available Chronic inflammation associated with inflammatory bowel disease (IBD results in increased oxidative stress that damages the colonic microenvironment. Low levels of serum bilirubin, an endogenous antioxidant, have been associated with increased risk for Crohn's disease (CD. Therefore, the aim of this study was to examine whether total serum bilirubin levels are associated with ulcerative colitis (UC. We identified a retrospective case-control population (n = 6,649 from a single tertiary care center, Penn State Hershey Medical Center (PSU and a validation cohort (n = 1,996 from Virginia Commonwealth University Medical Center (VCU. Cases were age- and sex-matched to controls (PSU: CD n = 254, UC n = 187; VCU: CD n = 233, UC n = 124. Total serum bilirubin levels were obtained from de-identified medical records and segregated into quartiles. Logistic regression analysis was performed on each quartile of total serum bilirubin compared to the last quartile (highest bilirubin levels to determine the association of total serum bilirubin with UC. Similar to CD patients, UC patients demonstrated reduced levels of total serum bilirubin compared to controls at PSU and VCU. The lowest quartile of total serum bilirubin was independently associated with UC for the PSU (OR: 1.98 [95% CI: 1.09-3.63] and VCU cohorts (OR: 6.07 [95% CI: 3.01-12.75]. Lower levels of the antioxidant bilirubin may reduce the capability of UC patients to remove reactive oxygen species leading to an increase in intestinal injury. Therapeutics that reduce oxidative stress may be beneficial for these patients.

Metabolism of bilirubin by human cytochrome P450 2A6

Energy Technology Data Exchange (ETDEWEB)

Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arthur, Dionne M. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Wikman, Anna S. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Department of Pharmaceutical Biosciences, Uppsala University, SE-75123 Uppsala (Sweden); Rahnasto, Minna; Juvonen, Risto O.; Vepsäläinen, Jouko; Raunio, Hannu [School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, POB 1627, 70211 Kuopio (Finland); Ng, Jack C. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Lang, Matti A. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)

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

Metabolism of bilirubin by human cytochrome P450 2A6

International Nuclear Information System (INIS)

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.

2012-01-01

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 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 CYP2A6

Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

Science.gov (United States)

Grillmair, Carl J; Burrows, Adam; Charbonneau, David; Armus, Lee; Stauffer, John; Meadows, Victoria; van Cleve, Jeffrey; von Braun, Kaspar; Levine, Deborah

2008-12-11

Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

Temperature and isotope effects on the shape of the optical absorption spectrum of solvated electrons in water

International Nuclear Information System (INIS)

Jou, F.Y.; Freeman, G.R.

1979-01-01

The optical absorption spectra of solvated electrons in H 2 O and D 2 O have been measured at 274, 298, 340, and 380 K. All the spectra were fitted very well with the Gaussian and Lorentzian shape functions at the low- and high-energy sides of the absorption maximum, respectively, excluding the high-energy tail. The spectrum does not shift uniformly with temperature. The temperature coefficient of absorption decreases rapidly with increasing energy on the low-energy side of the absorption maximum, while it changes only slightly on the high-energy side. When the temperature increases the Lorentzian width remains constant, the Gaussian width varies proportionally to T/sup 1/2/, and the spectrum becomes more symmetrical. On going from H 2 O to D 2 O we found that the spectrum at a given A/A/sub max/ shows a shift of +0.05 eV in the low-energy wing. The shift decreases with increasing energy, reaching 0.03 eV at the absorption maximum. On the high-energy side of the band the shift becomes negative at hν > 2.2 eV. The shift on the low-energy side seems to be related to the difference of the zero-point energies of the inter- and intramolecular vibrations. The wavelength dependence of the temperature and isotope effects is consistent with the model that different types of excitation occur on the low- and high-energy sides of the absorption band. The temperature and isotopic dependence of the low-energy side are consistent with its width being due to phonon interactions

Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

NARCIS (Netherlands)

Peters, W. H.; Jansen, P. L.

1986-01-01

Human liver microsomal bilirubin UDP-glucuronyltransferase catalyzes formation of bilirubin mono- and diglucuronide. KmUDPGA and Vmax of the enzyme are 0.6 mM and 1.69 nmol/mg protein X min. In vitro, bilirubin readily dissolves in the microsomal lipid phase. Taking this into account a Kmbilirubin

Percutaneous biliary drainage effectively lowers serum bilirubin to permit chemotherapy treatment.

Science.gov (United States)

Levy, Jennifer L; Sudheendra, Deepak; Dagli, Mandeep; Mondschein, Jeffrey I; Stavropoulos, S William; Shlansky-Goldberg, Richard D; Trerotola, Scott O; Teitelbaum, Ursina; Mick, Rosemarie; Soulen, Michael C

2016-02-01

For digestive tract cancers, the bilirubin threshold for administration of systemic chemotherapy can be 5 or 2 mg/dL (85.5 or 34.2 μmol/L) depending upon the regimen. We examined the ability of percutaneous biliary drainage (PBD) in patients with malignant biliary obstruction to achieve these clinically relevant endpoints. 106 consecutive patients with malignant biliary obstruction and a baseline serum bilirubin >2 mg/dL underwent PBD. Time to achieve a bilirubin of 5 mg/dL (85.5 μmol/L), 2 mg/dL (34.2 μmol/L), and survival was estimated by Kaplan-Meier analysis. Potential technical and clinical prognostic factors were subjected to univariate and multivariate analysis. Categorical variables were analyzed by the log rank test. Hazard ratios were calculated for continuous variables. Median survival was 100 days (range 1-3771 days). Among 88 patients with a pre-drainage bilirubin >5 mg/dL, 62% achieved a serum bilirubin ≤5 mg/dL within 30 days and 84% within 60 days, median 21 days. Among 106 patients with a pre-drainage bilirubin >2 mg/dL, 37% achieved a serum bilirubin ≤2 mg/dL by 30 days and 70% within 60 days, median 43 days. None of the technical or clinical factors evaluated, including pre-drainage bilirubin, were significant predictors of time to achieve a bilirubin ≤2 mg/dL (p = 0.51). Size and type of biliary device were the only technical variables found to affect time to bilirubin of 5 mg/dL (p = 0.016). PBD of malignant obstruction achieves clinically relevant reduction in serum bilirubin in the majority of patients within 1-2 months, irrespective of the pre-drainage serum bilirubin, sufficient to allow administration of systemic chemotherapy. However, the decision to undergo this procedure for this indication alone must be considered in the context of patients' prognosis and treatment goals.

Revalidation and rationale for high pKa values of unconjugated bilirubin

Directory of Open Access Journals (Sweden)

Ostrow J Donald

2007-05-01

Full Text Available Abstract Background Our prior solvent partition analysis, published in 1992, yielded pKa values for unconjugated bilirubin of about 8.1 and 8.4, but these results have been challenged and studies by other methods have suggested pKa values below 5.0. Methods We repeated our published solvent partition studies, using 14C-unconjugated bilirubin highly purified by extraction of residual labeled impurities from CHCl3 into an aqueous buffer, pH 7.0. Partition ratios at six pH values from 5.0 to 9.0 were determined by radioassay and compared with our prior values obtained by diazo assay. Results At pH values ranging from 4.8 to 9.2, stable aqueous/chloroform 14C-partition ratios did not differ significantly from our published partition ratios based on diazo assay. Conclusion These results support the high pKa values of unconjugated bilirubin, above 8.0, derived from our earlier solvent partition study. In both studies, our measurements were based on the rapid analysis of clearly under-saturated solutions of highly-purified bilirubin over a wide pH range, using properly purified and preserved solvents. No previous direct estimate of the aqueous pKa values of unconjugated bilirubin meets all these preconditions. Three theoretical factors acting in combination, each related to the unique, extensive internal H-bonding of the -COOH groups, are proposed to support high pKa values of unconjugated bilirubin in water: a donation of an H-bond from the -OH moiety of the -COOH group, which is broken on ionization; b hindered solvation of the -COO- group after ionization; and c restricted rotation of the -COO- and -COOH groups. Our findings and rationale rebut methodological and theoretical criticisms leveled against our prior work. High pKa values for unconjugated bilirubin dictate that: a bilirubin diacid, which readily diffuses across membranes and can cause neurotoxicity, is the dominant unbound bilirubin species of unconjugated bilirubin in plasma at

Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

Science.gov (United States)

Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

2016-05-23

The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PPARα: A Master Regulator of Bilirubin Homeostasis

Directory of Open Access Journals (Sweden)

Cyril Bigo

2014-01-01

Full Text Available 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.

NF3: UV Absorption Spectrum Temperature Dependence and the Atmospheric and Climate Forcing Implications

Science.gov (United States)

Papadimitriou, Vassileios C.; McGillen, Max R.; Fleming, Eric L.; Jackman, Charles H.; Burkholder, James B.

2013-01-01

Nitrogen trifluoride (NF3) is an atmospherically persistent greenhouse gas that is primarily removed by UV photolysis and reaction with O((sup 1)D) atoms. In this work, the NF3 gas-phase UV absorption spectrum, sigma(delta,T), was measured at 16 wavelengths between 184.95 and 250 nm at temperatures between 212 and 296 K. A significant spectrum temperature dependence was observed in the wavelength region most relevant to atmospheric photolysis (200-220 nm) with a decrease in sigma(210 nm,T) of approximately 45 percent between 296 and 212 K. Atmospheric photolysis rates and global annually averaged lifetimes of NF3 were calculated using the Goddard Space Flight Center 2-D model and the sigma(delta,T) parameterization developed in this work. Including the UV absorption spectrum temperature dependence increased the stratospheric photolysis lifetime from 610 to 762 years and the total global lifetime from 484 to 585 years; the NF3 global warming potentials on the 20-, 100-, and 500-year time horizons increased less than 0.3, 1.1, and 6.5 percent to 13,300, 17,700, and 19,700, respectively.

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

Science.gov (United States)

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

2015-01-01

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. PMID:26017184

Does bilirubin prevent hepatic steatosis through activation of the PPARα nuclear receptor?

Science.gov (United States)

Hinds, Terry D; Adeosun, Samuel O; Alamodi, Abdulhadi A; Stec, David E

2016-10-01

Several large population studies have demonstrated a negative correlation between serum bilirubin levels and the development of obesity, hepatic steatosis, and cardiovascular disease. Despite the strong correlative data demonstrating the protective role of bilirubin, the mechanism by which bilirubin can protect against these pathologies remains unknown. Bilirubin has long been known as a powerful antioxidant and also has anti-inflammatory actions, each of which may contribute to the protection afforded by increased levels. We have recently described a novel function of bilirubin as a ligand for the peroxisome proliferator-activated receptor-alpha (PPARα), which we show specifically binds to the nuclear receptor. Bilirubin may function as a selective PPAR modulator (SPPARM) to control lipid accumulation and blood glucose. However, it is not known to what degree bilirubin activation of PPARα is responsible for the protection afforded to reduce hepatic steatosis. We hypothesize that bilirubin, acting as a novel SPPARM, increases hepatic fatty acid metabolism through a PPARα-dependent mechanism which reduces hepatic lipid accumulation and protects against hepatic steatosis and non-alcoholic fatty liver disease (NAFLD). Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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.

Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter

Science.gov (United States)

Irwin, Patrick G. J.; Bowles, Neil; Braude, Ashwin S.; Garland, Ryan; Calcutt, Simon

2018-03-01

Observations of the visible/near-infrared reflectance spectrum of Jupiter have been made with the Very Large Telescope (VLT) Multi Unit Spectroscopic Explorer (MUSE) instrument in the spectral range 0.48-0.93 μm in support of the NASA/Juno mission. These spectra contain spectral signatures of gaseous ammonia (NH3), whose abundance above the cloud tops can be determined if we have reliable information on its absorption spectrum. While there are a number of sources of NH3 absorption data in this spectral range, they cover small sub-ranges, which do not necessarily overlap and have been determined from a variety of sources. There is thus considerable uncertainty regarding the consistency of these different sources when modelling the reflectance of the entire visible/near-IR range. In this paper we analyse the VLT/MUSE observations of Jupiter to determine which sources of ammonia absorption data are most reliable. We find that the band model coefficients of Bowles et al. (2008) provide, in general, the best combination of reliability and wavelength coverage over the MUSE range. These band data appear consistent with ExoMOL ammonia line data of Yurchenko et al. (2011), at wavelengths where they overlap, but these latter data do not cover the ammonia absorption bands at 0.79 and 0.765 μm, which are prominent in our MUSE observations. However, we find the band data of Bowles et al. (2008) are not reliable at wavelengths less than 0.758 μm. At shorter wavelengths we find the laboratory observations of Lutz and Owen (1980) provide a good indication of the position and shape of the ammonia absorptions near 0.552 μm and 0.648 μm, but their absorption strengths appear inconsistent with the band data of Bowles et al. (2008) at longer wavelengths. Finally, we find that the line data of the 0.648 μm absorption band of Giver et al. (1975) are not suitable for modelling these data as they account for only 17% of the band absorption and cannot be extended reliably to the cold

Bilirubin nanoparticle preconditioning protects against hepatic ischemia-reperfusion injury.

Science.gov (United States)

Kim, Jin Yong; Lee, Dong Yun; Kang, Sukmo; Miao, Wenjun; Kim, Hyungjun; Lee, Yonghyun; Jon, Sangyong

2017-07-01

Hepatic ischemia-reperfusion injury (IRI) remains a major concern in liver transplantation and resection, despite continuing efforts to prevent it. Accumulating evidence suggests that bilirubin possesses antioxidant, anti-inflammatory and anti-apoptotic properties. However, despite obvious potential health benefits of bilirubin, its clinical applications are limited by its poor solubility. We recently developed bilirubin nanoparticles (BRNPs) consisting of polyethylene glycol (PEG)-conjugated bilirubin. Here, we sought to investigate whether BRNPs protect against IRI in the liver by preventing oxidative stress. BRNPs exerted potent antioxidant and anti-apoptotic activity in primary hepatocytes exposed to hydrogen peroxide, a precursor of reactive oxygen species (ROS). In a model of hepatic IRI in mice, BRNP preconditioning exerted profound protective effects against hepatocellular injury by reducing oxidative stress, pro-inflammatory cytokine production, and recruitment of neutrophils. They also preferentially accumulated in IRI-induced inflammatory lesions. Collectively, our findings indicate that BRNP preconditioning provides a simple and safe approach that can be easily monitored in the blood like endogenous bilirubin, and could be a promising strategy to protect against IRI in a clinical setting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling the absorption spectrum of the permanganate ion in vacuum and in aqueous solution

DEFF Research Database (Denmark)

Olsen, Jógvan Magnus Haugaard; Hedegård, Erik Donovan

2017-01-01

The absorption spectrum of the MnO4(-) ion has been a test-bed for quantum-chemical methods over the last decades. Its correct description requires highly-correlated multiconfigurational methods, which are incompatible with the inclusion of finite-temperature and solvent effects due to their high...

The kinetics of oxidation of bilirubin and ascorbic acid in solution

Science.gov (United States)

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.

Subwavelength atom localization via amplitude and phase control of the absorption spectrum

International Nuclear Information System (INIS)

Sahrai, Mostafa; Tajalli, Habib; Kapale, Kishore T.; Zubairy, M. Suhail

2005-01-01

We propose a scheme for subwavelength localization of an atom conditioned upon the absorption of a weak probe field at a particular frequency. Manipulating atom-field interaction on a certain transition by applying drive fields on nearby coupled transitions leads to interesting effects in the absorption spectrum of the weak probe field. We exploit this fact and employ a four-level system with three driving fields and a weak probe field, where one of the drive fields is a standing-wave field of a cavity. We show that the position of an atom along this standing wave is determined when probe-field absorption is measured. We find that absorption of the weak probe field at a certain frequency leads to subwavelength localization of the atom in either of the two half-wavelength regions of the cavity field by appropriate choice of the system parameters. We term this result as sub-half-wavelength localization to contrast it with the usual atom localization result of four peaks spread over one wavelength of the standing wave. We observe two localization peaks in either of the two half-wavelength regions along the cavity axis

Investigation on 3H-labelled bilirubin for study of blood-brain barrier

International Nuclear Information System (INIS)

Cao Rongzhen; Dong Mo; Zhang Yulong; Zhou Ruiju

1996-01-01

Synthesis of 3 H-labelled bilirubin is described. 3 H-bilirubin is prepared by the reduction of biliverdin using sodium boro-[ 3 H]-hydride in methanol solvent. But biliverdin is synthesized through dehydrogenation of bilirubin with 2,3- dichloro-5, 6-dicyanobenzoquinone (DDQ) in dimethyl sulphoxide and sodium boro-[ 3 H]-hydride is produced by exchange of sodium boro-hydride with tritium gas using nickel catalyst at high temperature. The specific activity of obtained 3 H-bilirubin is 306 GBq/mmol, while the radiochemical purity is over 95% by HPLC and paper chromatography. The permeated profile of 3 H-labelled bilirubin in rat brain has been obtained in animal experiments

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

Science.gov (United States)

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.

Does bilirubin protect against hemochromatosis gene (HFE) related mortality?

NARCIS (Netherlands)

Alizadeh, Behrooz Z.; Njajou, Omer T.; Houwing-Duistermaat, Jeanine J.; de Jong, Gerard; Vergeer, Jeannette M.; Hofman, Albert; Pols, Huibert A.P.; van Duijn, Cornelia M.

2004-01-01

Serum bilirubin is an important antioxidant that is found at increased levels in hereditary hemochromatosis patients. We hypothesized that increased levels of serum bilirubin may play a protective role against oxidative stress induced by iron overload in carriers of mutations in the hereditary

What is the correct Fe L{sub 23} X-ray absorption spectrum of magnetite?

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiaohui; Kalirai, Samanbir S. [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4M1 (Canada); Hitchcock, Adam P., E-mail: aph@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4M1 (Canada); Bazylinski, Dennis A. [School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV 89154-4004 (United States)

2015-02-15

Highlights: • Fe L{sub 3} X-ray absorption spectra of biological (MV-1 magnetotactic bacteria) and abiotic (Sigma–Aldrich) nano-magnetite are reported. • An inconsistency in the literature for this spectrum is documented. • Powder diffraction shows the abiotic sample is partly oxidized, toward maghemite. • H{sub 2} thermal reduction converts the Fe L{sub 3} spectrum of the abiotic sample to that of the biotic. • Strong oxidation (air, 600 °C) is needed to convert the spectrum of the biotic magnetite to that of maghemite; magnetosome chains are protected by an air-impervious membrane. - Abstract: Various groups have reported Fe L{sub 23} X-ray absorption spectra (XAS) of magnetite (Fe{sub 3}O{sub 4}), each claiming to be that of magnetite, but which contradict each other. Here we report an XAS study of two kinds of magnetite: one is biogenic magnetite nanocrystals extracted from the magnetotactic bacterium Magnetovibrio blakemorei strain MV-1; the other is synthetic, abiogenically produced nano-magnetite. We see significantly different XAS spectra of these two materials. Only when the abiogenic magnetite was reduced under H{sub 2} did it give the same spectrum as the biogenic sample. Extensive heating of the biogenic magnetite in air produced spectra similar to that of the abiogenic magnetite. These two spectra are typical of the range of published Fe L{sub 23} spectra of magnetite. X-ray diffraction confirmed that the biogenic material is stoichiometric Fe{sub 3}O{sub 4}, and showed that the as-received or partly reduced abiogenic material is a non-stoichiometric oxide, intermediate between magnetite and maghemite (γ-Fe{sub 2}O{sub 3}). When the membrane which surrounds magnetosome chains was intact, the biotic magnetite single crystals were surprisingly resistant to oxidation. This study clarifies a significant confusion existing in the literature as to the correct Fe L{sub 23} X-ray absorption spectra of magnetite and maghemite.

Unconjugated Bilirubin Inhibits Proteolytic Cleavage of von Willebrand Factor by ADAMTS13 Protease

Science.gov (United States)

Lu, Rui-Nan; Yang, Shangbin; Wu, Haifeng M.; Zheng, X. Long

2015-01-01

Summary Background Bilirubin is a yellow breakdown product of heme catabolism. Increased serum levels of unconjugated bilirubin are conditions commonly seen in premature neonates and adults with acute hemolysis including thrombotic microangiopathy. Previous studies have shown that unconjugated bilirubin lowers plasma ADAMTS13 activity, but the mechanism is not fully understood. Objectives The study is to determine whether unconjugated bilirubin directly inhibits the cleavage of von Willebrand factor (VWF) and its analogs by ADAMTS13. Methods Fluorogenic, SELDI-TOF mass spectrometric assay, and Western blotting analyses were employed to address this question. Results Unconjugated bilirubin inhibits the cleavage of F485-rVWF73-H, D633-rVWF73-H, and GST-rVWF71-11K by ADAMTS13 in a concentration-dependent manner with a half-maximal inhibitory concentration (IC50) of ~13 μM, ~70 μM, and ~17 μM, respectively. Unconjugated bilirubin also dose-dependently inhibits the cleavage of multimeric VWF by ADAMTS13 under denaturing conditions. The inhibitory activity of bilirubin on the cleavage of D633-rVWF73-H and multimeric VWF, but not F485-rVWF73-H, was eliminated after incubation with bilirubin oxidase that converts bilirubin to biliverdin. Furthermore, plasma ADAMTS13 activity in patients with hyperbilirubinemia is lower prior to than after treatment with bilirubin oxidase. Conclusions unconjugated bilirubin directly inhibits ADAMTS13’s ability to cleave both peptidyl and native VWF substrates in addition to its interference with certain fluorogenic assays. Our findings may help proper interpretation of ADAMTS13 results under pathological conditions. Whether elevated serum unconjugated bilirubin has an adverse effect in vivo remains to be determined in our future study. PMID:25782102

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

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urinary bilirubin and its conjugates... Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test system. (a) Identification. A urinary bilirubin and its conjugates (nonquantitative) test system is a...

Quantitative analysis of the self-absorption and reemission effects on the emission spectrum of photoluminescence in right-angle excitation—detection configuration

International Nuclear Information System (INIS)

Wang Zhen-Hua; Wu Yu-E; Zhang Xin-Zheng; Yun Zhi-Qiang; Li Wei; Xu Jing-Jun

2013-01-01

A theoretical approach based on differential radiative transport is proposed to quantitatively analyze the self-absorption and reemission effects on the emission spectrum for right angle excitation—detection photoluminescence measurements, and the wavelength dependence of the reemission effect is taken into account. Simulations and experiments are performed using rhodamine 6G solutions in ethanol as model samples. It is shown that the self-absorption effect is the dominant effect on the detected spectrum by inducing pseudo red-shift and reducing total intensity; whereas the reemission effect partly compensates for signal decrease and also results in an apparent signal gain at the wavelengths without absorption. Both effects decrease with the decrease in the sample concentration and the propagation distance of the emission light inside the sample. We therefore suggest that diluted solutions are required for accurate photoluminescence spectrum measurements and photoluminescence-based measurements

Bilirubin-Induced Neurological Dysfunction: A Clinico-Radiological-Neurophysiological Correlation in 30 Consecutive Children.

Science.gov (United States)

van Toorn, Ronald; Brink, Philip; Smith, Johan; Ackermann, Christelle; Solomons, Regan

2016-12-01

The clinical expression of bilirubin-induced neurological dysfunction varies according to severity and location of the disease. Definitions have been proposed to describe different bilirubin-induced neurological dysfunction subtypes. Our objective was to describe the severity and clinico-radiological-neurophysiological correlation in 30 consecutive children with bilirubin-induced neurological dysfunction seen over a period of 5 years. Thirty children exposed to acute neonatal bilirubin encephalopathy were included in the study. The mean peak total serum bilirubin level was 625 μmol/L (range 480-900 μmol/L). Acoustic brainstem responses were abnormal in 73% (n = 22). Pallidal hyperintensity was observed on magnetic resonance imaging in 20 children. Peak total serum bilirubin levels correlated with motor severity (P = .03). Children with severe motor impairment were likely to manifest severe auditory neuropathy (P bilirubin-induced neurological dysfunction subtype, and the majority of children had abnormal acoustic brainstem responses and magnetic resonance imaging. © The Author(s) 2016.

Antioxidant mechanism of bilirubin: both HAT and SET are possible

International Nuclear Information System (INIS)

Adhikari, Soumyakanti; Joshi, Ravi; Mukherjee, Tulsi

2008-01-01

Bilirubin (BR) plays two extreme roles in physiology, one hand it is a toxic metabolite while at micromolar concentration it acts as antioxidant. It has been observed that hydroxyl, glutathiyl and Linoleic peroxyl radicals abstract hydrogen atom from bilirubin, whereas N 3 , Br 2 , CCl 3 OO, NO 2 radicals react via single electron transfer action. Our study demonstrates that oxidation of bilirubin occurs via both hydrogen atom transfer and single electron transfer depending on the nature of the radical. (author)

Liver function test with 99mTc-labelled bilirubin in children

International Nuclear Information System (INIS)

Teichmann, B.; Kaempfer, I.; Schneider, G.

1989-01-01

Because of central role of bilirubin in the metabolism of liver it is well suited for liver function tests. Different parameters of hepatocellular partial function and histological findings were studied in patients suffering from functional hyperbilirubinaemia (n = 15), liver cirrhosis (n = 7) and 6 patients recovering from acute hepatitis. After intravenous injection of 99m Tc-bilirubin blood clearance and intestinal excretion in percentages of bilirubin were determined. In patients with cirrhosis the initial phase as well as the intestinal excretion of bilirubin were delayed. This liver function test is useful in the pediatric special diagnosis for investigations during the course of the illness and for assessment of therapeutic activities. (author)

Unconjugated free bilirubin in preterm infants.

Science.gov (United States)

van der Schoor, Lori W E; Dijk, Peter H; Verkade, Henkjan J; Kamsma, Anna C J; Schreuder, Andrea B; Groen, Henk; Hulzebos, Christian V

Hyperbilirubinemia guidelines are based on total serum bilirubin (TSB), in combination with either gestational age (GA) or birth weight (BW), postnatal age and specific risk factors. However, TSB is a poor predictor of bilirubin-induced neurotoxicity (BIND). Free unconjugated bilirubin (UCBfree) and the UCBfree/TSB ratio are more directly related to BIND, but data on their postnatal courses are unknown. To characterize the postnatal courses of UCBfree and UCBfree/TSB ratio, and assess their relationships with clinical characteristics. 72 preterm infants≤32weeks GA, admitted to the University Medical Center Groningen, The Netherlands. During the first postnatal week, bilirubin plasma parameters were analyzed and their relationship with clinical parameters was analyzed. Postnatal changes were analyzed using Generalized Estimating Equations. Data are expressed as medians [ranges]. Less than 10% of the cohort (GA: 29 [26-31] weeks; BW: 1165 [600-1975] g) showed hyperbilirubinemic risk factors. We observed a large variation in UCBfree (27 [1-197] nmol/L), that could partly be explained by postnatal age and gender, but not by other risk factors. Maximal UCBfree levels of 50 [13-197] nmol/L occurred at day 4 and were higher in males. In contrast to TSB, UCBfree/TSB ratios (0.19 [0.01-1.04]) were higher in infants with low GA/BW. UCBfree levels vary considerably in preterm infants, despite a low incidence of hyperbilirubinemic risk factors and similar TSB-based phototherapy treatment. UCBfree could not be predicted by GA or BW, but UCBfree/TSB ratios are highest in the smallest preterms, while they have the lowest TSB levels. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of cholesterol, calcium carbonate and bilirubinate of gallstone

International Nuclear Information System (INIS)

Iqbal, Y.; Nazneen, B.I.

2004-01-01

Gallstones of seven patients were collected from different parts of North West Frontier and Punjab provinces. These stones were analyzed using Liebermann-Burchard method, estimation technique and Microlab-200 for cholesterol, calcium carbonate (CaCO/sub 3/) and bilirubinate respectively. The levels of cholesterol bilirubinate and CaCO/sub 3/ were found in the ranges of 50-81, 12-40 and 7-19% respectively. All of the stones were found to be mixed type stones that contain cholesterol, bilirubinate and calcium carbonate. The structures of the stones are also shown in the picture, which confirm our analysis data. Possible reasons, which cause formation of gallstones, are discussed in this paper. (author)

The relationship between serum bilirubin level with interleukin.6 ...

African Journals Online (AJOL)

Context: Bilirubin has been shown to influence the mechanisms of both apoptosis and inflammation. Aims: The aim of the following study is to investigate the relationship between the serum bilirubin level with sepsis progression. Settings and Design: A total of 20 patients from intensive care unit were included for this study.

Surprises from a Deep ASCA Spectrum of the Broad Absorption Line Quasar PHL 5200

Science.gov (United States)

Mathur, Smita; Matt, G.; Green, P. J.; Elvis, M.; Singh, K. P.

2002-01-01

We present a deep (approx. 85 ks) ASCA observation of the prototype broad absorption line quasar (BALQSO) PHL 5200. This is the best X-ray spectrum of a BALQSO yet. We find the following: (1) The source is not intrinsically X-ray weak. (2) The line-of-sight absorption is very strong, with N(sub H) = 5 x 10(exp 23)/sq cm. (3) The absorber does not cover the source completely; the covering fraction is approx. 90%. This is consistent with the large optical polarization observed in this source, implying multiple lines of sight. The most surprising result of this observation is that (4) the spectrum of this BALQSO is not exactly similar to other radio-quiet quasars. The hard X-ray spectrum of PHL 5200 is steep, with the power-law spectral index alpha approx. 1.5. This is similar to the steepest hard X-ray slopes observed so far. At low redshifts, such steep slopes are observed in narrow-line Seyfert 1 (NLS1) galaxies, believed to be accreting at a high Eddington rate. This observation strengthens the analogy between BALQSOs and NLS1 galaxies and supports the hypothesis that BALQSOs represent an early evolutionary state of quasars. It is well accepted that the orientation to the line of sight determines the appearance of a quasar: age seems to play a significant role as well.

Modeling the absorption spectrum of the permanganate ion in vacuum and in aqueous solution

Science.gov (United States)

Olsen, Jógvan Magnus Haugaard; Hedegård, Erik Donovan

The absorption spectrum of the MnO$_{4}$$^{-}$ ion has been a test-bed for quantum-chemical methods over the last decades. Its correct description requires highly-correlated multiconfigurational methods, which are incompatible with the inclusion of finite-temperature and solvent effects due to their high computational demands. Therefore, implicit solvent models are usually employed. Here we show that implicit solvent models are not sufficiently accurate to model the solvent shift of MnO$_{4}$$^{-}$, and we analyze the origins of their failure. We obtain the correct solvent shift for MnO$_{4}$$^{-}$ in aqueous solution by employing the polarizable embedding (PE) model combined with a range-separated complete active space short-range density functional theory method (CAS-srDFT). Finite-temperature effects are taken into account by averaging over structures obtained from ab initio molecular dynamics simulations. The explicit treatment of finite-temperature and solvent effects facilitates the interpretation of the bands in the low-energy region of the MnO$_{4}$$^{-}$ absorption spectrum, whose assignment has been elusive.

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

Science.gov (United States)

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 bilirubin-treated mice showed less fibrosis in the unilateral ureteral obstruction (UUO) model (P bilirubin treatment decreased fibronectin expression in tubular epithelial cells in a dose-dependent manner (P 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.

Bilirubin Albumin Binding and Unbound Unconjugated Hyperbilirubinemia in Premature Infants.

Science.gov (United States)

Amin, Sanjiv B; Wang, Hongyue

2018-01-01

To evaluate the associations between unbound bilirubin (UB) and total serum bilirubin (TSB), bilirubin:albumin molar ratio (BAMR), and bilirubin albumin binding affinity (Ka) as a function of gestational age (GA) in infants born at 24-33 weeks GA. In a prospective observational study, TSB and UB were measured twice daily at least 8 hours apart during the first postnatal week. Serum albumin was measured to calculate BAMR on each day. The highest UB on each day, corresponding TSB, and serum albumin were used to calculate the Ka on each day. For the 166 infants studied, peak UB significantly correlated with concomitant Ka (r = -0.44, P = .001) but not with concomitant TSB or BAMR after adjusting for GA. On multiple regression analyses, there was a significant association of concomitant Ka (-0.06, 95% CI -0.08 to -0.04, P = .0001), but not concomitant TSB or BAMR with peak UB after controlling for GA, birth weight, race, and sex. GA group was a significant effect modifier for the association between Ka and peak UB (0.03, 95% CI 0.02-0.04, P bilirubin-induced neurotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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

2016-01-01

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. 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. 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. Increases in serum bilirubin concentration were positively associated with a higher risk of incident MetS. Serum bilirubin increment might be a sensitive marker for the development

Bilirubin UDP-glucuronosyltransferase 1 is the only relevant bilirubin glucuronidating isoform in man

NARCIS (Netherlands)

Bosma, P. J.; Seppen, J.; Goldhoorn, B.; Bakker, C.; Oude Elferink, R. P.; Chowdhury, J. R.; Chowdhury, N. R.; Jansen, P. L.

1994-01-01

Crigler-Najjar syndrome type I (CN-I) is caused by an inherited absence of UDP-glucuronosyltransferase activity toward bilirubin (B-UGT), resulting in severe non-hemolytic unconjugated hyperbilirubinemia. Based on the expression of cDNAs in COS cells, two UGT isoforms in human liver, B-UGT1 and

Serum Bilirubin and Their Association With C-Reactive Protein in Patients With Migraine.

Science.gov (United States)

Peng, You-Fan; Xie, Li-Qiu; Xiang, Yang; Xu, Gui-Dan

2016-11-01

Increased levels of C-reactive protein (CRP) have been considered as a marker in assessing neurogenic inflammation of migraine patients. An inverse relationship between serum bilirubin and CRP has been observed in various diseases. Therefore, we analyzed serum bilirubin levels in migraine patients, and investigated the relationship between serum bilirubin and CRP in migraineurs. A total of 86 newly diagnosed migraine patients were consecutively recruited to this study. Significantly lower median serum total bilirubin, conjugated bilirubin (CB) and unconjugated bilirubin were found in patients with migraine than healthy controls, and the levels of CRP were significantly higher in migraine patients than healthy controls. A negative correlation between CRP and CB was observed in patients with migraine (r = -0.255, P = 0.018). In a multiple linear regression model, the concentrations of CRP remained negatively correlated with CB. Our study demonstrates that serum bilirubin concentrations are decreased in migraineurs, and CB levels were found to be positively correlated with CRP in migraine patents. However, larger cross-sectional and prospective studies are needed to establish whether serum bilirubin may be a useful biomarker for assessing neurogenic inflammation in migraine patients and eventually guiding the therapy. © 2016 Wiley Periodicals, Inc.

Labelling of bilirubin with /sup 99m/Tc and pharmacokinetic behavior

International Nuclear Information System (INIS)

Kaempfer, I.; Schneider, G.; Blottner, A.; Deckart, H.; Staedtisches Klinikum Berlin-Buch

1982-01-01

The yield of the bilirubin labelling with /sup 99m/Tc amounted to 97%. The labelled complex has been stable for 24 hours with the pH range 2-7.5. As evidenced in animal experiments the labelled bilirubin is probably subjected to natural degradation processes. Side effects could not be noticed. A disadvantage seems to be the slow transfer of /sup 99m/Tc-bilirubin from the hepatic cell to the biliary capillary

IN VITRO CHEMO-PREVENTATIVE ACTIVITY OF STRELITZIA NICOLAI ARIL EXTRACT CONTAINING BILIRUBIN.

Science.gov (United States)

Dwarka, Depika; Thaver, Veneesha; Naidu, Mickey; Koorbanally, Neil A; Baijnath, And Himansu

2017-01-01

The discovery of the only animal pigment, bilirubin, in the plant Strelitzia nicolai has triggered a vast number of questions regarding bilirubin's formation and its role in the human body. Recent studies have confirmed that bilirubin at certain levels have many medical benefits. Various case studies have revealed that bilirubin is a potent antioxidant. Cervical cancer is one of South Africa's largest womens' health crises. It is estimated that it affects one out of 41 South African women and kills approximately 8 women in the country every day. Thus, the aim of this study was to investigate if the aril extract of Strelitzia nicolai (Regel and Körn.) containing bilirubin possesses anti-cancer activity and to determine its effect on the induction of apoptosis. The DPPH activity was firstly used to determine the antioxidant effect of the extract. Thereafter, the cytotoxic effect was tested using the XTT assay. Apoptosis was confirmed and quantified using the Annexin V-PE kit and the morphology was studied using acridine orange and ethidium bromide. The aril extract decreased cell viability by 52% and induced apoptosis in HeLa cells; as shown by the Annexin V-PE Apoptosis detection kit and morphological studies with acridine orange/ethidium bromide staining. The activity of the extract as a potent antioxidant was immensely enhanced as compared to the bilirubin standard. These results suggest that S. nicolai aril extract containing bilirubin works synergistically as opposed to bilirubin on its own. Furthermore, this extract might be a good candidate for the therapeutic intervention of cervical cancer.

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

Energy Technology Data Exchange (ETDEWEB)

Shukla, Shashi P. [Bhabha Atomic Research Centre, Radiation and Photochemistry Division (India); Roy, Mainak [Bhabha Atomic Research Centre, Chemistry Division (India); Mukherjee, Poulomi [Bhabha Atomic Research Centre, Nuclear Agriculture and Biotechnology Division (India); Tyagi, A. K. [Bhabha Atomic Research Centre, Chemistry Division (India); Mukherjee, Tulsi [Bhabha Atomic Research Centre, Chemistry Group (India); Adhikari, Soumyakanti, E-mail: asoumya@barc.gov.in [Bhabha Atomic Research Centre, Radiation and Photochemistry Division (India)

2012-07-15

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.

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

Science.gov (United States)

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.

Bilirubin levels and phototherapy use before and after neonatal red blood cell transfusions.

Science.gov (United States)

Carroll, Patrick D; Christensen, Robert D; Baer, Vickie L; Sheffield, Mark J; Gerday, Erick; Ilstrup, Sarah J

2016-11-01

Our previous retrospective study suggested that red blood cell (RBC) transfusion of preterm neonates can be associated with an increase in bilirubin, but this has not been tested prospectively. We studied neonates before and after RBC transfusions, recording serial bilirubin levels and whether they qualified for phototherapy. Because lysed RBCs release plasma-free hemoglobin (Hb), a precursor to bilirubin, we also measured plasma free Hb and bilirubin from the donor blood. We studied 50 transfusions given to 39 neonates. Gestation ages of transfused neonates, at birth, were 26 (24-29) weeks (median [interquartile range]); birthweights were 750 (620-1070) g. The study transfusion was given on Day of Life 9.9 (3.4-19.2). In 20% (10/50) phototherapy was being administered at the beginning of and during the transfusion. In these patients neither the 4- to 6- nor the 24- to 36-hour-posttransfusion bilirubin levels were significantly higher than before transfusion. However, in 30% of the others (12/40) phototherapy was started (or restarted) after the transfusion and 15% had a posttransfusion bilirubin increase of at least 2.5 mg/dL. These neonates received donor blood with a higher plasma-free Hb (p bilirubin increase of at least 2.5 mg/dL. We speculate that neonates qualifying for a RBC transfusion, who are judged to be at high risk for bilirubin-induced neurotoxicity, might benefit from checking their serum bilirubin level after the transfusion and providing donor blood with low plasma-free Hb levels. © 2016 AABB.

Ultrafast self-modulation of the optical absorption spectrum under conditions of both the ultrashort optical pumping and superluminescence in GaAs

International Nuclear Information System (INIS)

Ageeva, N. N.; Bronevoi, I. L.; Krivonosov, A. N.; Stegantsov, S. V.

2006-01-01

Self-modulation of the optical absorption spectrum is observed during the picosecond photogeneration of charge carriers and intense superluminescence in GaAs. As the picosecond delay τ of the probing pulse with respect to the pump pulse is varied in the region of τ < 0, the local points of the absorption intensification (juts) shift along the spectrum (the modulation resembles a running wave). As the value of τ is varied in the vicinity of τ = 0, the juts in the spectrum arise and disappear at approximately fixed photon energies (the modulation resembles a standing wave). At certain photon energies, the dependence of the rate of variation in the absorption coefficient dα/dτ on τ is found to be modulated by pulsations, similarly to the previously observed modulation of the picosecond stimulated emission from GaAs. Presumably, the spectrum self-modulation represents (and, thus, reveals) the modulation of the electron distribution in the conduction band. This modulation is caused by the fact that the evolution of the electron-population depletion at the bottom of the conduction band during superluminescence reflects (due to the electron-phonon interaction) on the population of the upper energy levels in the band

Bilirubin Modulates Acetylcholine Receptors In Rat Superior Cervical Ganglionic Neurons In a Bidirectional Manner

Science.gov (United States)

Zhang, Chengmi; Wang, Zhenmeng; Dong, Jing; Pan, Ruirui; Qiu, Haibo; Zhang, Jinmin; Zhang, Peng; Zheng, Jijian; Yu, Weifeng

2014-01-01

Autonomic dysfunction as a partial contributing factor to cardiovascular instability in jaundiced patients is often associated with increased serum bilirubin levels. Whether increased serum bilirubin levels could directly inhibit sympathetic ganglion transmission by blocking neuronal nicotinic acetylcholine receptors (nAChRs) remains to be elucidated. Conventional patch-clamp recordings were used to study the effect of bilirubin on nAChRs currents from enzymatically dissociated rat superior cervical ganglia (SCG) neurons. The results showed that low concnetrations (0.5 and 2 μM) of bilirubin enhanced the peak ACh-evoked currents, while high concentrations (3 to 5.5 µM) of bilirubin suppressed the currents with an IC50 of 4 ± 0.5 μM. In addition, bilirubin decreased the extent of desensitization of nAChRs in a concentration-dependent manner. This inhibitory effect of bilirubin on nAChRs channel currents was non-competitive and voltage independent. Bilirubin partly improved the inhibitory effect of forskolin on ACh-induced currents without affecting the action of H-89. These data suggest that the dual effects of enhancement and suppression of bilirubin on nAChR function may be ascribed to the action mechanism of positive allosteric modulation and direct blockade. Thus, suppression of sympathetic ganglionic transmission through postganglionic nAChRs inhibition may partially contribute to the adverse cardiovascular effects in jaundiced patients. PMID:25503810

A structure preserving Lanczos algorithm for computing the optical absorption spectrum

Energy Technology Data Exchange (ETDEWEB)

Shao, Meiyue [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Div.; Jornada, Felipe H. da [Univ. of California, Berkeley, CA (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Div.; Lin, Lin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Div.; Univ. of California, Berkeley, CA (United States). Dept. of Mathematics; Yang, Chao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Div.; Deslippe, Jack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Louie, Steven G. [Univ. of California, Berkeley, CA (United States). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Div.

2016-11-16

We present a new structure preserving Lanczos algorithm for approximating the optical absorption spectrum in the context of solving full Bethe-Salpeter equation without Tamm-Dancoff approximation. The new algorithm is based on a structure preserving Lanczos procedure, which exploits the special block structure of Bethe-Salpeter Hamiltonian matrices. A recently developed technique of generalized averaged Gauss quadrature is incorporated to accelerate the convergence. We also establish the connection between our structure preserving Lanczos procedure with several existing Lanczos procedures developed in different contexts. Numerical examples are presented to demonstrate the effectiveness of our Lanczos algorithm.

Genetically elevated bilirubin and risk of ischaemic heart disease

DEFF Research Database (Denmark)

Stender, Stefan; Frikke-Schmidt, R; Nordestgaard, B G

2013-01-01

Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear.......Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear....

False high level in total bilirubin estimation in nonicteric serum

African Journals Online (AJOL)

estimation of total bilirubin by DiaSys and Randox reagents along with simultaneous re-estimation by Roche reagents in ... been used mainly due to slightly lower cost in ... MATERIALS AND METHODS ... air-conditioned laboratory overnight. ..... Elevated IgG causing spurious elevation in serum total bilirubin assay. Asia.

A Comparison between Transcutaneous and Total Serum Bilirubin in Healthy-term Greek Neonates with Clinical Jaundice

Directory of Open Access Journals (Sweden)

Charalambos Neocleous

2014-01-01

Full Text Available 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.

Development and optimization of a noncontact optical device for online monitoring of jaundice in human subjects

Science.gov (United States)

Polley, Nabarun; Saha, Srimoyee; Singh, Soumendra; Adhikari, Aniruddha; Das, Sukhen; Choudhury, Bhaskar Roy; Pal, Samir Kumar

2015-06-01

Jaundice is one of the notable markers of liver malfunction in our body, revealing a significant rise in the concentration of an endogenous yellow pigment bilirubin. We have described a method for measuring the optical spectrum of our conjunctiva and derived pigment concentration by using diffused reflection measurement. The method uses no prior model and is expected to work across the races (skin color) encompassing a wide range of age groups. An optical fiber-based setup capable of measuring the conjunctival absorption spectrum from 400 to 800 nm is used to monitor the level of bilirubin and is calibrated with the value measured from blood serum of the same human subject. We have also developed software in the LabVIEW platform for use in online monitoring of bilirubin levels in human subjects by nonexperts. The results demonstrate that relative absorption at 460 and 600 nm has a distinct correlation with that of the bilirubin concentration measured from blood serum. Statistical analysis revealed that our proposed method is in agreement with the conventional biochemical method. The innovative noncontact, low-cost technique is expected to have importance in monitoring jaundice in developing/underdeveloped countries, where the inexpensive diagnosis of jaundice with minimally trained manpower is obligatory.

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

International Nuclear Information System (INIS)

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

Albumin-Bilirubin and Platelet-Albumin-Bilirubin Grades Accurately Predict Overall Survival in High-Risk Patients Undergoing Conventional Transarterial Chemoembolization for Hepatocellular Carcinoma.

Science.gov (United States)

Hansmann, Jan; Evers, Maximilian J; Bui, James T; Lokken, R Peter; Lipnik, Andrew J; Gaba, Ron C; Ray, Charles E

2017-09-01

To evaluate albumin-bilirubin (ALBI) and platelet-albumin-bilirubin (PALBI) grades in predicting overall survival in high-risk patients undergoing conventional transarterial chemoembolization for hepatocellular carcinoma (HCC). This single-center retrospective study included 180 high-risk patients (142 men, 59 y ± 9) between April 2007 and January 2015. Patients were considered high-risk based on laboratory abnormalities before the procedure (bilirubin > 2.0 mg/dL, albumin 1.2 mg/dL); presence of ascites, encephalopathy, portal vein thrombus, or transjugular intrahepatic portosystemic shunt; or Model for End-Stage Liver Disease score > 15. Serum albumin, bilirubin, and platelet values were used to determine ALBI and PALBI grades. Overall survival was stratified by ALBI and PALBI grades with substratification by Child-Pugh class (CPC) and Barcelona Liver Clinic Cancer (BCLC) stage using Kaplan-Meier analysis. C-index was used to determine discriminatory ability and survival prediction accuracy. Median survival for 79 ALBI grade 2 patients and 101 ALBI grade 3 patients was 20.3 and 10.7 months, respectively (P  .05). ALBI and PALBI grades are accurate survival metrics in high-risk patients undergoing conventional transarterial chemoembolization for HCC. Use of these scores allows for more refined survival stratification within CPC and BCLC stage. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

The inverse association of incident cardiovascular disease with plasma bilirubin is unaffected by adiponectin

NARCIS (Netherlands)

Dullaart, Robin P. F.; Boersema, Jeltje; Lefrandt, Joop D.; Wolffenbuttel, Bruce H. R.; Bakker, Stephan J. L.

Objective: Bilirubin may protect against atherosclerotic cardiovascular disease (CVD). The heme oxygenase pathway is crucial for bilirubin generation, and is stimulated by adiponectin. We tested the relationship of plasma bilirubin with adiponectin, and determined whether the association of incident

Bilirubin metabolism in the spiny dogfish, Squalus acanthias, and the small skate, Raja erinacea

NARCIS (Netherlands)

Jansen, P. L.; Arias, I. M.

1977-01-01

1. The main bilirubin conjugate in bile of spiny dogfish (Squalus Acanthias) and small skate (Raja Erinacea) is bilirubin monoglucuronide. 2. Microsomal preparations from dogfish and small skate liver have similar bilirubin UDPglucuronyltransferase (UDPGT) activity and catalyze the conjugation of

Prognostic impact of serum bilirubin level on long-term renal survival in IgA nephropathy.

Science.gov (United States)

Tanaka, Shigeru; Ninomiya, Toshiharu; Masutani, Kosuke; Nagata, Masaharu; Tsuchimoto, Akihiro; Tsuruya, Kazuhiko; Kitazono, Takanari

2015-12-01

Serum bilirubin has been recognized as a novel endogenous antioxidant. The aim of our study was to evaluate the impact of serum bilirubin on kidney prognosis in IgA nephropathy (IgAN). We followed retrospectively 694 patients with IgAN diagnosed by renal biopsy between 1982 and 2010. The risk factors for developing end-stage renal disease (ESRD) were estimated using a Cox proportional hazard model. Predictive performance between models with or without serum bilirubin was evaluated by calculating the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Seventy-seven patients developed ESRD during the median 4.9 years of follow-up. Estimated glomerular filtration rate, proteinuria and histological severity were inversely related to bilirubin levels. In multivariate analysis, serum bilirubin was an independent risk factor for ESRD (hazard ratio for every 0.1 mg/dL decrease in serum bilirubin, 1.18; 95 % CI, 1.04-1.33). The incidence rate of ESRD decreased linearly with the increases in bilirubin levels (P for trend bilirubin was incorporated into a model with conventional ESRD risk factors, the NRI and IDI were 0.281 (P = 0.02) and 0.019 (P = 0.01), respectively. We demonstrated that lower bilirubin levels were significantly associated with higher risk of ESRD in IgAN. In addition, bilirubin provided incremental predictive value in the risk assessment for progression of IgAN beyond that provided by standard risk factors.

The Relation of Serum Bilirubin Level With Coronary Artery Disease Based on Angiographic Findings

Directory of Open Access Journals (Sweden)

Taban Sadeghi Mohammadreza

2015-10-01

Full Text Available Objective: Lipid oxidation and generation of free radicals are important factors contributing to the formation of atherosclerotic plaque. Bilirubin is supposed to play a protective role against atherosclerosis, coronary artery diseases (CAD and inflammation for its strong antioxidant property. Thus, this study aims at investigating the relationship of bilirubin level with the severity and type of coronary artery stenosis (CAS in different patient groups. Materials and Methods: In this cross-sectional study 200 consecutive patients, who underwent elective angiography in Madani Heart hospital, Tabriz, Iran, were selected and their blood samples were measured for total, direct, and indirect bilirubin level, with Diazo method using colorimetric technique. Following angiography, comparisons were made between the severity and location of CAS and therapeutic follow-up plan with total, direct, and indirect bilirubin level. Results: Of 200 studied patients, 129 (64.5% and 71 (35.5% subjects were male and female, respectively. The cases were classified into 5 subgroups based on angiography results as follows: 59 (29.5% cases with normal angiography, 11 cases (5.5% with minimal CAD, 56 cases (28% with single vessel involvement, 35 (17.5% cases with two vessel involvement and 39 cases (19.5% with three vessel involvement. The mean total bilirubin level was 1.47 ± 0.8 mg/dl, 1.27 ± 0.12 mg/dl, 1.27 ± 0.06 mg/dl, 1.6 ± 0.04 mg/dl and 0.98 ± 0.05 mg/dl, respectively for the cases with above order. The mean difference in serum total bilirubin between normal angiography group and three-vessel involvement group was 0.49 mg/dl (P < .0001. There was a significant inverse relation between bilirubin level (total, direct and indirect and number of involved vessels and involvement intensity increased as serum bilirubin level decreased. Severity of coronary arteries stenosis as well as the number of involved vessels increased as serum bilirubin level decreased

Analysis of urinary stone based on a spectrum absorption FTIR-ATR

International Nuclear Information System (INIS)

Asyana, V; Haryanto, F; Fitri, L A; Ridwan, T; Anwary, F; Soekersi, H

2016-01-01

This research analysed the urinary stone by measuring samples using Fourier transform infrared-attenuated total reflection spectroscopy and black box analysis. The main objective of this study is to find kinds of urinary stone and determine a total spectrum, which is a simple model of the chemical and mineral composition urinary stone through black box analysis using convolution method. The measurements result showed that kinds of urinary stone were pure calcium oxalate monohydrate, ion amino acid calcium oxalate monohydrate, a mixture of calcium oxalate monohydrate with calcium phosphate, a mixture of ion amino acid calcium oxalate monohydrate and calcium phosphate,pure uric acid, ion amino acid uric acid, and a mixture of calcium oxalate monohydrate with ion amino acid uric acid. The results of analysis of black box showed characteristics as the most accurate and precise to confirm the type of urinary stones based on theregion absorption peak on a graph, the results of the convolution, and the shape of the total spectrum on each urinary stones. (paper)

Bilirubin glucuronidation revisited: proper assay conditions to estimate enzyme kinetics with recombinant UGT1A1.

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Zhou, Jin; Tracy, Timothy S; Remmel, Rory P

2010-11-01

Bilirubin, an end product of heme catabolism, is primarily eliminated via glucuronic acid conjugation by UGT1A1. Impaired bilirubin conjugation, caused by inhibition of UGT1A1, can result in clinical consequences, including jaundice and kernicterus. Thus, evaluation of the ability of new drug candidates to inhibit UGT1A1-catalyzed bilirubin glucuronidation in vitro has become common practice. However, the instability of bilirubin and its glucuronides presents substantial technical challenges to conduct in vitro bilirubin glucuronidation assays. Furthermore, because bilirubin can be diglucuronidated through a sequential reaction, establishment of initial rate conditions can be problematic. To address these issues, a robust high-performance liquid chromatography assay to measure both bilirubin mono- and diglucuronide conjugates was developed, and the incubation conditions for bilirubin glucuronidation by human embryonic kidney 293-expressed UGT1A1 were carefully characterized. Our results indicated that bilirubin glucuronidation should be assessed at very low protein concentrations (0.05 mg/ml protein) and over a short incubation time (5 min) to assure initial rate conditions. Under these conditions, bilirubin total glucuronide formation exhibited a hyperbolic (Michaelis-Menten) kinetic profile with a K(m) of ∼0.2 μM. In addition, under these initial rate conditions, the relative proportions between the total monoglucuronide and the diglucuronide product were constant across the range of bilirubin concentration evaluated (0.05-2 μM), with the monoglucuronide being the predominant species (∼70%). In conclusion, establishment of appropriate incubation conditions (i.e., very low protein concentrations and short incubation times) is necessary to properly characterize the kinetics of bilirubin glucuronidation in a recombinant UGT1A1 system.

Mg I absorption features in the solar spectrum near 9 and 12 microns

Science.gov (United States)

Glenar, David A.; Reuter, Dennis C.; Deming, Drake; Chang, Edward S.

1988-01-01

High-resolution FTS observations from the Kitt Peak National Solar Observatory and the Spacelab 3 ATMOS experiment have revealed additional infrared transitions due to Mg I in the spectra of both quiet sun and sunspot penumbra. In contrast to previous observations, these transitions are seen in absorption, not emission. Absorption intensities range from 1 to 7 percent of the continuum in the quiet sun. In the penumbra, the same features appear to show Zeeman splitting. Modeling of the line profiles in the photospheric spectrum shows evidence for a factor of three overabundance in the n = 5 or more levels of Mg I in the upper photosphere, but with no deviations from a Planck source function. It is concluded that whatever the process that produces the emission (including the Lemke and Holweger mechanism), it must occur well above the tau(5000) = 0.01 level.

Relationship between red blood cell distribution width, bilirubin, and clinical characteristics of patients with gastric cancer.

Science.gov (United States)

Wei, T-T; Wang, L-L; Yin, J-R; Liu, Y-T; Qin, B-D; Li, J-Y; Yin, X; Zhou, L; Zhong, R-Q

2017-10-01

Red blood cell distribution width (RDW) and bilirubin have been proved to be prognostic factors for various types of cancer. However, their prognostic value in patients with gastric cancer (GC) remains largely unknown. To verify whether RDW and bilirubin are prognostic factors for patients with GC, we performed a cross-sectional study to analyze the relationship between RDW, bilirubin, and the clinical characteristics of patients with GC. Medical records of all newly diagnosed and pathologically proved patients with GC admitted to Changzheng Hospital between January 2016 and July 2016 were retrospectively reviewed. The relationship between RDW, bilirubin, and the clinical characteristics of patients with GC was analyzed. A total of 144 patients with GC were enrolled. Patients with GC had significantly higher RDW than healthy controls, even after adjusting for hemoglobin, while total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) were significantly decreased. Furthermore, RDW and bilirubin were significantly correlated with tumor stage, as well as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). Our study indicated that RDW and bilirubin could be potential prognostic factors for patients of GC. © 2017 John Wiley & Sons Ltd.

Increased conjugated bilirubin is sufficient to initiate screening for biliary atresia

DEFF Research Database (Denmark)

Madsen, Stine Skipper; Kvist, Nina; Thorup, Jørgen

2015-01-01

INTRODUCTION: Biliary atresia is the leading cause of liver transplantation in children. It affects 1:15,000 in Denmark. With a national birth rate of 60,000, four children are born every year with biliary atresia. Early correction of biliary obstruction is essential to prevent fatal biliary...... cirrhosis. The Danish Health and Medicines Authority (DHMA) demands diagnostic evaluation of children with elevated level of serum bilirubin after two weeks of age. Biliary atresia has to be excluded if conjugated bilirubin level is above than 20 μmol/l, and/or more than 20% of total bilirubin...

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

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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.

Serum bilirubin levels are inversely associated with PAI-1 and fibrinogen in Korean subjects.

Science.gov (United States)

Cho, Hyun Sun; Lee, Sung Won; Kim, Eun Sook; Shin, Juyoung; Moon, Sung Dae; Han, Je Ho; Cha, Bong Yun

2016-01-01

Oxidative stress may contribute to atherosclerosis and increased activation of the coagulation pathway. Bilirubin may reduce activation of the hemostatic system to inhibit oxidative stress, which would explain its cardioprotective properties shown in many epidemiological studies. This study investigated the association of serum bilirubin with fibrinogen and plasminogen activator inhibitor-1 (PAI-1), respectively. A cross-sectional analysis was performed on 968 subjects (mean age, 56.0 ± 11.2 years; 61.1% men) undergoing a general health checkup. Serum biochemistry was analyzed including bilirubin subtypes, insulin resistance (using homeostasis model of assessment [HOMA]), C-reactive protein (CRP), fibrinogen, and PAI-1. Compared with subjects with a total bilirubin (TB) concentration of 17.1 μmol/L had a smaller waist circumference, a lower triglyceride level, a lower prevalence of metabolic syndrome, and decreased HOMA-IR and CRP levels. Correlation analysis revealed linear relationships of fibrinogen with TB and direct bilirubin (DB), whereas PAI-1 was correlated with DB. After adjustment for confounding factors, bilirubin levels were inversely associated with fibrinogen and PAI-1 levels, respectively. Multivariate regression models showed a negative linear relationship between all types of bilirubin and fibrinogen, whereas there was a significant linear relationship between PAI-1 and DB. High bilirubin concentrations were independently associated with low levels of fibrinogen and PAI-1, respectively. The association between TB and PAI-1 was confined to the highest TB concentration category whereas DB showed a linear association with PAI-1. Bilirubin may protect against the development of atherothrombosis by reducing the hemostatic response. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

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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. Copyright © 2015 Elsevier Inc. All rights reserved.

The integrated radio continuum spectrum of M33 - Evidence for free-free absorption by cool ionized gas

Science.gov (United States)

Israel, F. P.; Mahoney, M. J.; Howarth, N.

1992-01-01

We present measurements of the integrated radio continuum flux density of M33 at frequencies between 22 and 610 MHz and discuss the radio continuum spectrum of M33 between 22 MHz and 10 GHz. This spectrum has a turnover between 500 and 900 MHz, depending on the steepness of the high frequency radio spectrum of M33. Below 500 MHz the spectrum is relatively flat. We discuss possible mechanisms to explain this spectral shape and consider efficient free-free absorption of nonthermal emission by a cool (not greater than 1000 K) ionized gas to be a very likely possibility. The surface filling factor of both the nonthermal and the thermal material appears to be small (of order 0.001), which could be explained by magnetic field/density fluctuations in the M 33 interstellar medium. We briefly speculate on the possible presence of a nuclear radio source with a steep spectrum.

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

Science.gov (United States)

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-NH 2 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.

Transport and metabolism at blood-brain interfaces and in neural cells: relevance to bilirubin-induced encephalopathy

Directory of Open Access Journals (Sweden)

Silvia eGazzin

2012-05-01

Full Text Available Bilirubin, the end-product of heme catabolism, circulates in non pathological plasma mostly as a protein-bound species. When bilirubin concentration builds up, the free fraction of the molecule increases. Unbound bilirubin then diffuses across blood-brain interfaces into the brain, where it accumulates and exerts neurotoxic effects. In this classical view of bilirubin neurotoxicity, blood-brain interfaces act merely as structural barriers impeding the penetration of the pigment-bound carrier protein, and neural cells are considered as passive targets of its toxicity. Yet, the role of blood-brain interfaces in the occurrence of bilirubin encephalopathy appears more complex than being simple barriers to the diffusion of bilirubin, and neural cells such as astrocytes and neurons can play an active role in controlling the balance between the neuroprotective and neurotoxic effects of bilirubin. This article reviews the emerging in vivo and in vitro data showing that transport and metabolic detoxification mechanisms at the blood-brain and blood-CSF barriers may modulate bilirubin flux across both cellular interfaces, and that these protective functions can be affected in chronic hyperbilirubinemia. Then the in vivo and in vitro arguments in favor of the physiological antioxidant function of intracerebral bilirubin are presented, as well as with the potential role of transporters such as ABCC-1 and metabolizing enzymes such as cytochromes P-450 in setting the cerebral cell- and structure-specific toxicity of bilirubin following hyperbilirubinemia. The relevance of these data to the pathophysiology of bilirubin-induced neurological diseases is discussed.

Constitutive androstane receptor activation promotes bilirubin clearance in a murine model of alcoholic liver disease.

Science.gov (United States)

Wang, Xiuyan; Zheng, Liyu; Wu, Jinming; Tang, Binbin; Zhang, Mengqin; Zhu, Debin; Lin, Xianfan

2017-06-01

Increased plasma levels of bilirubin have been reported in rat models and patients with alcoholic liver disease (ALD). The constitutive androstane receptor (CAR) is a known xenobiotic receptor, which induces the detoxification and transport of bilirubin. In the present study, the bilirubin transport regulatory mechanisms, and the role of CAR activation in hepatic and extrahepatic bilirubin clearance were investigated in a murine model of ALD. The mice were fed a Lieber-DeCarli ethanol diet or an isocaloric control diet for 4 weeks, followed by the administration of CAR agonists, 1,4-bis-[2‑(3,5-dichlorpyridyloxy)]benzene (TCPOBOP) and phenobarbital (PB), and their vehicles to examine the effect of the pharmacological activation of CAR on serum levels of bilirubin and on the bilirubin clearance pathway in ALD by serological survey, western blotting and reverse transcription‑quantitative polymerase chain reaction. The results showed that chronic ethanol ingestion impaired the nuclear translocation of CAR, which was accompanied by elevated serum levels of bilirubin, suppression of the expression of hepatic and renal organic anion transporting polypeptide (OATP) 1A1 and hepatic multidrug resistance‑associated protein 2 (MRP2), and induction of the expression of UDP-glucuronosyltransferase (UGT) 1A1. The activation of CAR by TCPOBOP and PB resulted in downregulation of the serum levels of bilirubin followed by selective upregulation of the expression levels of OATP1A1, OATP1A4, UGT1A1 and MRP2 in ALD. These results revealed the bilirubin transport regulatory mechanisms and highlighted the importance of CAR in modulating the bilirubin clearance pathway in the ALD mouse model.

Serum bilirubin: a simple routine surrogate marker of the progression of chronic kidney disease.

Science.gov (United States)

Moolchandani, K; Priyadarssini, M; Rajappa, M; Parameswaran, S; Revathy, G

2016-10-01

Studies suggest that Chronic Kidney Disease (CKD) is a global burden health associated with significant comorbid conditions. Few biochemical parameters have gained significance in predicting the disease progression. The present work aimed to study the association of the simple biochemical parameter of serum bilirubin level with the estimated glomerular filtration rate (eGFR), and to assess their association with the co-morbid conditions in CKD. We recruited 188 patients with CKD who attended a Nephrology out-patient department. eGFR values were calculated based on the serum creatinine levels using CKD-EPI formula. Various biochemical parameters including glucose, creatinine, uric acid, total and direct bilirubin were assayed in all study subjects. Study subjects were categorized into subgroups based on their eGFR values and their diabetic status and the parameters were compared among the different subgroups. We observed a significantly decreased serum bilirubin levels (p bilirubin levels (r = 0.92). We also observed a significant positive correlation between the eGFR levels and the direct bilirubin levels (r = 0.76). On multivariate linear regression analysis, we found that total and direct bilirubin independently predict eGFR, after adjusting for potential confounders (p bilirubin may help in predicting the early progression of CKD and more so in diabetic CKD.

Magnetic polymer-silica composites as bioluminescent sensors for bilirubin detection

Energy Technology Data Exchange (ETDEWEB)

Timin, Alexander S., E-mail: a_timin@mail.ru [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); RASA Center in Tomsk, Tomsk Polytechnic University, pros. Lenina, 30, Tomsk (Russian Federation); Solomonov, Alexey V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation); Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001 (Israel); Kumagai, Akiko; Miyawaki, Atsushi [Cell Function Dynamics, Brain Science Institute RIKEN, 2-1 Hirosawa, Wako-city, Saitama, 351-0198 (Japan); Khashirova, Svetlana Yu; Zhansitov, Azamat [Kabardino-Balkar State University, 173 Chernyshevskogo St., Nal' chik, 360004, Kabardino-Balkaria (Russian Federation); Rumyantsev, Evgeniy V. [Inorganic Chemistry Department, Ivanovo State University of Chemistry and Technology (ISUCT), 7, Sheremetevsky prosp., 153000, Ivanovo (Russian Federation)

2016-11-01

The synthesis of multifunctional nano-sized materials is leading to the rapid development of key application, including improved drug delivery, bioimaging and protein separation. In this work, magnetic silica particles modified with novel guanidine containing co-polymers were manufactured via sol-gel method. To evaluate the chemical composition of our prepared samples, FT-IR spectroscopy and thermogravimetry were conducted. Scanning electron microscopy was used in order to investigate the morphology of final products after modification by guanidine containing co-polymers and iron nanoparticles. In addition, the surface of polymer-silica composites was functionalized by the novel bilirubin-inducible fluorescent protein UnaG. In an aqueous bilirubin solution, the silica particles decorated with the polymer-UnaG have showed bright fluorescence. Synthesis and characterization of these hybrid materials allow developing of new multifunctional nano-sized materials, which will be used for detection and separation of bilirubin, a lipophilic heme catabolite that is a clinical diagnostic for liver function. - Highlights: • Novel magnetic silicas grafted by guanidine containing co-polymers were prepared. • Unag protein was effectively loaded into polymer coated silicas. • The fluorescent properties depend on content of bilirubin.

Magnetic polymer-silica composites as bioluminescent sensors for bilirubin detection

International Nuclear Information System (INIS)

Timin, Alexander S.; Solomonov, Alexey V.; Kumagai, Akiko; Miyawaki, Atsushi; Khashirova, Svetlana Yu; Zhansitov, Azamat; Rumyantsev, Evgeniy V.

2016-01-01

The synthesis of multifunctional nano-sized materials is leading to the rapid development of key application, including improved drug delivery, bioimaging and protein separation. In this work, magnetic silica particles modified with novel guanidine containing co-polymers were manufactured via sol-gel method. To evaluate the chemical composition of our prepared samples, FT-IR spectroscopy and thermogravimetry were conducted. Scanning electron microscopy was used in order to investigate the morphology of final products after modification by guanidine containing co-polymers and iron nanoparticles. In addition, the surface of polymer-silica composites was functionalized by the novel bilirubin-inducible fluorescent protein UnaG. In an aqueous bilirubin solution, the silica particles decorated with the polymer-UnaG have showed bright fluorescence. Synthesis and characterization of these hybrid materials allow developing of new multifunctional nano-sized materials, which will be used for detection and separation of bilirubin, a lipophilic heme catabolite that is a clinical diagnostic for liver function. - Highlights: • Novel magnetic silicas grafted by guanidine containing co-polymers were prepared. • Unag protein was effectively loaded into polymer coated silicas. • The fluorescent properties depend on content of bilirubin.

Hepatic bilirubin uptake in the isolated perfused rat liver is not facilitated by albumin binding

International Nuclear Information System (INIS)

Stollman, Y.R.; Gaertner, U.; Theilmann, L.; Ohmi, N.; Wolkoff, A.W.

1983-01-01

Bilirubin uptake by the liver has kinetic characteristics which suggest carrier-mediation. Bilirubin is readily bound to albumin. A liver cell surface receptor for albumin has been postulated. The present study was designed to examine directly whether albumin facilitates the hepatic uptake of bilirubin and whether uptake of bilirubin depends on binding to albumin. Rat liver was perfused with a protein-free fluorocarbon medium, and single-pass uptake of 1, 10, or 200 nmol of [ 3 H]bilirubin was determined after injection as an equimolar complex with 125 I-albumin, with 125 I-ligandin, or free with only a [ 14 C]sucrose reference. Uptake of 10 nmol of [ 3 H]bilirubin was 67.5 +/- 3.7% of the dose when injected with 125 I-albumin, 67.4 +/- 6.5% when injected with 125 I-ligandin, and 74.9 +/- 2.4% when injected with [ 14 C]sucrose (P greater than 0.1). At 200 nmol, uptake fell to 46.4 +/- 3.1% ( 125 I-albumin) and 63.3 +/- 3.4% [( 14 C]sucrose) of injected [ 3 H]bilirubin (P less than 0.01), which suggests saturation of the uptake mechanism. When influx was quantitated by the model of Goresky, similar results were obtained. When [ 3 H]bilirubin was injected simultaneously with equimolar 125 I-albumin and a [ 14 C]sucrose reference, there was no delay in 125 I-albumin transit as compared with that of [ 14 C]sucrose. This suggested that the off-rate of albumin from a putative hepatocyte receptor would have to be very rapid, which is unusual for high affinity receptor-ligand interaction. There was no evidence for facilitation of bilirubin uptake by binding to albumin or for interaction of albumin with a liver cell surface receptor. These results suggest that the hepatic bilirubin uptake mechanism is one of high affinity which can extract bilirubin from circulating carriers such as albumin, ligandin, or fluorocarbon

Reduction of bilirubin by targeting human heme oxygenase-1 through siRNA.

Science.gov (United States)

Xia, Zhen-Wei; Li, Chun-E; Jin, You-Xin; Shi, Yi; Xu, Li-Qing; Zhong, Wen-Wei; Li, Yun-Zhu; Yu, Shan-Chang; Zhang, Zi-Li

2007-04-01

Neonatal hyperbilirubinemia is a common clinical condition caused mainly by the increased production and decreased excretion of bilirubin. Current treatment is aimed at reducing the serum levels of bilirubin. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that generates bilirubin. In this study we intended to suppress HO-1 using the RNA interference technique. Small interfering RNA (siRNA)-A, -B, and -C were designed based on human HO-1 (hHO-1) mRNA sequences. siRNA was transfected into a human hepatic cell line (HL-7702). hHO-1 transcription and protein levels were then determined. In addition, the inhibitory effect of siRNA on hHO-1 was assessed in cells treated with hemin or transfected with an hHO-1 plasmid. siRNA-C showed the most potent suppressive effect on hHO-1. This inhibition is dose and time dependent. Compared with control, both hemin and hHO-1 plasmids up-regulated hHO-1 expression in HL-7702 cells. However, the up-regulation was significantly attenuated by siRNA-C. Furthermore, the decrease in hHO-1 activity was coincident with the suppression of its transcription. Finally, siRNA-C was shown to reduce hHO-1 enzymatic activity and bilirubin levels. Thus, this study provides a novel therapeutic rationale by blocking bilirubin formation via siRNA for preventing and treating neonatal hyperbilirubinemia and bilirubin encephalopathy at an early clinical stage.

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

Science.gov (United States)

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.

Serum bilirubin levels are positively associated with glycemic variability in women with type 2 diabetes.

Science.gov (United States)

Kim, Lee Kyung; Roh, Eun; Kim, Min Joo; Kim, Min Kyeong; Park, Kyeong Seon; Kwak, Soo Heon; Cho, Young Min; Park, Kyong Soo; Jang, Hak Chul; Jung, Hye Seung

2016-11-01

Glycemic variability is known to induce oxidative stress. We investigated the relationships between glycemic variability and serum bilirubin levels, an endogenous anti-oxidant, in patients with diabetes. A cross-sectional study was carried out with 77 patients with type 2 diabetes who had been recruited to two clinical studies from 2008 to 2014. There were no participants with diseases of the pancreas, liver, biliary tract and chronic renal insufficiency. Glycemic variation was calculated by a continuous glucose monitoring system, and correlation analyses were carried out to evaluate their association with bilirubin levels. Multiple linear regression was carried out to identify independent factors influencing bilirubin levels and glycemic variation. Among the participants, 42.3% were men. The mean (standard deviation) age was 61.5 years (10.4 years), body mass index was 24.2 kg/m 2 (2.8 kg/m 2 ), diabetes duration was 17.7 years (9.5 years), hemoglobin A 1c was 60.7 mmol/mol (7.1 mmol/mol; 7.7 [0.7]%) and bilirubin was 11.8 μmol/L (4.10 μmol/L). Serum bilirubin levels were not different according to age, body mass index and hemoglobin A 1c . However, the mean amplitude of glucose excursion was positively associated with bilirubin levels in women (r = 0.588, P bilirubin and mean amplitude of glucose excursion remained significant (r = 0.566, P bilirubin was an independent determinant for the mean amplitude of glucose excursion in women. 1,5-Anhydroglucitol was also associated with bilirubin levels in women. Bilirubin level within the physiological range might be an independent predictor for glycemic variability in women with type 2 diabetes. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

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

Science.gov (United States)

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. Copyright © 2016. Published by Elsevier B.V.

A Novel Newborn Rat Kernicterus Model Created by Injecting a Bilirubin Solution into the Cisterna Magna

Science.gov (United States)

Song, Sijie; Hu, Ying; Gu, Xianfang; Si, Feifei; Hua, Ziyu

2014-01-01

Background Kernicterus still occurs around the world; however, the mechanism of bilirubin neurotoxicity remains unclear, and effective treatment strategies are lacking. To solve these problems, several kernicterus (or acute bilirubin encephalopathy) animal models have been established, but these models are difficult and expensive. Therefore, the present study was performed to establish a novel kernicterus model that is simple and affordable by injecting unconjugated bilirubin solution into the cisterna magna (CM) of ordinary newborn Sprague-Dawley (SD) rats. Methods On postnatal day 5, SD rat pups were randomly divided into bilirubin and control groups. Then, either bilirubin solution or ddH2O (pH = 8.5) was injected into the CM at 10 µg/g (bodyweight). For model characterization, neurobehavioral outcomes were observed, mortality was calculated, and bodyweight was recorded after bilirubin injection and weaning. Apoptosis in the hippocampus was detected by H&E staining, TUNEL, flow cytometry and Western blotting. When the rats were 28 days old, learning and memory ability were evaluated using the Morris water maze test. Results The bilirubin-treated rats showed apparently abnormal neurological manifestations, such as clenched fists, opisthotonos and torsion spasms. Bodyweight gain in the bilirubin-treated rats was significantly lower than that in the controls (Pbilirubin-treated rats were both dramatically higher than those of the controls (P = 0.004 and 0.017, respectively). Apoptosis and necrosis in the hippocampal nerve cells in the bilirubin-treated rats were observed. The bilirubin-treated rats performed worse than the controls on the Morris water maze test. Conclusion By injecting bilirubin into the CM, we successfully created a new kernicterus model using ordinary SD rats; the model mimics both the acute clinical manifestations and the chronic sequelae. In particular, CM injection is easy to perform; thus, more stable models for follow-up study are

Absorption study of pentachlorophenol in persons working with wood preservatives

Energy Technology Data Exchange (ETDEWEB)

Jones, R.D.; Winter, D.P.; Cooper, A.J.

1986-05-01

Plasma and urinary pentachlorophenol (PCP) was measured in 209 workers who had occupational exposure to wood preservatives containing this compound and 101 workers not exposed occupationally to PCP. Workers were examined for chloracne and blood concentrations of bilirubin, gamma-glutamyltransferase (GGT), cholesterol and high-density lipoproteins (HDL) were determined. All the occupationally exposed groups showed evidence of PCP absorption; highest mean concentrations were found in remedial timber-treatment operatives (6.0 mmol/l for plasma and 274 nmol/mmol of creatinine for urine). Timber-yard workers also showed substantial evidence of absorption (mean plasma concentration 4.8 mmol/l). Persons formulating PCP-containing wood preservatives had the lowest concentrations of any exposed group sampled (mean plasma concentration 1.3 mmol/l, mean urinary concentration 39.6 nmol/mmol of creatinine). The occupational groups studied were not standardized for factors known to affect bilirubin, GGT, cholesterol and HDL. The inference that can be drawn from the results of these measurements is therefore limited. There was, however, no evidence of any disadvantageous effect of PCP on health as measured by these parameters. No overt case of chloracne was found.

Pulse radiolysis investigations on oxidation reactions of bilirubin in aqueous solutions (Preprint No. RC-3)

International Nuclear Information System (INIS)

Mohan, Hari; Gopinathan, C.

1988-02-01

The oxidation of bilirubin in aqueous solutions have been investigated by different oxidizing species such as CH 3 I.OH, Br 2 - and CO 3 - . The rate constant for the oxidation of bilirubin has been determined from the formation kinetics of bilirubin cations. (author). 3 refs

Imbalance between production and conjugation of bilirubin: a fundamental concept in the mechanism of neonatal jaundice.

Science.gov (United States)

Kaplan, Michael; Muraca, Maurizio; Hammerman, Cathy; Rubaltelli, Firmino F; Vilei, Maria T; Vreman, Hendrik J; Stevenson, David K

2002-10-01

The objective of this study was to evaluate the roles of production and conjugation of bilirubin, individually and in combination, in the mechanism of neonatal jaundice. A cohort of healthy, term male newborns was sampled on the third day of life, coincident with routine metabolic screening, for blood carboxyhemoglobin determination, a reflection of heme catabolism, and for serum unconjugated and conjugated bilirubin fractions, reflecting bilirubin conjugation. The former was determined by gas chromatography, corrected for inspired CO (COHbc), and expressed as percentage of total hemoglobin. Serum bilirubin fractions were quantified by alkaline methanolysis and reverse phase high performance liquid chromatography. The sum of all bilirubin fractions comprised serum total bilirubin (STB). Total conjugated bilirubin (TCB) was comprised of the sum of the conjugated fractions and was expressed as percentage of STB (TCB[%]). A "bilirubin production/conjugation index" (COHbc/[TCB(%)] represented the combined roles of these modalities in the mechanism of bilirubinemia. Relationships between STB concentrations on the one hand, and COHbc values, TCB(%) proportions, and the production/conjugation index on the other, were determined by applying a best-fit regression analysis methodology. Mean (+/- standard deviation) STB concentration at the time of sampling was 114 +/- 48 micro mol/L (range: 8-263 micro mol/L). Mean COHbc value was 0.77 +/- 0.19%, and median (interquartile range) TCB(%) was 0.737 (0.465-1.260)%. COHbc values correlated directly with STB concentrations (r = 0.38; s = 46.1), and TCB(%) correlated inversely with STB (r = 0.40; s = 45.8). The production/conjugation index correlated positively with STB values (r = 0.61; s = 45.8), the r value for the index being higher than that of either COHbc or TCB(%), individually. The bilirubin production/conjugation index seemed to have a biphasic relationship to STB: STB values rose steeply in concert with increasing index

The origin of blueshifted absorption features in the X-ray spectrum of PG 1211+143: outflow or disc

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Gallo, L. C.; Fabian, A. C.

2013-07-01

In some radio-quiet active galactic nuclei (AGN), high-energy absorption features in the X-ray spectra have been interpreted as ultrafast outflows (UFOs) - highly ionized material (e.g. Fe XXV and Fe XXVI) ejected at mildly relativistic velocities. In some cases, these outflows can carry energy in excess of the binding energy of the host galaxy. Needless to say, these features demand our attention as they are strong signatures of AGN feedback and will influence galaxy evolution. For the same reason, alternative models need to be discussed and refuted or confirmed. Gallo and Fabian proposed that some of these features could arise from resonance absorption of the reflected spectrum in a layer of ionized material located above and corotating with the accretion disc. Therefore, the absorbing medium would be subjected to similar blurring effects as seen in the disc. A priori, the existence of such plasma above the disc is as plausible as a fast wind. In this work, we highlight the ambiguity by demonstrating that the absorption model can describe the ˜7.6 keV absorption feature (and possibly other features) in the quasar PG 1211+143, an AGN that is often described as a classic example of a UFO. In this model, the 2-10 keV spectrum would be largely reflection dominated (as opposed to power law dominated in the wind models) and the resonance absorption would be originating in a layer between about 6 and 60 gravitational radii. The studies of such features constitute a cornerstone for future X-ray observatories like Astro-H and Athena+. Should our model prove correct, or at least important in some cases, then absorption will provide another diagnostic tool with which to probe the inner accretion flow with future missions.

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

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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...

Role of brain cytochrome P450 mono-oxygenases in bilirubin oxidation-specific induction and activity.

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Gambaro, Sabrina E; Robert, Maria C; Tiribelli, Claudio; Gazzin, Silvia

2016-02-01

In the Crigler-Najjar type I syndrome, the genetic absence of efficient hepatic glucuronidation of unconjugated bilirubin (UCB) by the uridine 5'-diphospho-glucuronosyltransferase1A1 (UGT1A1) enzyme produces the rise of UCB level in blood. Its entry to central nervous system could generate toxicity and neurological damage, and even death. In the past years, a compensatory mechanism to liver glucuronidation has been indicated in the hepatic cytochromes P450 enzymes (Cyps) which are able to oxidize bilirubin. Cyps are expressed also in the central nervous system, the target of bilirubin toxicity, thus making them theoretically important to confer a protective activity toward bilirubin accumulation and neurotoxicity. We therefore investigated the functional induction (mRNA, EROD/MROD) and the ability to oxidize bilirubin of Cyp1A1, 1A2, and 2A3 in primary astrocytes cultures obtained from two rat brain region (cortex: Cx and cerebellum: Cll). We observed that Cyp1A1 was the Cyp isoform more easily induced by beta-naphtoflavone (βNF) in both Cx and Cll astrocytes, but oxidized bilirubin only after uncoupling by 3, 4,3',4'-tetrachlorobiphenyl (TCB). On the contrary, Cyp1A2 was the most active Cyp in bilirubin clearance without uncoupling, but its induction was confined only in Cx cells. Brain Cyp2A3 was not inducible. In conclusion, the exposure of astrocytes to βNF plus TCB significantly enhanced Cyp1A1 mediating bilirubin clearance, improving cell viability in both regions. These results may be a relevant groundwork for the manipulation of brain Cyps as a therapeutic approach in reducing bilirubin-induced neurological damage.

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

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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 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.

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

Science.gov (United States)

2010-04-01

... levels of bilirubin (total and unbound) in the blood (serum) of newborn infants to aid in indicating the risk of bilirubin encephalopathy (kernicterus). (b) Classification. Class I. [54 FR 30206, July 19...

Serum bilirubin concentration is associated with eGFR and urinary albumin excretion in patients with type 1 diabetes mellitus.

Science.gov (United States)

Nishimura, Takeshi; Tanaka, Masami; Sekioka, Risa; Itoh, Hiroshi

2015-01-01

Although relationships of serum bilirubin concentration with estimated glomerular filtration rate (eGFR) and urinary albumin excretion (UAE) in patients with type 2 diabetes have been reported, whether such relationships exist in patients with type 1 diabetes is unknown. A total of 123 patients with type 1 diabetes were investigated in this cross-sectional study. The relationship between bilirubin (total and indirect) concentrations and log(UAE) as well as eGFR was examined by Pearson's correlation analyses. Multivariate regression analyses were used to assess the association of bilirubin (total and indirect) with eGFR as well as log(UAE). A positive correlation was found between serum bilirubin concentration and eGFR; total bilirubin (r=0.223, p=0.013), indirect bilirubin (r=0.244, p=0.007). A negative correlation was found between serum bilirubin concentration and log(UAE); total bilirubin (r=-0.258, p=0.005), indirect bilirubin (r=-0.271, p=0.003). Multivariate regression analyses showed that indirect bilirubin concentration was an independent determinant of eGFR and log(UAE). Bilirubin concentration is associated with both eGFR and log(UAE) in patients with type 1 diabetes. Bilirubin might have a protective role in the progression of type 1 diabetic nephropathy. Copyright © 2015 Elsevier Inc. All rights reserved.

Higher hydrocortisone dose increases bilirubin in hypopituitary patients- results from an RCT.

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Werumeus Buning, Jorien; Kootstra-Ros, Jenny E; Brummelman, Pauline; van den Berg, Gerrit; van der Klauw, Melanie; Wolffenbuttel, Bruce H R; van Beek, André P; Dullaart, Robin P F

2016-05-01

Bilirubin has anti-oxidative and anti-inflammatory properties, which may explain its proposed protective effects on the development of cardiometabolic disorders. Glucocorticoids affect heme oxygenase regulation in vitro, which plays a key role in bilirubin production. Effects of variations in glucocorticoid exposure on circulating bilirubin levels in humans are unknown. Here we tested whether a higher hydrocortisone replacement dose affects circulating bilirubin in hypopituitary patients. A randomized double-blind cross-over study (ClinicalTrials.gov, number NCT01546992) was performed in 47 patients with secondary adrenal failure [10-week exposure to a higher hydrocortisone dose (0·4-0·6 mg/kg body weight) vs. 10 weeks of a lower hydrocortisone dose (0·2-0·3 mg/kg body weight)]. Plasma total bilirubin was increased by 10% from 7 to 8 μM in response to the higher hydrocortisone dose (P = 0·033). This effect was inversely related to age (P = 0·042), but was unaffected by sex, obesity and (replacement for) other hormonal insufficiencies. The higher hydrocortisone dose also resulted in lower alkaline phosphatase (P = 0·006) and aspartate aminotransferase activities (P = 0·001). Bilirubin is modestly increased in response to higher glucocorticoid exposure in humans, in conjunction with lower alkaline phosphatase and aspartate aminotransferase activities, which are supposed to represent biomarkers of a pro-inflammatory state and enhanced liver fat accumulation. © 2016 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.

Multiple binding of bilirubin to human serum albumin and cobinding with laurate

DEFF Research Database (Denmark)

Sato, H; Honoré, B; Brodersen, R

1988-01-01

Numerical analysis of multiple binding of two ligands to one carrier has been accomplished, using the principle of several sets of acceptable binding constants, with bilirubin-laurate-albumin as an example. Binding of bilirubin to defatted human serum albumin was investigated by a spectroscopic...

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

Science.gov (United States)

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.

Variation in the serum bilirubin levels in newborns according to gender and seasonal changes

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Jyoti Bala

2015-01-01

Full Text Available Introduction: Bilirubin is a substance that is produced during the process of hemolysis. Gender influences on neonatal illnesses and outcomes have remained a topic of debate and investigation. Empirical neonatological experience suggests that prevalence and degree of neonatal jaundice might be dependent on seasonal variation also. The aim of our study is to interpret the bilirubin levels in newborns according to gender and seasonal variation. Materials and Methods: The study was done from October 2012 to July of 2013 (differentiated by seasonal variation. A total of 1000 jaundiced newborn (500 of each sex diagnosed clinically and divided equally in summer and winter season were studied to assess the total, direct and indirect serum bilirubin levels using colorimetry. Results: Out of total 1676 deliveries (439 were caesarean, 13 were assisted and rest were normal during winter season and 1475 deliveries (399 were Cesarean, 14 were assisted and rest were normal during summer season, 500 male newborn and 500 female newborn were analysed, divided equally in both seasons. Serum bilirubin was higher in males in summers and mainly comprised unconjugated bilirubin while direct bilirubin was higher in females in winters. Raised indirect bilirubin was more common in males born in summer than those born in winters (P = 041. In winters raised direct bilirubin was more common in females as compared to males (P = 0.019. Among female neonates total and indirect bilirubin was significantly raised in those born in summers (P = < 0.001 and <0.001, respectively while direct was raised in those born in winters (P = 0.003. Conclusion: Physiological and pathologic phenomena associated with male gender must be integrated in the frame of understanding of both susceptibility and protection of the male newborn which has not been available for adequate investigation in the past. The higher temperature during the summer, with a greater influence of higher breastfeeding

First animal experiments and clinical investigations with sup(99m)Tc-bilirubin

International Nuclear Information System (INIS)

Schneider, G.; Kaempfer, I.; Blottner, A.; Rogos, R.; Deckart, H.

1986-01-01

Labelling of bilirubin with sup(99m)Tc is described. The distribution and elimination of the labelled substance was investigated in mice, rabbits, dogs and pigs. Within 5 minutes p.i. the labelled substance accumulated in the liver and was eliminated within several hours. Comparative studies of 14 C bilirubin and 14 C sup(99m)Tc bilirubin showed identical distribution patterns. Clinial trials were conducted in 60 patients who received 0.0015 mg/kg i.v. (total dose, 60-80 MBq of sup(99m)Tc bilirubin -> 1.6 - 2.2 mCi). Images were obtained in the first 20 min p.i. as well as after 2 and 24 hours. To determine the blood clearance blood samples were taken in the first hours and activity curves were recorded over the cardiac and temporal regions. As elimination from the liver was slow, gall bladder and bile duct imaging was not successful before 1 to 3 hours p.i. The severity of liver damage can be established on the basis of blood clearance, onset of active liver uptake, elimination from the liver and 24 hours excretion in percent. Labelled bilirubin is a suitable material for morphologic and dynamic functional imaging of the liver (e.g. for SPECT studies). Incidents were absent throughout. (Author)

Effect of Sn on the optical band gap determined using absorption spectrum fitting method

Energy Technology Data Exchange (ETDEWEB)

Heera, Pawan, E-mail: sramanb70@mailcity.com [Department of Physics, Himachal Pradesh University, Shimla, INDIA, 171005 (India); Govt. College Amb, Himachal Pradesh, INDIA,177203 (India); Kumar, Anup, E-mail: kumar.anup.sml@gmail.com [Department of Physics, Himachal Pradesh University, Shimla, INDIA, 171005 (India); Physics Department, Govt. College, Kullu, H. P., INDIA, 175101 (India); Sharma, Raman, E-mail: pawanheera@yahoo.com [Department of Physics, Himachal Pradesh University, Shimla, INDIA, 171005 (India)

2015-05-15

We report the preparation and the optical studies on tellurium rich glasses thin films. The thin films of Se{sub 30}Te{sub 70-x} Sn{sub x} system for x= 0, 1.5, 2.5 and 4.5 glassy alloys prepared by melt quenching technique are deposited on the glass substrate using vacuum thermal evaporation technique. The analysis of absorption spectra in the spectral range 400nm–4000 nm at room temperature obtained from UV-VIS-NIR spectrophotometer [Perkin Elmer Lamda-750] helps us in the optical characterization of the thin films under study. The absorption spectrum fitting method is applied by using the Tauc’s model for estimating the optical band gap and the width of the band tail of the thin films. The optical band gap is calculated and is found to decrease with the Sn content.

A Perspective on a Possible Relation Between the Psychopathology of the Schizophrenia/Schizoaffective Spectrum and Unconjugated Bilirubin: A Longitudinal Protocol Study.

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Gama Marques, João; Arantes-Gonçalves, Filipe

2018-01-01

Some authors suggest a relation between Unconjugated Bilirubin (UCB) plasma high levels and schizophrenia, as schizophrenia patients have been showing higher UCB levels when compared with other psychiatric patients and general population. These higher UCB levels have been already correlated with acute psychotic states, positive symptoms, and poor outcome in patients with schizophrenia. Schizophrenia and schizoaffective disorders share common symptoms but there aren't yet accepted biomarkers for their distinction. In our study protocol we propose an observational longitudinal study on a sample composed of two subgroups: patients with schizophrenia and patients with schizoaffective disorder. We will compare the UCB levels between groups, and search for a possible correlation with patient's psychopathology. For that purpose we will use nosological, psychopathological, neuropsychological, and psychosocial instruments. Thus we will be testing two different hypotheses: (1) Is UCB serum level a diagnosis indicator, with categorical distinction potential, between groups of patients with different psychotic disorders? (2) Is UCB serum level a severity indicator, with dimensional distinction potential, among groups of patients with the same psychotic disorder? We believe that UCB mean levels may contribute to some clarification of this controversy, as a potential biological indicator, facilitating the distinction between these two diagnostic categories and\\or discriminating the dimensional severity among each of these psychotic conditions. Thus we may be opening a new opportunities for innovative and exciting biological psychiatry research regarding organic aspects in the schizophrenia spectrum.

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

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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 (CO 2 ) 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. Copyright © 2016 Elsevier B.V. All rights reserved.

Pulse radiolytic and spectrophotometric investigation of the binding of bilirubin to bovine serum albumin

International Nuclear Information System (INIS)

Adhikari, S.; Guha, S.N.; Gopinathan, C.

1994-01-01

Bilirubin (BR) exhibits marked change in its absorption properties in the presence of bovine serum albumin (BSA). The λ max of BR observed at 440 nm is red shifted by about 20 nm with 8% increase in band intensity when BSA is present in the matrix. Medium polarity and salt effects were also studied in this system and it was inferred that BR is bound to BSA to form a complex, which becomes unstable at high salt concentration or in a medium of low dielectric constant such as water-alcohol mixture. Pulse radiolysis study of this system employing CO 2 .- radical revealed that BR blocks the sites of CO 2 .- attack in the BSA molecule. (author). 3 refs., 2 figs

Plasma malondialdehyde, bilirubin, homocysteine and total ...

African Journals Online (AJOL)

Oxidative stress has been implicated in coronary artery disease (CAD). Malondialdehyde (MDA) is lipid peroxidation end product. Bilirubin may act as an antioxidant that suppresses lipid oxidation. The role of MDA and antioxidant capacity and their inter-relationship in patients with and without CAD was investigated.

The correlation of serum bilirubin levels with disease activity in patients with rheumatoid arthritis.

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Peng, You-Fan; Wang, Jun-Li; Pan, Guo-Gang

2017-06-01

We investigated the relationship between serum bilirubin and disease activity in patients with rheumatoid arthritis (RA). We included a total of 173 consecutive RA patients without steroid treatment and 346 healthy subjects; the disease activity score in 28 joints (DAS28) was used to assess disease activity in patients with RA. Serum bilirubin concentrations were significantly lower in RA patients than in controls. Serum bilirubin was found to be negatively correlated with C-reactive protein (CRP) concentration and erythrocyte sedimentation rate (ESR) (r=-0.165, P=0.030; r=-192, P=0.012) in patients with RA. There was a negative correlation between the serum bilirubin and DAS28 score (r=-0.331, Pbilirubin was independently associated with the DAS28 score (b=-0.225, P=0.001) in the multiple linear regression analysis. Serum bilirubin concentrations are lower in patients with RA compared to controls and correlate with disease activity in patients with RA. Copyright © 2017. Published by Elsevier B.V.

Bilirubin Decreases Macrophage Cholesterol Efflux and ATP-Binding Cassette Transporter A1 Protein Expression.

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Wang, Dongdong; Tosevska, Anela; Heiß, Elke H; Ladurner, Angela; Mölzer, Christine; Wallner, Marlies; Bulmer, Andrew; Wagner, Karl-Heinz; Dirsch, Verena M; Atanasov, Atanas G

2017-04-28

Mild but chronically elevated circulating unconjugated bilirubin is associated with reduced total and low-density lipoprotein cholesterol concentration, which is associated with reduced cardiovascular disease risk. We aimed to investigate whether unconjugated bilirubin influences macrophage cholesterol efflux, as a potential mechanism for the altered circulating lipoprotein concentrations observed in hyperbilirubinemic individuals. Cholesterol efflux from THP-1 macrophages was assessed using plasma obtained from normo- and hyperbilirubinemic (Gilbert syndrome) humans (n=60 per group) or (heterozygote/homozygote Gunn) rats (n=20 per group) as an acceptor. Hyperbilirubinemic plasma from patients with Gilbert syndrome and Gunn rats induced significantly reduced cholesterol efflux compared with normobilirubinemic plasma. Unconjugated bilirubin (3-17.1 μmol/L) exogenously added to plasma- or apolipoprotein A1-supplemented media also decreased macrophage cholesterol efflux in a concentration- and time-dependent manner. We also showed reduced protein expression of the ATP-binding cassette transporter A1 (ABCA1), a transmembrane cholesterol transporter involved in apolipoprotein A1-mediated cholesterol efflux, in THP-1 macrophages treated with unconjugated bilirubin and in peripheral blood mononuclear cells obtained from hyperbilirubinemic individuals. Furthermore, we demonstrated that bilirubin accelerates the degradation rate of the ABCA1 protein in THP-1 macrophages. Cholesterol efflux from THP-1 macrophages is decreased in the presence of plasma obtained from humans and rats with mild hyperbilirubinemia. A direct effect of unconjugated bilirubin on cholesterol efflux was demonstrated and is associated with decreased ABCA1 protein expression. These data improve our knowledge concerning bilirubin's impact on cholesterol transport and represent an important advancement in our understanding of bilirubin's role in cardiovascular disease. © 2017 The Authors. Published on

Plasma bilirubin values on admission and ventricular remodeling after a first anterior ST-segment elevation acute myocardial infarction.

Science.gov (United States)

Miranda, Berta; Barrabés, José A; Figueras, Jaume; Pineda, Victor; Rodríguez-Palomares, José; Lidón, Rosa-Maria; Sambola, Antonia; Bañeras, Jordi; Otaegui, Imanol; García-Dorado, David

2016-01-01

Bilirubin may elicit cardiovascular protection and heme oxygenase-1 overexpression attenuated post-infarction ventricular remodeling in experimental animals, but the association between bilirubin levels and post-infarction remodeling is unknown. In 145 patients with a first anterior ST-segment elevation acute myocardial infarction (STEMI), we assessed whether plasma bilirubin on admission predicted adverse remodeling (left ventricular end-diastolic volume [LVEDV] increase ≥20% between discharge and 6 months, estimated by magnetic resonance imaging). Patients' baseline characteristics and management were comparable among bilirubin tertiles. LVEDV increased at 6 months (P bilirubin tertiles (10.8 [30.2], 10.1 [22.9], and 12.7 [24.3]%, P = 0.500). Median (25-75 percentile) bilirubin values in patients with and without adverse remodeling were 0.75 (0.60-0.93) and 0.73 (0.60-0.92) mg/dL (P = 0.693). Absence of final TIMI flow grade 3 (odds ratio 3.92, 95% CI 1.12-13.66) and a history of hypertension (2.04, 0.93-4.50), but not admission bilirubin, were independently associated with adverse remodeling. Bilirubin also did not predict the increase in ejection fraction at 6 months. Admission bilirubin values are not related to LVEDV or ejection fraction progression after a first anterior STEMI and do not predict adverse ventricular remodeling. Key messages Bilirubin levels are inversely related to cardiovascular disease, and overexpression of heme oxygenase-1 (the enzyme that determines bilirubin production) has prevented post-infarction ventricular remodeling in experimental animals, but the association between bilirubin levels and the progression of ventricular volumes and function in patients with acute myocardial infarction remained unexplored. In this cohort of patients with a first acute anterior ST-segment elevation myocardial infarction receiving contemporary management, bilirubin levels on admission were not predictive of the changes in left

Photodissociation dynamics in the first absorption band of pyrrole. I. Molecular Hamiltonian and the Herzberg-Teller absorption spectrum for the A12(π σ* ) ←X˜ 1 A1(π π ) transition

Science.gov (United States)

Picconi, David; Grebenshchikov, Sergy Yu.

2018-03-01

This paper opens a series in which the photochemistry of the two lowest πσ* states of pyrrole and their interaction with each other and with the ground electronic state X ˜ are studied using ab initio quantum mechanics. New 24-dimensional potential energy surfaces for the photodissociation of the N-H bond and the formation of the pyrrolyl radical are calculated using the multiconfigurational perturbation theory (CASPT2) for the electronic states X ˜ (π π ) , 11A2(πσ*), and 11B1(πσ*) and locally diabatized. In this paper, the ab initio calculations are described and the photodissociation in the state 11A2(πσ*) is analyzed. The excitation 11 A2←X ˜ is mediated by the coordinate dependent transition dipole moment functions constructed using the Herzberg-Teller expansion. Nuclear dynamics, including 6, 11, and 15 active degrees of freedom, are studied using the multi-configurational time-dependent Hartree method. The focus is on the frequency resolved absorption spectrum as well as on the dissociation time scales and the resonance lifetimes. Calculations are compared with available experimental data. An approximate convolution method is developed and validated, with which absorption spectra can be calculated and assigned in terms of vibrational quantum numbers. The method represents the total absorption spectrum as a convolution of the diffuse spectrum of the detaching H-atom and the Franck-Condon spectrum of the heteroaromatic ring. Convolution calculation requires a minimal quantum chemical input and is a promising tool for studying the πσ* photodissociation in model biochromophores.

Comparison of bilirubin level in term infants born by vaginal delivery and C/S

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Ahmad Shah Farhat

2016-12-01

Full Text Available Background: Given the overriding importance of neonatal jaundice and scarcity of studies on the role of route of delivery on its occurrence, this study aimed to investigate the association between neonatal bilirubin level and the route of delivery (i.e., normal vaginal delivery [NVD] and cesarean section [CS]. Methods: This prospective, cross-sectional study was conducted in 2012 in Imam Reza Hospital of Mashhad, Iran, 2012. In all term infants, who met the inclusion criteria, serum bilirubin level was measured by the bili-test device between the second and seventh days after birth. In cases with skin bilirubin level>5 mg/dl, serum bilirubin was also checked. The collected data were analyzed using SPSS, version 16. Results: A total of 182 neonates were enrolled in the study, 56% of whom were male. The mean bilirubin levels in the NVD and CS groups were 9.4±2.9 mg/dl and 9.8±3.4 mg/dl, respectively (P=0.53. Additionally, comparison of the mean bilirubin levels between the two groups based of demographic characteristics demonstrated no significant differences. Conclusion: This study showed no significant correlation between neonatal jaundice in term infants and the route of delivery.

Molecular imprinting polymer with polyoxometalate/carbon nitride nanotubes for electrochemical recognition of bilirubin

International Nuclear Information System (INIS)

Yola, Mehmet Lütfi; Göde, Ceren; Atar, Necip

2017-01-01

Highlights: •Bilirubin-imprinted sensor is developed for the sensitive detection of bilirubin •The prepared based on nanocomposite were characterized by several methods. •Bilirubin-imprinted sensor offers the important advantages •Bilirubin-imprinted sensor is preferred to the other methods for analysis -- Abstract: In this work, a new molecular imprinted sensor based on polyoxometalate (H 3 PW 12 O 40 , POM) functionalized carbon nitride nanotubes (C 3 N 4 NTs) nanocomposite was prepared for bilirubin (BR) analysis. The structures of prepared surfaces based on the nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray analysis (EDX). After that, BR imprinted electrode on H 3 PW 12 O 40 /C 3 N 4 NTs nanocomposite was developed by cyclic voltammetry (CV) in 100 mM pyrrole containing 25 mM BR. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10 −12 –1.0 × 10 −10 M and 3.0 × 10 −13 M, respectively. In addition, the imprinted sensor was applied to human plasma samples with high recovery and selectivity.

Chronically elevated bilirubin protects from cardiac reperfusion injury in the male Gunn rat.

Science.gov (United States)

Bakrania, B; Du Toit, E F; Ashton, K J; Wagner, K-H; Headrick, J P; Bulmer, A C

2017-08-01

Bilirubin is associated with reduced risk of cardiovascular disease, as evidenced in conditions of mild hyperbilirubinaemia (Gilbert's Syndrome). Little is known regarding myocardial stress resistance in hyperbilirubinaemic conditions or whether life-long exposure modifies cardiac function, which might contribute to protection from cardiovascular disease. Hyperbilirubinaemic rats and littermate controls underwent echocardiography at 3, 6 and 12 months of age, with hearts subsequently assessed for resistance to 30 min of ischaemia. Heart tissue was then collected for assessment of bilirubin content. No difference in baseline cardiac function was evident until 6 months onwards, where Gunn rats demonstrated aortic dilatation and reduced peak ejection velocities. Additionally, duration of ventricular ejection increased progressively, indicating a negative inotropic effect of bilirubin in vivo. Ex vivo analysis of baseline function revealed reduced left ventricular pressure development (LVDP) and contractility in hyperbilirubinaemic rats. Furthermore, stress resistance was improved in Gunn hearts: post-ischaemic recoveries of LVDP (76 ± 22% vs. 29 ± 17% Control, P bilirubin exerts sex-independent effects on vascular structure, myocardial function and ischaemic tolerance, the latter likely mediated via bilirubin's antioxidant properties. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Transcutaneous Bilirubin Nomogram for Healthy Term and Late Preterm Neonates in First 96 Hours of Life.

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Thakkar, Pareshkumar; Chavda, Hardas; Doshi, Vikas

2017-05-15

To develop nomogram of Transcutaneous Bilirubin among healthy term and late-preterm neonates during first 96 hours of age. Longitudinal observational study. Neonatal unit of a tertiary care Hospital of Central Gujarat, India. 1075 healthy term and late preterm neonates (≥35weeks). Six-hourly transcutaneous bilirubin was obtained from birth to 96 hour of life using Drager JM 103 Transcutaneous Bilirubinometer. Main outcome measures: Nomogram of Transcutaneous Bilirubin with percentile values was obtained, rate of rise of bilirubin was calculated and predictive ability of normative data was analyzed for subsequent need of phototherapy. The age-specific percentile curves and nomogram were developed from the transcutaneous bilirubin readings of 1,010 neonates. Rate of rise in first 12 hour was 0.2 mg/dL and was 0.17 mg/dL in 12 to 24 hour of life which decreased on second day of life. Neonates who required phototherapy had consistently higher readings of transcutaneous bilirubin and also higher rate of rise in first 48 hrs. Neonates whose transcutaneous bilirubin is above the 50th percentile should be monitored for the development of significant hyperbilirubinemia.

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

Science.gov (United States)

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 (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 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.

Predictors of the change in bilirubin levels over twelve weeks of treatment with atazanavir

LENUS (Irish Health Repository)

Cotter, Aoife G

2013-05-16

AbstractObjectiveTo determine the factors associated with change in bilirubin concentration 12 weeks after the initiation of an atazanavir (ATV)-containing antiretroviral regimen.MethodsWe performed a retrospective case note review of all patients prescribed ATV between January 2004 and October 2007 in a cohort of HIV infected subjects. Data collected included baseline demographics, hepatitis B and C serology, current antiretroviral therapy, baseline and week 12 routine bloods. The primary endpoint was the change in bilirubin concentration at 12 weeks after start of ATV. Multvariable linear regression was performed to assess the relationships between the change in bilirubin and variables of interest. Results: Eighty-three ATV-treated patients were included in the analysis of whom 46 (60.5%) were hepatitis C antibody positive. The median (interquartile range) change in bilirubin by week 12 was 16 (4, 22) umol\\/L; only 1 patient developed grade 4 hyperbilirubinaemia at week 12. After controlling for baseline bilirubin levels, HCV seropositivity and baseline ALP were associated with a smaller change in bilirubin over the 12 weeks with a trend towards lower increases in those receiving tenofovir. Sensitivity analyses reported similar associations with methadone use and injection drug use, when these variables replaced HCV sero-positivity in the model. Conclusion: Patients with hepatitis C co-infection experience smaller changes in bilirubin upon exposure to ATV. Although the underlying mechanism for this association remains unclear, these data support the safe use of this drug in this patient setting. Further research into the clinical predictors of ATV-related hyperbilirubinaemia is warranted.

The Mean Metal-line Absorption Spectrum of Damped Ly α Systems in BOSS

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Mas-Ribas, Lluís [Institute of Theoretical Astrophysics, University of Oslo, Postboks 1029, NO-0315 Oslo (Norway); Miralda-Escudé, Jordi; Pérez-Ràfols, Ignasi; Arinyo-i-Prats, Andreu [Institut de Ciències del Cosmos, Universitat de Barcelona (UB-IEEC), Barcelona E-08028, Catalonia (Spain); Noterdaeme, Pasquier; Petitjean, Patrick [Institut d’Astrophysique de Paris, UPMC and CNRS, UMR7095 98bis Boulevard Arago, F-75014—Paris (France); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); York, Donald G. [Department of Astronomy and Astrophysics and the Enrico Fermi Institute, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Ge, Jian, E-mail: l.m.ribas@astro.uio.no [Department of Astronomy, University of Florida, Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)

2017-09-01

We study the mean absorption spectrum of the Damped Ly α (DLA) population at z ∼ 2.6 by stacking normalized, rest-frame-shifted spectra of ∼27,000 DLA systems from the DR12 of the Baryon Oscillation Spectroscopic Survey (BOSS)/SDSS-III. We measure the equivalent widths of 50 individual metal absorption lines in five intervals of DLA hydrogen column density, five intervals of DLA redshift, and overall mean equivalent widths for an additional 13 absorption features from groups of strongly blended lines. The mean equivalent width of low-ionization lines increases with N {sub H} {sub i}, whereas for high-ionization lines the increase is much weaker. The mean metal line equivalent widths decrease by a factor ∼1.1–1.5 from z ∼ 2.1 to z ∼ 3.5, with small or no differences between low- and high-ionization species. We develop a theoretical model, inspired by the presence of multiple absorption components observed in high-resolution spectra, to infer mean metal column densities from the equivalent widths of partially saturated metal lines. We apply this model to 14 low-ionization species and to Al iii, S iii, Si iii, C iv, Si iv, N v, and O vi. We use an approximate derivation for separating the equivalent width contributions of several lines to blended absorption features, and infer mean equivalent widths and column densities from lines of the additional species N i, Zn ii, C ii*, Fe iii, and S iv. Several of these mean column densities of metal lines in DLAs are obtained for the first time; their values generally agree with measurements of individual DLAs from high-resolution, high signal-to-noise ratio spectra when they are available.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 A

International Nuclear Information System (INIS)

Deng Lunhua; Li Chuanliang; Zhang Junli; Yang Xiaohua; Chen Yangqin

2010-01-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 A using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm -1 . Empirical line intensities were provided covering four orders of magnitude.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 Å

Science.gov (United States)

Deng, Lunhua; Li, Chuanliang; Zhang, Junli; Yang, Xiaohua; Chen, Yangqin

2010-12-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 Å using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm-1. Empirical line intensities were provided covering four orders of magnitude.

Evaluation of BiliCare™ transcutaneous bilirubin device in Japanese newborns.

Science.gov (United States)

Yamana, Keiji; Morioka, Ichiro; Kurokawa, Daisuke; Fukushima, Sachiyo; Nishida, Kosuke; Ohyama, Shohei; Nishimura, Noriyuki; Nozu, Kandai; Taniguchi-Ikeda, Mariko; Nagase, Hiroaki; Fujioka, Kazumichi; Iwatani, Sota; Nakamura, Hajime; Iijima, Kazumoto

2017-10-01

Non-invasive transcutaneous bilirubin (TcB) monitoring has been widely used to screen for hyperbilirubinemia. TcB measured using the recently developed BiliCare™ system, however, has not been fully evaluated. One hundred and seven TcB measurements were obtained from 82 Japanese newborns ≥35 weeks' gestational age within 2 weeks after birth. Measurements were taken at the scaphoid fossa, conchal cavity, and lobe of the ear using BiliCare. BiliCare TcB were compared with total serum bilirubin (TB) and TcB obtained using another bilirubinometer (JM-105™). Transcutaneous bilirubin measured at all three sites significantly correlated with TB (r = 0.91, 0.93, and 0.93 at the scaphoid fossa, conchal cavity, and lobe, respectively). The mean differences were 0.1, -0.3, and 3.6 at the scaphoid fossa, conchal cavity, and lobe, respectively. BiliCare TcB at the scaphoid fossa significantly correlated with that using the JM-105 (r = 0.91). The mean difference was 0.0. BiliCare, however, produced a significantly higher and lower TcB than the JM-105 for TB bilirubin measurements taken at the scaphoid fossa or conchal cavity using BiliCare were more reliable than those at the earlobe. BiliCare TcB differed from those of the JM-105, for TB <7 or ≥15 mg/dL. © 2017 Japan Pediatric Society.

Absorption spectrum and absorption cross sections of the 2ν1 band of HO2 between 20 and 760 Torr air in the range 6636 and 6639 cm-1

Science.gov (United States)

Assaf, Emmanuel; Liu, Lu; Schoemaecker, Coralie; Fittschen, Christa

2018-05-01

The absorption spectrum of HO2 radicals has been measured in the range 6636-6639 cm-1 at several pressures between 20 and 760 Torr of air. Absolute absorption cross sections of the strongest line at around 6638.2 cm-1 have been determined from kinetic measurements, taking advantage of the well known rate constant of the self-reaction. Peak absorption cross sections of 22.6, 19.5, 14.4, 7.88, 5.12 and 3.23 × 10-20 cm2 were obtained at 20, 50, 100, 200, 400 and 760 Torr, respectively. By fitting these data, an empirical expression has been obtained for the absorption cross section of HO2 in the range 20-760 Torr air: σ6638.2cm-1 = 1.18 × 10-20 + (2.64 × 10-19 × (1-exp (-63.1/p (Torr))) cm2.

Higher Bilirubin Levels of Healthy Living Liver Donors Are Associated With Lower Posttransplant Hepatocellular Carcinoma Recurrence.

Science.gov (United States)

Han, Sangbin; Yang, Ju Dong; Sinn, Dong Hyun; Ko, Justin Sangwook; Kim, Jong Man; Shin, Jun Chul; Son, Hee Jeong; Gwak, Mi Sook; Joh, Jae-Won; Kim, Gaab Soo

2016-09-01

Serum bilirubin level, which may reflect the host defense against increased oxidative stress, is inversely associated with the risk of cancer development. In liver transplantation, the intrinsic bilirubin metabolism of donor liver is subsequently translated into recipient. Thus, we hypothesized that liver transplantation conducted with living donors with higher serum bilirubin reduces hepatocellular carcinoma (HCC) recurrence. Two hundred fifty recipients who underwent liver transplantation for treating HCC within the Milan criteria were included in the study. The association between donor preoperative total bilirubin concentration and the risk of HCC recurrence was analyzed using the Fine and Gray regression model with posttransplant death as a competing risk event with adjustment for tumor biology including α-fetoprotein, histological differentiation, and microvascular invasion. All donors were confirmed to have no underlying hepatobiliary diseases or hematological disorders. Donor preoperative total bilirubin concentration was 0.7 mg/dL in median and ranged from 0.2 to 2.7 mg/dL. Thirty-five (14.0%) recipients developed HCC recurrence. Multivariable analysis demonstrated that donor preoperative total bilirubin concentration was inversely associated with the recurrence risk (hazard ratio, 0.22; 95% confidence interval, 0.07-0.72; P = 0.013). The highest (≥1.0 mg/dL) versus lowest (≤0.6 mg/dL) tertile of donor preoperative total bilirubin showed a significant reduction of the recurrence risk (hazard ratio, 0.28; 95% confidence interval, 0.11-0.70; P = 0.006). Hepatocellular carcinoma recurrence risk decreases in relation to the increase in total serum bilirubin level of healthy living donors without underlying hepatobiliary or hematological disorders. Further validation of bilirubin as a potent anticancer substance against HCC is warranted.

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

Science.gov (United States)

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

2014-01-01

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. PMID

Physiologic Doses of Bilirubin Contribute to Tolerance of Islet Transplants by Suppressing the Innate Immune Response.

Science.gov (United States)

Adin, Christopher A; VanGundy, Zachary C; Papenfuss, Tracey L; Xu, Feng; Ghanem, Mostafa; Lakey, Jonathan; Hadley, Gregg A

2017-01-24

Bilirubin has been recognized as a powerful cytoprotectant when used at physiologic doses and was recently shown to have immunomodulatory effects in islet allograft transplantation, conveying donor-specific tolerance in a murine model. We hypothesized that bilirubin, an antioxidant, acts to suppress the innate immune response to islet allografts through two mechanisms: 1) by suppressing graft release of damage-associated molecular patterns (DAMPs) and inflammatory cytokines, and 2) by producing a tolerogenic phenotype in antigen-presenting cells. Bilirubin was administered intraperitoneally before pancreatic procurement or was added to culture media after islet isolation in AJ mice. Islets were exposed to transplant-associated nutrient deprivation and hypoxia. Bilirubin significantly decreased islet cell death after isolation and hypoxic stress. Bilirubin supplementation of islet media also decreased the release of DAMPs (HMGB1), inflammatory cytokines (IL-1β and IL-6), and chemokines (MCP-1). Cytoprotection was mediated by the antioxidant effects of bilirubin. Treatment of macrophages with bilirubin induced a regulatory phenotype, with increased expression of PD-L1. Coculture of these macrophages with splenocytes led to expansion of Foxp3+ Tregs. In conclusion, exogenous bilirubin supplementation showed cytoprotective and antioxidant effects in a relevant model of islet isolation and hypoxic stress. Suppression of DAMP release, alterations in cytokine profiles, and tolerogenic effects on macrophages suggest that the use of this natural antioxidant may provide a method of preconditioning to improve outcomes after allograft transplantation.

Circulating Total Bilirubin and Risk of Incident Cardiovascular Disease in the General Population

NARCIS (Netherlands)

Kunutsor, Setor K.; Bakker, Stephan J. L.; Gansevoort, Ronald T.; Chowdhury, Rajiv; Dullaart, Robin P. F.

OBJECTIVE: To assess the association of circulating total bilirubin and cardiovascular disease (CVD) risk in a new prospective study and to determine whether adding information on total bilirubin values to established cardiovascular risk factors is associated with improvement in prediction of CVD

Bilirubin in Urine: MedlinePlus Lab Test Information

Science.gov (United States)

... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Bilirubin (Urine); 86–87 p. Lab ...

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

Science.gov (United States)

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.

Bilirubin as a potential causal factor in type 2 diabetes risk: a Mendelian randomization study

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Abbasi, Ali; Deetman, Petronella E.; Corpeleijn, Eva; Gansevoort, Ron T.; Gans, Rijk O.B.; Hillege, Hans L.; van der Harst, Pim; Stolk, Ronald P.; Navis, Gerjan; Alizadeh, Behrooz Z.; Bakker, Stephan J.L.

2014-01-01

Circulating bilirubin, a natural antioxidant, is associated with decreased risk of type 2 diabetes (T2D), but the nature of the relationship remains unknown. We performed Mendelian randomization in a prospective cohort of 3,381 participants free of diabetes at baseline (aged 28-75 years; women, 52.6%). We used rs6742078 located in UDP-glucuronosyltransferase (UGT1A1) locus as instrumental variable (IV) to study a potential causal effect of serum total bilirubin on T2D risk. T2D developed in a total of 210 (6.2%) participants during a median follow-up of 7.8 years. In adjusted analyses, rs6742078, which explained 19.5% of bilirubin variation, was strongly associated with total bilirubin (a 0.68-SD increase in bilirubin levels per T allele; Pbilirubin levels, we observed a 25% (OR 0.75 [95%CI, 0.62-0.92]; P=0.004) lower risk of T2D. In Mendelian randomization analysis, the causal risk reduction for T2D was estimated to be 42% (causal ORIVestimation per 1-SD increase in log-transformed bilirubin 0.58 [95%CI, 0.39-0.84]; P=0.005), which was comparable to the observational estimate (Durbin-Wu-Hausman chi-square test Pfor difference =0.19). These novel results provide evidence that elevated bilirubin is causally associated with risk of T2D and support its role as a protective determinant. PMID:25368098

Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

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G.M. Shub

2009-09-01

Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

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

Science.gov (United States)

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

2016-08-03

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.

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

Science.gov (United States)

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. Copyright © 2015. Published by Elsevier Ireland Ltd.

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

Science.gov (United States)

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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

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

1982-01-01

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

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

Science.gov (United States)

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.

Bilirubin nomogram for prediction of significant hyperbilirubinemia in north Indian neonates.

Science.gov (United States)

Pathak, Umesh; Chawla, Deepak; Kaur, Saranjit; Jain, Suksham

2013-04-01

(i) To construct hour-specific serum total bilirubin (STB) nomogram in neonates born at =35 weeks of gestation; (ii)To evaluate efficacy of pre-discharge bilirubin measurement in predicting hyperbilirubinemia needing treatment. Diagnostic test performance in a prospective cohort study. Teaching hospital in Northern India. Healthy neonates with gestation =35 weeks or birth weight =2000 g. Serum total bilirubin was measured in all enrolled neonates at 24 ± 6, 72-96 and 96-144 h of postnatal age and when indicated clinically. Neonates were followed up during hospital stay and after discharge till completion of 7th postnatal day. Key outcome was significant hyperbilirubinemia (SHB) defined as need of phototherapy based on modified American Academy of Pediatrics (AAP) guidelines. In neonates born at 38 or more weeks of gestation middle line and in neonates born at 37 or less completed weeks of gestation, lower line of phototherapy thresholds were used to initiate phototherapy. For construction of nomogram, STB values were clubbed in six-hour epochs (age ± 3 hours) for postnatal age up to 48 h and twelve-hour epochs (age ± 6 hours) for age beyond 48 h. Predictive ability of the nomogram was assessed by calculating sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio, by plotting receiver-operating characteristics (ROC) curve and calculating c-statistic. 997 neonates (birth weight: 2627 ± 536 g, gestation: 37.8 ± 1.5 weeks) were enrolled, of which 931 completed followup. Among enrolled neonates 344 (34.5%) were low birth weight. Rate of exclusive breastfeeding during hospital stay was more than 80%. Bilirubin nomogram was constructed using 40th, 75th and 95th percentile values of hour-specific bilirubin. Pre-discharge STB of =95th percentile was assigned to be in high-risk zone, between 75th and 94th centile in upper-intermediate risk zone, between 40th and 74th centile in lower-intermediate risk zone and below 40th

Application of the correction's system of bottom by deuterium's lamp of a spectrophotometer of atomic absorption to the obtaining of ultraviolet spectrums

International Nuclear Information System (INIS)

Villalobos Chaves, Alberto Enrique

2002-01-01

The correction system of bottom by lamp of deuterium's arch of a spectrophotometer of atomic absorption has been utilized with sweep's capacity of wavelength to get spectrums of ultraviolet absorption of samples in gaseous phase, whether in presence as in absence of flame, in the region between 200 nm and 365 nm. The spectral information was obtained after of a process of electronic subtraction of the source's signal, except for the source's signal plus the sample and its subsequent analysis by a programmed data's processor to give a report in terms of wavelength. The spectrums obtained in absence of flame were practiced in samples contained in a gas's sell for infrared spectroscopy with polyethylene's windows, it is located of the burner and directly in front to the radiation's beam, comparable spectrums with the reported in the literature were obtained and with a bigger resolution than the measure with an conventional ultraviolet absorption's spectrophotometer utilized like reference. The spectrums in presence of flame have been of flame have been obtained from dissolved samples and directly suctioned, it achieves to obtain spectral information that is normally not detected conveniently when it performs qualitative analysis by emission of flame in elements such like zinc, lead, cobalt, mercury and nickel among other. The information obtained on this way has been utilized like an alternative method to the elemental analysis by humid way with a view to increase the reliability of the results that have been utilized like basis in the determination of the tariff classification of imported or exported products. (Author) [es

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

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

2015-01-01

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. PMID:25990790

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

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

2017-01-26

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 (Pbilirubin quartiles were linearly and negatively correlated with MetS prevalence and hypertriglyceridemia (HTG) in females (Pbilirubin 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.

Measurements of neonatal bilirubin and albumin concentrations : a need for improvement and quality control

NARCIS (Netherlands)

van Imhoff, Deirdre E.; Dijk, Peter H.; Weykamp, Cas W.; Cobbaert, Christa M.; Hulzebos, Christian V.

Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human

Measurements of neonatal bilirubin and albumin concentrations: a need for improvement and quality control

NARCIS (Netherlands)

Imhoff, D.E. van; Dijk, P.H.; Weykamp, C.W.; Cobbaert, C.M.; Hulzebos, C.V.; Liem, K.D.; et al.,

2011-01-01

Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human

PEGylated bilirubin nanoparticle as an anti-oxidative and anti-inflammatory demulcent in pancreatic islet xenotransplantation.

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Kim, Min Jun; Lee, Yonghyun; Jon, Sangyong; Lee, Dong Yun

2017-07-01

Transplanted islets suffer hypoxic stress, which leads to nonspecific inflammation. This is the major cause of islet graft failure during the early stage of intrahepatic islet transplantation. Although bilirubin has shown potent anti-oxidative and anti-inflammatory functions, its clinical applications have been limited due to its insolubility and short half-life. To overcome this problem, novel amphiphilic bilirubin nanoparticles are designed. Hydrophilic poly(ethylene glycol) (PEG) is conjugated to the hydrophobic bilirubin molecule. Then, the PEG-bilirubin conjugates form nanoparticles via self-assembly, i.e., so-called to BRNPs. BRNPs can protect islet cells not only from chemically induced oxidative stress by scavenging reactive oxygen species molecules, but also from activated macrophages by suppressing cytokine release. Importantly, in vivo experiments demonstrate that BRNP treatment can dramatically and significantly prolong islet graft survival compared to bilirubin treatment. In addition, immunohistochemical analysis shows BRNPs have potent anti-oxidative and anti-inflammatory capabilities. Collectively, novel BRNPs can be a new potent remedy for successful islet transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Blue emitting copper nanoclusters as colorimetric and fluorescent probe for the selective detection of bilirubin

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R. S., Aparna; J. S., Anjali Devi; John, Nebu; Abha, K.; S. S., Syamchand; George, Sony

2018-06-01

Hurdles to develop point of care diagnostic methods restrict the translation of progress in the health care sector from bench side to bedside. In this article a simple, cost effective fluorescent as well as colorimetric nanosensor was developed for the early and easy detection of hyperbilirubinemia. A stable, water soluble bovine serum albumin stabilised copper nanocluster (BSA CuNC) was used as the fluorescent probe which exhibited strong blue emission (404 nm) upon 330 nm excitation. The fluorescence of the BSA CuNC can be effectively quenched by the addition of bilirubin by the formation of copper-bilirubin complex. Meanwhile the copper-bilirubin complex resulted in an observable colour change from pale violet to green facilitating colorimetric detection. The prepared sensor displayed good selectivity and sensitivity over other co-existing molecules, and can be used for quantifying bilirubin with a detection limit down to 257 fM. Additionally, the as-prepared probe was coated on a paper strip to develop a portable paper strip sensor of bilirubin. Moreover, the method was successfully applied in real sample analysis and obtained promising result.

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

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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. Copyright © 2015

Studying neonatal bilirubin encephalopathy with conventional MRI, MRS, and DWI

International Nuclear Information System (INIS)

Wang, Xiaoyi; Wu, Wulin; Chineah, Ashley; Liu, Fan; Liao, Weihua; Hou, Bob L.; Zhang, Ping

2008-01-01

The purpose of this study was to evaluate the diagnostic value of conventional magnetic resonance imaging (MRI), proton magnetic resonance spectroscopy ( 1 H-MRS), and diffusion-weighted imaging (DWI) for neonatal bilirubin encephalopathy. We collected conventional MRI in 24 neonates with neonatal bilirubin encephalopathy. We performed 1 H-MRS and DWI sequences to nine of the 24 patients and seven age-matched healthy control subjects. Multiple-voxel 1 H-MRS data were acquired using PRESS pulse sequence with TE=135 ms and TR=1500 ms. The spectroscopic regions of interest were the bilateral basal ganglia and thalamus with a 1.0 mL spatial resolution. The data from DWI were collected by using a single shot-spin echo-echo planar imaging sequence with TR/TE: 2900/98, and imaging regions were also focused on the bilateral basal ganglia and thalamus. Nineteen of the 24 patients had abnormal T 1 -weighted image hyperintensity in the globus pallidus, but these lesions appeared as normal T 2 -weighted image intensity in the same region. Ten of the 24 patients had T 1 -weighted image high signal intensity in the subthalamic nucleus and appeared as normal intensity in the region for the T 2 -weighted images. The peak area ratios of NAA/Cho and NAA/Cr were significantly decreased (t-test, P 1 H-MRS are important complementary tools in the diagnosis of neonatal bilirubin encephalopathy. The study provides important information for applying these MR modalities to evaluate neonates with bilirubin encephalopathy. (orig.)

Photodamage of the cells in culture sensitized with bilirubin

Science.gov (United States)

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

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

Science.gov (United States)

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. Copyright © 2015 the American Physiological Society.

The role of magnetic resonance imaging in the prediction of the neurodevelopmental outcome of acute bilirubin encephalopathy in newborns

OpenAIRE

TATLI, Mustafa Mansur

2009-01-01

Aim: Magnetic resonance imaging (MRI) is widely used in the diagnosis of acute bilirubin encephalopathy, but the relationship between MRI findings and neurodevelopmental outcome in newborns with acute bilirubin encephalopathy remains unclear. The aim of this study was to investigate the relationship between acute bilirubin encephalopathy, MRI findings, and neurodevelopmental outcome. Materials and Methods: The study included 13 infants with acute bilirubin encephalopathy. MRI was performed ...

Is there any relationship between serum levels of total bilirubin and the severity of erectile dysfunction?

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Keskin, Ercüment; Karabakan, Mehmet; Bozkurt, Aliseydi; Hirik, Erkan; Karabulut, İbrahim; Gunay, Murat; Çakan, Murat

2018-04-01

Recent studies have shown that atherosclerosis is associated with erectile dysfunction and the serum bilirubin level. In this study, the serum total bilirubin levels of patients with erectile dysfunction were measured to investigate the relationship between the levels of erectile dysfunction and total bilirubin. A total of 94 patients with erectile dysfunction were divided into three groups; severe erectile dysfunction (33 patients), moderate erectile dysfunction (31 patients), and mild erectile dysfunction (30 patients). In addition, a control group was formed with 31 healthy men. The International Index of Erectile Function-5 Questionnaire was used to measure the quality of erection in all the groups. The body mass index was calculated for all the participants. The serum glucose, low-density lipoprotein and high-density lipoprotein, cholesterol, triglyceride, total bilirubin, and total testosterone levels were also determined. No statistically significant difference was observed between the groups in terms of the mean age, hypertension, smoking status, alcohol use, cardiovascular diseases, hepatobiliary disease, diabetes mellitus, and levels of total testosterone, low-density lipoprotein-cholesterol, and triglyceride. However, high-density lipoprotein, body mass index, and total bilirubin were significantly lower compared to the control group (p < 0.001). The serum total bilirubin level was found to be 0.41 ± 0.21 ng/dL in the severe erectile dysfunction, 0.43 ± 0.19 ng/dL in the moderate erectile dysfunction, and 0.48 ± 0.11 ng/dL in the mild erectile dysfunction groups (p < 0.001). Considering the significant differences between the erectile dysfunction and control groups in terms of serum total bilirubin levels, a low level of bilirubin may have a role in the etiology of erectile dysfunction.

Relationship between serum bilirubin concentrations and diabetic nephropathy in Shanghai Han's patients with type 1 diabetes mellitus.

Science.gov (United States)

Li, Xu; Zhang, Lei; Chen, Haibing; Guo, Kaifeng; Yu, Haoyong; Zhou, Jian; Li, Ming; Li, Qing; Li, Lianxi; Yin, Jun; Liu, Fang; Bao, Yuqian; Han, Junfeng; Jia, Weiping

2017-03-31

Recent studies highlight a negative association between total bilirubin concentrations and albuminuria in patients with type 2 diabetes mellitus. Our study evaluated the relationship between bilirubin concentrations and the prevalence of diabetic nephropathy (DN) in Chinese patients with type 1 diabetes mellitus (T1DM). A total of 258 patients with T1DM were recruited and bilirubin concentrations were compared between patients with or without diabetic nephropathy. Multiple stepwise regression analysis was used to examine the relationship between bilirubin concentrations and 24 h urinary microalbumin. Binary logistic regression analysis was performed to assess independent risk factors for diabetic nephropathy. Participants were divided into four groups according to the quartile of total bilirubin concentrations (Q1, 0.20-0.60; Q2, 0.60-0.80; Q3, 0.80-1.00; Q4, 1.00-1.90 mg/dL) and the chi-square test was used to compare the prevalence of DN in patients with T1DM. The median bilirubin level was 0.56 (interquartile: 0.43-0.68 mg/dL) in the DN group, significantly lower than in the non-DN group (0.70 [interquartile: 0.58-0.89 mg/dL], P 1). Spearman's correlational analysis showed bilirubin concentrations were inversely correlated with 24 h urinary microalbumin (r = -0.13, P 1.90% to 2.00%. High bilirubin concentrations are independently and negatively associated with albuminuria and the prevalence of DN in patients with T1DM.

Influence of photoisomers in bilirubin determinations on Kodak Ektachem and Hitachi analysers in neonatal specimens study of the contribution of structural and configurational isomers.

Science.gov (United States)

Gulian, J M; Dalmasso, C; Millet, V; Unal, D; Charrel, M

1995-08-01

We compared data obtained with the Kodak Ektachem and Hitachi 717 Analysers and HPLC from 83 neonates under phototherapy. Total bilirubin values determined with the Kodak and Hitachi are in good agreement, but we observed a large discrepancy in the results for conjugated (Kodak) and direct (Hitachi) bilirubin. HPLC revealed that all the samples contained configurational isomers, while only 7.7% and 30.8% contained conjugated bilirubin and structural isomers, respectively. We developed a device for the specific and quantitative production of configurational or structural isomers, by irradiation with blue or green light. In vitro, total bilirubin values are coherent for the routine analysers in the presence of configurational or structural isomers. With configurational isomers, unconjugated bilirubin (Kodak) is lower than total bilirubin (Kodak), and conjugated bilirubin (Kodak) is always equal to zero, so the apparatus gives a false positive response for delta bilirubin. In contrast, the direct bilirubin (Hitachi) is constant. Furthermore, in the presence of structural isomers, unconjugated bilirubin (Kodak) is unexpectedly higher than total bilirubin (Kodak), conjugated bilirubin (Kodak) is proportional to the quantity of these isomers, and direct bilirubin (Hitachi) is constant. The contribution of photoisomers in bilirubin measurements is discussed.

Cell damage by bilirubin and light

International Nuclear Information System (INIS)

Granli, T.

1993-01-01

Large doses of light are given to newborns during phototherapy for hyperbilirubinemia. Tissues containing concentrations of bilirubin almost in the mM range may be subjected to irradiation. Therefore it is of interest to study cellular effects of light and bilirubin on cells. In order to select the optimal wavelength, possible detrimental effects of light on cells must be taken into consideration among a number of other factors. In this study cellular effects of selected wavelengths of blue-green light are compared. It is not clear whether cullular damage occurs in vivo during phototherapy of newborns. Since a possibility exists that some adverse effects are caused by light, one should choose wavelengths where these effects are minimal without loosing therapeutic efficiency. Todays knowledge of the photochemical mechanisms of phototherapy, indicates that short waved light with wavelengths below 450 nm has a low therapeutic effect. The data in this paper indicate that the cellular damage is most severe at short wavelengths, and these should be reduced to a minimum in the spectra of phototherapy lamps. Further studies of possible side effects of phototherapy should be made. 64 refs., 34 figs., 1 tab

Prevalence of Bilirubin Encephalopathy in Calabar, South-South Nigeria: A Five-year Review Study

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Sunny Oteikwu Ochigbo

2016-03-01

Full Text Available Background: Bilirubin encephalopathy is a clinical syndrome, associated with bilirubin toxicity in the central nervous system, resulting in chronic and permanent sequelae. It has been estimated that approximately 60% and 80% of term and preterm newborns develop jaundice in the first week of life, respectively. In the present study, we aimed to determine the prevalence, morbidity, and mortality of bilirubin encephalopathy in the neonatal unit of the University of Calabar Teaching Hospital, Calabar, Nigeria. Methods: In this retrospective, descriptive review, medical records of all newborns, diagnosed with bilirubin encephalopathy over the past five years (from January 2010 to December 2014, were studied. Information retrieved from the medical records included age, sex, presence of fever, duration of disease, place of delivery, causes of the disease, and selected treatments. Variables such as hospital discharge, discharge against medical advice, and mortality were also evaluated. Results: Out of 2,820 newborns, 21 (0.74% cases were admitted on account of bilirubin encephalopathy. Among these affected cases, 17 (81% were male and 4 (19% were female (male-to-female ratio of 5:1. Based on the findings, 18 newborns (85.7% had pyrexia, while 8 (38.1% and 6 (28.6% cases were hypertonic and hypotonic, respectively upon admission. Only 33.3% of deliveries took place in healthcare facilities. The established factors responsible for jaundice included infection, i.e., septicemia (n=15, 71.4%, ABO incompatibility (n=4, 19.1%, and glucose-6-phosphate-dehydrogenase (G6PD deficiency (n=2, 9.5%. The mean maximum total bilirubin level in subjects was 321.3 μmol/L (range: 242.5–440.3 μmol/L. Also, mortality was reported in 4 (19% out of 21 cases. Conclusion: Based on the findings, neonatal septicemia is associated with bilirubin encephalopathy. Therefore, identification and prompt treatment are of utmost importance in preventing the associated morbidity and

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

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Min Du

2016-12-01

Full Text Available 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.

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

Directory of Open Access Journals (Sweden)

Levitt DG

2014-09-01

Full Text Available David G Levitt,1 Michael D Levitt2 1Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA; 2Research Service, Veterans Affairs Medical Center, Minneapolis, MN, USAAbstract: 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.Keywords: liver, conjugation, diazo, albumin, Rotor

Can Excess Bilirubin Levels Cause Learning Difficulties?

Science.gov (United States)

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…

Optical absorption in recycled waste plastic polyethylene

Science.gov (United States)

Aji, M. P.; Rahmawati, I.; Priyanto, A.; Karunawan, J.; Wati, A. L.; Aryani, N. P.; Susanto; Wibowo, E.; Sulhadi

2018-03-01

We investigated the optical properties of UV spectrum absorption in recycled waste plastic from polyethylene polymer type. Waste plastic polyethylene showed an optical spectrum absorption after it’s recycling process. Spectrum absorption is determined using spectrophotometer UV-Nir Ocean Optics type USB 4000. Recycling method has been processed using heating treatment around the melting point temperature of the polyethylene polymer that are 200°C, 220°C, 240°C, 260°C, and 280°C. In addition, the recycling process was carried out with time variations as well, which are 1h, 1.5h, 2h, and 2.5h. The result of this experiment shows that recycled waste plastic polyethylene has a spectrum absorption in the ∼ 340-550 nm wavelength range. The absorbance spectrum obtained from UV light which is absorbed in the orbital n → π* and the orbital π → π*. This process indicates the existence of electron transition phenomena. This mechanism is affected by the temperature and the heating time where the intensity of absorption increases and widens with the increase of temperature and heating time. Furthermore this study resulted that the higher temperature affected the enhancement of the band gap energy of waste plastic polyethylene. These results show that recycled waste plastic polyethylene has a huge potential to be absorber materials for solar cell.

Thyroid hormone uptake in cultured rat anterior pituitary cells: effects of energy status and bilirubin

NARCIS (Netherlands)

F.W.J.S. Wassen (Frank); E.P.C.M. Moerings (Ellis); H. van Toor (Hans); G. Hennemann; M.E. Everts (Maria)

2000-01-01

textabstractTransport of thyroxine (T(4)) into the liver is inhibited in fasting and by bilirubin, a compound often accumulating in the serum of critically ill patients. We tested the effects of chronic and acute energy deprivation, bilirubin and its precursor

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

Science.gov (United States)

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 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.

Efficacy of Human Adipose Tissue-Derived Stem Cells on Neonatal Bilirubin Encephalopathy in Rats.

Science.gov (United States)

Amini, Naser; Vousooghi, Nasim; Hadjighassem, Mahmoudreza; Bakhtiyari, Mehrdad; Mousavi, Neda; Safakheil, Hosein; Jafari, Leila; Sarveazad, Arash; Yari, Abazar; Ramezani, Sara; Faghihi, Faezeh; Joghataei, Mohammad Taghi

2016-05-01

Kernicterus is a neurological syndrome associated with indirect bilirubin accumulation and damages to the basal ganglia, cerebellum and brain stem nuclei particularly the cochlear nucleus. To mimic haemolysis in a rat model such that it was similar to what is observed in a preterm human, we injected phenylhydrazine in 7-day-old rats to induce haemolysis and then infused sulfisoxazole into the same rats at day 9 to block bilirubin binding sites in the albumin. We have investigated the effectiveness of human adiposity-derived stem cells as a therapeutic paradigm for perinatal neuronal repair in a kernicterus animal model. The level of total bilirubin, indirect bilirubin, brain bilirubin and brain iron was significantly increased in the modelling group. There was a significant decreased in all severity levels of the auditory brainstem response test in the two modelling group. Akinesia, bradykinesia and slip were significantly declined in the experience group. Apoptosis in basal ganglia and cerebellum were significantly decreased in the stem cell-treated group in comparison to the vehicle group. All severity levels of the auditory brainstem response tests were significantly decreased in 2-month-old rats. Transplantation results in the substantial alleviation of walking impairment, apoptosis and auditory dysfunction. This study provides important information for the development of therapeutic strategies using human adiposity-derived stem cells in prenatal brain damage to reduce potential sensori motor deficit.

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

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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

Serum bilirubin value predicts hospital admission in carbon monoxide-poisoned patients. Active player or simple bystander?

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Gianfranco Cervellin

Full Text Available OBJECTIVES: Although carbon monoxide poisoning is a major medical emergency, the armamentarium of recognized prognostic biomarkers displays unsatisfactory diagnostic performance for predicting cumulative endpoints. METHODS: We performed a retrospective and observational study to identify all patients admitted for carbon monoxide poisoning during a 2-year period. Complete demographical and clinical information, along with the laboratory data regarding arterial carboxyhemoglobin, hemoglobin, blood lactate and total serum bilirubin, was retrieved. RESULTS: The study population consisted of 38 poisoned patients (23 females and 15 males; mean age 39±21 years. Compared with discharged subjects, hospitalized patients displayed significantly higher values for blood lactate and total serum bilirubin, whereas arterial carboxyhemoglobin and hemoglobin did not differ. In a univariate analysis, hospitalization was significantly associated with blood lactate and total serum bilirubin, but not with age, sex, hemoglobin or carboxyhemoglobin. The diagnostic performance obtained after combining the blood lactate and total serum bilirubin results (area under the curve, 0.90; 95% CI, 0.81-0.99; p<0.001 was better than that obtained for either parameter alone. CONCLUSION: Although it remains unclear whether total serum bilirubin acts as an active player or a bystander, we conclude that the systematic assessment of bilirubin may, alongside lactate levels, provide useful information for clinical decision making regarding carbon monoxide poisoning.

The use of molecular dynamics to simulate the temperature dependence of the calculated absorption spectrum for Nd3+ :YAG

International Nuclear Information System (INIS)

Klintenberg, M.; Thomas, J.O.; Edvardsson, S.

1998-01-01

Full text: We have previously shown that the use of molecular dynamics (MD) and the inclusion of configuration interaction (CI) effects are important when simulating polarized absorption spectra for rare-earth doped compounds. In this work, we focus on how well the MD approach can account for the temperature dependence of the calculated absorption spectrum for Nd 3+ :YAG (yttrium aluminium garnet), using the standard MD pair-potential of the Born-Mayer-Huggins form. All simulated spectra are compared to the corresponding experimental spectra. The results indicate that the simple pair-potential must be replaced by a many-body potential to describe the motion of the ions sufficiently accurately

Intracellular distribution of organic anions (131I-BSP and 3H-bilirubin)

International Nuclear Information System (INIS)

Kamisaka, Kazuaki; Iida, Yoshitaka; Azegami, Nobuhisa; Oda, Hiroyuki; Maezawa, Hidenori

1981-01-01

About 2 μ Ci of 131 I-BSP were injected intravenously into normal wister rats and the distributions of the isotope were determined in subcellular fractions of rat liver by the method of De Duve et al. Approximately 33% of the total activity was localized in nuclear fraction and cell debris, 28.5% was in supernatant fraction, 16.5% in microsome, 13% in lysosome and 8% in mitochondrial fraction. The subcellular distributions of radioactivity remained unchanged for 1.5 hours. Using autoradiographic method, the intracellular distribution of 3 H-bilirubin was examined by the extracted liver, 5 min, after intravenous injection of 3 H-bilirubin. 3 H-bilirubin was localized mainly in the cytoplasm and small amounts was already distributed on the canalicular membrane. It is suggested that these small molecules are mainly transported through cytoplasm and there is no specific pathway for the hepatic intracellular transport system. (author)

Bilirubin: an endogenous molecule with antiviral activity in vitro.

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Rosaria eSantangelo

2012-03-01

Full Text Available Bilirubin-IX-alpha (BR is the final product of heme metabolism through the heme oxygenase/biliverdin reductase (HO/BVR system. Previous papers reported on the microbicidal effects of the HO by-products biliverdin-IX-alpha, carbon monoxide and iron, through either direct or indirect mechanisms. In this paper the evidence of a virucidal effect of BR against human herpes simplex virus type 1 (HSV-1 and the enterovirus EV71 was provided. Bilirubin-IX-alpha, at concentrations 1-10 µM, close to those found in blood and tissues, significantly reduced HSV-1 and EV71 replication in Hep-2 and Vero cell lines, respectively. Bilirubin-IX-alpha inhibited viral infection of Hep-2 and Vero cells when given 2 hours before, concomitantly and 2 hours after viral infection. Furthermore, BR retained its antiviral activity even complexed with a saturating concentration of human serum-albumin. Moreover, 10 µM BR increased the formation of nitric oxide and the phosphorylation of JNK in Vero and Hep-2 cell lines, respectively, thus implying a role of these two pathways in the mechanism of antiviral activity of the bile pigment. In conclusion, these results support the antiviral effect of BR against HSV-1 and enterovirus in vitro, and put the basis for further basic and clinical studies to understand the real role of BR as an endogenous antiviral molecule.

Bilirubin nanoparticles ameliorate allergic lung inflammation in a mouse model of asthma.

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Kim, Dong Eon; Lee, Yonghyun; Kim, MinGyo; Lee, Soyoung; Jon, Sangyong; Lee, Seung-Hyo

2017-09-01

Although asthma, a chronic inflammatory airway disease, is relatively well-managed by inhaled corticosteroids, the side effects associated with the long-term use of these agents precipitate the need for alternative therapeutic options based on differing modes of action. Bilirubin, a potent endogenous antioxidant, and anti-inflammatory molecule have been shown to ameliorate asthmatic symptoms; however, its clinical translation has been limited owing to its water insolubility and associated potential toxicity. Here we report the first application of bilirubin-based nanoparticles (BRNPs) as a nanomedicine for the treatment of allergic lung inflammatory disease. BRNPs were prepared directly from self-assembly of PEGylated bilirubin in aqueous solution and had a hydrodynamic diameter of ∼100 nm. Because allergen-specific type 2 T-helper (Th2) cells play a key role in the pathogenesis and progression of allergic asthma, the effects of BRNPs on Th2 immune responses were investigated both in vivo and in vitro. BRNPs after intravenous injection (i.v.) showed much higher serum concentration and a longer circulation time of bilirubin than the intraperitoneal injection (i.p.) of BRNPs or unconjugated bilirubin (UCB). The anti-asthmatic effects of BRNPs were assessed in a mouse model of allergen-induced asthma. Compared with UCB, treatment with BRNPs suppressed the symptoms of experimental allergic asthma and dramatically ameliorated Th2-related allergic lung inflammation. Consistent with these results, BRNPs caused a reduction of Th2 cell populations and the expression of related cytokines by antibody-stimulated CD4 + T cells in vitro. Therefore, our results establish BRNPs as an important immunomodulatory agent that may be useful as a therapeutic for allergic lung inflammatory disease and other immune-mediated disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Luminescence and optical absorption determination in porous silicon

International Nuclear Information System (INIS)

Nogal, U.; Calderon, A.; Marin, E.; Rojas T, J. B.; Juarez, A. G.

2012-10-01

We applied the photoacoustic spectroscopy technique in order to obtain the optical absorption spectrum in porous silicon samples prepared by electrochemical anodic etching on n-type, phosphorous doped, (100)-oriented crystal-line silicon wafer with thickness of 300 μm and 1-5 ωcm resistivity. The porous layers were prepared with etching times of 13, 20, 30, 40 and 60 minutes. Also, we realized a comparison among the optical absorption spectrum with the photoluminescence and photo reflectance ones, both obtained at room temperature. Our results show that the absorption spectrum of the samples of porous silicon depends notably of the etching time an it consist of two distinguishable absorption bands, one in the Vis region and the other one in the UV region. (Author)

Analysis of Urobilinogen and Urine Bilirubin for Intra-Abdominal Injury in Blunt Trauma Patients

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Gorchynski, Julie

2009-05-01

Full Text Available OBJECTIVE: To determine the point prevalence of urine bilirubin, urine hemoglobin and urobilinogen in blunt trauma patients, and to evaluate its utility as a screening tool for intra-abdominal injury.METHODS: Data analysis of 986 consecutive trauma patients of which 698 were adult blunt trauma patients. Five-hundred sixteen subjects had a urinalysis and a CT scan of the abdomen/pelvis or exploratory laparotomy. We reviewed initial urinalysis results from trauma patients in the emergency department (ED for the presence of urine hemoglobin, uroblinogen and urine bilirubin. Computed tomography (CT scan results and operative reports were reviewed from the trauma registry for evidence of liver laceration, spleen laceration, bowel or mesenteric injuries.RESULTS: There were 73 injuries and 57/516 patients (11% with intra-abdominal injury. Urinalysis was positive for urobilinogen in 28/516 (5.4% patients, urine bilirubin in 15/516 (2.9% patients and urine hemoglobin in 313/516 (61% patients. Nineteen/forty-seven (4% subjects had liver lacerations, 28/56 (5% splenic lacerations, and 15/5 (3% bowel or mesenteric injury. Comparing the proportion of patients that had urobilinogen detected in the group with and without intra-abdominal injury, 8/28 (29% subjects with urobilinogen, 5/15 (33% subjects with bilirubin and 47/313 (15% subjects with urine hemoglobin were found to have liver lacerations, spleen lacerations, or bowel/mesenteric injuries. Preexisting liver or biliary conditions were not statistically associated with elevation of urine bilirubin, urine hemoglobin or urobilinogen on initial urinalysis after blunt abdominal trauma. Point prevalence for urobilinogen, urine bilirubin and urine hemoglobin are 5.43% (28/516, 2.91% (15/516 and 60.7% (313/516 respectively.CONCLUSIONS: The utility of the initial routine urinalysis in the ED for adult blunt abdominal trauma patients should not be used as a screening tool for the evaluation of intra

Analysis of urobilinogen and urine bilirubin for intra-abdominal injury in blunt trauma patients.

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Gorchynski, Julie; Dean, Kevin; Anderson, Craig L

2009-05-01

To determine the point prevalence of urine bilirubin, urine hemoglobin and urobilinogen in blunt trauma patients, and to evaluate its utility as a screening tool for intra-abdominal injury. Data analysis of 986 consecutive trauma patients of which 698 were adult blunt trauma patients. Five-hundred sixteen subjects had a urinalysis and a CT scan of the abdomen/pelvis or exploratory laparotomy. We reviewed initial urinalysis results from trauma patients in the emergency department (ED) for the presence of urine hemoglobin, uroblinogen and urine bilirubin. Computed tomography (CT) scan results and operative reports were reviewed from the trauma registry for evidence of liver laceration, spleen laceration, bowel or mesenteric injuries. There were 73 injuries and 57/516 patients (11%) with intra-abdominal injury. Urinalysis was positive for urobilinogen in 28/516 (5.4%) patients, urine bilirubin in 15/516 (2.9%) patients and urine hemoglobin in 313/516 (61%) patients. Nineteen/forty-seven (4%) subjects had liver lacerations, 28/56 (5%) splenic lacerations, and 15/5 (3%) bowel or mesenteric injury. Comparing the proportion of patients that had urobilinogen detected in the group with and without intra-abdominal injury, 8/28 (29%) subjects with urobilinogen, 5/15 (33%) subjects with bilirubin and 47/313 (15%) subjects with urine hemoglobin were found to have liver lacerations, spleen lacerations, or bowel/mesenteric injuries. Preexisting liver or biliary conditions were not statistically associated with elevation of urine bilirubin, urine hemoglobin or urobilinogen on initial urinalysis after blunt abdominal trauma. Point prevalence for urobilinogen, urine bilirubin and urine hemoglobin are 5.43% (28/516), 2.91% (15/516) and 60.7% (313/516) respectively. The utility of the initial routine urinalysis in the ED for adult blunt abdominal trauma patients should not be used as a screening tool for the evaluation of intra-abdominal injury.

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

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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…

Studies on the kinetics of unconjugated [14C]bilirubin metabolism in normal subjects and patients with compensated cirrhosis

International Nuclear Information System (INIS)

Owens, D.; Jones, E.A.; Carson, E.R.

1977-01-01

The kinetics of unconjugated 14 C-bilirubin metabolism have been investigated and analysed in terms of a three-pool model in a group of seven normal subjects and in a group of eight cirrhotic patients who had appreciable impairment of liver cell function. The results indicate that, in patients with compensated cirrhosis, the efficiency of the liver in extracting unconjugated bilirubin from plasma against a concentration gradient is impaired, even though the liver's capacity to conjugate bilirubin may be normal. As a consequence of the increased volume of distribution, the absolute hepatic clearance of unconjugated bilirubin is relatively well maintained. (author)

Pulse radiolysis investigations on the oxidation of bilirubin by chlorinated peroxyl radicals (Preprint No. RC.18)

International Nuclear Information System (INIS)

Mohan, Hari; Gopinathan, C.

1989-01-01

Chlorinated peroxyl radicals were observed to oxidize bilirubin. The rate constants, estimated from the formation kinetics of bilirubin cation, were observed to decrease with decrease in the chlorine substitution of various chlorinated peroxyl radicals. (author)

Significance of change in serum bilirubin in predicting left ventricular reverse remodeling and outcomes in heart failure patients with cardiac resynchronization therapy.

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Hosoda, Junya; Ishikawa, Toshiyuki; Matsumoto, Katsumi; Iguchi, Kohei; Matsushita, Hirooki; Ogino, Yutaka; Taguchi, Yuka; Sugano, Teruyasu; Ishigami, Tomoaki; Kimura, Kazuo; Tamura, Kouichi

2017-11-01

Research on the correlation of serum bilirubin level with cardiac function as well as outcomes in heart failure patients with cardiac resynchronization therapy (CRT) has not yet been reported. The aim of this study was to analyze the relationship between change in serum bilirubin level and left ventricular reverse remodeling, and also to clarify the impact of bilirubin change on clinical outcomes in CRT patients. We evaluated 105 consecutive patients who underwent CRT. Patients who had no serum total-bilirubin data at both baseline and 3-9 months' follow-up or had died less than 3 months after CRT implantation were excluded. Accordingly, a total of 69 patients were included in the present analysis. The patients were divided into two groups: decreased bilirubin group (serum total-bilirubin level at follow-up≤that at baseline; n=48) and increased bilirubin group (serum total-bilirubin level at follow-up>that at baseline; n=21). Mean follow-up period was 39.3 months. In the decreased bilirubin group, mean left ventricular end-systolic diameter decreased from 54.5mm to 50.2mm (p=0.001) and mean left ventricular ejection fraction increased significantly from 29.8% to 37.0% (p=0.001). In the increased bilirubin group, there was no significant change in echocardiographic parameters from baseline to follow-up. In Kaplan-Meyer analysis, cardiac mortality combined with heart failure hospitalization in the increased bilirubin group was significantly higher than that in the decreased bilirubin group (log-rank p=0.018). Multivariate Cox regression analysis revealed that increased bilirubin was an independent predictor of cardiac mortality combined with heart failure hospitalization (OR=2.66, p=0.023). The change in serum bilirubin is useful for assessment of left ventricular reverse remodeling and prediction of outcomes in heart failure patients with CRT. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

A product of heme catabolism modulates bacterial function and survival.

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Christopher L Nobles

Full Text Available Bilirubin is the terminal metabolite in heme catabolism in mammals. After deposition into bile, bilirubin is released in large quantities into the mammalian gastrointestinal (GI tract. We hypothesized that intestinal bilirubin may modulate the function of enteric bacteria. To test this hypothesis, we investigated the effect of bilirubin on two enteric pathogens; enterohemorrhagic E. coli (EHEC, a Gram-negative that causes life-threatening intestinal infections, and E. faecalis, a Gram-positive human commensal bacterium known to be an opportunistic pathogen with broad-spectrum antibiotic resistance. We demonstrate that bilirubin can protect EHEC from exogenous and host-generated reactive oxygen species (ROS through the absorption of free radicals. In contrast, E. faecalis was highly susceptible to bilirubin, which causes significant membrane disruption and uncoupling of respiratory metabolism in this bacterium. Interestingly, similar results were observed for other Gram-positive bacteria, including B. cereus and S. aureus. A model is proposed whereby bilirubin places distinct selective pressure on enteric bacteria, with Gram-negative bacteria being protected from ROS (positive outcome and Gram-positive bacteria being susceptible to membrane disruption (negative outcome. This work suggests bilirubin has differential but biologically relevant effects on bacteria and justifies additional efforts to determine the role of this neglected waste catabolite in disease processes, including animal models.

Theoretical study of the absorption spectrum and the thermochemistry of the CF{sub 3}OSO{sub 3} radical

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Cobos, Carlos J.; Croce, Adela E. [Inst. de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Univ. Nacional de La Plata, CCT La Plata-CONICET (Argentina)

2010-08-15

The UV-visible absorption spectrum of the recently reported CF{sub 3}OSO{sub 3} radical has been studied by using the time-dependent generalization of the density functional theory (TDDFT). For this a set of eleven hybrid functionals combined with the 6-311+G(3df) basis set were employed. The main features of the three experimental absorption bands of CF{sub 3}OSO{sub 3} recorded over the 220-530 nm range are well reproduced by the calculations. A dissociation enthalpy for the CF{sub 3}OSO{sub 3} bond of 19.1 kcal mol{sup -1} is predicted at the BAC-G3MP2//B3LYP/6-311+G(3df) level of theory. (orig.)

Association Of Serum Total Bilirubin Level With Diabetic Retinopathy In Type 2 Diabetes Mellitus.

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Ghaffar, Tahir; Marwat, Zahid Irfan; Ullah, Fahim; Khan, Salman; Hassan Aamir, Aziz Ul

2016-01-01

Serum bilirubin has anti-inflammatory, antioxidant and immunological properties. It is considered a protective substance against atherosclerotic and microvascular complications of diabetes mellitus (DM). This study was designed to find the association between total serum bilirubin concentration and diabetic retinopathy (DR). This case control study was conducted in the Department of Endocrinology, Diabetes and Metabolic Diseases, Hayatabad Medical Complex, Peshawar. Type-2 DM patients more than 18 years of age of either gender with duration of T2DM more than 6 months were included and sub categorized in two groups. Cases (DM with DR) and Controls (DM without DR) while patients with acute and chronic liver diseases, haemolytic anaemia, history of chronic alcohol consumption, use of hepatotoxic drugs (anti-tuberculous, anti-epileptic), women on oral contraceptive pills were excluded. All participants underwent ophthalmic examination at diabetic retinopathy screening clinic followed by pre designed set of investigations. A total of 152 patients, 76 cases and 76 controls were included. Serum bilirubin concentration was found inversely and independently (p 0.000) associated and inversely co related (r -0.345and p 0.000) with prevalence of DR. Cases were concentrated in the lower quartiles of serum bilirubin concentration and vice versa. Low haemoglobin (p 0.00) and longer duration of DM (0.003) were independently and directly associated with prevalence of DR. Serum bilirubin concentration is inversely and independently associated and inversely correlated with the prevalence of DR and may predict progression of DR over time.

The influence of bilirubin, haemolysis and turbidity on 20 analytical tests performed on automatic analysers. Results of an interlaboratory study.

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Grafmeyer, D; Bondon, M; Manchon, M; Levillain, P

1995-01-01

The director of a laboratory has to be sure to give out reliable results for routine tests on automatic analysers regardless of the clinical context. However, he may find hyperbilirubinaemia in some circumstances, parenteral nutrition causing turbidity in others, and haemolysis occurring if sampling is difficult. For this reason, the Commission for Instrumentation of the Société Française de Biologie Clinique (SFBC) (president Alain Feuillu) decided to look into "visible" interferences--bilirubin, haemolysis and turbidity--and their effect on 20 major tests: 13 substrates/chemistries: albumin, calcium, cholesterol, creatinine, glucose, iron, magnesium, phosphorus, total bilirubin, total proteins, triacylglycerols, uric acid, urea, and 7 enzymatic activities: alkaline phosphatase, alanine aminotransferase, alpha-amylase, aspartate aminotransferase, creatine kinase, gamma-glutamyl transferase and lactate dehydrogenase measured on 15 automatic analysers representative of those found on the French market (Astra 8, AU 510, AU 5010, AU 5000, Chem 1, CX 7, Dax 72, Dimension, Ektachem, Hitachi 717, Hitachi 737, Hitachi 747, Monarch, Open 30, Paramax, Wako 30 R) and to see how much they affect the accuracy of results under routine conditions in the laboratory. The study was carried out following the SFBC protocol for the validation of techniques using spiked plasma pools with bilirubin, ditauro-bilirubin, haemoglobin (from haemolysate) and Intralipid (turbidity). Overall, the following results were obtained: haemolysis affects tests the most often (34.5% of cases); total bilirubin interferes in 21.7% of cases; direct bilirubin and turbidity seem to interfere less at around 17%. The different tests are not affected to the same extent; enzyme activity is hardly affected at all; on the other hand certain major tests are extremely sensitive, increasingly so as we go through the following: creatinine (interference of bilirubin), triacylglycerols (interference of bilirubin and

Derivation of water vapour absorption cross-sections in the red region

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Lal, M.; Chakrabarty, D. K.

1994-01-01

Absorption spectrum in 436 to 448 nm wavelength region gives NO2 and O3 column densities. This spectrum can also give H2O column density. The spectrum in the range of 655 to 667 nm contains absorption due to NO3 and H2O. Combining the absorption spectra in the wavelength ranges of 436 to 448 and 655 to 667 nm, water vapor absorption cross-sections in this range comes out to be of the order of 2.0 x 10(exp -24) cm(exp -2).

Evaluation of 99mTc-Mercaptoacetyltriglycine-Biocytin as a new hepatobiliary imaging agent in mice coinjected with bilirubin

International Nuclear Information System (INIS)

Kim, Meyoung-kon; Seidel, Juergen; Le Nhat; Kim, In-Sook; Yoo, Tae-Moo; Barker, Craig; Kobayashi, Hisataka; Green, Michael V.; Carrasquillo, Jorge A.; Paik, Chang H.

1999-01-01

We evaluated 99m Tc-labeled mercaptoacetyltriglycine ( 99m Tc-MAG3)-biocytin as a hepatobiliary imaging agent in the absence and presence of bilirubin in mice. We then compared its pharmacokinetic parameters; peak liver/heart activity ratio (r max ) and half clearance time (HCT) with those of 99m Tc-labeled diisopropyl-iminodiacetic acid ( 99m Tc-disofenin). Balb/c mice were injected intravenously with hepatobiliary agent ( 99m Tc-MAG3-biocytin or 99m Tc-disofenin) alone or in combination with bilirubin at two doses (7 and 14 mg/kg) dissolved in 5% human serum albumin. Images were acquired every 15 s for 30 min with a gamma-camera equipped with a pinhole collimator. Dynamic images showed rapid hepatic uptake of 99m Tc-MAG3-biocytin, with rapid clearance from the blood and rapid excretion via the biliary system. Its hepatic uptake was not affected by bilirubin coinjection, whereas 99m Tc-disofenin coinjected with bilirubin showed a higher blood background than 99m Tc-disofenin alone. These qualitative findings were reflected in pharmacokinetic parameters, r max and HCT. The r max was obtained from plots of time versus liver/heart activity ratios obtained in equal-area regions of interest over the heart and liver. The HCT was calculated from the hepatic clearance curve from plots of time versus liver activity. 99m Tc-MAG3-biocytin without bilirubin coinjection showed an r max of 8.9±1.3 and an HCT of 399±36 s. These values did not change even when 14 mg/kg of bilirubin were coinjected. By contrast, the parameters for 99m Tc-disofenin with bilirubin were significantly (p max was decreased from 7.9±2.5 to 1.4±0.2 and HCT was increased from 292±32 s to 782±133 s. 99m Tc-MAG3-biocytin hepatobiliary scintigraphy in mice is not affected by bilirubin coinjection, and this hepatobiliary agent appears to offer promise for estimating hepatic function in patients with high bilirubin levels

Electrochemical Sensor for Bilirubin Detection Using Screen Printed Electrodes Functionalized with Carbon Nanotubes and Graphene

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Madasamy Thangamuthu

2018-03-01

Full Text Available Practice oriented point-of-care diagnostics require easy-to-handle, miniaturized, and low-cost analytical tools. In a novel approach, screen printed carbon electrodes (SPEs, which were functionalized with nanomaterials, are employed for selective measurements of bilirubin, which is an important biomarker for jaundice. Multi-walled carbon nanotubes (MWCNT and graphene separately deposited on SPEs provide the core of an electrochemical sensor for bilirubin. The electrocatalytic activity towards bilirubin oxidation (bilirubin to biliverdin was observed at +0.25 V. In addition, a further peak corresponding to the electrochemical conversion of biliverdin into purpurin appeared at +0.48 V. When compared to MWCNT, the graphene type shows a 3-fold lower detection limit (0.3 ± 0.022 nM and 0.1 ± 0.018 nM, respectively, moreover, the graphene type exhibits a larger linear range (0.1–600 µM than MWCNT (0.5–500 µM with a two-fold better sensitivity, i.e., 30 nA µM−1 cm−2, and 15 nA µM−1 cm−2, respectively. The viability is validated through measurements of bilirubin in blood serum samples and the selectivity is ensured by inhibiting common interfering biological substrates using an ionic nafion membrane. The presented approach enables the design and implementation of low cost and miniaturized electrochemical sensors.

Electrochemical Sensor for Bilirubin Detection Using Screen Printed Electrodes Functionalized with Carbon Nanotubes and Graphene.

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Thangamuthu, Madasamy; Gabriel, Willimann Eric; Santschi, Christian; Martin, Olivier J F

2018-03-07

Practice oriented point-of-care diagnostics require easy-to-handle, miniaturized, and low-cost analytical tools. In a novel approach, screen printed carbon electrodes (SPEs), which were functionalized with nanomaterials, are employed for selective measurements of bilirubin, which is an important biomarker for jaundice. Multi-walled carbon nanotubes (MWCNT) and graphene separately deposited on SPEs provide the core of an electrochemical sensor for bilirubin. The electrocatalytic activity towards bilirubin oxidation (bilirubin to biliverdin) was observed at +0.25 V. In addition, a further peak corresponding to the electrochemical conversion of biliverdin into purpurin appeared at +0.48 V. When compared to MWCNT, the graphene type shows a 3-fold lower detection limit (0.3 ± 0.022 nM and 0.1 ± 0.018 nM, respectively), moreover, the graphene type exhibits a larger linear range (0.1-600 µM) than MWCNT (0.5-500 µM) with a two-fold better sensitivity, i.e., 30 nA µM -1 cm -2 , and 15 nA µM -1 cm -2 , respectively. The viability is validated through measurements of bilirubin in blood serum samples and the selectivity is ensured by inhibiting common interfering biological substrates using an ionic nafion membrane. The presented approach enables the design and implementation of low cost and miniaturized electrochemical sensors.

Significance and prognostic value of increased serum direct bilirubin level for lymph node metastasis in Chinese rectal cancer patients.

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Gao, Chun; Fang, Long; Li, Jing-Tao; Zhao, Hong-Chuan

2016-02-28

To determine the significance of increased serum direct bilirubin level for lymph node metastasis (LNM) in Chinese rectal cancer patients, after those with known hepatobiliary and pancreatic diseases were excluded. A cohort of 469 patients, who were treated at the China-Japan Friendship Hospital, Ministry of Health (Beijing, China), in the period from January 2003 to June 2011, and with a pathological diagnosis of rectal adenocarcinoma, were recruited. They included 231 patients with LNM (49.3%) and 238 patients without LNM. Follow-up for these patients was taken through to December 31, 2012. The baseline serum direct bilirubin concentration was (median/inter-quartile range) 2.30/1.60-3.42 μmol/L. Univariate analysis showed that compared with patients without LNM, the patients with LNM had an increased level of direct bilirubin (2.50/1.70-3.42 vs 2.10/1.40-3.42, P = 0.025). Multivariate analysis showed that direct bilirubin was independently associated with LNM (OR = 1.602; 95%CI: 1.098-2.338, P = 0.015). Moreover, we found that: (1) serum direct bilirubin differs between male and female patients; a higher concentration was associated with poor tumor classification; (2) as the baseline serum direct bilirubin concentration increased, the percentage of patients with LNM increased; and (3) serum direct bilirubin was associated with the prognosis of rectal cancer patients and higher values indicated poor prognosis. Higher serum direct bilirubin concentration was associated with the increased risk of LNM and poor prognosis in our rectal cancers.

Antioxidant status of serum bilirubin and uric acid in patients with polymyositis and dermatomyositis.

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Chen, Zhibo; Su, Zhongqian; Pang, Wanhui; Huang, Yuanyuan; Lin, Jie; Ding, Zhangna; Wu, Senmin; Xu, Shunyao; Quan, Weiwei; Zheng, Juzeng; Chen, Huale; Li, Zhengzheng; Li, Xiang; Li, Jia; Weng, Yiyun; Zhang, Xu

2017-07-01

Oxidative stress and variations in antioxidant status are implicated in the pathogenesis of inflammatory and autoimmune diseases. Polymyositis and dermatomyositis (PM/DM) are autoimmune diseases with inflammatory cells infiltrating into skeletal muscles, and the antioxidant status is still controversial. The aim of our study was to investigate the correlation between PM/DM and the antioxidant status of serum bilirubin (Tbil, Dbil and Ibil) and uric acid (UA). We measured serum concentrations of bilirubin (Tbil, Dbil and Ibil) and uric acid in 384 individuals, including 110 PM/DM patients and 274 healthy controls. We found that PM/DM patients had significantly lower serum concentrations of bilirubin (Tbil and Ibil) and uric acid than healthy controls, whether male or female. Also, after separately adjusting the covariances of age and gender, Tbil, Dbil, Ibil and UA were all relevant factors for PM/DM. Moreover, there were no significant differences in serum antioxidant molecule levels between PM and DM subgroups. Our study demonstrated the low serum levels of bilirubin and uric acid in patients with PM/DM. This suggested low antioxidant status in PM/DM patients with excessive oxidative stress.

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

Science.gov (United States)

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 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.

Association of serum total bilirubin level with diabetic retinopathy in type 2 diabetes mellitus

International Nuclear Information System (INIS)

Ghaffar, T.; Khan, S.; Aamir, A.U.H.; Marwat, Z.I.

2016-01-01

Serum bilirubin has anti-inflammatory, antioxidant and immunological properties. It is considered a protective substance against atherosclerotic and microvascular complications of diabetes mellitus (DM). This study was designed to find the association between total serum bilirubin concentration and diabetic retinopathy (DR). Methods: This case control study was conducted in the Department of Endocrinology, Diabetes and Metabolic Diseases, Hayatabad Medical Complex, Peshawar. Type-2 DM patients more than 18 years of age of either gender with duration of T2DM more than 6 months were included and sub categorized in two groups. Cases (DM with DR) and Controls (DM without DR) while patients with acute and chronic liver diseases, haemolytic anaemia, history of chronic alcohol consumption, use of hepatotoxic drugs (anti-tuberculous, anti-epileptic), women on oral contraceptive pills were excluded. All participants underwent ophthalmic examination at diabetic retinopathy screening clinic followed by pre designed set of investigations. Results: A total of 152 patients, 76 cases and 76 controls were included. Serum bilirubin concentration was found inversely and independently (p 0.000) associated and inversely co related (r -0.345 and p 0.000) with prevalence of DR. Cases were concentrated in the lower quartiles of serum bilirubin concentration and vice versa. Low haemoglobin (p 0.00) and longer duration of DM (0.003) were independently and directly associated with prevalence of DR. Conclusion: Serum bilirubin concentration is inversely and independently associated and inversely correlated with the prevalence of DR and may predict progression of DR over time. (author)

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

Science.gov (United States)

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.

Persistent high serum bilirubin level after percutaneous transhepatic biliary drainage: analysis of 32 cases

International Nuclear Information System (INIS)

Choo, In Wook; Choi, Byung Ihn; Park, Jae Hyung; Han, Man Chung; Kim, Chu Wan

1986-01-01

The aim of percutaneous transhepatic biliary drainage (PTBD) is to decrease serum bilirubin level and promote liver function in patient with biliary tract disease, especially obstruction by malignant disease. But some patients showed persistent high serum bilirubin level or higher than pre-PTBD level. Percutaneous transhepatic biliary drainage was performed in 341 patients of obstructive jaundice for 5 years form July, 1981 to July, 1986 at department of radiology, Seoul National University Hospital. Follow up check of the serum bilirubin level was possible in 188 patients. Among them the authors analysed 32 patients who showed persistent high serum bilirubin level after PTBD. The results were as follows: 1. The male to female ratio was 3.4:1 and the age ranged from 33 to 75. 2. The causes of obstructive jaundice included 30 malignant diseases and 2 benign diseases. Malignant disease were 16 cases of bile duct carcinoma, 7 cases of pancreatic cancer and 7 cases of metastasis from stomach, colon and uterine cervix. Benign disease were 1 case of common hepatic duct stone and 1 case of intrahepatic duct stones. 3. The most common level of obstruction was trifurcation in 17 cases. 4. The most common indication of PTBD was palliative drainage of obstruction secondary to malignant tumor in 28 cases. 5. Change of serum bilirubin level ratio (post-PTBD level/pre-PTBD level) was 1.28, 1.22, 1.38, 1.51 in serial period of 1-3 days, 4-6 days, 1-2 week 2-3 week after PTBD. 6. Causes of persistent high serum bilirubin level after PTBD were 12 cases of partial drainage of intrahepatic bile, 13 cases of hepatic dysfunction including 9 cases of metastatic nodule, 2 cases of biliary cirrhosis, 2 cases of multiple liver abscess, and 7 cases of poor function of catheter including 4 cases of hemobilia, 1 case of multiple intrahepatic stones, pyobilia and intrahepatic Clonorchis sinensis.

Persistent high serum bilirubin level after percutaneous transhepatic biliary drainage: analysis of 32 cases

Energy Technology Data Exchange (ETDEWEB)

Choo, In Wook; Choi, Byung Ihn; Park, Jae Hyung; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1986-12-15

The aim of percutaneous transhepatic biliary drainage (PTBD) is to decrease serum bilirubin level and promote liver function in patient with biliary tract disease, especially obstruction by malignant disease. But some patients showed persistent high serum bilirubin level or higher than pre-PTBD level. Percutaneous transhepatic biliary drainage was performed in 341 patients of obstructive jaundice for 5 years form July, 1981 to July, 1986 at department of radiology, Seoul National University Hospital. Follow up check of the serum bilirubin level was possible in 188 patients. Among them the authors analysed 32 patients who showed persistent high serum bilirubin level after PTBD. The results were as follows: 1. The male to female ratio was 3.4:1 and the age ranged from 33 to 75. 2. The causes of obstructive jaundice included 30 malignant diseases and 2 benign diseases. Malignant disease were 16 cases of bile duct carcinoma, 7 cases of pancreatic cancer and 7 cases of metastasis from stomach, colon and uterine cervix. Benign disease were 1 case of common hepatic duct stone and 1 case of intrahepatic duct stones. 3. The most common level of obstruction was trifurcation in 17 cases. 4. The most common indication of PTBD was palliative drainage of obstruction secondary to malignant tumor in 28 cases. 5. Change of serum bilirubin level ratio (post-PTBD level/pre-PTBD level) was 1.28, 1.22, 1.38, 1.51 in serial period of 1-3 days, 4-6 days, 1-2 week 2-3 week after PTBD. 6. Causes of persistent high serum bilirubin level after PTBD were 12 cases of partial drainage of intrahepatic bile, 13 cases of hepatic dysfunction including 9 cases of metastatic nodule, 2 cases of biliary cirrhosis, 2 cases of multiple liver abscess, and 7 cases of poor function of catheter including 4 cases of hemobilia, 1 case of multiple intrahepatic stones, pyobilia and intrahepatic Clonorchis sinensis.

Increased large VLDL and small LDL particles are related to lower bilirubin in Type 2 diabetes mellitus

NARCIS (Netherlands)

Dullaart, Robin P F; de Vries, Rindert; Lefrandt, Joop D

2014-01-01

OBJECTIVES: Bilirubin may protect against atherosclerotic cardiovascular disease by virtue of its anti-oxidative properties, but lower bilirubin may also be associated to atherogenic lipoprotein abnormalities. We determined associations of plasma (apo)lipoproteins and lipoprotein subfractions in

Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory

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Neha Dhungana

2017-08-01

Full Text Available Objectives: The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Design and methods: Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR. Results: Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6% exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5% exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1% of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Conclusions: Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations. Keywords: Bilirubin, Clinical chemistry tests, Hemolysis, Hyperlipidemias, Jaundice, Photometry

Surface modifying of microporous PTFE capillary for bilirubin removing from human plasma and its blood compatibility

International Nuclear Information System (INIS)

Jin Gu; Yao Qizhi; Zhang Shanzi; Zhang Lei

2008-01-01

In this study, human serum albumin (HSA) was covalently immobilized onto the inner surface of microporous poly(tetrafluoroethylene) (MPTFE) capillaries for direct bilirubin removal from human plasma. To obtain active binding sites for HSA, the MPTFE capillaries were chemically functionalized by using a coating of poly(vinyl alcohol) (PVA)-glycidyl methacrylate (GMA) copolymers. Characterization of grafted MPTFE capillaries was verified by XPS, Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM). Non-specific adsorption on the PVA-GMA coated capillary remains low (< 0.38 mg bilirubin/g), and higher affinity adsorption capacity, of up to 73.6 mg bilirubin/g polymer was obtained after HSA is immobilized. Blood compatibility of the grafted MPTFE capillary was evaluated by SEM and platelet rich plasma (PRP) contacting experiments. The experimental data on blood compatibility indicated that PVA-coated and PVA-GMA-HSA coated PTFE capillary showed a sharp suppress on platelets adhesion. The proposed method has the potential of serving in bilirubin removal in clinical application

Bilirubin exposure is associated with neonatal sepsis in the eight days preceding symptoms: a retrospective study.

Science.gov (United States)

Raimondi, Francesco; Borrelli, Angela Carla; Ferrara, Teresa; Giannattasio, Antonietta; Capasso, Letizia

2017-09-01

To compare levels of bilirubin (using the area under the curve, AUC) in preterm infants before the onset of sepsis with healthy matched-controls. Preterm infants born between January 2011 and December 2015 with late-onset sepsis were enrolled in our retrospective study and were matched with healthy controls (sex, birth weight and gestational age). Levels of bilirubin were registered in the eight days preceding the onset of sepsis and the AUC was calculated for both groups. Eighty-eight neonates (44 cases) were studied. GA and BW did not differ between cases and controls. In cases, we found a higher value of AUC (30.7 versus 22.5; p = 0.021). In our retrospective cohort, we found that the levels of bilirubin and the AUC in the first eight days before the onset of sepsis in preterm infants were significantly higher than the healthy controls. These data suggest that the prolonged exposition to high levels of bilirubin could increase the infection susceptibility in preterm infants.

The lowering of bilirubin levels in patients with neonatal jaundice using massage therapy: A randomized, double-blind clinical trial.

Science.gov (United States)

Eghbalian, Fatemeh; Rafienezhad, Haneyeh; Farmal, Javad

2017-11-01

Due to the effects of massage on various laboratory parameters (including those related to jaundice) in infants and the expansion of existing studies to achieve effective and safe therapy in the treatment of neonatal jaundice, this study aimed to investigate the effect of massage on bilirubin levels in cases of neonatal jaundice. In this study, 134 patients were randomly assigned to either an intervention group (massage combined with phototherapy, n=67) or a control group (phototherapy only, n=67). In both groups, serum total bilirubin level and frequency of daily bowel movements were measured and compared during each of the first four days of treatment. Baseline levels of bilirubin were similar between the two groups (P>0.05). During the measurements obtained post-intervention, significant differences surfaces between the two groups in bilirubin levels and frequency of daily bowel movements (Pmassage therapy between daily frequency of bowel movements and serum bilirubin level (P>0.05); this relationship became significant during the third and fourth days (PMassage therapy combined with phototherapy is an effective method for reducing serum total bilirubin in infants with neonatal jaundice. Copyright © 2017 Elsevier Inc. All rights reserved.

Bilirubin Increases Insulin Sensitivity in Leptin-Receptor Deficient and Diet-Induced Obese Mice Through Suppression of ER Stress and Chronic Inflammation

Science.gov (United States)

Dong, Huansheng; Huang, Hu; Yun, Xinxu; Kim, Do-sung; Yue, Yinan; Wu, Hongju; Sutter, Alton; Chavin, Kenneth D.; Otterbein, Leo E.; Adams, David B.; Kim, Young-Bum

2014-01-01

Obesity-induced endoplasmic reticulum (ER) stress causes chronic inflammation in adipose tissue and steatosis in the liver, and eventually leads to insulin resistance and type 2 diabetes (T2D). The goal of this study was to understand the mechanisms by which administration of bilirubin, a powerful antioxidant, reduces hyperglycemia and ameliorates obesity in leptin-receptor-deficient (db/db) and diet-induced obese (DIO) mouse models. db/db or DIO mice were injected with bilirubin or vehicle ip. Blood glucose and body weight were measured. Activation of insulin-signaling pathways, expression of inflammatory cytokines, and ER stress markers were measured in skeletal muscle, adipose tissue, and liver of mice. Bilirubin administration significantly reduced hyperglycemia and increased insulin sensitivity in db/db mice. Bilirubin treatment increased protein kinase B (PKB/Akt) phosphorylation in skeletal muscle and suppressed expression of ER stress markers, including the 78-kDa glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein, X box binding protein (XBP-1), and activating transcription factor 4 in db/db mice. In DIO mice, bilirubin treatment significantly reduced body weight and increased insulin sensitivity. Moreover, bilirubin suppressed macrophage infiltration and proinflammatory cytokine expression, including TNF-α, IL-1β, and monocyte chemoattractant protein-1, in adipose tissue. In liver and adipose tissue of DIO mice, bilirubin ameliorated hepatic steatosis and reduced expression of GRP78 and C/EBP homologous protein. These results demonstrate that bilirubin administration improves hyperglycemia and obesity by increasing insulin sensitivity in both genetically engineered and DIO mice models. Bilirubin or bilirubin-increasing drugs might be useful as an insulin sensitizer for the treatment of obesity-induced insulin resistance and type 2 diabetes based on its profound anti-ER stress and antiinflammatory properties. PMID

Origin of absorption peaks in reflection loss spectrum in Ku- frequency band of Co-Zr substituted strontium hexaferrites prepared using sucrose precursor

Energy Technology Data Exchange (ETDEWEB)

Narang, Sukhleen Bindra, E-mail: sukhleen2@yahoo.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Pubby, Kunal, E-mail: kunalpubby02@gmail.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Chawla, S.K., E-mail: sschawla118@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India); Kaur, Prabhjyot, E-mail: prabhjyot.2525@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India)

2017-03-15

This study presents the detailed explanation of the factors, contributing towards the absorption peaks in reflection loss spectrum of hexaferrites. Cobalt-Zirconium substituted strontium hexaferrites, synthesized using sucrose precursor sol-gel technique, were analyzed in 12.4–18 GHz frequency range. The concepts of impedance matching through quarter wavelength condition, complex thickness, dielectric phase angle and attenuation constant have been used to determine the location as well as intensity of absorption peaks. This study also demonstrates the potential application of three compositions of this series with doping content (x)==0.0, 0.6 and 0.8 as an effective microwave absorbers in Ku-frequency band. - Highlights: • EM analysis of Sr Hexaferrites in Ku-band. • Factors towards absorption peak intensity & location.

Spectral interferences in atomic absorption spectrometry, (5)

International Nuclear Information System (INIS)

Daidoji, Hidehiro

1979-01-01

Spectral interferences were observed in trace element analysis of concentrated solutions by atomic absorption spectrometry. Molecular absorption and emission spectra for strontium chloride and nitrate, barium chloride and nitrate containing 12 mg/ml of metal ion in airacetylene flame were measured in the wavelength range from 200 to 700 nm. The absorption and emission spectra of SrO were centered near 364.6 nm. The absorption spectra of SrOH around 606.0, 671.0 and 682.0 nm were very strong. And, emission spectrum of BaOH in the wavelength range from 480 to 550 nm was stronger. But, the absorption of this band spectrum was very weak. In the wavelength range from 200 to 400 nm, some unknown bands of absorption were observed for strontium and barium. Absorption spectra of SrCl and BaCl were observed in the argon-hydrogen flame. Also, in the carbon tube atomizer, the absorption spectra of SrCl and BaCl were detected clearly in the wavelength range from 185 to 400 nm. (author)

Two-dimensional atom localization via a coherence-controlled absorption spectrum in an N-tripod-type five-level atomic system

International Nuclear Information System (INIS)

Ding Chunling; Li Jiahua; Yang Xiaoxue; Zhan Zhiming; Liu Jibing

2011-01-01

A scheme of two-dimensional atom localization based on a coherence-controlled absorption spectrum in an N-tripod-type five-level system is proposed, in which the atom interacts with a weak probe field and three standing-wave fields. Position information of the atom can be achieved by measuring the probe absorption. It is found that the localization properties are significantly improved due to the interaction of dark resonances. It is also shown that the localization factors depend strongly on the system parameters that lead to such spatial structures of localization as chain-like, wave-like, '8'-like, spike-like, crater-like and heart-like patterns. By properly adjusting the system parameters, we can achieve a high-precision and high-resolution atom localization under certain conditions.

Serum bilirubin concentrations and incident coronary heart disease risk among patients with type 2 diabetes: the Dongfeng-Tongji cohort.

Science.gov (United States)

Wang, Jing; Wu, Xiaofen; Li, Yaru; Han, Xu; Hu, Hua; Wang, Fei; Yu, Caizheng; Li, Xiulou; Yang, Kun; Yuan, Jing; Yao, Ping; Miao, Xiaoping; Wei, Sheng; Wang, Youjie; Chen, Weihong; Liang, Yuan; Guo, Huan; Yang, Handong; Wu, Tangchun; Zhang, Xiaomin; He, Meian

2017-03-01

Elevated serum bilirubin levels are associated with decreased coronary heart disease (CHD) risk in cross-sectional studies among diabetic patients, but prospective evidence is limited. We investigated the relationship of serum bilirubin levels with incident CHD risk among type 2 diabetes patients. In a prospective study of 2918 type 2 diabetes embedded in the Dongfeng-Tongji cohort, serum total bilirubin (TBil), direct bilirubin (DBil), and indirect bilirubin (IBil) were measured at baseline. Cox proportional hazards models were used to examine the association between serum bilirubin levels and CHD risk. A total of 440 CHD cases were identified during 12,017 person-years of follow-up. Compared with extreme quartiles, the adjusted hazard ratio and 95% confidence interval of incident CHD were 0.74 (0.56-0.99) with P trend = 0.08 in IBil, while in TBil and DBil, the bilirubin-CHD associations were not significant. Moreover, serum TBil and IBil levels were interacted with drinking status on the risk of incident CHD (P interaction = 0.021 and 0.037, respectively), and the associations were evident in ever drinkers. In drinkers, when serum TBil or IBil concentrations increased 1 μmol/L, the CHD risk both decreased 6% (95% CIs 0.89-0.99 and 0.87-1.00, respectively). Serum IBil levels were marginally related to decreased incident CHD risk among type 2 diabetes. Drinking could potentially enhance the associations of serum TBil and DBil levels with incident CHD risk.

Analysis of the red and green optical absorption spectrum of gas phase ammonia

Science.gov (United States)

Zobov, Nikolai F.; Coles, Phillip A.; Ovsyannikov, Roman I.; Kyuberis, Aleksandra A.; Hargreaves, Robert J.; Bernath, Peter F.; Tennyson, Jonathan; Yurchenko, Sergei N.; Polyansky, Oleg L.

2018-04-01

Room temperature NH3 absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm-1 and 17,950 - 18,250 cm-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 - 7 are determined from analysis of the experimental spectrum in the 5νNH (red) region and 46 for 6νNH (green) region. These levels span four vibrational bands in each of the two regions, associated with stretching overtones.

[Bilirubin in the early neonatal period. Is there a positive aspect of hyperbilirubinemia?--A medical hypothesis].

Science.gov (United States)

Bervoets, K; Schlenzig, J S; Böhles, H

1994-05-10

The fact that almost all neonates exhibit a "physiological" jaundice, prompts the question whether bilirubin, usually exclusively considered a potentially toxic endproduct of the metabolism of heme, might not also have a positive task in the first days of life. A recently discovered property of bilirubin under in vitro conditions is its ability to combine with free oxygen radicals such as are produced in the oxidative metabolic processes of the neonate immediately following birth. In the present article, the concept of the anti-oxidative effect of bilirubin, and its translation to the early neonatal period is presented and discussed on the basis of a number of examples.

The methane absorption spectrum near 1.73 μm (5695-5850 cm-1): Empirical line lists at 80 K and 296 K and rovibrational assignments

Science.gov (United States)

Ghysels, M.; Mondelain, D.; Kassi, S.; Nikitin, A. V.; Rey, M.; Campargue, A.

2018-07-01

The methane absorption spectrum is studied at 297 K and 80 K in the center of the Tetradecad between 5695 and 5850 cm-1. The spectra are recorded by differential absorption spectroscopy (DAS) with a noise equivalent absorption of about αmin≈ 1.5 × 10-7 cm-1. Two empirical line lists are constructed including about 4000 and 2300 lines at 297 K and 80 K, respectively. Lines due to 13CH4 present in natural abundance were identified by comparison with a spectrum of pure 13CH4 recorded in the same temperature conditions. About 1700 empirical values of the lower state energy level, Eemp, were derived from the ratios of the line intensities at 80 K and 296 K. They provide accurate temperature dependence for most of the absorption in the region (93% and 82% at 80 K and 296 K, respectively). The quality of the derived empirical values is illustrated by the clear propensity of the corresponding lower state rotational quantum number, Jemp, to be close to integer values. Using an effective Hamiltonian model derived from a previously published ab initio potential energy surface, about 2060 lines are rovibrationnally assigned, adding about 1660 new assignments to those provided in the HITRAN database for 12CH4 in the region.

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

Science.gov (United States)

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

Modulation of bilirubin neurotoxicity by the Abcb1 transporter in the Ugt1-/- lethal mouse model of neonatal hyperbilirubinemia.

Science.gov (United States)

Bockor, Luka; Bortolussi, Giulia; Vodret, Simone; Iaconcig, Alessandra; Jašprová, Jana; Zelenka, Jaroslav; Vitek, Libor; Tiribelli, Claudio; Muro, Andrés F

2017-01-01

Moderate neonatal jaundice is the most common clinical condition during newborn life. However, a combination of factors may result in acute hyperbilirubinemia, placing infants at risk of developing bilirubin encephalopathy and death by kernicterus. While most risk factors are known, the mechanisms acting to reduce susceptibility to bilirubin neurotoxicity remain unclear. The presence of modifier genes modulating the risk of developing bilirubin-induced brain damage is increasingly being recognised. The Abcb1 and Abcc1 members of the ABC family of transporters have been suggested to have an active role in exporting unconjugated bilirubin from the central nervous system into plasma. However, their role in reducing the risk of developing neurological damage and death during neonatal development is still unknown.To this end, we mated Abcb1a/b-/- and Abcc1-/- strains with Ugt1-/- mice, which develop severe neonatal hyperbilirubinemia. While about 60% of Ugt1-/- mice survived after temporary phototherapy, all Abcb1a/b-/-/Ugt1-/- mice died before postnatal day 21, showing higher cerebellar levels of unconjugated bilirubin. Interestingly, Abcc1 role appeared to be less important.In the cerebellum of Ugt1-/- mice, hyperbilirubinemia induced the expression of Car and Pxr nuclear receptors, known regulators of genes involved in the genotoxic response.We demonstrated a critical role of Abcb1 in protecting the cerebellum from bilirubin toxicity during neonatal development, the most clinically relevant phase for human babies, providing further understanding of the mechanisms regulating bilirubin neurotoxicity in vivo. Pharmacological treatments aimed to increase Abcb1 and Abcc1 expression, could represent a therapeutic option to reduce the risk of bilirubin neurotoxicity. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bilirubin Prevents Atherosclerotic Lesion Formation in Low-Density Lipoprotein Receptor-Deficient Mice by Inhibiting Endothelial VCAM-1 and ICAM-1 Signaling.

Science.gov (United States)

Vogel, Megan E; Idelman, Gila; Konaniah, Eddy S; Zucker, Stephen D

2017-04-01

Numerous epidemiological studies support an inverse association between serum bilirubin levels and the incidence of cardiovascular disease; however, the mechanism(s) by which bilirubin may protect against atherosclerosis is undefined. The goals of the present investigations were to assess the ability of bilirubin to prevent atherosclerotic plaque formation in low-density lipoprotein receptor-deficient ( Ldlr -/- ) mice and elucidate the molecular processes underlying this effect. Bilirubin, at physiological concentrations (≤20 μmol/L), dose-dependently inhibits THP-1 monocyte migration across tumor necrosis factor α-activated human umbilical vein endothelial cell monolayers without altering leukocyte binding or cytokine production. A potent antioxidant, bilirubin effectively blocks the generation of cellular reactive oxygen species induced by the cross-linking of endothelial vascular cell adhesion molecule 1 (VCAM-1) or intercellular adhesion molecule 1 (ICAM-1). These findings were validated by treating cells with blocking antibodies or with specific inhibitors of VCAM-1 and ICAM-1 signaling. When administered to Ldlr -/- mice on a Western diet, bilirubin (30 mg/kg intraperitoneally) prevents atherosclerotic plaque formation, but does not alter circulating cholesterol or chemokine levels. Aortic roots from bilirubin-treated animals exhibit reduced lipid and collagen deposition, decreased infiltration of monocytes and lymphocytes, fewer smooth muscle cells, and diminished levels of chlorotyrosine and nitrotyrosine, without changes in VCAM-1 or ICAM-1 expression. Bilirubin suppresses atherosclerotic plaque formation in Ldlr -/- mice by disrupting endothelial VCAM-1- and ICAM-1-mediated leukocyte migration through the scavenging of reactive oxygen species signaling intermediaries. These findings suggest a potential mechanism for the apparent cardioprotective effects of bilirubin. © 2017 The Authors. Published on behalf of the American Heart Association, Inc

Hopping absorption edge in silicon inversion layers

International Nuclear Information System (INIS)

Kostadinov, I.Z.

1983-09-01

The low frequency gap observed in the absorption spectrum of silicon inversion layers is related to the AC variable range hopping. The frequency dependence of the absorption coefficient is calculated. (author)

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

Science.gov (United States)

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.

Fingerprint extraction from interference destruction terahertz spectrum.

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Xiong, Wei; Shen, Jingling

2010-10-11

In this paper, periodic peaks in a terahertz absorption spectrum are confirmed to be induced from interference effects. Theoretically, we explained the periodic peaks and calculated the locations of them. Accordingly, a technique was suggested, with which the interference peaks in a terahertz spectrum can be eliminated and therefore a real terahertz absorption spectrum can be obtained. Experimentally, a sample, Methamphetamine, was investigated and its terahertz fingerprint was successfully extracted from its interference destruction spectrum. This technique is useful in getting samples' terahertz fingerprint spectra, and furthermore provides a fast nondestructive testing method using a large size terahertz beam to identify materials.

Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory.

Science.gov (United States)

Dhungana, Neha; Morris, Cory; Krasowski, Matthew D

2017-08-01

The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR). Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6%) exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5%) exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1%) of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations.

Diagnostic value of blood urea and bilirubin levels determination in patients with gastroduodenal zone diseases

Directory of Open Access Journals (Sweden)

I. B. Zhakun

2017-12-01

Full Text Available The study of relationships of urea and bilirubin blood levels in patients with Helicobacter pylori associated gastroduodenal pathology (HP-aGDP has the considerable relevance for clinicians, since these indicators represent the status and function of the gastroduodenal zone. The aim of this study was to estimate changes of bilirubin and urea blood levels in patients with HP-aGDP before and after treatment. Materials and methods. Our study has included 59 patients of the main group with different HP-aGDP and 40 patients of the control group with community-acquired pneumonia (CAP. Results. In patients with HP-aGDP the doubly severe reduction of urea concentration was observed in significantly greater number of patients, while half of the patients in the controls had an increase of its level by 10.4 %. The bilirubin concentration decrease was more pronounced (37.1 % vs. 3.5 % and significant (p < 0.05 in patients with HP-aGDP. Its rate depended on the dynamics of urea exactly in patients with HP-aGDP and it was more pronounced in case of urea reduction (p < 0.05. Thus, the revealed association of bilirubin and urea levels changes, namely their decrease owing to the treatment, was inherent only to patients with HP-aGDP unlike to the patients with CAD. We also determined the involvement of lipid, carbohydrate and protein metabolism, electrolytes, composition of blood in the processes of local and systemic inflammation caused by HP and its relationship with adaptive reactions, which generally depended on other individual characteristics of patients in the study group (age, duration of disease, ulcer size, etc.. Conclusions. The monitoring of urea and bilirubin blood levels in patients especially with HP-aGDP during the eradication has a specific diagnostic and prognostic value. The bilirubin level in such cases reflects the severity of cholestasis, inflammatory lesions of the duodenal mucosa, comorbid hepatobiliary disease, while the urea level

A QM/MM study of the absorption spectrum of harmane in water solution and interacting with DNA: the crucial role of dynamic effects.

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Etienne, Thibaud; Very, Thibaut; Perpète, Eric A; Monari, Antonio; Assfeld, Xavier

2013-05-02

We present a time-dependent density functional theory computation of the absorption spectra of one β-carboline system: the harmane molecule in its neutral and cationic forms. The spectra are computed in aqueous solution. The interaction of cationic harmane with DNA is also studied. In particular, the use of hybrid quantum mechanics/molecular mechanics methods is discussed, together with its coupling to a molecular dynamics strategy to take into account dynamic effects of the environment and the vibrational degrees of freedom of the chromophore. Different levels of treatment of the environment are addressed starting from purely mechanical embedding to electrostatic and polarizable embedding. We show that a static description of the spectrum based on equilibrium geometry only is unable to give a correct agreement with experimental results, and dynamic effects need to be taken into account. The presence of two stable noncovalent interaction modes between harmane and DNA is also presented, as well as the associated absorption spectrum of harmane cation.

Investigation of influence of electronic irradiation on photoluminescence spectrum and ir-spectrum of porous silicon

International Nuclear Information System (INIS)

Daineko, E.A.; Dihanbayev, K.K.; Akhtar, P.; Hussain, A.

2007-01-01

In this article we study the influence of 2-Mev electron irradiation on porous silicon (PS). Photoluminescence (PL) spectrum and IR-spectrum have been done on both newly-prepared PS samples and samples prepared a year ago after the irradiation. We analyzed PL spectrum for both types of PS samples. The experimental results suggest that the peak position in PL spectrum decreases for newly-prepared PS samples. The size of the nanocrystals calculated by the method of singling out of spectrum components was equal to 3.0-3.2 nm. Porosity of the samples was 60-75%. From IR-spectrum of newly-prepared PS samples wide absorption band was observed at 1100 cm/sup -1/ (Si-O-Si bond). Another peak of Si-O-Si group was observed at 850 cm/sub -1/. Also hydrogen absorption bands were appearing from 2000 to 2200 cm/sup -1/, corresponding to vibration modes SiH, SiH/sub 2/, SiH/sub 3/. As a result of electron irradiation the PL intensity of newly-prepared PS samples decreases abruptly by a factor of 30 without peak shifting. As for the samples prepared a year ago we observed a decrease in the PL intensity by 25-30%. From IR-spectrum of PS samples prepared a year ago it was shown that the intensity of bridge bonds corresponding to absorption band 850 cm/sup -1/, decreases gradually. Our experimental data shows that PS samples stored for longer time have better radiation resistant properties than the newly-prepared PS samples due to the replacement of Si-H bonds with more resistant Si-O bonds. Porous silicon, electrochemical anodizing, photoluminescence spectrum, IR-spectrum, electronic irradiation. (author)

Two-dimensional atom localization via a coherence-controlled absorption spectrum in an N-tripod-type five-level atomic system

Energy Technology Data Exchange (ETDEWEB)

Ding Chunling; Li Jiahua; Yang Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhan Zhiming [School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Liu Jibing, E-mail: clding2006@126.com, E-mail: huajia_li@163.com [Department of Physics, Hubei Normal University, Huangshi 435002 (China)

2011-07-28

A scheme of two-dimensional atom localization based on a coherence-controlled absorption spectrum in an N-tripod-type five-level system is proposed, in which the atom interacts with a weak probe field and three standing-wave fields. Position information of the atom can be achieved by measuring the probe absorption. It is found that the localization properties are significantly improved due to the interaction of dark resonances. It is also shown that the localization factors depend strongly on the system parameters that lead to such spatial structures of localization as chain-like, wave-like, '8'-like, spike-like, crater-like and heart-like patterns. By properly adjusting the system parameters, we can achieve a high-precision and high-resolution atom localization under certain conditions.

Impairment of enzymatic antioxidant defenses is associated with bilirubin-induced neuronal cell death in the cerebellum of Ugt1 KO mice

Science.gov (United States)

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

Bilirubin provides perforator flap protection from ischaemia-reperfusion injury in a rat model: a preliminary result.

Science.gov (United States)

Kim, Sung Young; Rah, Dong Kyun; Chong, Yosep; Lee, Song Hyun; Park, Tae Hwan

2016-10-01

The use of bilirubin, a well-known and powerful antioxidant, has gained popularity in recent years because of its role in the prevention of ischaemic heart disease in patients with Gilbert's syndrome. We investigate the effects of bilirubin on ischaemia-reperfusion (I/R) injury using a rat perforator flap model. Forty-eight rats were randomly divided into two groups: experimental (bilirubin) group (n = 24) and control group (n = 24). In each group, elevated bilateral deep inferior epigastric perforator (DIEP) flaps were created. The right (no ischaemia side) and left (ischaemia side) DIEP flaps were separated according to the presence of ischaemia induction. Ischaemia was induced in anaesthetised rats by perforator clamping for 15 or 30 minutes. After surgery, the flap survival was assessed daily on postoperative days 0 to 5, and overall histological changes of DIEP flaps above the perforator were analysed at postoperative day 5. The flap survival rate in the bilirubin group was significantly higher than that in the control group at the ischaemia side following perforator clamping for 15 or 30 minutes (93·42 ± 4·48% versus 89·63 ± 3·98%, P = 0·002; and 83·96 ± 4·23% versus 36·46 ± 6·38%, P bilirubin was found to alleviate perforator flap necrosis caused by I/R injury in this experimental rat model. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

DECREASED BILIRUBIN TRANSPORT IN THE PERFUSED LIVER OF ENDOTOXEMIC RATS

NARCIS (Netherlands)

ROELOFSEN, H; VANDERVEERE, CN; OTTENHOFF, R; SCHOEMAKER, B; JANSEN, PLM; ELFERINK, RPJO

1994-01-01

Background/Aims: Hyperbilirubinemia associated with sepsis is frequently observed in humans. In this study, an experimental rat model was developed to study bilirubin metabolism and transport during endotoxemia. Methods: Rats were injected intravenously with a single bolus of lipopolysaccharide (1

Bilirubin and beyond : A review of lipid status in Gilbert's syndrome and its relevance to cardiovascular disease protection

NARCIS (Netherlands)

Bulmer, A. C.; Verkade, H. J.; Wagner, K. -H.

Gilbert's syndrome (GS) is characterized by a benign, mildly elevated bilirubin concentration in the blood. Recent reports show clear protection from cardiovascular disease in this population. Protection of lipids, proteins and other macromolecules from oxidation by bilirubin represents the most

Parametric resonances in the amplitude-modulated probe-field absorption spectrum of a two-level atom driven by a resonance amplitude- and phase-modulated pumping field

International Nuclear Information System (INIS)

Sushilov, N.V.; Kholodkevich, E.D.

1995-01-01

An analytical expression is derived for the polarization induced by a weak probe field with periodically modulated amplitude in a two-level medium saturated by a strong amplitude-and phase-modulated resonance field. It is shown that the absorption spectrum of the probe field includes parametric resonances, the maxima corresponding to the condition δ= 2nΓ-Ω w and the minima to that of δ= (2n + 1)Γ- w , where δ is the probe-field detuning front the resonance frequency, Ω w is the modulation frequency of the probe-field amplitude, and Γ is the transition line width, n = 1, 2, 3, hor-ellipsis. At the specific modulation parameters, a substantial region of negative values (i.e., the region of amplification without the population inversion) exists in the absorption spectrum of the probe field

IR absorption spectrum (4200-3100 cm-1) of H2O and (H2O)2 in CCl4. Estimates of the equilibrium constant and evidence that the atmospheric water absorption continuum is due to the water dimer

International Nuclear Information System (INIS)

Nicolaisen, Flemming M.

2009-01-01

IR absorption spectra, 4200-3100 cm -1 , of water in CCl 4 solutions are presented. It is shown that for saturated solutions significant amounts of water are present as dimer (ca. 2%). The IR spectra of the monomer and dimer are retrieved. The integrated absorption coefficients of the monomer absorption are significantly enhanced relative to the gas phase values. The dimer spectrum consists of 5 bands, of which 4 were expected from data from cold beams and cold matrices. The origin of the 'extra' band is discussed. In addition it is argued that the dimer absorption bands intensities must be enhanced relative to the gas phase values. Based on recent calculations of band strengths, and observed frequency shifts relative to the gas phase, the intensity enhancement factors are estimated as well as the monomer/dimer equilibrium constant in CCl 4 solution at T=296 K (K c =1.29 mol -1 L). It is noted that the observed dimer spectrum has a striking resemblance with the water vapour continuum determined by Burch in 1985 which was recently remeasured by Paynter et al. and it is concluded that the atmospheric water absorption continuum in the investigated spectral region must be due to water dimer. Based on the newly published spectral data a revised value of the gas phase equilibrium constant is suggested (K p =0.035 atm -1 at T=296 K) as well as a value for the standard enthalpy of formation, ΔH 0 =15.4 kJ mol -1 .

Absorption spectrum of a two-level atom in a bad cavity with injected squeezed vacuum

Science.gov (United States)

Zhou, Peng; Swain, S.

1996-02-01

We study the absorption spectrum of a coherently driven two-level atom interacting with a resonant cavity mode which is coupled to a broadband squeezed vacuum through its input-output mirror in the bad cavity limit. We study the modification of the two-photon correlation strength of the injected squeezed vacuum inside the cavity, and show that the equations describing probe absorption in the cavity environment are formally identical to these in free space, but with modified parameters describing the squeezed vacuum. The two photon correlations induced by the squeezed vacuum are always weaker than in free space. We pay particular attention to the spectral behaviour at line centre in the region of intermediate trength driving intensities, where anomalous spectral features such as hole-burning and dispersive profiles are displayed. These unusual spectral features are very sensitive to the squeezing phase and the Rabi frequency of the driving field. We also derive the threshold value of the Rabi frequency which gives rise to the transparency of the probe beam at the driving frequency. When the Rabi frequency is less than the threshold value, the probe beam is absorbed, whilst the probe beam is amplified (without population inversion under certain conditions) when the Rabi frequency is larger than this threshold. The anomalous spectral features all take place in the vicinity of the critical point dividing the different dynamical regimes, probe absorption and amplification, of the atomic radiation. The physical origin of the strong amplification without population inversion, and the feasibility of observing it, are discussed.

Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

KAUST Repository

Tiwari, Surya Prakash

2018-03-16

This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non-algal particles (aNAP) to the total particulate absorption coefficients are determined using a numerical decomposition method (NDM). The NDM is validated by comparing the NDM derived values of aph and aNAP with simulated values of aph and aNAP are found to be in excellent agreement for the selected wavelengths (i.e., 443, 490, 555, and 676nm) with high correlation coefficient (R2), low root mean square error (RMSE), mean relative error (MRE), and with a slope close to unity. Further analyses showed that the total particulate absorption coefficients (i.e., ap(443)average = 0.01995m−1) were dominated by phytoplankton absorption (i.e., aph(443)average = 0.01743m−1) with a smaller contribution by non-algal particles absorption (i.e., aNAP(443)average = 0.002524m−1). The chlorophyll a is computed using the absorption based Line Height Method (LHM). The derived chlorophyll-specific absorption ((a⁎ph = aph(λ)/ChlLH)) showed more variability in the blue part of spectrum as compared to the red part of spectrum representative of the package effect and changes in pigment composition. A new parametrization proposed also enabled the reconstruction of a⁎ph(λ) for the Red Sea. Comparison of derived spectral constants with the spectral constants of existing models showed that our study A(λ) values are consistent with the existing values, despite there is a divergence with the B(λ) values. This study provides valuable information derived from the particulate absorption properties and its spectral variability and this would help us to determine the relationship between the phytoplankton absorption coefficients and chlorophyll a and its host of variables for the Red Sea.

F K-edge soft X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Sugimura, Tetsuro; Kawai, Jun; Maeda, Kuniko; Fukushima, Akiko; Shin, S.; Motoyama, Muneyuki; Nakajima Tsuyoshi

2001-01-01

We measured F X-ray absorption spectra of various fluorine compounds using a synchrotron radiation at KEK-PF. The absorption spectra were measured using X-ray fluorescence yield (XFY) and total electron yield (TEY) methods. Change of the spectral shape has a relation to the metal-fluorine bond distance. By comparing with the experimental spectrum and calculated spectrum, F 2p state density is divined into up and down states. (author)

Decreased bilirubin transport in the perfused liver of endotoxemic rats

NARCIS (Netherlands)

Roelofsen, H.; van der Veere, C. N.; Ottenhoff, R.; Schoemaker, B.; Jansen, P. L.; Oude Elferink, R. P.

1994-01-01

Hyperbilirubinemia associated with sepsis is frequently observed in humans. In this study, an experimental rat model was developed to study bilirubin metabolism and transport during endotoxemia. Rats were injected intravenously with a single bolus of lipopolysaccharide (1 mg/kg); after 18 hours, the

The value of transcutaneous method of bilirubin measurement in newborn population with the risk of ABO hemolytic disease.

Science.gov (United States)

Stoniene, Dalia; Buinauskiene, Jūrate; Markūniene, Egle

2009-01-01

OBJECTIVE OF THE STUDY. To evaluate the correlation between total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) levels in newborn infants at risk of ABO hemolytic disease. MATERIAL AND METHODS. During a prospective study, 130 full-term (>or=37 weeks of gestation) newborn infants with diagnosed ABO blood group incompatibility were examined. TSB level was measured at the age of 6 hours; further measurements were performed at 24, 48, and 72 hours following the first measurement. Blood samples were collected from the peripheral veins. In clinical laboratory, total serum bilirubin level was measured using Jendrassik-Grof method. TcB level in the forehead was measured using a noninvasive bilirubinometer BiliCheck (SpectRX Inc, Norcross, GA) according to the manufacturer's instructions within +/-30 min after getting a blood sample. RESULTS. During the study, 387 double tests were performed to measure TSB and TcB levels. TSB level (114.83 [62.85] micromol/L) closely correlated with TcB level (111.51 [61.31] micromol/L) (r=0.92, Por=98 micromol/L, ABO hemolytic disease in newborns may be diagnosed with 100% sensitivity and 98% specificity; positive predictive value was 62% and negative predictive value was 100%. While a newborn's age increases, TcB sensitivity and specificity for diagnosing ABO hemolytic disease decrease. CONCLUSION. While evaluating bilirubin level transcutaneously according to nomograms of serum bilirubin level, the results should be considered with caution, especially for newborns with a risk of ABO hemolytic disease. The hour-specific nomograms of transcutaneous bilirubin level should be used to evaluate hyperbilirubinemia using only a noninvasive method.

Low antioxidant status of serum bilirubin, uric acid, albumin and creatinine in patients with myasthenia gravis.

Science.gov (United States)

Yang, Dehao; Su, Zhongqian; Wu, Shengjie; Bi, Yong; Li, Xiang; Li, Jia; Lou, Kangliang; Zhang, Hongyu; Zhang, Xu

2016-12-01

Oxidative stress and low antioxidant status play a major role in the pathogenesis of inflammatory and autoimmune diseases. Myasthenia gravis (MG) is an autoimmune condition targeting the neuromuscular junction, and its antioxidant status is still controversial. Our study aimed to investigate the correlation between the clinical characteristics of MG and the serum antioxidant status of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine. We measured serum antioxidant molecule levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine in 380 individuals, including 166 MG and 214 healthy controls. We found that MG patients had significantly lower serum levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine than healthy controls, whether male or female. Moreover, it was also shown in our study that uric acid, albumin and creatinine levels in patients with MG were correlated with disease activity and classifications performed by the Myasthenia Gravis Foundation of America. Our findings demonstrated that serum levels of bilirubin (Tbil, Dbil and Ibil), uric acid, albumin and creatinine were reduced in patients with MG. This suggested an active oxidative process in MG patients who had low antioxidant status.

Increment of serum bilirubin as an independent marker predicting new-onset type 2 diabetes mellitus in a Korean population.

Science.gov (United States)

Lee, S-E; Lee, Y-B; Jun, J E; Jin, S-M; Jee, J H; Bae, J C; Kim, J H

2017-03-01

Several cross-sectional studies reported that serum bilirubin concentrations had an inverse association with type 2 diabetes mellitus (T2DM) prevalence. The aim of the current study was to investigate the relationship between percentage change in bilirubin levels (PCB) and incident risk of T2DM using a longitudinal model. 22,084 participants who received regular health check-ups between 2006 and 2012 were enrolled. Multivariable-adjusted Cox regression models were used to determine the hazard ratio (HR) of incident T2DM based on PCB. PCB was determined by subtracting baseline serum bilirubin level (BB) from the bilirubin level at the end of follow-up or a year before the last date of diagnosis, dividing by BB and multiplying by 100. Compared to non-diabetics, BB was lower in the diabetic group at the initial visit. There were 20,098 participants without T2DM at the initial visit; 1253 new cases occurred during follow-up. As PCB increased, T2DM incidence also increased (P bilirubin level of the Incident T2DM group increased before T2DM development and decreased rapidly thereafter compared to others (P Bilirubin level increment over time is associated with T2DM development. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arthur, Dionne Maioha [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Aganovic, Simona [Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden); Ng, Jack C. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Lang, Matti A. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden)

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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: ► CYP2A5 metabolizes bilirubin to biliverdin and dipyrroles. ► Bilirubin increased the hepatic CYP2A5 protein and activity levels. ► Bilirubin does not change the hepatic CYP2A5 mRNA levels. ► Co-treatment with a protein synthesis inhibitor

Higher Serum Direct Bilirubin Levels Were Associated with a Lower Risk of Incident Chronic Kidney Disease in Middle Aged Korean Men

Science.gov (United States)

Ryu, Seungho; Chang, Yoosoo; Zhang, Yiyi; Woo, Hee-Yeon; Kwon, Min-Jung; Park, Hyosoon; Lee, Kyu-Beck; Son, Hee Jung; Cho, Juhee; Guallar, Eliseo

2014-01-01

Background The association between serum bilirubin levels and incident chronic kidney disease (CKD) in the general population is unknown. We aimed to examine the association between serum bilirubin concentration (total, direct, and indirect) and the risk of incident CKD. Methods and Findings Longitudinal cohort study of 12,823 Korean male workers 30 to 59 years old without CKD or proteinuria at baseline participating in medical health checkup program in a large worksite. Study participants were followed for incident CKD from 2002 through 2011. Estimated glomerular filtration rate (eGFR) was estimated by using the CKD-EPI equation. CKD was defined as eGFR bilirubin were 0.93 (95% CI 0.67–1.28), 0.88 (0.60–1.27) and 0.60 (0.42–0.88), respectively. In multivariable models, the adjusted hazard ratio for CKD comparing the highest to the lowest quartile of serum direct bilirubin levels was 0.60 (95% CI 0.41–0.87; P trend = 0.01). Neither serum total nor indirect bilirubin levels were significantly associated with the incidence of CKD. Conclusions Higher serum direct bilirubin levels were significantly associated with a lower risk of developing CKD, even adjusting for a variety of cardiometabolic parameters. Further research is needed to elucidate the mechanisms underlying this association and to establish the role of serum direct bilirubin as a marker for CKD risk. PMID:24586219

Spectrum interpretation problems with well-type Ge(Li) detectors due to self-absorption variations

International Nuclear Information System (INIS)

Bruin, M. de; Korthoven, P.J.M.; Bode, P.

1979-01-01

For use in instrumental neutron activation analysis, a well-type Ge(Li) detector compares favourably with a comparable detector without well. It combines a good energy resolution with a relatively high detector efficiency. Moreover, this efficiency is almost independent of sample dimensions. But the use of a well-type Ge(Li) detector also has been some drawbacks, as large summation effects will result from the high detector efficiency. The least severe aspect of this summation is the additional formation of many extra sum peaks in gamma-ray spectra of nuclides with moderate or highly complex decay schemes. This leads to higher computation times, but in general, the accuracy of the analysis will not be affected. A far more important aspect of the summation is found in the fact that the intensity ratios between high energy peaks and the sum peaks of self-absorption effects, which in a flat detector is limited to only the low energy part of the spectrum, may be extended to the high energy region. This leads to sample-dependent distortion of the high energy part of the gamma-ray spectrum which may result in misinterpretation of instrumental neutron activation analysis data. The only solution to this problem seems to be to prevent the relevant low energy photons from reaching the detector. This can be accomplished by using a high Z absorber inside the detector well. (Auth.)

Direction dependence of the magneto-optical absorption in nanowires with Rashba interaction

Energy Technology Data Exchange (ETDEWEB)

Sakr, M.R., E-mail: msakr@alexu.edu.eg

2016-09-16

We study the directional dependence of the absorption spectrum of ballistic nanowires in the presence of gate-controlled Rashba spin–orbit interaction and an in-plane magnetic field. In the weak Rashba regime, our analytical and numerical results show that the absorption peaks associated with the first and third intersubband transitions exhibit frequency shifts and strong amplitude modulations as the direction of the magnetic field changes. If the field is parallel to the nanowire axis, these peaks disappear and the resonance frequencies of the whole absorption spectrum are given merely in terms of the Zeeman splitting and the energy scale characterizing the confinement potential. The second transition has an absorption peak that suffers an opposite frequency shift with amplitude that is largely direction independent. The amplitude modulation and frequency shift of the absorption spectrum is periodic in the angle that the magnetic field makes with the nanowire axis. - Highlights: • Absorption spectrum of the nanowire is calculated in the weak Rashba regime. • First and third absorption peaks show amplitude and frequency modulation. • They disappear if the magnetic field is along the wire axis, forbidden transitions. • The second transition peak shows frequency shift with minor amplitude modulation. • The frequency and amplitude modulations are periodic in the direction of the field.

Mildly Elevated Serum Bilirubin Levels Are Negatively Associated with Carotid Atherosclerosis among Elderly Persons

Science.gov (United States)

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

2014-01-01

Serum bilirubin may have a beneficial role in preventing oxidative changes in atherosclerosis. Limited information is available on whether serum total bilirubin is an independent confounding factor for carotid atherosclerosis {for example, intima-media thickness (IMT), plaque} measured noninvasively by B-mode ultrasonography only among elderly persons. The study subjects were 325 men aged 79±8 (mean ± standard deviation) years and 509 women aged 81±8 years that were enrolled consecutively from patients aged ≥60 years in the medical department. Carotid IMT and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that in men age (β = 0.199, p = 0.002), smoking status (β = 0.154, p = 0.006), GGT (β = -0.139, p = 0.039), and GGT (β = -0.133, p = 0.022) were significantly and independently associated with carotid IMT, and in women age (β = 0.186, pbilirubin (β = -0.119, p = 0.006), and prevalence of cardiovascular disease (CVD) (β = 0.103, p = 0.017) were also independently associated with carotid IMT. The odds ratios (ORs) {95% confidence interval (CI)} of increasing serum bilirubin category were negatively associated with carotid IMT ≥1.0 mm and plaque in both genders. Compared to subjects with a serum bilirubin of Quartile-1, the multivariate-OR (95% CI) of carotid plaque was 0.25 (0.11–0.57) in the Quartile-4 male group, and 0.41 (0.21–0.78) in the Quartile-2 female group, 0.51 (0.26–0.98) in the Quartile-3 female group, and 0.46 (0.24–0.89) in the Quartile-4 female group. Our data demonstrated an independently negative association between serum bilirubin and carotid atherosclerosis in both genders. PMID:25479598

Oxidation reactions of bilirubin in aqueous solutions

International Nuclear Information System (INIS)

Mohan, Hari; Gopinathan, C.

1990-01-01

The radical cation of bilirubin (BR) has been tentatively identified as a transient intermediate in the reactions of BR with different oxidizing species such as Br 2 - , I 2 - and CH 3 I . OH. The rate constants for these reactions have been determined as 2.4 x 10 9 , l.0 x 10 9 and 2.7 x 10 9 dm 3 mol -1 s -1 , respectively. Biliverdin is likely to be among the stable products formed on oxidation of BR by these oxidizing species. (author)

Signs of strong Na and K absorption in the transmission spectrum of WASP-103b

Science.gov (United States)

Lendl, M.; Cubillos, P. E.; Hagelberg, J.; Müller, A.; Juvan, I.; Fossati, L.

2017-09-01

Context. Transmission spectroscopy has become a prominent tool for characterizing the atmospheric properties on close-in transiting planets. Recent observations have revealed a remarkable diversity in exoplanet spectra, which show absorption signatures of Na, K and H2O, in some cases partially or fully attenuated by atmospheric aerosols. Aerosols (clouds and hazes) themselves have been detected in the transmission spectra of several planets thanks to wavelength-dependent slopes caused by the particles' scattering properties. Aims: We present an optical 550-960 nm transmission spectrum of the extremely irradiated hot Jupiter WASP-103b, one of the hottest (2500 K) and most massive (1.5 MJ) planets yet to be studied with this technique. WASP-103b orbits its star at a separation of less than 1.2 times the Roche limit and is predicted to be strongly tidally distorted. Methods: We have used Gemini/GMOS to obtain multi-object spectroscopy throughout three transits of WASP-103b. We used relative spectrophotometry and bin sizes between 20 and 2 nm to infer the planet's transmission spectrum. Results: We find that WASP-103b shows increased absorption in the cores of the alkali (Na, K) line features. We do not confirm the presence of any strong scattering slope as previously suggested, pointing towards a clear atmosphere for the highly irradiated, massive exoplanet WASP-103b. We constrain the upper boundary of any potential cloud deck to reside at pressure levels above 0.01 bar. This finding is in line with previous studies on cloud occurrence on exoplanets which find that clouds dominate the transmission spectra of cool, low surface gravity planets while hot, high surface gravity planets are either cloud-free, or possess clouds located below the altitudes probed by transmission spectra. The spectrophotometric time series data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http

Association between serum bilirubin levels and decline in estimated glomerular filtration rate among patients with type 2 diabetes.

Science.gov (United States)

Wang, Jing; Li, Yaru; Han, Xu; Hu, Hua; Wang, Fei; Yu, Caizheng; Li, Xiulou; Yang, Kun; Yuan, Jing; Yao, Ping; Miao, Xiaoping; Wei, Sheng; Wang, Youjie; Chen, Weihong; Liang, Yuan; Zhang, Xiaomin; Guo, Huan; Pan, An; Yang, Handong; Wu, Tangchun; He, Meian

2016-01-01

Studies indicate that elevated serum total bilirubin (TBil) levels are associated with lower risk of diabetic kidney disease (DKD). Few studies examined the associations of direct bilirubin (DBil) and indirect bilirubin (IBil) with the development of DKD. Type 2 diabetes patients (n=2,958) with estimated glomerular filtration (eGFR)≥60mlmin(-1) 1.73m(-2) from the Dongfeng-Tongji cohort were selected and followed up for 5years. Development of DKD was defined as decline in eGFR≥30% during follow-up. Generalize linear model was used to assess the associations of bilirubin levels with DKD development. Compared with those in the first tertile of serum TBil, the relative risks (RRs) and 95% confidence intervals (CIs) of incident eGFR decline for tertile 2 to 3 were 0.83 (0.64-1.09) and 0.74 (0.56-0.98), Ptrend=0.04. The counterpart RRs (95% CIs) in IBil were 0.74 (0.57-0.97) and 0.75 (0.57-0.98), Ptrend=0.04. No significant associations were observed in DBil. Moreover, TBil and IBil interacted with smoking, the bilirubin-DKD associations were evident in ever smokers. Our findings suggest that elevation of serum TBil or IBil levels are independent protective factors for development of DKD, particularly in smokers. Copyright © 2016 Elsevier Inc. All rights reserved.

Bile Gastritis Following Laparoscopic Single Anastomosis Gastric Bypass: Pilot Study to Assess Significance of Bilirubin Level in Gastric Aspirate.

Science.gov (United States)

Shenouda, Michael M; Harb, Shady ElGhazaly; Mikhail, Sameh A A; Mokhtar, Sherif M; Osman, Ayman M A; Wassef, Arsany T S; Rizkallah, Nayer N H; Milad, Nader M; Anis, Shady E; Nabil, Tamer Mohamed; Zaki, Nader Sh; Halepian, Antoine

2018-02-01

Laparoscopic single anastomosis gastric bypass (SAGB) is increasingly performed for morbidly obese patients. This pilot study aims primarily at evaluating the incidence of bile gastritis after SAGB. The occurrence of reflux oesophagitis and reflux symptoms were also assessed. This study included 20 patients having no reflux symptoms. All patients underwent a SAGB as a primary bariatric procedure by a single surgeon. Patients included consented to have an upper GI endoscopy done at 6 months postoperatively. Gastric aspirate was sent for bilirubin level assessment. Gastric and esophageal biopsies were submitted for histopathology and campylobacter-like organism (CLO) test. In our study, the rate of bile gastritis was 30%. In 18 patients, the level of bilirubin in gastric aspirate seems to be related to the degree of mucosal inflammation. The remaining two patients had microscopic moderate to severe gastritis with normal aspirate bilirubin level. Two patients with bilirubin level in aspirate more than 20 mg/dl had severe oesophagitis, gastritis with erosions, and metaplasia. Relationship between bilirubin level and histopathological findings of gastric biopsy examination was statistically significant with a P value of 0.001. The incidence of bile gastritis in this cohort is higher than reported in the literature, and this may be worrying. The correlation between endoscopic findings and patients' symptoms is poor. Bilirubin level and pH in aspirate might be useful tools to confirm alkaline reflux. Its level might help to choose candidates for revision surgery after SAGB. This needs further validation with larger sample size.

Direct and quantitative broadband absorptance spectroscopy with multilayer cantilever probes

Science.gov (United States)

Hsu, Wei-Chun; Tong, Jonathan Kien-Kwok; Liao, Bolin; Chen, Gang

2015-04-21

A system for measuring the absorption spectrum of a sample is provided that includes a broadband light source that produces broadband light defined within a range of an absorptance spectrum. An interferometer modulates the intensity of the broadband light source for a range of modulation frequencies. A bi-layer cantilever probe arm is thermally connected to a sample arm having at most two layers of materials. The broadband light modulated by the interferometer is directed towards the sample and absorbed by the sample and converted into heat, which causes a temperature rise and bending of the bi-layer cantilever probe arm. A detector mechanism measures and records the deflection of the probe arm so as to obtain the absorptance spectrum of the sample.

Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue).

Science.gov (United States)

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.

Bilirubin levels determine vascular complications in diabetes mellitus type 2

Directory of Open Access Journals (Sweden)

Yu V Pankratova

2013-03-01

Full Text Available Реферат по материалам статьи Katsiki N, Karagiannis A, Mikhailidis DP. Diabetes, bilirubin and amputations: is there a link? Diabetologia. DOI 10.1007/s00125-013-2840-1

Structure and dynamics in liquid water from x-ray absorption spectroscopy

International Nuclear Information System (INIS)

Wernet, Philippe

2009-01-01

Oxygen K-edge x-ray absorption spectra of water are discussed. The spectra of gas-phase water, liquid water and ice illustrate the sensitivity of oxygen K-edge x-ray absorption spectroscopy to hydrogen bonding in water. Transmission mode spectra of amorphous and crystalline ice are compared to x-ray Raman spectra of ice. The good agreement consolidates the experimental spectrum of crystalline ice and represents an incentive for theoretical calculations of the oxygen K-edge absorption spectrum of crystalline ice. Time-resolved infrared-pump and x-ray absorption probe results are finally discussed in the light of this structural interpretation.

Structures of bilirubin conjugates synthesized in vitro from bilirubin and uridine diphosphate glucuronic acid, uridine diphosphate glucose or uridine diphosphate xylose by preparations from rat liver

NARCIS (Netherlands)

Fevery, J.; Leroy, P.; van de Vijver, M.; Heirwegh, K. P.

1972-01-01

1. In incubation mixtures containing digitonin-activated or untreated preparations from rat liver, albumin-solubilized bilirubin as the acceptor substrate and (a) UDP-glucuronic acid, (b) UDP-glucose or (c) UDP-xylose as the sugar donor, formation of the following ester glycosides was demonstrated:

VARIATIONS OF ABSORPTION TROUGHS IN THE QUASAR SDSS J125216.58+052737.7

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhi-Fu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qin, Yi-Ping, E-mail: zhichenfu@126.com [Department of Physics and Telecommunication Engineering, Baise University, Baise 533000 (China)

2015-01-20

In this work, we analyze the spectra of quasar J125216.58+052737.7 (z {sub em} = 1.9035) which was observed by SDSS-I/II on 2003 January 30 and by BOSS on 2011 April 2. Both the continuum and the absorption spectra of this quasar show obvious variations between the two epochs. In the SDSS-I/II spectrum, we detect 8 C IV λλ1548,1551 absorption systems, which are detected at z {sub abs} = 1.9098, 1.8948, 1.8841, 1.8770, 1.8732, 1.8635, 1.8154, and 1.7359, respectively, and one Mg II λλ2796,2803 absorption system at z {sub abs} = 0.9912. Among these absorption systems, two C IV λλ1548,1551 absorption systems at z {sub abs} = 1.9098 and 1.7359 and the Mg II λλ2796,2803 absorption system are imprinted on the BOSS spectrum as well, and have similar absorption strengths when compared to those measured from the SDSS-I/II spectrum. Three C IV λλ1548,1551 absorption systems at z {sub abs} = 1.8948, 1.8841, and 1.8770 are also detected in the BOSS spectrum, while their absorption strengths are much weaker than those measured from the SDSS-I/II spectrum; three systems at z {sub abs} = 1.8732, 1.8635, and 1.8154 disappeared from the BOSS spectrum. Based on the variability analysis, the absorption systems that disappeared and weakened are likely to be intrinsic to the quasar. If these intrinsic absorption gases are blown away from the central region of the quasar, with respect to the quasar system, the absorption systems that disappeared would have separation velocities of 3147 kms{sup –1}, 4161 km s{sup –1}, and 9241 km s{sup –1}, while the absorption systems that weakened would have separation velocities of 900 km s{sup –1}, 2011 km s{sup –1}, and 2751 km s{sup –1}. Well-coordinated variations of the six C IV λλ1548,1551 absorption systems that disappeared and weakened, occurring on a timescale of 1026.7 days at the quasar rest frame, can be interpreted as a result of global changes in the ionization state of the absorbing gas.

Direct antioxidant properties of bilirubin andbiliverdin. Is there a role for biliverdin reductase?

Directory of Open Access Journals (Sweden)

Thomas eJansen

2012-03-01

Full Text Available Reactive oxygen species (ROS and signaling events are involved in the pathogenesis of endothelial dysfunction and represent a major contribution to vascular regulation. Molecular signaling is highly dependent on reactive oxygen species. But depending on the amount of ROS production it might have toxic or protective effects. Despite a large number of negative outcomes in large clinical trials (e.g. HOPE, HOPE-TOO, antioxidant molecules and agents are important players to influence the critical balance between production and elimination of RONS. However, chronic systemic antioxidant therapy lacks clinical efficacy, probably by interfering with important physiological redox signaling pathways. Therefore, it may be a much more promising attempt to induce intrinsic antioxidant pathways in order to increase the antioxidants not systemically but at the place of oxidative stress and complications. Among others, heme oxygenase (HO has been shown to be important for attenuating the overall production of ROS in a broad range of disease states through its ability to degrade heme and to produce carbon monoxide (CO, biliverdin/bilirubin, and the release of free iron with subsequent ferritin induction. With the present review we would like to highlight the important antioxidant role of the heme oxygenase system and especially discuss the contribution of the biliverdin, bilirubin and biliverdin reductase to these beneficial effects. The bilierdin reductase was reported to confer an antioxidant redox amplification cycle by which low, physiological bilirubin concentrations confer potent antioxidant protection via recycling of biliverdin from oxidized bilirubin by the biliverdin reductase, linking this sink for oxidants to the NADPH pool. To date the existence and role of this antioxidant redox cycle is still under debate and we present and discuss the pros and cons as well as our own findings on this topic.

Total serum bilirubin levels and sensorineural hearing loss in the US adolescents: NHANES 2007-2010.

Science.gov (United States)

Zhou, Guoli; Fu, Wenjiang

2018-02-01

We aimed to investigate whether current levels of total serum bilirubin are associated with different subtypes of sensorineural hearing loss (SNHL) in adolescents. A set of cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) (2007-2010) was used. A subset of 1404 adolescents was sampled for measurements of total serum bilirubin, tympanometry, and average pure tone threshold at low-frequencies (LPTA: 500, 1000, 2000 Hz) or high-frequencies (HPTA: 3000, 4000, 6000, and 8000 Hz). SNHL was defined as the hearing loss that had type A tympanograms with a peak admittance of 0.3 ml or greater. Associations between serum bilirubin (square-root transformed) and different subtypes of SNHL were evaluated using binary or multinomial logistic regression models with 4-year sampling weights. The bootstrap method was used for estimation of variance and 10-fold cross-validation for assessment of overfitting issue. Total serum bilirubin levels were found to be associated with any high-frequency (HPTA>15 dB in at least one ear, adjusted odds-ratio (OR a )(bootstrap 95% confidence interval) = 3.29(1.31-8.19), p = 0.011), but not with any low-frequency (LPTA>15 dB in at least one ear), SNHL in the US adolescents. Furthermore, high-frequency SNHL with HPTA>15 dB in both ears (bilateral) or HPTA≥25 dB in at least one ear, compared to that with HPTA>15 dB in one ear only (unilateral) or HPTA = 15-25 dB in at least one ear, had a stronger association with total serum bilirubin levels (OR a  = 5.37(1.27-22.65), p = 0.022 for bilateral; OR a  = 2.64(0.84-8.25), p = 0.094 for unilateral; OR a  = 5.00(0.95-26.58), p = 0.058 for HPTA≥25 dB in at least one ear; as well as OR a  = 3.06(1.15-8.25), p = 0.025 for HPTA = 15-25 dB in at least one ear). No severe overfitting problems were found. Our findings suggest that current levels of total serum bilirubin may be informative in predicting and/or targeting high-frequency SNHL

Clinical value of serum bilirubin subfractionation by high-performance liquid chromatography and conventional methods in patients with primary biliary cirrhosis

NARCIS (Netherlands)

Jansen, P. L.; Peters, W. H.; Janssens, A. R.

1986-01-01

The clinical value of serum bilirubin subfractionation, using high-performance liquid chromatography (HPLC), was studied in 26 patients with primary biliary cirrhosis (PBC) from whom 59 serum samples were obtained. Total bilirubin (TB) levels were determined by alkaline methanolysis and HPLC

Enhanced index and negative dispersion without absorption in driven cascade media

International Nuclear Information System (INIS)

Hu Xiangming; Xu Jun

2004-01-01

In this paper we investigate the dispersive and absorptive properties of a system of three-level cascade atoms driven by a strong coherent field. Three characteristic features are found. First, for the same set of atom-light interaction parameters, the indices of refraction are large at three different frequencies where the absorption vanishes. These three frequencies are determined by the resonance transition frequencies between dressed states produced by the strong driving field. Second, negative dispersion without absorption, which leads to superluminal light propagation, is achievable in the central resonance structure of the dispersion spectrum. Third, the whole absorption spectrum displays, in general, three pairs of absorption peaks and three pairs of gain (negative absorption) peaks. The minimal spacing between dressed states determines whether the outer adjacent gain peaks are separated from each other

Total bilirubin in nasogastric aspirates: A potential new indicator of ...

African Journals Online (AJOL)

Background: The aim of our study was to investigate if total bilirubin (T-bil), amylase (Amy), and sodium (Na) in nasogastric (NG) aspirates can refl ect gastrointestinal motility reliably. Materials and Methods: NG aspirates from all laparotomies lasting more than 150 min in children less than 12 months old were studied for 3 ...

Exploring the relationship of peripheral total bilirubin, red blood cell, and hemoglobin with blood pressure during childhood and adolescence.

Science.gov (United States)

Chen, Xiao-Tian; Yang, Song; Yang, Ya-Ming; Zhao, Hai-Long; Chen, Yan-Chun; Zhao, Xiang-Hai; Wen, Jin-Bo; Tian, Yuan-Rui; Yan, Wei-Li; Shen, Chong

2017-11-04

Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents. A total of 3776 students (aged from 6 to 16 years old) were examined using cluster sampling. Pre-high blood pressure and high blood pressure were respectively defined as the point of 90th and 95th percentiles based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Both systolic and diastolic blood pressure were standardized into z-scores. Peripheral total bilirubin, red blood cell and hemoglobin levels were significantly correlated with age, and also varied with gender. Peripheral total bilirubin was negatively correlated with systolic blood pressure in 6- and 9-year-old boys, whilst positively correlated with diastolic blood pressure in the 12-year-old boys and 13- to 15-year-old girls (p0.05). Total bilirubin could be weakly correlated with both systolic and diastolic blood pressure, as correlations varied with age and gender in children and adolescents; in turn, the increased levels of red blood cell and hemoglobin are proposed to be positively associated with the prevalence of high blood pressure. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Relationship between serum total bilirubin levels and mortality in uremia patients undergoing long-term hemodialysis: A nationwide cohort study.

Science.gov (United States)

Su, Hui-Hsien; Kao, Chia-Man; Lin, Yi-Chun; Lin, Yen-Chung; Kao, Chih-Chin; Chen, Hsi-Hsien; Hsu, Chih-Cheng; Chen, Kuan-Chou; Peng, Chiung-Chi; Wu, Mai-Szu

2017-10-01

Previous studies show that serum bilirubin has potent antioxidant effect and is associated with protection from kidney damage and reduce cardiovascular events. The aim of this study was to examine the association of serum total bilirubin level and mortality in uremia patients who underwent hemodialysis. This is a nationwide retrospective long-term cohort study. Patients were registered in the Taiwan Renal Registry Data System (TWRDS) from 2005 to 2012. A total of 115,535 hemodialysis patients were surveyed and those with valid baseline total bilirubin (TB) data were enrolled. All-cause mortality was the primary outcome. A total of 47,650 hemodialysis patients followed for 27.6 ± 12 months, were divided into 3 groups according to different baseline serum total bilirubin levels (0.1-0.3, 0.3-0.7, 0.7-1.2 mg/dL). Mean age was 61.4 ± 13.6 years, 50% were male, 13% were hepatitis B carriers, and 20% were hepatitis C carriers. Primary outcome was the 3-year mortality. The TB level 0.7-1.2 mg/dL group had high mortality, statistically significant hazard ratio of mortality was 1.14 (crude HR, 95% 1.07-1.20, p bilirubin on hemodialysis patients are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrastructural changes in the isolated rat kidney induced by conjugated bilirubin and bile acids.

Science.gov (United States)

Gollan, J L; Billing, B H; Huang, S N

1976-10-01

The effects of bilirubin and bile acids on the ultrastructure of proximal renal tubules have been studied using an isolated rat kidney preparation, perfused with a protein-free dextran medium. Control kidneys perfused for 1 h had a normal glomerular filtration rate and effective renal plasma flow; the ultrastructure of proximal tubular cells was well preserved, with normal mitochondria, nuclear and plasma membranes, and microvilli of the brush border. When conjugated bilirubin, prepared from human hepatic bile, was added to the perfusion medium (5-0-7-5 mg/100 ml), marked alterations were observed in some cells, particularly with regard to the mitochondria and plasma membranes. These changes were greatly diminished by the inclusion of bovine albumin in the medium, indicating that the unbound fraction was primarily responsible for the tubular damage. The addition of taurocholate (450 muM), taurochenodeoxycholate (550 muM) or taurolithocholate (250 muM, bound to albumin) also produced plasma membrane changes, but only slight abnormalities were seen in the mitochondria and other structures. These ultrastructural observations support the concept that the elevated plasma levels of conjugated bilirubin and to a lesser extent bile acids are related to the renal failure associated with obstructive jaundice.

Saturated two-photon absorption by atoms in a perturber gas

International Nuclear Information System (INIS)

Nienhuis, G.

1980-01-01

We derive a general expression for the two-photon absorption spectrum of a three-state atom excited by two mono-chromatic radiation fields. Collisional line-broadening effects are incorporated, and the result allows inclusion of profiles with a validity outside the impact limit. Results of previous work are recovered in the appropriate limits. Saturation affects the different lines in the two-photon absorption spectrum in a different fashion. (orig.)

Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

International Nuclear Information System (INIS)

Song, Shasha; Wang, Shuang; Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin; Zhu, Daling

2013-01-01

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

Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

Energy Technology Data Exchange (ETDEWEB)

Song, Shasha [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Wang, Shuang [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Zhu, Daling, E-mail: dalingz@yahoo.com [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

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.

Measurement of absorption spectrum of deuterium oxide (D2O) and its application to signal enhancement in multiphoton microscopy at the 1700-nm window

International Nuclear Information System (INIS)

Wang, Yuxin; Wen, Wenhui; Wang, Kai; Wang, Ke; Zhai, Peng; Qiu, Ping

2016-01-01

1700-nm window has been demonstrated to be a promising excitation window for deep-tissue multiphoton microscopy (MPM). Long working-distance water immersion objective lenses are typically used for deep-tissue imaging. However, absorption due to immersion water at 1700 nm is still high and leads to dramatic decrease in signals. In this paper, we demonstrate measurement of absorption spectrum of deuterium oxide (D 2 O) from 1200 nm to 2600 nm, covering the three low water-absorption windows potentially applicable for deep-tissue imaging (1300 nm, 1700 nm, and 2200 nm). We apply this measured result to signal enhancement in MPM at the 1700-nm window. Compared with water immersion, D 2 O immersion enhances signal levels in second-harmonic generation imaging, 3-photon fluorescence imaging, and third-harmonic generation imaging by 8.1, 24.8, and 24.7 times with 1662-nm excitation, in good agreement with theoretical calculation based on our absorption measurement. This suggests D 2 O a promising immersion medium for deep-tissue imaging

Serum bilirubin and antioxidant levels in first degree relatives of patients with ischemic heart disease and normal subjects

International Nuclear Information System (INIS)

Mahmood, N.; Naseem, T.; Mukhtar, F.; Basheer, R.

2011-01-01

Background: Coronary diseases appear to result from an overbalance between radical-generating, compared with radical-scavenging systems, a condition called as oxidative stress. Total antioxidant status (TAS) in human plasma reflects the balance between oxidants and antioxidants in each system. Bilirubin has been considered an antioxidant, with capacity to remove reactive species of oxygen. Present study tried to measure the total antioxidant status of first degree relatives of patients with IHD. Study also tried to evaluate the prognostic role of serum bilirubin in disease prevention or progression. Methods: Seventy five apparently healthy subjects in age group 20-50 years, comprising equal number of males and females, who were first degree relatives of ischemic heart disease patients, were included in the study. Family members were divided on the bases of their numbers, i.e., one family member (Group-A), 2 family members (Group-B) and more than 3 family members (Group-C). Study was cross sectional and carried out in a period of 6 months (Jun 2008-Jan 2009). Subjects with letter of consent were taken from general population. Seventy five healthy age matched people with no history of ischemic heart disease in family were taken as control. An overnight fasting blood sample was taken. Total antioxidant status was determined using a commercially available kit. Serum bilirubin was estimated by auto analyzer. Results: Family history of ischemic heart disease with serum bilirubin showed a significant negative correlation (p<0.05). But the values of TAS failed to show any significant correlation with the family history. It was observed that the value of serum bilirubin was decreased significantly (p<0.05) with an increased number of family members. Total antioxidant status failed to show any significant difference among all the three groups. Conclusion: Our data demonstrated that reduced serum levels of bilirubin were seen in people with a higher prevalence of coronary

Electron localization and optical absorption of polygonal quantum rings

Science.gov (United States)

Sitek, Anna; Serra, Llorenç; Gudmundsson, Vidar; Manolescu, Andrei

2015-06-01

We investigate theoretically polygonal quantum rings and focus mostly on the triangular geometry where the corner effects are maximal. Such rings can be seen as short core-shell nanowires, a generation of semiconductor heterostructures with multiple applications. We show how the geometry of the sample determines the electronic energy spectrum, and also the localization of electrons, with effects on the optical absorption. In particular, we show that irrespective of the ring shape low-energy electrons are always attracted by corners and are localized in their vicinity. The absorption spectrum in the presence of a magnetic field shows only two peaks within the corner-localized state domain, each associated with different circular polarization. This picture may be changed by an external electric field which allows previously forbidden transitions, and thus enables the number of corners to be determined. We show that polygonal quantum rings allow absorption of waves from distant ranges of the electromagnetic spectrum within one sample.

No effect modification of serum bilirubin or coffee consumption on the association of gamma-glutamyltransferase with glycated hemoglobin in a cross-sectional study of Japanese men and women

Directory of Open Access Journals (Sweden)

Wang Zhenjie

2012-10-01

Full Text Available Abstract Background Oxidative stress has been implicated in the development of type 2 diabetes mellitus. Bilirubin is a potent endogenous antioxidant, and coffee is a major source of exogenous antioxidants. Serum gamma-glutamyltransferase (GGT, a marker of oxidative stress, is a strong predictor of the risk of type 2 diabetes mellitus. This study evaluated the effect modification of bilirubin and coffee consumption on the association of serum GGT with glycated hemoglobin (HbA1c and the combined effect of bilirubin and coffee on HbA1c concentrations. Methods The subjects were 4492 men and 6242 women aged 49–76 years who participated in the baseline survey of an on-going cohort study on lifestyle-related diseases in Fukuoka, Japan. Geometric means of HbA1c were examined according to quartile categories of GGT, with stratification by serum total bilirubin (≥ 0.6 mg/dL versus less in men and ≥ 0.5 mg/dL versus less in women and coffee consumption ( Results HbA1 concentrations increased progressively with increasing levels of GGT in both men and women. The increasing trend of HbA1c concentrations associated with GGT did not differ by either bilirubin status or coffee consumption. Both men and women with high bilirubin had consistently lower concentrations of HbA1c across the GGT quartiles. Higher coffee consumption was associated with lower concentrations of HbA1c in women with low bilirubin (trend P = 0.04, but not with high bilirubin (trend P = 0.37. There was no such association between coffee and HbA1c in men with either low or high bilirubin levels. Conclusions Bilirubin is possibly protective against deterioration of glucose metabolism. Further studies are needed regarding the combined effect of bilirubin and coffee on glucose metabolism.

Solvated electron: criticism of a suggested correlation of chemical potential with optical absorption energy

International Nuclear Information System (INIS)

Farhataziz, M.

1984-01-01

A recent theoretical treatment of the absorption spectrum of the solvated electron, e - sub(s), maintains that rigorously μ 0 >= -0.75 Esub(av), which gives empirical relationship, μ 0 >= -(0.93 +- 0.02)Esub(max). For e - sub(s) in a particular solvent at a temperature and pressure, μ 0 , Esub(av) and Esub(max) are standard chemical potential, average energy of the absorption spectrum and the energy at the absorption maximum respectively. The temperature and pressure effects on the absorption spectrum of e - sub(s) in water and liquid ammonia do not support the equality sign in the above cited relationships. The implications of inequality expressed above are discussed for e - sub(s) in water and liquid ammonia. (author)

First-principles calculations of K-shell X-ray absorption spectra for warm dense nitrogen

International Nuclear Information System (INIS)

Li, Zi; Zhang, Shen; Kang, Wei; Wang, Cong; Zhang, Ping

2016-01-01

X-ray absorption spectrum is a powerful tool for atomic structure detection on warm dense matter. Here, we perform first-principles molecular dynamics and X-ray absorption spectrum calculations on warm dense nitrogen along a Hugoniot curve. From the molecular dynamics trajectory, the detailed atomic structures are examined for each thermodynamical condition. The K-shell X-ray absorption spectrum is calculated, and its changes with temperature and pressure along the Hugoniot curve are discussed. The warm dense nitrogen systems may contain isolated nitrogen atoms, N 2 molecules, and nitrogen clusters, which show quite different contributions to the total X-ray spectrum due to their different electron density of states. The changes of X-ray spectrum along the Hugoniot curve are caused by the different nitrogen structures induced by the temperature and the pressure. Some clear signatures on X-ray spectrum for different thermodynamical conditions are pointed out, which may provide useful data for future X-ray experiments.

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

Energy Technology Data Exchange (ETDEWEB)

Muhsain, Siti Nur Fadzilah, E-mail: sitinurfadzilah077@ppinang.uitm.edu.my [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Faculty of Pharmacy, University Teknologi Mara (Malaysia); Lang, Matti A., E-mail: m.lang@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)

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

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

International Nuclear Information System (INIS)

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

Study the multi-photon absorption process in two types of molecules

International Nuclear Information System (INIS)

Al-azawi, H.R.

1986-01-01

The aim of the present work was to study the multi-photon absorption process in two types of molecules; spherical top such as SF 6 molecules and assymetric top such as CHOOH and C 2 H 4 molecules. This work also aimed to study the effect of buffer gas pressure (Ar), which is transparent to the infrared (IR) laser on the multiphoton absorption of both types of molecules. A pulsed (TEA) CO 2 laser was used as a source which generates multi-lines in the IR-region of the spectrum and an optoacoustic detector was used to detect the energy absorbed by the molecules. In this study, the relaxation process was found to be faster in the heavy molecules than that in the light ones. A limit in the Ar pressure was observed. Below this limit, the gas acted as an active buffer gas and above it, the multi-photon absorption process was quenched. This work also aimed to study the multi-photon absorption spectrum for the CHOOH molecules in the range (1067-1090 cm -1 ). This spectrum was found to be consistent with the linear absorption spectrum obtained for the same range. The density of the vibrational states as a function of the vibrational energy was studied for the molecules SF 6 , CHOOH and C 2 H 4 . The results were used to interpret (i) the difference in the energy absorbed by difference molecules at the same energy density and (ii) the non-linearity in the multi-photon absorption for CHOOH molecules. 1 tab.; 40 figs.; 70 refs

Transcutaneous bilirubin--comparing the accuracy of BiliChek(R) and JM 103(R) in a regional postnatal unit.

LENUS (Irish Health Repository)

Qualter, Yvonne M

2012-01-31

OBJECTIVE: Transcutaneous bilirubin (TcB) has the potential to reduce serum bilirubin sampling. During a recent survey on the use of TcB in postnatal units in the Republic of Ireland, we identified that only 58% of the 19 units were using TcB and that only two devices were in use, the BiliChek(R) and JM 103(R). We aimed to evaluate and compare these two devices in a regional postnatal unit. METHODS: To evaluate and compare the accuracy of the BiliChek(R) and JM 103(R), we studied simultaneous TcB and total serum bilirubin (TSB) measurements from a population of jaundiced term and near term infants. We evaluated each device with regard to correlation with TSB and potential to safely reduce serum bilirubin testing. RESULTS: Both TcB devices strongly correlated with TSB (r = 0.88 for BiliChek(R) and r = 0.70 for JM 103(R). The BiliChek(R) and JM 103(R) were accurate up to cut-off values of 200 mumol\\/L and 180 mumol\\/L, respectively. Using Bhutani\\'s nomogram, 100% sensitivity was achieved using the 75th percentile for BiliChek(R) and the 40th percentile for JM 103(R). CONCLUSION: Both TcB devices correlated closely with moderately increased TSB levels and are suitable screening tools to identify jaundiced infants that require a serum bilirubin, with upper limit cut-off values. Both devices reduced the need for TSB levels. We found the BiliChek(R) slightly more accurate than the JM 103(R) for our study population. TcB however, is not in widespread use.

Influence of bilirubin on the distribution of 99mTc-HIDA and 99mTc-IODIDA in rats and their interaction with HSA

International Nuclear Information System (INIS)

Jovanovic, M.S.; Zmbova, B.; Zivanov-Stakic, D.; Vladimirov, S.

1993-01-01

The interaction of bilirubin and 99m Tc-HIDA and 99m Tc-IODIDA has been studied in rats. The mechanism of this interaction has been examined at the level of binding with human serum albumin (HSA) by the in vitro method. Percentage of binding with HSA, and affinity constants for 99m Tc-IODIDA were determined with and without bilirubin. Bilirubin was labeled with 99m Tc and its interaction with HSA was also examined. (author) 8 refs.; 2 figs.; 4 tabs

Absorption Spectrum and Density of States of Square, Rectangular, and Triangular Frenkel Exciton Systems with Gaussian Diagonal Disorder

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Ibrahim Avgin

2017-01-01

Full Text Available Using the coherent potential approximation, we investigate the effects of disorder on the optical absorption and the density of states of Frenkel exciton systems on square, rectangular, and triangular lattices with nearest-neighbor interactions and a Gaussian distribution of transition energies. The analysis is based on an elliptic integral approach that gives results over the entire spectrum. The results for the square lattice are in good agreement with the finite-array calculations of Schreiber and Toyozawa. Our findings suggest that the coherent potential approximation can be useful in interpreting the optical properties of two-dimensional systems with dominant nearest-neighbor interactions and Gaussian diagonal disorder provided the optically active states are Frenkel excitons.

Comparison of the vanadate oxidase method with the diazo method for serum bilirubin determination in dog, monkey, and rat.

Science.gov (United States)

Ameri, Mehrdad; Schnaars, Henry; Sibley, John; Honor, David

2011-01-01

The most widely used method for bilirubin concentration determination is the diazo method, which measures the color of azobilirubin. The vanadate oxidase method is based on oxidation of bilirubin to biliverdin by vanadate. The objective of this study was to compare total and direct bilirubin concentration ([Bt] and [Bd], respectively) determined by the diazo and vanadate oxidase methods in pooled serum samples from dogs, monkeys, and rats spiked with panels of different concentrations of bilirubin standards. Pooled serum samples from 40 dogs, 40 monkeys, and 60 rats were spiked with either ditaurine conjugates of bilirubin or a standard reference material. The results obtained from both assays were compared using Deming regression analysis. The intra- and interassay precision, expressed as a percentage of the coefficient of variation (%CV), was determined for [Bt] and [Bd], and the mean percentage of recovery was calculated. The vanadate oxidase method displayed an excellent correlation (r  =  0.99-1.00) with the diazo method. Using Deming regression, there were minimal negative or positive constant and proportional biases for [Bt] and [Bd]. The precision studies revealed that the vanadate oxidase method has comparable between-run and within-run CVs to those of the diazo method. The recovery study demonstrated that the diazo method more closely approximates the expected values of [Bt]. In conclusion, the vanadate oxidase method is a simple and rapid method that can be employed as an alternative to the diazo method when interfering substances are present in the serum samples of dog, monkey, and rat.

Spectroscopy of the 4.6 - 4.7 micron interstellar absorption features

International Nuclear Information System (INIS)

Geballe, T.R.

1984-01-01

Perhaps the most successful application of spectroscopy to the study of interstellar solid state infrared absorption features has been in the case of the previously unidentified feature near 4.6 μm first seen in absorption toward the protostar W33A. Whereas the original spectrum of this object, obtained at a resolving power of 70, revealed only a single deep absorption feature, a later spectrum, using a single channel grating spectrometer at ten times the resolving power, indicates that it is made up of three separate components. The central narrow absorption feature at 2140 cm -1 (4.67 μm) coincides in wavelength precisely with that of solid CO. It and its unresolved shoulder at just lower frequency have now been seen quite commonly in absorption toward other protostars. The broad absorption seen in W33A at 2165 cm -1 (4.62 μm) is apparently much less common. (author)

Optical absorption of charged excitons in semiconducting carbon nanotubes

DEFF Research Database (Denmark)

Rønnow, Troels Frimodt; Pedersen, Thomas Garm; Cornean, Horia

2012-01-01

In this article we examine the absorption coefficient of charged excitons in carbon nanotubes. We investigate the temperature and damping dependence of the absorption spectra. We show that the trion peak in the spectrum is asymmetric for temperatures greater than approximately 1 K whereas...

Spectrum of absorption of a weak signal by an atom in a strong field

International Nuclear Information System (INIS)

Bakaev, D.S.; Vdovin, Y.A.; Ermachenko, V.M.; Yakovlenko, S.I.

1985-01-01

An analysis is made of the spectrum of absorption of a weak probe electromagnetic field by two-level atoms in a strong resonant laser field, undergoing collision with buffer gas atoms. The analysis is made using an approach that allows for the direct influence of a strong electromagnetic field on the dynamics of an elastic collision between an active atom and a buffer gas atom. Rate equations are analyzed for a combined ''atom--strong electromagnetic field'' system (an atom ''dressed'' by the field) allowing for spontaneous and optical collisional transitions, and also for the interaction with the probe field. In the steady-state case, an expression is derived for the electric susceptibility of the medium at the small-signal frequency. This expression contains the rates of the optical collisional transitions that depend nontrivially on the parameters of the strong electromagnetic field. The phenomenological characteristics of optical collisional transitions generally used are only valid at low intensities and for small frequency detunings of the strong electromagnetic field, i.e., in the impact limit

Independent and combined effect of bilirubin and smoking on the progression of chronic kidney disease

Directory of Open Access Journals (Sweden)

Wang J

2018-01-01

Full Text Available Jiancheng Wang,1,* Binyan Wang,1,2,* Min Liang,1 Guobao Wang,1 Jianping Li,3 Yan Zhang,3 Yong Huo,3 Yimin Cui,4 Xiping Xu,1,5 Xianhui Qin1 1National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Renal Division, Nanfang Hospital, Southern Medical University, Guangzhou, 2Institute for Biomedicine, Anhui Medical University, Hefei, 3Department of Cardiology, 4Department of Pharmacy, Peking University First Hospital, Beijing, 5Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China *These authors contributed equally to this work Objective: Whether serum bilirubin and cigarette smoking affect the risk of renal function decline remains inconclusive. We aimed to test the independent and combined effects of bilirubin and cigarette smoking on the progression of chronic kidney disease (CKD in hypertensive adults. Methods: The study population consisted of 12,633 patients in the renal sub-study of the China Stroke Primary Prevention Trial. The primary outcome was progression of CKD, defined as a decrease in estimated glomerular filtration rate (eGFR of ≥30% and to a level of <60 mL/min/1.73 m2 if baseline eGFR was ≥60 mL/min/1.73 m2, or a decrease in eGFR of ≥50% if baseline eGFR was <60 mL/min/1.73 m2, or end-stage renal disease. The secondary outcomes included 1 rapid decline in renal function and 2 annual rate of eGFR decline. Results: The median follow-up duration was 4.4 years. Cigarette smoking had no significant effect on the progression of CKD (odds ratio [OR]: 1.11, 95% confidence interval [95% CI]: 0.78–1.57. However, a significantly lower risk of the primary event (OR: 0.72, 95% CI: 0.55–0.95 was found in participants in tertile 3 compared to those in tertiles 1–2 for total bilirubin (TBiL levels. More importantly, there was an interaction

A mathematical procedure to estimate solar absorptance of shallow water ponds

International Nuclear Information System (INIS)

Wu Hongbo; Tang Runsheng; Li Zhimin; Zhong Hao

2009-01-01

In this article, a mathematical procedure is developed for estimating solar absorption of shallow water ponds with different pond floor based on the fact that the solar radiation trapped inside the water layer undergoes multiplicative reflection and absorption and on that the solar absorption of water is selective. Theoretical model indicates that the solar absorption of a water pond is related to the reflectivity of the pond floor, the solar spectrum and the water depth. To validate the mathematical model, a concrete water pond measuring 3 x 3 x 0.24 m was constructed. Experimental results indicate that solar reflectivity calculated based on the mathematical model proposed in this work were in good agreement with those measured. For water ponds with a water-permeable floor, such as concrete floor, theoretical calculations of the solar absorptance of a water pond should be done based on the reflectivity of full wet floor, whereas for water ponds with a non-water-permeable floor, theoretical calculations should be done based on the fact that solar reflection on the floor is neither perfect specular reflection nor prefect isotropic diffuse reflection. Results of numerical calculation show that theoretical calculations of solar absorption of a water pond by dividing solar spectrum into six bands were pretty agreement with those by dividing solar spectrum into 20 bands.

Intracellular accumulation of bilirubin as a defense mechanism against increased oxidative stress

Czech Academy of Sciences Publication Activity Database

Zelenka, Jaroslav; Muchová, L.; Zelenková, M.; Váňová, K.; Vreman, H.J.; Wong, R.J.; Vítek, L.

2012-01-01

Roč. 94, č. 8 (2012), s. 1821-1827 ISSN 0300-9084 Grant - others:GA MZd(CZ) NT11327 Institutional research plan: CEZ:AV0Z50110509 Keywords : bilirubin * heme oxygenase * hyperbilirubinemia * lipopolysacccharide * oxidative stress Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.142, year: 2012

Preparation of chitosan/amino multiwalled carbon nanotubes nanocomposite beads for bilirubin adsorption in hemoperfusion.

Science.gov (United States)

Zong, Wenhui; Chen, Jian; Han, Wenyan; Chen, Jie; Wang, Yue; Wang, Weichao; Cheng, Guanghui; Ou, Lailiang; Yu, Yaoting

2018-01-01

Chitosan-carbon nanotube composite beads combines the advantages of chitosan in forming a stable biocompatible framework and carbon nanotube that provide nanometer effects (high strength and high specific surface area etc.). In this study, chitosan/amino multiwalled carbon nanotubes (CS/AMWCNT) composite beads was prepared by phase-inversion method, in which CS and AMWCNT was crosslinked by ethylene glycol diglycidyl ether (EGDE). The CS/AMWCNT nanocomposite beads produced has been characterized by BET, SEM, TGA, and Raman spectroscopy which exhibited enhanced thermal stability due to the incorporation of AMWCNT. Mechanical test results showed that mechanical strength of the CS/AMWCNT composite beads was significantly enhanced when comparing to unmodified chitosan beads, the breakage percentage decreased from 34.1% to 0.67%. The adsorption capacity for bilirubin was measured in PBS and BSA solutions, and the CS/AMWCNT composite beads with 5 wt% AMWCNT showed much higher adsorption capacity (12.7 mg/g in PBS and 7.6 mg/g in BSA) to bilirubin than chitosan beads (8.5 mg/g in PBS and 4.2 mg/g in BSA). Our nanocomposite beads with excellent hemocompatibility has a high potential application in blood purification as an efficient adsorbent for bilirubin. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 96-103, 2018. © 2016 Wiley Periodicals, Inc.

and three-dimensional models for analysis of optical absorption in ...

Indian Academy of Sciences (India)

Unknown

The optical energy gaps of WS2 single crystal were determined from the analysis of the absorption spectrum near ... Optical band gap; two- and three-dimensional; optical absorption. 1. ..... ssion, New Delhi, in the form of a research project is.

Studies on the optical absorption of copper-dopped myoglobin: conformational changes

International Nuclear Information System (INIS)

Lamy, M.T.M.

1976-03-01

Optical absorption changes in the visible and near U.V. spectrum of myoglobin molecules are observed when copper ions are added to the macromolecule. The heme optical transitions are investigated through a theoretical simulation of the optical absorption spectrum. A study of the absorption band in the region of 700 nm associated with the copper - myoglobin complexes indicated the existence of two kinds of metal-protein complexes: one associated with the six or eitht first added copper ions and the other related with the higher concentrations. Conformational changes caused by thermal treatment are studied in myoglobin water solutions and solutions containing copper ions. The phenomenon named pre-denaturation is observed through the optical absorption at 245 nm. It is shown that interactions between myoglobin molecules occur in the pre-denaturation phenomenon. (Author) [pt

Update on phototherapy in jaundiced neonates

DEFF Research Database (Denmark)

Ebbesen, Finn; Hansen, Thor Willy Ruud; Maisels, M Jeffrey

2017-01-01

is the current treatment of choice. OBJECTIVE: To present an update on the most important issues involved in phototherapy for jaundiced infants. RESULTS: Light absorption by bilirubin in the skin transforms the native Z,Z-bilirubin to conformational photoisomers Z,E-bilirubin and E,Z-bilirubin and structural...

The albumin-bilirubin grade uncovers the prognostic relationship between hepatic reserve and immune dysfunction in HIV-associated hepatocellular carcinoma.

Science.gov (United States)

Pinato, D J; Sharma, R; Citti, C; Platt, H; Ventura-Cots, M; Allara, E; Chen, T-Y; Dalla Pria, A; Jain, M; Mínguez, B; Kikuchi, L; Kaufman West, E; Merli, M; Kaplan, D E; Hasson, H; Marks, K; Nelson, M; Núñez, M; Aytaman, A; Bower, M; Bräu, N

2018-01-01

Hepatocellular carcinoma (HCC) is a leading cause of liver-related mortality in people living with HIV, where co-infection with hepatotropic viruses accelerates the course of chronic liver disease. To evaluate whether the albumin-bilirubin (ALBI) grade, a more accurate marker of liver dysfunction in HCC, might identify patients with progressive liver dysfunction in the context of HIV/hepatitis co-infection. Using uni- and multi-variable analyses, we studied the albumin-bilirubin grade as a predictor of overall survival (OS) in a large, multi-center cohort of patients with HIV-associated HCC recruited from 44 centres in 9 countries within the Liver Cancer in HIV study group. Patients who underwent liver transplantation were excluded. A total of 387 patients, predominantly HCV co-infected (78%) with balanced representation of all Barcelona Clinic Liver Cancer (BCLC) stages (A = 33%, B = 18%, C = 37%, D = 12%) were recruited. At HCC diagnosis, 84% had been on anti-retrovirals for a median duration of 8.8 years. The albumin-bilirubin grade identified significant differences in median survival of 97 months for grade 1 (95% CI 13-180 months), 17 months for grade 2 (95% CI 11-22 months) and 6 months for grade 3 (95% CI 4-9 months, P bilirubin grade correlated with lower CD4 counts (464/373/288 cells/mm 3 for grades 1/2/3) and higher HIV viraemia (3.337/8.701/61.845 copies/mL for grades 1/2/3, P bilirubin grade highlights the interplay between liver reserve and immune dysfunction as prognostic determinants in HIV-associated HCC. © 2017 John Wiley & Sons Ltd.

Predictive effects of bilirubin on response of colorectal cancer to irinotecan-based chemotherapy.

Science.gov (United States)

Yu, Qian-Qian; Qiu, Hong; Zhang, Ming-Sheng; Hu, Guang-Yuan; Liu, Bo; Huang, Liu; Liao, Xin; Li, Qian-Xia; Li, Zhi-Huan; Yuan, Xiang-Lin

2016-04-28

To examine the predictive effects of baseline serum bilirubin levels and UDP-glucuronosyltransferase (UGT) 1A1*28 polymorphism on response of colorectal cancer to irinotecan-based chemotherapy. The present study was based on a prospective multicenter longitudinal trial of Chinese metastatic colorectal cancer (mCRC) patients treated with irinotecan-based chemotherapy (NCT01282658). Baseline serum bilirubin levels, including total bilirubin (TBil) and unconjugated bilirubin (UBil), were measured, and genotyping of UGT1A1*28 polymorphism was performed. Receiver operating characteristic curve (ROC) analysis was used to determine cutoff values of TBil and UBil. The TBil values were categorized into > 13.0 or ≤ 13.0 groups; the UBil values were categorized into > 4.1 or ≤ 4.1 groups. Combining the cutoff values of TBil and UBil, which was recorded as CoBil, patients were classified into three groups. The classifier's performance of UGT1A1*28 and CoBil for predicting treatment response was evaluated by ROC analysis. Associations between response and CoBil or UGT1A1*28 polymorphism were estimated using simple and multiple logistic regression models. Among the 120 mCRC patients, the serum bilirubin level was significantly different between the UGT1A1*28 wild-type and mutant genotypes. Patients with the mutant genotype had an increased likelihood of a higher TBil (P = 0.018) and a higher UBil (P = 0.014) level compared with the wild-type genotype. Patients were stratified into three groups based on CoBil. Group 1 was patients with TBil > 13.0 and UBil > 4.1; Group 2 was patients with TBil ≤ 13.0 and UBil > 4.1; and Group 3 was patients with TBil ≤ 13.0 and UBil ≤ 4.1. Patients in Group 3 had more than a 10-fold higher likelihood of having a response in the simple (OR = 11.250; 95%CI: 2.286-55.367; P = 0.003) and multiple (OR = 16.001; 95%CI: 2.802 -91.371; P = 0.002) analyses compared with the Group 1 individuals. Patients carrying the UGT1A1*28 (TA)7 allele were 4

Dynamic Change of Total Bilirubin after Portal Vein Embolization is Predictive of Major Complications and Posthepatectomy Mortality in Patients with Hilar Cholangiocarcinoma.

Science.gov (United States)

Ou Yang, Qing; Zhang, Sheng; Cheng, Qing-Bao; Li, Bin; Feng, Fei-Ling; Yu, Yong; Luo, Xiang-Ji; Lin, Zhao-Fen; Jiang, Xiao-Qing

2016-05-01

This study aims to evaluate the role of dynamic change in total bilirubin after portal vein embolization (PVE) in predicting major complications and 30-day mortality in patients with hilar cholangiocarcinoma (HCCA). Retrospective analysis of prospectively maintained data of 64 HCCA patients who underwent PVE before hepatectomy in our institution was used. Total bilirubin and other parameters were measured daily in peri-PVE period. The difference between them and the baseline value from days 0-5 to day -1 (∆D1) and days 5-14 to day -1 (∆D2) were calculated. The relationship between ∆D1 and ∆D2 of total bilirubin and major complications as well as 30-day mortality was analyzed. Out of 64 patients, 10 developed major complications (15.6 %) and 6 patients (9.3 %) had died within 30 days after surgery. The ∆D2 of total bilirubin after PVE was most significantly associated with major complications (P 3 (OR = 12.048; 95 % CI 1.019-143.321), ∆D2 of total bilirubin (OR = 1.058; 95 % CI 1.007-1.112), and ∆D2 of prealbumin (OR = 0.975; 95 % CI 0.952-0.999) were associated with higher risk of 30-day mortality after PVE. Receiver operating characteristic curves showed that ∆D2 of total bilirubin were better predictors than ∆D1 for major complications (AUC (∆D2) 0.817; P = 0.002 vs. AUC (∆D1) 0.769; P = 0.007) and 30-day mortality (ACU(∆D2) 0.868; P = 0.003 vs. AUC(∆D1) 0.721;P = 0.076). Patients with increased total bilirubin in 5-14 days after PVE may indicate a higher risk of major complications and 30-day mortality if the major hepatectomy were performed.

Association of human liver bilirubin UDP-glucuronyltransferase activity with a polymorphism in the promoter region of the UGT1A1 gene

NARCIS (Netherlands)

Raijmakers, MTM; Jansen, PLM; Steegers, EAP; Peters, WHM

Background/Aims: Gilbert's syndrome is a benign form of a deficiency in bilirubin glucuronidation. It is associated with a homozygous polymorphism, A(TA)(7)TAA instead of A(TA)(6)TAA, in the TATA-box of the promoter region of the bilirubin UDP-glucuronyltransferase gene. In this study the

Assessment of adjuvant ademetionine therapy for the bilirubin metabolism and target organ function of neonatal jaundice

Directory of Open Access Journals (Sweden)

Fang Xu

2017-11-01

Full Text Available Objective: To study the effect of adjuvant ademetionine (SAMe therapy on the bilirubin metabolism and target organ function of neonatal jaundice. Methods: A total of 68 children who were diagnosed with neonatal jaundice in Hubei Jianghan Oilfield General Hospital between March 2015 and April 2017 were selected as the research subjects and randomly divided into the SAMe group who received ademetionine combined with blue ray irradiation and the control group who received blue ray irradiation. The serum contents of bilirubin metabolism indexes and target organ injury markers before treatment as well as 3 d and 7 d after treatment. Results: 3 d and 7 d after treatment, serum TBIL, ALT, AST, GGT, TBA, CK-MB, cTnT, MYO, HBDH, NSE, S100B and GFAP levels of both groups were lower than those before treatment, and serum TBIL, ALT, AST, GGT, TBA, CK-MB, cTnT, MYO, HBDH, NSE, S100B and GFAP levels of SAMe group were lower than those of control group. Conclusion: Adjuvant ademetionine therapy can improve the bilirubin metabolism of neonatal jaundice and reduce the central nerve, myocardial and liver injury.

Unilobar versus bilobar biliary drainage: effect on quality of life and bilirubin level reduction

Directory of Open Access Journals (Sweden)

Shivanand Gamanagatti

2016-01-01

Conclusion: Percutaneous biliary drainage provides good palliation of malignant obstructive jaundice. Partial-liver drainage achieved results as good as those after complete liver drainage with significant improvements in QOL and reduction of the bilirubin level.

Analytical model of diffuse reflectance spectrum of skin tissue

Energy Technology Data Exchange (ETDEWEB)

Lisenko, S A; Kugeiko, M M; Firago, V A [Belarusian State University, Minsk (Belarus); Sobchuk, A N [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

2014-01-31

We have derived simple analytical expressions that enable highly accurate calculation of diffusely reflected light signals of skin in the spectral range from 450 to 800 nm at a distance from the region of delivery of exciting radiation. The expressions, taking into account the dependence of the detected signals on the refractive index, transport scattering coefficient, absorption coefficient and anisotropy factor of the medium, have been obtained in the approximation of a two-layer medium model (epidermis and dermis) for the same parameters of light scattering but different absorption coefficients of layers. Numerical experiments on the retrieval of the skin biophysical parameters from the diffuse reflectance spectra simulated by the Monte Carlo method show that commercially available fibre-optic spectrophotometers with a fixed distance between the radiation source and detector can reliably determine the concentration of bilirubin, oxy- and deoxyhaemoglobin in the dermis tissues and the tissue structure parameter characterising the size of its effective scatterers. We present the examples of quantitative analysis of the experimental data, confirming the correctness of estimates of biophysical parameters of skin using the obtained analytical expressions. (biophotonics)

Laser frequency locking based on the normal and abnormal saturated absorption spectroscopy of 87Rb

International Nuclear Information System (INIS)

Wan Jian-Hong; Liu Chang; Wang Yan-Hui

2016-01-01

We present a practical method to avoid the mis-locking phenomenon in the saturated-absorption-spectrum laser-frequency-locking system and set up a simple theoretical model to explain the abnormal saturated absorption spectrum. The method uses the normal and abnormal saturated absorption spectra of the same transition 5 2 S 1/2 , F = 2–5 2 P 3/2 , F′ = 3 saturated absorption of the 87 Rb D 2 resonance line. After subtracting these two signals with the help of electronics, we can obtain a spectrum with a single peak to lock the laser. In our experiment, we use the normal and inverse signals of the transitions 5 2 S 1/2 , F = 2–5 2 P 3/2 , F′ = 3 saturated absorption of the 87 Rb D 2 resonance line to lock a 780-nm distributed feedback (DFB) diode laser. This method improves the long-term locking performance and is suitable for other kinds of diode lasers. (paper)

Studies on preparing and adsorption property of grafting terpolymer microbeads of PEI-GMA/AM/MBA for bilirubin.

Science.gov (United States)

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.

Prediction of Neonatal Hyperbilirubinemia Using 1st Day Serum Bilirubin Levels.

Science.gov (United States)

Spoorthi, S M; Dandinavar, Siddappa F; Ratageri, Vinod H; Wari, Prakash K

2018-02-15

The study was conducted on Full term neonates with birth weight > 2.5 kg born in KIMS, Hubballi with an objective to determine the first day Total Serum Bilirubin (TSB) value so as to predict subsequent development of significant hyperbilirubinemia in term neonates. All enrolled neonates were sampled for TSB and blood group on Day 1 at 20 ± 4 h and then followed up clinically by Kramer's rule and when the clinical jaundice by Kramer's rule was >10 mg/dl, TSB levels were repeated. A total of 180 newborns were enrolled for the study and 165 babies completed the study. Out of these, 17(10.3%) babies had significant hyperbilirubinemia by day 5 of life. Using Receiver Operating Characteristic (ROC) Curve, a cut off TSB value of 6.15 mg/dl was determined with sensitivity of 82.4%, specificity of 81.8%, positive predictive value of 32.8%, negative predictive value 97.6%. In term neonates, the first day total bilirubin level at 20 ± 4 h of life <6.15 predicts the low risk of subsequent significant hyperbilirubinemia with high probability.

Efficient Photocatalytic Bilirubin Removal over the Biocompatible Core/Shell P25/g-C3N4 Heterojunctions with Metal-free Exposed Surfaces under Moderate Green Light Irradiation

Science.gov (United States)

Kang, Shifei; Qin, Hengfei; Zhang, Lu; Huang, Yongkui; Bai, Xia; Li, Xi; Sun, Di; Wang, Yangang; Cui, Lifeng

2017-03-01

Highly-monodispersed g-C3N4/TiO2 hybrids with a core/shell structure were synthesized from a simple room temperature impregnation method, in which g-C3N4 was coated through self-assembly on the commercially available Degussa P25 TiO2 nanoparticles. Structural and surface characterizations showed that the presence of g-C3N4 notably affected the light absorption characteristics of TiO2. The g-C3N4/TiO2 heterojunctions with metal-free exposed surfaces were directly used as biocompatible photocatalysts for simulated jaundice phototherapy under low-power green-light irradiation. The photocatalytic activity and stability of g-C3N4/TiO2 were enhanced relative to pure P25 or g-C3N4, which could be ascribed to the effective Z-scheme separation of photo-induced charge carriers in g-C3N4/TiO2 heterojunction. The photoactivity was maximized in the 4 wt.% g-C3N4-coated P25, as the bilirubin removal rate under green light irradiation was more than 5-fold higher than that under the clinically-used blue light without any photocatalyst. This study approves the future applications of the photocatalyst-assisted bilirubin removal in jaundice treatment under moderate green light which is more tolerable by humans.

Infrared absorption of human breast tissues in vitro

Energy Technology Data Exchange (ETDEWEB)

Liu Chenglin [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Zhang Yuan [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Yan Xiaohui [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Zhang Xinyi [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China) and Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)]. E-mail: xy-zhang@fudan.edu.cn; Li Chengxiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yang Wentao [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China); Shi Daren [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China)

2006-07-15

The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared (SR-FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR) source, higher resolving power is achieved in SR-FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some specific absorption peaks were found in breast cancer tissues by SR-FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer.

ON NEUTRAL ABSORPTION AND SPECTRAL EVOLUTION IN X-RAY BINARIES

International Nuclear Information System (INIS)

Miller, J. M.; Cackett, E. M.; Reis, R. C.

2009-01-01

Current X-ray observatories make it possible to follow the evolution of transient and variable X-ray binaries across a broad range in luminosity and source behavior. In such studies, it can be unclear whether evolution in the low-energy portion of the spectrum should be attributed to evolution in the source, or instead to evolution in neutral photoelectric absorption. Dispersive spectrometers make it possible to address this problem. We have analyzed a small but diverse set of X-ray binaries observed with the Chandra High Energy Transmission Grating Spectrometer across a range in luminosity and different spectral states. The column density in individual photoelectric absorption edges remains constant with luminosity, both within and across source spectral states. This finding suggests that absorption in the interstellar medium strongly dominates the neutral column density observed in spectra of X-ray binaries. Consequently, evolution in the low-energy spectrum of X-ray binaries should properly be attributed to evolution in the source spectrum. We discuss our results in the context of X-ray binary spectroscopy with current and future X-ray missions.

Bioelectrocatalytic mediatorless dioxygen reduction at carbon ceramic electrodes modified with bilirubin oxidase

International Nuclear Information System (INIS)

Nogala, Wojciech; Celebanska, Anna; Szot, Katarzyna; Wittstock, Gunther; Opallo, Marcin

2010-01-01

Carbon ceramic electrodes were prepared by sol-gel processing of a hydrophobic precursor - methyltrimethoxysilane (MTMOS) - together with dispersed graphite microparticles according to a literature procedure. Bilirubin oxidase (BOx) was adsorbed on this electrode from buffer solution and this process was followed by atomic force microscopy (AFM). The electrodes exhibited efficient mediatorless electrocatalytic activity towards dioxygen reduction. The activity depends on the time of adsorption of the enzyme and the pH. The electrode remains active in neutral solution. The bioelectrocatalytic activity is further increased when a fraction of the carbon microparticles is replaced by sulfonated carbon nanoparticles (CNPs). This additive enhances the electrical communication between the enzyme and the electronic conductor. At pH 7 the carbon ceramic electrode modified with bilirubin oxidase retains ca. half of its highest activity. The role of the modified nanoparticles is confirmed by experiments in which a film embedded in a hydrophobic silicate matrix also exhibited efficient mediatorless biocatalytic dioxygen reduction. Scanning electrochemical microscopy (SECM) of the studied electrodes indicated a rather even distribution of the catalytic activity over the electrode surface.

PG 1700 + 518 - a low-redshift, broad absorption line QSO

International Nuclear Information System (INIS)

Pettini, M.; Boksenberg, A.

1985-01-01

The first high-resolution optical spectra and lower resolution UV spectra of PG 1700 + 518, the only known broad-absorption-line (BAL) QSO at low emission redshift (0.288) are presented. The optical data were obtained with the Isaac Newton Telescope on the island of La Palma and the UV data with the International Ultraviolet Explorer satellite. The outstanding feature of the optical spectrum is a strong, broad Mg II absorption trough, detached from the Mg II emission line and indicative of ejection velocities of between 7000 and 18,000 km/s. Also detected were narrow (FWHM = 350 km/s) Mg II absorption lines at absolute z = 0.2698, which are probably related to the mass ejection phenomenon. It is concluded that the emission-line spectrum is similar to that of other low-redshift QSOs although there are some obvious differences from typical BAL QSOs, most notably in the unusually low level of ionization of both emission-line and broad absorption line gas. 21 references

A green and facile approach for synthesizing imine to develop optical biosensor for wide range detection of bilirubin in human biofluids.

Science.gov (United States)

Ellairaja, Sundaram; Shenbagavalli, Kathiravan; Ponmariappan, Sarkaraisamy; Vasantha, Vairathevar Sivasamy

2017-05-15

Bilirubin, a key biomarker for the jaundice and its clinical diagnosis needs a better analytical tool. A novel and simple fluorescent platform based on (2,2'-((1E,1'E)-((6-bromopyridine-2,3-diyl) bis(azanylylidene)) bis(methanylylidene diphenol) (BAMD) was designed. BAMD showed a remarkable fluorescent intensity with a very good quantum yield of 0.85 and lifetime of 870ps. Hence, it was applied for the determination of bilirubin using both colorimetric and fluorimetric techniques in physiological and basic pH. Under optimized experimental conditions, the probe detects bilirubin selectively in the presence of other interfering biomolecules and metal ions. The linear range of detection is 1pM-500µM at pH=7.4 and LOD is 2.8 and 3.3 pM at pH=7.4 and 9.0, respectively, which were reported so far. The probe detects the bilirubin through FRET mechanism. The practical application of the probe was successfully tested in the human blood and urine samples. Based on all above advantages, this simple idea can be applied to design a simple clinical diagnostic tool for jaundice. Copyright © 2016. Published by Elsevier B.V.

A cross-sectional study to evaluate second line virological failure and elevated bilirubin as a surrogate for adherence to atazanavir/ritonavir in two urban HIV clinics in Lilongwe, Malawi.

Science.gov (United States)

Ongubo, Dennis Miyoge; Lim, Robertino; Tweya, Hannock; Stanley, Christopher Chikhosi; Tembo, Petros; Broadhurst, Richard; Gugsa, Salem; Ngongondo, McNeil; Speight, Colin; Heller, Tom; Phiri, Sam; Hosseinipour, Mina C

2017-07-03

Malawi's national antiretroviral therapy program provides atazanavir/ritonavir-based second line regimens which cause concentration-dependent rise in indirect bilirubin. We sought to determine if elevated bilirubin, as a surrogate of atazanavir/ritonavir adherence, can aid in the evaluation of second line virological failure in Malawi. We conducted a cross-sectional study of HIV-infected patients ≥15 years who were on boosted protease inhibitor-based second line antiretroviral therapy for at least 6 months in two urban HIV clinics in Lilongwe, Malawi. Antiretroviral therapy history and adherence data were extracted from the electronic medical records and blood was drawn for viral load, complete blood count, total bilirubin, and CD4 cell count at a clinic visit. Factors associated with virological failure were assessed using multivariate logistic regression model. Out of 376 patients on second line antiretroviral therapy evaluated, 372 (98.9%) were on atazanavir/ritonavir-based therapy and 142 (37.8%) were male. Mean age was 40.9 years (SD ± 10.1), mean duration on second line antiretroviral therapy was 41.9 months (SD ± 27.6) and 256 patients (68.1%) had elevated bilirubin >1.3 mg/dL. Overall, 35 (9.3%) patients had viral load >1000 copies/ml (virological failure). Among the virologically failing vs. non-failing patients, bilirubin was elevated in 34.3% vs. 72.0% respectively (p bilirubin levels (aOR 5.4, p bilirubin levels better predicted virological failure than pill count adherence. Therefore, strategic use of bilirubin and viral load testing to target adherence counseling and support may be cost-effective in monitoring second line antiretroviral therapy adherence and virological failure. Drug resistance testing targeted for patients with virological failure despite elevated bilirubin levels would facilitate timely switch to third line antiretroviral regimens whenever available.

First-principles calculation of optical absorption spectra in conjugated polymers: Role of electron-hole interaction

International Nuclear Information System (INIS)

Rohlfing, Michael; Tiago, M.L.; Louie, Steven G.

2000-01-01

Experimental and theoretical studies have shown that excitonic effects play an important role in the optical properties of conjugated polymers. The optical absorption spectrum of trans-polyacetylene, for example, can be understood as completely dominated by the formation of exciton bound states. We review a recently developed first-principles method for computing the excitonic effects and optical spectrum, with no adjustable parameters. This theory is used to study the absorption spectrum of two conjugated polymers: trans-polyacetylene and poly-phenylene-vinylene(PPV)

First-principles calculation of optical absorption spectra in conjugated polymers: Role of electron-hole interaction

Energy Technology Data Exchange (ETDEWEB)

Rohlfing, Michael; Tiago, M.L.; Louie, Steven G.

2000-03-20

Experimental and theoretical studies have shown that excitonic effects play an important role in the optical properties of conjugated polymers. The optical absorption spectrum of trans-polyacetylene, for example, can be understood as completely dominated by the formation of exciton bound states. We review a recently developed first-principles method for computing the excitonic effects and optical spectrum, with no adjustable parameters. This theory is used to study the absorption spectrum of two conjugated polymers: trans-polyacetylene and poly-phenylene-vinylene(PPV).

Association of serum bilirubin and promoter variations in HMOX1 and UGT1A1 genes with sporadic colorectal cancer

Czech Academy of Sciences Publication Activity Database

Jirásková, A.; Novotný, J.; Novotný, L.; Vodička, Pavel; Pardini, Barbara; Naccarati, Alessio; Schwertner, H. A.; Hubáček, J. A.; Punčochářová, L.; Šmerhovský, Z.; Vítek, L.

2012-01-01

Roč. 131, č. 7 (2012), s. 1549-1555 ISSN 0020-7136 R&D Projects: GA ČR GA310/07/1430 Grant - others:GA MŠk(CZ) ME849; GA MŠk(CZ) 2B06155; GA MŠk(CZ) LH11030 Program:2B Institutional research plan: CEZ:AV0Z50390703 Keywords : bilirubin * bilirubin UDP-glucuronosyl transferase * colorectal cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.198, year: 2012

Bilirubin oxidase bound to multi-walled carbon nanotube-modified gold

International Nuclear Information System (INIS)

Schubert, Kirsten; Goebel, Gero; Lisdat, Fred

2009-01-01

We report on direct electron transfer (DET) reactions of bilirubin oxidase at multi-walled carbon nanotube-(MWCNT) modified gold electrodes. MWCNTs are very suitable for protein immobilisation and provide surface groups that can be used for the stable fixation on electrodes. They can also effectively replace the natural substrate of BOD - bilirubin, the electron donor for oxygen reduction. The bioelectrocatalytic oxygen reduction was recorded using linear sweep voltammetry (LSV) with BOD covalently linked to the nanotubes. The start potential of the bioelectrocatalytic oxygen reduction at pH 7 and a scan rate of 10 mV/s was determined to be 485 ± 10 mV vs. Ag/AgCl, 1 M KCl (720 mV vs. SHE). Current densities up to 500 μA/cm 2 were detected in an air-saturated buffer at room temperature (25 ± 5 deg. C). Experiments with a rotating disk electrode (RDE) indicate a diffusion controlled electrode reaction. A k s value in the range of 80-100 s -1 could be estimated. The DET could also be observed directly by the redox conversion of a copper centre of BOD under anaerobic conditions. A peak pair with a formal potential of 680 ± 10 mV vs. SHE was found. The T1 site is probably addressed by the electrode as indicated by several experimental studies

Selective optical contacting for solar spectrum management

Science.gov (United States)

Yang, Jianfeng; Chen, Weijian; Wang, Bo; Zhang, Zhilong; Huang, Shujuan; Shrestha, Santosh; Wen, Xiaoming; Patterson, Robert; Conibeer, Gavin

2017-02-01

Solar spectrum management using up/down conversion is an important method to improve the photovoltaic energy conversion efficiency. It asks for a monochromatic luminescence absorption at the band edge of the photovoltaic device to reduce both the sub-band-gap and over-band-gap energy losses. Here, we demonstrate an energy selective optical contacting concept to improve the luminescence transfer efficiency for spectrum management. By increasing both the luminescence emission and re-absorption ability through photonic resonance, an efficient photon transfer channel could be established between the luminescence emitter and the photovoltaic component in a near-field region. This concept is not only able to compensate the insufficient band edge absorption ability of the photovoltaic device, but also to break the far-field limitation of luminescence radiation. The energy selection on the optical spectrum naturally imposed by the mode resonance is also helpful to improve the monochromaticity of the luminescence yield. In this paper, a photonic crystal cavity is used to realize the optical contacting concept between a thin silicon film and spectrum converter. The optical power and photon flux transferred between different components are calculated analytically using the electromagnetic Green's function. The corresponding radiative dipole moment is estimated by the fluctuation-dissipation theorem. The example shows an over 80 times enhancement in the luminescence absorbance by the silicon layer, illustrating the great potential of this concept to be applied on nano-structured photovoltaic devices.

Extreme Variability in a Broad Absorption Line Quasar

Energy Technology Data Exchange (ETDEWEB)

Stern, Daniel; Jun, Hyunsung D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Graham, Matthew J.; Djorgovski, S. G.; Donalek, Ciro; Drake, Andrew J.; Mahabal, Ashish A.; Steidel, Charles C. [California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Arav, Nahum; Chamberlain, Carter [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Barth, Aaron J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Glikman, Eilat, E-mail: daniel.k.stern@jpl.nasa.gov [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

2017-04-20

CRTS J084133.15+200525.8 is an optically bright quasar at z = 2.345 that has shown extreme spectral variability over the past decade. Photometrically, the source had a visual magnitude of V ∼ 17.3 between 2002 and 2008. Then, over the following five years, the source slowly brightened by approximately one magnitude, to V ∼ 16.2. Only ∼1 in 10,000 quasars show such extreme variability, as quantified by the extreme parameters derived for this quasar assuming a damped random walk model. A combination of archival and newly acquired spectra reveal the source to be an iron low-ionization broad absorption line quasar with extreme changes in its absorption spectrum. Some absorption features completely disappear over the 9 years of optical spectra, while other features remain essentially unchanged. We report the first definitive redshift for this source, based on the detection of broad H α in a Keck/MOSFIRE spectrum. Absorption systems separated by several 1000 km s{sup −1} in velocity show coordinated weakening in the depths of their troughs as the continuum flux increases. We interpret the broad absorption line variability to be due to changes in photoionization, rather than due to motion of material along our line of sight. This source highlights one sort of rare transition object that astronomy will now be finding through dedicated time-domain surveys.

MODULATION OF THE INFLAMMATORY CYTOKINES AND CYTOPROTECTIVE ENZYME BY BILIRUBIN TREATMENT TO ENHANCE CUTANEOUS WOUND HEALING IN RATS

Directory of Open Access Journals (Sweden)

Raju Prasad

2017-06-01

Full Text Available Inflammation is the main process of wound healing where expression of certain cytokines likes Interleukin-10 (IL-10 and Tumour necrosis factor ∝ (TNF ∝ plays an important role. In view of the antioxidant potential of bilirubin, the present study was aimed to evaluate time-dependent (day 3, 7, 14 wound healing effects of bilirubin ointment (0.3% in excisional wound model in rats. Thirty-six acclimatized healthy male Wistar rats (120-150g were divided into control and treated groups containing 18 rats each. Each group was further sub- divided into three sub-groups (day 3, 7 and 14 days, n= 6. The ointment base (soft paraffin 90%, lanolin 5% and hard paraffin 5% and bilirubin ointment (0.3% were applied topically once daily for 14 days in control and treated group respectively. The wound area was determined on days 3, 7, and 14. The mRNA expression of TNF ∝ gene and IL-10 gene were determined on days 3, 7 and 14 by Real Time PCR and their protein levels by ELISA method. The protein expression of cyto-protective enzyme HO-1 (Heme oxygenage-1 and growth factor VEGF (Vascular growth factor was determined by western blotting method. The mRNA expression and protein level of TNF ∝ was significantly reduced and IL-10 was significantly increased whereas the expression of HO-1 enzyme and VEGF was significantly increased in treated group on days 3, 7 and 14. It may be concluded that the bilirubin has pro-healing potential.

A study of the Nb3Ge system by Ge K-edge extended x-ray absorption fine structure and x-ray absorption near-edge structure spectroscopy

International Nuclear Information System (INIS)

Saini, N L; Filippi, M; Wu Ziyu; Oyanagi, H; Ihara, H; Iyo, A; Agrestini, S; Bianconi, A

2002-01-01

The local structure of Nb 3 Ge intermetallic superconductor has been studied by Ge K-edge absorption spectroscopy. Extended x-ray absorption fine structure (EXAFS) experiments show two Ge-Nb distances. In addition to the crystallographic distance of ∼2.87 A, there exists a second Ge-Nb distance, shorter than the first by ∼0.2 A, assigned to a phase with short-range symmetry related to local displacements in the Nb-Nb chains. The x-ray absorption near-edge structure (XANES) spectrum has been simulated by full multiple-scattering calculations considering the local displacements determined by the EXAFS analysis. The XANES spectrum has been well reproduced by considering a cluster of 99 atoms within a radius of about 7 A from the central Ge atom and introducing determined local displacements

Indicators of inflammation and cellular damage in chronic asymptomatic or oligosymptomatic alcoholics: correlation with alteration of bilirubin and hepatic and pancreatic enzymes

Directory of Open Access Journals (Sweden)

Borini Paulo

1999-01-01

Full Text Available Biochemical and hematimetric indicators of inflammation and cell damage were correlated with bilirubin and hepatic and pancreatic enzymes in 30 chronic male alcoholics admitted into psychiatric hospital for detoxification and treatment of alcoholism. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, and total bilirubin were altered, respectively, in 90%, 63%, 87%, 23% and 23% of the cases. None of the indicators of inflammation (lactic dehydrogenase, altered in 16% of the cases; alpha-1 globulin, 24%; alpha-2 globulin, 88%; leucocyte counts, 28% was correlated with alterations of bilirubin or liver enzymes. Lactic dehydrogenase was poorly sensitive for detection of hepatocytic or muscular damage. Alterations of alpha-globulins seemed to have been due more to alcohol metabolism-induced increase of lipoproteins than to inflammation. Among indicators of cell damage, serum iron, increased in 40% of the cases, seemed to be related to liver damage while creatine phosphokinase, increased in 84% of the cases, related to muscle damage. Hyperamylasemia was found in 20% of the cases and significantly correlated with levels of bilirubin, alkaline phosphatase and gamma-glutamyltransferase. It was indicated that injuries of liver, pancreas, salivary glands, and muscle occurred in asymptomatic or oligosymptomatic chronic alcoholics.

In situ gas temperature measurements by UV-absorption spectroscopy

DEFF Research Database (Denmark)

Fateev, Alexander; Clausen, Sønnik

2009-01-01

The absorption spectrum of the NO A(2)Sigma(+) uniform and stable gas temperatures over a 0.533 m path....... The accuracy of both methods is discussed. Validation of the classical Lambert-Beer law has been demonstrated at NO concentrations up to 500 ppm and gas temperatures up to 1,500 degrees C over an optical absorption path length of 0.533 m....

Absorption spectrum of the firefly luciferin anion isolated in vacuo.

Science.gov (United States)

Støchkel, Kristian; Milne, Bruce F; Brøndsted Nielsen, Steen

2011-03-24

The excited-state physics of the firefly luciferin anion depends on its chemical environment, and it is therefore important to establish the intrinsic behavior of the bare ion. Here we report electronic absorption spectra of the anion isolated in vacuo obtained at an electrostatic ion storage ring and an accelerator mass spectrometer where ionic dissociation is monitored on a long time scale (from 33 μs and up to 3 ms) and on a short time scale (0-3 μs), respectively. In the ring experiment the yield of all neutrals (mainly CO(2)) as a function of wavelength was measured whereas in the single pass experiment, the abundance of daughter ions formed after loss of CO(2) was recorded to provide action spectra. We find maxima at 535 and 265 nm, and that the band shape is largely determined by the sampling time interval, which is due to the kinetics of the dissociation process. Calculations at the TD-B3LYP/TZVPP++ level predict maximum absorption at 533 and 275 nm for the carboxylate isomer in excellent agreement with the experimental findings. The phenolate isomer lies higher in energy by 0.22 eV, and also its absorption maximum is calculated to be at 463 nm, which is far away from the experimental value. Our data serve to benchmark future theoretical models for bioluminescence from fireflies.

Indicators of inflammation and cellular damage in chronic asymptomatic or oligosymptomatic alcoholics: correlation with alteration of bilirubin and hepatic and pancreatic enzymes

OpenAIRE

Borini, Paulo; Guimarães, Romeu Cardoso

1999-01-01

Biochemical and hematimetric indicators of inflammation and cell damage were correlated with bilirubin and hepatic and pancreatic enzymes in 30 chronic male alcoholics admitted into psychiatric hospital for detoxification and treatment of alcoholism. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, and total bilirubin were altered, respectively, in 90%, 63%, 87%, 23% and 23% of the cases. None of the indicators of inflammation (lactic dehy...

A Prospective Comparison of Transcutaneous and Serum Bilirubin Within Brief Time Intervals.

Science.gov (United States)

Jones, Denise F; McRea, Abigail R; Knowles, James D; Lin, Feng-Chang; Burnette, Erin; Reller, Lara A; Lohr, Jacob A

2017-10-01

The American Academy of Pediatrics recommends screening newborns ≥35 weeks' gestation with total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) to detect hyperbilirubinemia. Retrospective studies show TcB measurements strongly correlate with TSB; however, few prospective trials document this relationship. Furthermore, Dräger's newest TcB instrument, JM-105, remains unstudied in the United States. We measure TcB on foreheads and sternums of newborns using JM-105 and Bilichek devices within 30 minutes of TSB measurement. We find best overall TcB/TSB correlation with JM-105 on the sternum (mean TcB-TSB difference: -0.21 ± 1.15 mg/dL). Correlations between paired measurements for TcB on the sternum using JM-105 were 0.93 for all TSB levels (n = 178), 0.82 for TSB > 10 (n = 19), 0.69 for TSB > 12 (n = 11), and 0.52 for TSB > 15 (n = 6). TcB accuracy via JM-105 on the sternum significantly differed among races ( P < .001). For 5% of paired measurements, TcB with JM-105 on the sternum underestimated TSB by ≥2 mg/dL, and for <1% by ≥3 mg/dL.

Avaliação laboratorial da estabilidade do padrão calibrador de bilirrubina Laboratorial evaluation of standard bilirubin stability

Directory of Open Access Journals (Sweden)

Maria das Graças da Cunha Leite

2003-01-01

Full Text Available Introdução: O preparo do padrão calibrador de bilirrubina é essencial para um controle adequado das dosagens laboratoriais da bilirrubinemia, visto que estas estão sujeitas a grande variabilidade nos resultados, dependendo do método de dosagem escolhido e da falta de padronização rigorosa na sua execução. Uma vez preparado, este padrão calibrador deve ser dividido em alíquotas e estocado para ser utilizado de rotina. Objetivo: Avaliar os efeitos de diferentes condições de armazenamento de um padrão calibrador de bilirrubina sobre sua estabilidade, com finalidade de calibração de equipamentos utilizados na determinação da bilirrubinemia em neonatos. Material e métodos: Após o preparo de um padrão calibrador com 25mg/dl de bilirrubina, este foi armazenado a 4°C, congelado a - 20°C e a - 70°C. Durante nove meses foram feitas dosagens consecutivas da bilirrubina da solução padrão, as quais foram analisadas através da análise de variância de duas vias com blocagem. Resultados: As amostras congeladas a - 70°C não sofreram degradação significativa nos nove meses estudados, enquanto que, no período de três meses, as congeladas a - 20°C e a 4°C sofreram uma degradação de 5% e 24,18%, respectivamente, dos níveis iniciais de bilirrubina. Conclusão: A estocagem do padrão calibrador de bilirrubina a - 70°C é a recomendada para a preservação dos níveis de bilirrubina.Background: The preparation of a standard bilirubin is essential for an adequate quality control of laboratorial bilirubinemia measurements because they are subjected to a large variability in results depending on the dosage method used and the lack of a rigorous standardization of its performance. Once prepared, this standard solution has to be divided in aliquots and stored to be routinely used. Objective: To evaluate the effect of different conditions of the standard solution storage in the stability of bilirubin with the purpose of using it for

X-ray analysis of bilirubin oxidase from Myrothecium verrucaria at 2.3 Å resolution using a twinned crystal

International Nuclear Information System (INIS)

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

The crystal structure of bilirubin oxidase (BOD) from M. verrucaria has been determined at 2.3 Å resolution using a merohedrally twinned crystal. BOD has four copper-coordination sites that are almost identical to those of other multicopper oxidases and is also very similar to them in overall structure. 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 P6 3 . 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

The CO_2 absorption spectrum in the 2.3 µm transparency window by high sensitivity CRDS: (II) Self-absorption continuum

International Nuclear Information System (INIS)

Mondelain, D.; Vasilchenko, S.; Čermák, P.; Kassi, S.; Campargue, A.

2017-01-01

The CO_2 absorption continuum near 2.3 µm is determined for a series of sub atmospheric pressures (250–750 Torr) by high sensitivity Cavity Ring Down Spectroscopy. An experimental procedure consisting in injecting successively a gas flow of CO_2 and synthetic air, keeping constant the gas pressure in the CRDS cell, has been developed. This procedure insures a high stability of the spectra baseline by avoiding changes of the optical alignment due to pressure changes. The CO_2 continuum was obtained as the difference between the CO_2 absorption coefficient and a local lines simulation using a Voigt profile truncated at ±25 cm"−"1. Following the results of the preceding analysis of the CO_2 rovibrational lines (Vasilchenko S et al. J Quant Spectrosc Radiat Transfer (10.1016/j.jqsrt.2016.07.002), a CO_2 line list with intensities obtained by variational calculations and empirical line positions was preferred to the HITRAN line list. A quadratic pressure dependence of the absorption continuum is observed, with an average binary absorption coefficient increasing from 2 to 4×10"−"8 cm"−"1 amagat"−"2 between 4320 and 4380 cm"−"1. The obtained continuum is found in good agreement with a previous measurement using much higher densities (20 amagat) and a low resolution grating spectrograph and is consistent with values currently used in the analysis of Venus spectra. - Highlights: • The CO_2 absorption continuum is measured by CRDS in the 2.3 µm window. • The achieved sensitivity and stability allow measurements at sub-atmospheric pressure. • The absorption coefficient is on the order of 3×10"−"8 cm"−"1 amagat"−"2 near 4350 cm"−"1. • A good agreement is obtained with previous results at much higher density (20 amagat).

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

Science.gov (United States)

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

Quasi-Resonant Absorption for Quantum Efficiency Improvement in Detectors

Data.gov (United States)

National Aeronautics and Space Administration — Quasi-resonant absorption has been demonstrated to enhance the quantum efficiency of devices across the spectrum, but specifically it is a challenge in the UV...

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

Science.gov (United States)

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. Copyright © 2011 Wiley-Liss, Inc.

Spectrum of excess partial molar absorptivity. Part II: a near infrared spectroscopic study of aqueous Na-halides.

Science.gov (United States)

Sebe, Fumie; Nishikawa, Keiko; Koga, Yoshikata

2012-04-07

Our earlier thermodynamic studies suggested that F(-) and Cl(-) form hydration shells with the hydration number 14 ± 2 and 2.3 ± 0.6, respectively, and leave the bulk H(2)O away from hydration shells unperturbed. Br(-) and I(-), on the other hand, form hydrogen bonds directly with the momentarily existing hydrogen bond network of H(2)O, and retard the degree of entropy-volume cross fluctuation inherent in liquid H(2)O. The effect of the latter is stronger for I(-) than Br(-). Here we seek additional information about this qualitative difference between Cl(-) and (Br(-) and I(-)) pair by near infrared (NIR) spectroscopy. We analyze the ν(2) + ν(3) band of H(2)O in the range 4600-5500 cm(-1) of aqueous solutions of NaCl, NaBr and NaI, by a new approach. From observed absorbance, we calculate excess molar absorptivity, ε(E), excess over the additive contributions of solute and solvent. ε(E) thus contains information about the effect of inter-molecular interactions in the ν(2) + ν(3) spectrum. The spectrum of ε(E) shows three bands; two negative ones at 5263 and 4873 cm(-1), and the positive band at 5123 cm(-1). We then define and calculate the excess partial molar absorptivity of each salt, ε(E)(salt). From the behaviour of ε(E)(salt) we suggest that the negative band at 5263 cm(-1) represents free H(2)O without much hydrogen bonding under the influence of local electric field of ions. Furthermore, from a sudden change in the x(salt) (mole fraction of salt) dependence of ε(E)(salt), we suggest that there is an ion-pairing in x(salt) > 0.032, 0.036, and 0.04 for NaCl, NaBr and NaI respectively. The positive band of ε(E) at 5123 cm(-1) is attributed to a modestly organized hydrogen bond network of H(2)O (or liquid-likeness), and the x(salt) dependence of ε indicated a qualitative difference in the effect of Cl(-) from those of Br(-) and I(-). Namely, the values of ε(E)(salt) stay constant for Cl(-) but those for Br(-) and I(-) decrease smoothly on

Identification of a liver growth factor as an albumin-bilirubin complex.

OpenAIRE

Díaz-Gil, J J; Gavilanes, J G; Sánchez, G; García-Cañero, R; García-Segura, J M; Santamaría, L; Trilla, C; Escartín, P

1987-01-01

We have reported the purification and characterization of a protein that behaves as a liver growth factor, showing activity either in vivo or in vitro [Díaz-Gil et al. (1986) Biochem. J. 235, 49-55]. In the present paper, we identify this liver growth factor (LGF) as an albumin-bilirubin complex. This conclusion is supported by the results of chemical and spectroscopic characterization of this protein as well as by experiments in vivo. Incubation of albumin isolated from normal rats with bili...

Soft x-ray absorption spectra of ilmenite family.

Science.gov (United States)

Agui, A; Mizumaki, M; Saitoh, Y; Matsushita, T; Nakatani, T; Fukaya, A; Torikai, E

2001-03-01

We have carried out soft x-ray absorption spectroscopy to study the electronic structure of ilmenite family, such as MnTiO3, FeTiO3, and CoTiO3 at the soft x-ray beamline, BL23SU, at the SPring-8. The Ti and M L2,3 absorption spectra of MTiO3 (M=Mn, Fe, and Co) show spectra of Ti4+ and M2+ electron configurations, respectively. Except the Fe L2,3 spectrum, those spectra were understood within the O(h) symmetry around the transition metal ions. The Fe L3-edge spectrum clearly shows a doublet peak at the L3 edge, which is attributed to Fe2+ state, moreover the very high-resolution the L-edge spectra of transition metals show fine structures. The spectra of those ilmenites are compared.

Adjusting CA19-9 values to predict malignancy in obstructive jaundice: Influence of bilirubin and C-reactive protein

Science.gov (United States)

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

An absorption profile centred at 78 megahertz in the sky-averaged spectrum

Science.gov (United States)

Bowman, Judd D.; Rogers, Alan E. E.; Monsalve, Raul A.; Mozdzen, Thomas J.; Mahesh, Nivedita

2018-03-01

After stars formed in the early Universe, their ultraviolet light is expected, eventually, to have penetrated the primordial hydrogen gas and altered the excitation state of its 21-centimetre hyperfine line. This alteration would cause the gas to absorb photons from the cosmic microwave background, producing a spectral distortion that should be observable today at radio frequencies of less than 200 megahertz. Here we report the detection of a flattened absorption profile in the sky-averaged radio spectrum, which is centred at a frequency of 78 megahertz and has a best-fitting full-width at half-maximum of 19 megahertz and an amplitude of 0.5 kelvin. The profile is largely consistent with expectations for the 21-centimetre signal induced by early stars; however, the best-fitting amplitude of the profile is more than a factor of two greater than the largest predictions. This discrepancy suggests that either the primordial gas was much colder than expected or the background radiation temperature was hotter than expected. Astrophysical phenomena (such as radiation from stars and stellar remnants) are unlikely to account for this discrepancy; of the proposed extensions to the standard model of cosmology and particle physics, only cooling of the gas as a result of interactions between dark matter and baryons seems to explain the observed amplitude. The low-frequency edge of the observed profile indicates that stars existed and had produced a background of Lyman-α photons by 180 million years after the Big Bang. The high-frequency edge indicates that the gas was heated to above the radiation temperature less than 100 million years later.

An absorption profile centred at 78 megahertz in the sky-averaged spectrum.

Science.gov (United States)

Bowman, Judd D; Rogers, Alan E E; Monsalve, Raul A; Mozdzen, Thomas J; Mahesh, Nivedita

2018-02-28

After stars formed in the early Universe, their ultraviolet light is expected, eventually, to have penetrated the primordial hydrogen gas and altered the excitation state of its 21-centimetre hyperfine line. This alteration would cause the gas to absorb photons from the cosmic microwave background, producing a spectral distortion that should be observable today at radio frequencies of less than 200 megahertz. Here we report the detection of a flattened absorption profile in the sky-averaged radio spectrum, which is centred at a frequency of 78 megahertz and has a best-fitting full-width at half-maximum of 19 megahertz and an amplitude of 0.5 kelvin. The profile is largely consistent with expectations for the 21-centimetre signal induced by early stars; however, the best-fitting amplitude of the profile is more than a factor of two greater than the largest predictions. This discrepancy suggests that either the primordial gas was much colder than expected or the background radiation temperature was hotter than expected. Astrophysical phenomena (such as radiation from stars and stellar remnants) are unlikely to account for this discrepancy; of the proposed extensions to the standard model of cosmology and particle physics, only cooling of the gas as a result of interactions between dark matter and baryons seems to explain the observed amplitude. The low-frequency edge of the observed profile indicates that stars existed and had produced a background of Lyman-α photons by 180 million years after the Big Bang. The high-frequency edge indicates that the gas was heated to above the radiation temperature less than 100 million years later.

Emission and Absorption in the M87 LINER

Science.gov (United States)

Sabra, Bassem M.; Shields, Joseph C.; Ho, Luis C.; Barth, Aaron J.; Filippenko, Alexei V.

2003-02-01

The nucleus of M87 displays a LINER spectrum at optical wavelengths, with a nuclear disk of nebulosity that is resolved by the Hubble Space Telescope (HST). We present new results from optical and ultraviolet spectra of the central ~40 pc as measured by HST. In contrast with previous results for the extended disk, the emission-line spectrum of the central region is best reproduced by a multicomponent photoionization scenario, rather than shock heating. The nebular properties as well as energetic considerations suggest a transition on scales of several tens of parsecs, from predominantly photoionization by a central accretion source to shock ionization within the disk. If this source is at all representative, it suggests that many LINERs may be composite in terms of the energetic processes that give rise to the emission spectrum. We also report measurements of resonance-line absorption for the nucleus. The absorption spectrum, like the emission lines, is characterized by low ionization. The absorption-line measurements coupled with independent constraints suggest a total hydrogen column density of 1019-1020 cm-2, outflowing from the galaxy center with a velocity of ~126 km s-1. The kinematic signature of an outflow, along with evidence that the absorber covers the power-law continuum source but not the emission-line clouds, suggests that the absorbing matter is related to accretion phenomena in the nucleus. The presence of such an outflow resembles similar behavior in luminous active galactic nuclei, although the low ionization that characterizes LINERs is probably indicative of a different mode of accretion in these sources. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

High-resolution observations of low-luminosity gigahertz-peaked spectrum and compact steep-spectrum sources

Science.gov (United States)

Collier, J. D.; Tingay, S. J.; Callingham, J. R.; Norris, R. P.; Filipović, M. D.; Galvin, T. J.; Huynh, M. T.; Intema, H. T.; Marvil, J.; O'Brien, A. N.; Roper, Q.; Sirothia, S.; Tothill, N. F. H.; Bell, M. E.; For, B.-Q.; Gaensler, B. M.; Hancock, P. J.; Hindson, L.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kapińska, A. D.; Lenc, E.; Morgan, J.; Procopio, P.; Staveley-Smith, L.; Wayth, R. B.; Wu, C.; Zheng, Q.; Heywood, I.; Popping, A.

2018-06-01

We present very long baseline interferometry observations of a faint and low-luminosity (L1.4 GHz GPS) and compact steep-spectrum (CSS) sample. We select eight sources from deep radio observations that have radio spectra characteristic of a GPS or CSS source and an angular size of θ ≲ 2 arcsec, and detect six of them with the Australian Long Baseline Array. We determine their linear sizes, and model their radio spectra using synchrotron self-absorption (SSA) and free-free absorption (FFA) models. We derive statistical model ages, based on a fitted scaling relation, and spectral ages, based on the radio spectrum, which are generally consistent with the hypothesis that GPS and CSS sources are young and evolving. We resolve the morphology of one CSS source with a radio luminosity of 10^{25} W Hz^{-1}, and find what appear to be two hotspots spanning 1.7 kpc. We find that our sources follow the turnover-linear size relation, and that both homogeneous SSA and an inhomogeneous FFA model can account for the spectra with observable turnovers. All but one of the FFA models do not require a spectral break to account for the radio spectrum, while all but one of the alternative SSA and power-law models do require a spectral break to account for the radio spectrum. We conclude that our low-luminosity sample is similar to brighter samples in terms of their spectral shape, turnover frequencies, linear sizes, and ages, but cannot test for a difference in morphology.

Force-detected nanoscale absorption spectroscopy in water at room temperature using an optical trap

Science.gov (United States)

Parobek, Alexander; Black, Jacob W.; Kamenetska, Maria; Ganim, Ziad

2018-04-01

Measuring absorption spectra of single molecules presents a fundamental challenge for standard transmission-based instruments because of the inherently low signal relative to the large background of the excitation source. Here we demonstrate a new approach for performing absorption spectroscopy in solution using a force measurement to read out optical excitation at the nanoscale. The photoinduced force between model chromophores and an optically trapped gold nanoshell has been measured in water at room temperature. This photoinduced force is characterized as a function of wavelength to yield the force spectrum, which is shown to be correlated to the absorption spectrum for four model systems. The instrument constructed for these measurements combines an optical tweezer with frequency domain absorption spectroscopy over the 400-800 nm range. These measurements provide proof-of-principle experiments for force-detected nanoscale spectroscopies that operate under ambient chemical conditions.

Laser induced transient absorptions of the excited triplet state of 9,10-anthraquinone-2-sulfonate. A further study by 248 nm laser photolysis

International Nuclear Information System (INIS)

Ma Jianhua; Lin Weizheng; Wang Wenfen; Yao Side; Lin Nianyun

1999-01-01

Transient absorption spectrum of triplet state of 9,10-anthraquinone-2-sulfonate (AQS) in aqueous solution has been investigated using 248 nm (KrF) laser photolysis. A whole transient absorption spectrum with absorption maxim at 380 nm and 580 nm has been assigned to triple AQS from detailed kinetic analysis of decay of 380 nm and 580 nm signals, which is the neat characteristic absorption of triplet AQS reported for the first time. In addition, the difference in feature of the spectrum of triplet AQS in H 2 O and that in CH 3 CN was eliminated by further study using 248 nm laser pulses

Absorption by Spinning Dust: A Contaminant for High-redshift 21 cm Observations

Science.gov (United States)

Draine, B. T.; Miralda-Escudé, Jordi

2018-05-01

Spinning dust grains in front of the bright Galactic synchrotron background can produce a weak absorption signal that could affect measurements of high-redshift 21 cm absorption. At frequencies near 80 MHz where the Experiment to Detect the Global EoR Signature (EDGES) has reported 21 cm absorption at z≈ 17, absorption could be produced by interstellar nanoparticles with radii a≈ 50 \\mathringA in the cold interstellar medium (ISM), with rotational temperature T ≈ 50 K. Atmospheric aerosols could contribute additional absorption. The strength of the absorption depends on the abundance of such grains and on their dipole moments, which are uncertain. The breadth of the absorption spectrum of spinning dust limits its possible impact on measurement of a relatively narrow 21 cm absorption feature.

The effect of the pre-pregnancy weight of the mother and the gestational weight gain on the bilirubin level of term newborn.

Science.gov (United States)

Özdek, Suat; Kul, Mustafa; Barış Akcan, Abdullah; Çekmez, Ferhat; Aydemir, Gökhan; Aydınöz, Seçil; Karademir, Ferhan; Süleymanoğlu, Selami

2016-01-01

Jaundice is a problem in newborns. There are many maternal and infant-related factors affecting neonatal jaundice. The maternal pre-pregnancy weight, maternal body mass index (BMI) and gestational weight gain may have an effect on the newborn bilirubin levels. We research the effect of the maternal pre-pregnancy weight and gestational weight gain on the bilirubin levels of the newborn infants in the first 2 weeks prospectively. Term and healthy infants who were born between 38 and 42 weeks in our clinic were included in the study. Maternal pre-pregnancy BMIs were calculated. Babies were divided into three groups according to their mothers' advised amount of gestational weight gain. Total serum bilirubin (TSB) values of the newborns were measured in the 2nd, 5th and 15th postnatal days. In our study, the 5th and 15th day capillary bilirubin level of the babies with mothers who gained more weight than the advised amount during pregnancy were found statistically significant higher compared to the other two groups (p mothers who gained more weight than the advised amount were found statistically significant higher compared to the other two groups (p mothers who gained more weight than the advised amount were under risk for newborn jaundice. Therefore, these babies should be monitored more closely for neonatal jaundice and prolonged jaundice.

Linear optical absorption spectra of mesoscopic structures in intense THz fields: Free-particle properties

DEFF Research Database (Denmark)

Johnsen, Kristinn; Jauho, Antti-Pekka

1998-01-01

We theoretically study the effect of THz radiation on the linear optical absorption spectra of semiconductor structures. A general theoretical framework, based on nonequilibrium Green functions, is formulated and applied to the calculation of linear optical absorption spectrum for several...

Model Atmosphere Spectrum Fit to the Soft X-Ray Outburst Spectrum of SS Cyg

Directory of Open Access Journals (Sweden)

V. F. Suleimanov

2015-02-01

Full Text Available The X-ray spectrum of SS Cyg in outburst has a very soft component that can be interpreted as the fast-rotating optically thick boundary layer on the white dwarf surface. This component was carefully investigated by Mauche (2004 using the Chandra LETG spectrum of this object in outburst. The spectrum shows broad ( ≈5 °A spectral features that have been interpreted as a large number of absorption lines on a blackbody continuum with a temperature of ≈250 kK. Because the spectrum resembles the photospheric spectra of super-soft X-ray sources, we tried to fit it with high gravity hot LTE stellar model atmospheres with solar chemical composition, specially computed for this purpose. We obtained a reasonably good fit to the 60–125 °A spectrum with the following parameters: Teff = 190 kK, log g = 6.2, and NH = 8 · 1019 cm−2, although at shorter wavelengths the observed spectrum has a much higher flux. The reasons for this are discussed. The hypothesis of a fast rotating boundary layer is supported by the derived low surface gravity.

Enhanced absorption of graphene in the visible region by use of plasmonic nanostructures

DEFF Research Database (Denmark)

Hashemi, Mahdieh; Farzad, Mahmood Hosseini; Mortensen, N. Asger

2013-01-01

Low absorption of graphene in the visible range of the spectrum makes it difficult to uniquely benefit from this material in ultra-fast optoelectronic applications. We numerically propose to utilize patterned metallic nanostructures to increase light absorption in single-layer graphene. Simulation...... results show that excitation of surface plasmon resonances in the metallic nanostructures significantly enhances the local electromagnetic field near the graphene layer, therefore leading to a dramatic enhancement of the absorption in the graphene layer itself. Broadband high optical absorption can...

A SURVEY OF ALKALI LINE ABSORPTION IN EXOPLANETARY ATMOSPHERES

International Nuclear Information System (INIS)

Jensen, Adam G.; Redfield, Seth; Endl, Michael; Cochran, William D.; Koesterke, Lars; Barman, Travis S.

2011-01-01

We obtained over 90 hr of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope. Observations were taken in transit and out of transit, and we analyzed the differenced spectra—i.e., the transmission spectra—to inspect it for absorption at the wavelengths of the neutral sodium (Na I) doublet at λλ5889, 5895 and neutral potassium (K I) at λ7698. We used the transmission spectrum at Ca I λ6122—which shows strong stellar absorption but is not an alkali metal resonance line that we expect to show significant absorption in these atmospheres—as a control line to examine our measurements for systematic errors. We use an empirical Monte Carlo method to quantify these systematic errors. In a reanalysis of the same data set using a reduction and analysis pipeline that was derived independently, we confirm the previously seen Na I absorption in HD 189733b at a level of (– 5.26 ± 1.69) × 10 –4 (the average value over a 12 Å integration band to be consistent with previous authors). Additionally, we tentatively confirm the Na I absorption seen in HD 209458b (independently by multiple authors) at a level of (– 2.63 ± 0.81) × 10 –4 , though the interpretation is less clear. Furthermore, we find Na I absorption of (– 3.16 ± 2.06) × 10 –4 at <3σ in HD 149026b; features apparent in the transmission spectrum are consistent with real absorption and indicate this may be a good target for future observations to confirm. No other results (Na I in HD 147506b and Ca I and K I in all four targets) are significant to ≥3σ, although we observe some features that we argue are primarily artifacts.

Optical absorption of copper met-myoglobin complexes

International Nuclear Information System (INIS)

Lamy, M.T.; Ribeiro, P.C.; Nascimento, O.R.; Bemski, G.

1976-01-01

It is reported on the use of a known denaturing agent, namely Cu 2+ ions, to induce a gradual change in the optical spectrum of Mb solutions, in order to identify the absorption bands that undergo similar changes which may be attributed to the transitions between correlated energy levels [pt

Estimation of anisotropy factor spectrum for determination of optical properties in biological tissues

Science.gov (United States)

Iwamoto, Misako; Honda, Norihiro; Ishii, Katsunori; Awazu, Kunio

2017-07-01

Spectroscopic setup for measuring anisotropy factor g spectrum of biological tissues was constructed. g of chicken liver tissue was lower than chicken breast tissue. High absorption of hemoglobin can have an influence on g spectrum.

Identification of bilirubin reduction products formed by Clostridium perfringens isolated from human neonatal fecal flora

Czech Academy of Sciences Publication Activity Database

Vítek, L.; Majer, F.; Muchová, L.; Zelenka, J.; Jirásková, A.; Branny, Pavel; Malina, J.; Ubik, Karel

2006-01-01

Roč. 833, - (2006), s. 149-157 ISSN 1570-0232 R&D Projects: GA ČR GA310/02/1436 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z40550506 Keywords : bilirubin * bacteria l reduction * intestinal microflora Subject RIV: EE - Microbiology, Virology Impact factor: 2.647, year: 2006

Absorption Mode FT-ICR Mass Spectrometry Imaging

Energy Technology Data Exchange (ETDEWEB)

Smith, Donald F.; Kilgour, David P.; Konijnenburg, Marco; O' Connor, Peter B.; Heeren, Ronald M.

2013-12-03

Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image and then these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode ?Datacubes? for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

Statistical moments of the angular spectrum of normal waves in a turbulent collisional magnetized plasma

International Nuclear Information System (INIS)

Aistov, A.V.; Gavrilenko, V.G.

1996-01-01

The normal incidence of a small-amplitude electromagnetic wave upon a semi-infinite turbulent collisional plasm with an oblique external magnetic field is considered. Within a small-angle-scattering approximation of the radiative transport theory, a system of differential equations is derived for statistical moments of the angular power spectrum of radiation. The dependences of the spectrum centroid, dispersion, and asymmetry on the depth of penetration are studied numerically. The nonmonotonic behavior of the dispersion is revealed, and an increase in the spectrum width with absorption anisotropy is found within some depth interval. It is shown that, at large depths, the direction of the displacement of the spectrum centroid, does not always coincide with the direction of minimum absorption

Sound absorption in a field of a strong electromagnetic wave in a quantizied magnetic field

International Nuclear Information System (INIS)

Chajkovskij, I.A.

1974-01-01

A coefficient of sound absorption GAMMA in a semiconductor and semi-metal in the quantized magnetic field is calculated for a system exposed to a field of strong electromagnetic radiation. The cases E parallel H and E orthogonal H are considered. Along with the already known strong oscillations of sound absorption in magnetic fields, the absorption spectrum GAMMAsub(par) and GAMMAsub(orth) shows new oscillations representing a manifestation of the quasi-energetic electron spectrum in the field of a strong electromagnetic wave. The oscillation height at E parallel H is modulated by the electromagnetic field. It is shown that the ratio GAMMAsub(par)/GAMMAsub(orth) allows the determination of the effective mass of the carriers

Localization of a two-level atom via the absorption spectrum

International Nuclear Information System (INIS)

Xu, Jun; Hu, Xiang-Ming

2007-01-01

We show that it is possible to localize a two-level atom as it passes through a standing-wave field by measuring the probe-field absorption. There is 50% detecting probability of the atom at the nodes of the standing-wave field in the subwavelength domain when the probe field is tuned resonant with the atomic transition

A narrow window of Rabi frequency for competition between electromagnetically induced transparency and Raman absorption

International Nuclear Information System (INIS)

Chang, Ray-Yuan; Fang, Wei-Chia; Lee, Ming-Tsung; He, Zong-Syun; Ke, Bai-Cian; Lee, Yi-Chi; Tsai, Chin-Chun

2010-01-01

This investigation clarifies the transition phenomenon between the electromagnetically induced transparency (EIT) and Raman absorption in a ladder-type system of Doppler-broadened cesium vapor. A competition window of this transition was found to be as narrow as 2 MHz defined by the probe Rabi frequency. For a weak probe, the spectrum of EIT associated with quantum interference suggests that the effect of the Doppler velocity on the spectrum is negligible. When the Rabi frequency of the probe becomes comparable with the effective decay rate, an electromagnetically induced absorption (EIA) dip emerges at the center of the power broadened EIT peak. While the Rabi frequency of the probe exceeds the effective decay rate, decoherence that is generated by the intensified probe field occurs and Raman absorption dominates the interaction process, yielding a pure absorption spectrum; the Doppler velocity plays an important role in the interaction. A theory that is based on density matrix simulation, with or without the Doppler effect, can qualitatively fit the experimental data. In this work, the coherence of atom-photon interactions is created or destroyed using the probe Rabi frequency as a decoherence source.

Two models for absorption by coloured dissolved organic matter (CDOM

Directory of Open Access Journals (Sweden)

Jill N. Schwarz

2002-06-01

Full Text Available The standard exponential model for CDOM absorption has been applied to data from diverse waters. Absorption at 440 nm (ag440 ranged between close to zero and 10 m-1, and the slope of the semilogarithmic absorption spectrum over a minimum range of 400 to 440 nm (s440 ranged between < 0.01 and 0.04 nm-1. No relationship was found between ag440 or s440 and salinity. Except in the southern Baltic, s440 was found to have a broad distribution (0.0165 ± 0.0035, suggesting that it should be introduced as an additional variable in bio-optical models when ag440 is large. An alternative model for CDOM absorption was applied to available high quality UV-visible absorption spectra from the Wisla river (Poland. This model assumes that the CDOM absorption spectrum comprises distinct Gaussian absorption bands in the UV, similar to those of benzene. Five bands were fit to the data. The mean central energy of all bands was higher in early summer (E~7.2, 6.6, 6.4, 6.2 and 5.5 eV or 172, 188, 194, 200 and 226 nm than in winter. The higher energy bands were found to decay in both height and width with increasing salinity, while lower energy bands broadened with increasing salinity. s440 was found to be correlated with shape parameters of the bands centred at 6.4 and 5.5 eV. While the exponential model is convenient for optical modelling and remote sensing applications, these results suggest that the Gaussian model offers a deeper understanding of chemical interactions affecting CDOM molecular structure.

Interpretation of the optical absorption spectrum of uranium germanate

International Nuclear Information System (INIS)

Gajek, Z.; Krupa, J.C.

1993-01-01

Visible and infrared absorption spectra of U 4+ in UGeO 4 are described and interpreted in terms of the standard parametrization scheme. One of the two models considered is consistent with available interpretations of other uranium germanates and silicates. The second one originating from theoretical estimation of the crystal-field effect permits exceptional properties of the compound under consideration, in particular, an untypical assignation of the electronic energy levels and values of the crystal-field parameters in comparison with other tetragonal oxides. (author)

Interpretation of the optical absorption spectrum of uranium germanate

Energy Technology Data Exchange (ETDEWEB)

Gajek, Z.; Krupa, J.C. (Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire); Zolnierek, Z. (Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych); Antic-Fidancev, E.; Lamaitre-Blaise, M. (Centre National de la Recherche Scientifique (CNRS), 92 - Meudon-Bellevue (France))

1993-12-06

Visible and infrared absorption spectra of U[sup 4+] in UGeO[sub 4] are described and interpreted in terms of the standard parametrization scheme. One of the two models considered is consistent with available interpretations of other uranium germanates and silicates. The second one originating from theoretical estimation of the crystal-field effect permits exceptional properties of the compound under consideration, in particular, an untypical assignation of the electronic energy levels and values of the crystal-field parameters in comparison with other tetragonal oxides. (author).

Anti-cancer effects of blue-green alga Spirulina platensis, a natural source of bilirubin-like tetrapyrrolic compounds

Czech Academy of Sciences Publication Activity Database

Koníčková, R.; Vaňková, K.; Vaníková, J.; Váňová, K.; Muchová, L.; Subhanová, I.; Zadinová, M.; Zelenka, Jaroslav; Dvořák, Aleš; Kolář, Michal; Strnad, Hynek; Rimpelová, S.; Ruml, T.; Wong, R.J.; Vítek, L.

2014-01-01

Roč. 13, č. 2 (2014), s. 273-283 ISSN 1665-2681 Institutional support: RVO:67985823 ; RVO:68378050 Keywords : bilirubin * chlorophyll * heme oxygenase * phycocyanin * phycocyanobilin * Spirulina platensis * tetrapyrroles Subject RIV: FD - Oncology ; Hematology Impact factor: 2.065, year: 2014

[The Lambert-Beer's law characterization of formal analysis in Terahertz spectrum quantitative testing].

Science.gov (United States)

Su, Hai-Xia; Zhang, Zhao-Hui; Zhao, Xiao-Yan; Li, Zhi; Yan, Fang; Zhang, Han

2013-12-01

The present paper discusses the Lambert-Beer' s law application in the terahertz spectrum, studies the single amino acid tablet sample (glutamine) and two kinds of amino acids mixture tablet (threonine and cystine) under the condition of different concentrations. Absorbance and absorption coefficient was analyzed in the description of the terahertz optical properties of matter. By comparing absorption coefficient and absorbance value of the single component in the vicinity of 1. 72 THz, we verified the material under two kinds of absorption characterization of quantity of THz wave absorption along with the change in the concentration. Using the index of goodness of fit R , it studied the stand or fall of linear relationship between the terahertz absorption quantity of material and concentration under two kinds of representation. This paper analyzes the two components mixture under two kinds of absorption characterization of quantity of terahertz absorption in 0. 3-2. 6 THz. Using the similarity co- efficient and the estimate concentration error as evaluation index, it has been clear that the absorbance of additivity instead of the absorption coefficient should be used during the terahertz spectrum quantitative test, and the Lambert-Beer's law application in the terahertz wave band was further clarified.

Plant Growth Absorption Spectrum Mimicking Light Sources

Directory of Open Access Journals (Sweden)

Jwo-Huei Jou

2015-08-01

Full Text Available Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED, for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.

Acute effect of weight loss on levels of total bilirubin in obese, cardiovascular high-risk patients: an analysis from the lead-in period of the Sibutramine Cardiovascular Outcome trial

DEFF Research Database (Denmark)

Andersson, Charlotte; Weeke, Peter; Fosbøl, Emil Loldrup

2009-01-01

Low levels of bilirubin are associated with an increased risk of cardiovascular adverse events. Weight reduction is known to reduce several cardiovascular risk factors, but effects on bilirubin levels have not been reported. We studied the response of weight loss therapy with sibutramine and life......Low levels of bilirubin are associated with an increased risk of cardiovascular adverse events. Weight reduction is known to reduce several cardiovascular risk factors, but effects on bilirubin levels have not been reported. We studied the response of weight loss therapy with sibutramine...... and lifestyle change on levels of total bilirubin in an overweight or obese, cardiovascular high-risk population. Data from the first 4 weeks of the lead-in period of the Sibutramine Cardiovascular Outcome study were analyzed. A total of 10 198 patients provided body weight measurements before and after 4 weeks...... of sibutramine treatment (10 mg daily), of whom 1059 (10.4%) gained weight, 1467 (13.7%) lost greater than 0% to 1%, 2492 (23.2%) lost greater than 1% to 2%, 2280 (21.2%) lost greater than 2% to 3%, 1498 (13.9%) lost greater than 3% to 4%, and 1402 (13.1%) lost greater than 4% of their initial weight...

Phenobarbital and Phototherapy Combination Enhances Decline of Total Serum Bilirubin and May Decrease the Need for Blood Exchange Transfusion in Newborns with Isoimmune Hemolytic Disease

Science.gov (United States)

Kaabneh, Mahmoud AF; Salama, Ghassan SA; Shakkoury, Ayoub GA; Al-abdallah, Ibrahim MH; Alshamari, Afrah; Halaseh, Ruba AA

2015-01-01

OBJECTIVE The objective of this study was to evaluate the effect of phenobarbital and phototherapy combination on the total serum bilirubin of the newborn infants with isoimmune hemolytic disease (IHD) and its impact on blood exchange transfusion rates. PATIENTS AND METHOD This single-blinded, prospective, randomized, controlled trial was conducted between March 2013 and December 2014 at the pediatric ward of two Military Hospitals in Jordan. A total of 200 full-term neonates with IHD were divided randomly into two groups: (1) the phenobarbital plus phototherapy group (n = 103), and (2) the phototherapy-only group (n = 97). Infants in group 1 received an oral dose of 2.5 mg/kg phenobarbital every 12 hours for 3 days in addition to phototherapy. The total serum bilirubin was observed. RESULTS Of the total 200 included newborn infants, 186 infants completed the study: 97 infants were included in group 1 and 89 infants in group 2. The difference between the mean total serum bilirubin levels at 24, 48, and 72 hours after starting the trial was clinically and statistically significant at P newborn infants with IHD, as it results in a faster decline in total serum bilirubin, thus decreasing the need for blood exchange transfusion than phototherapy alone. PMID:26309423

The CO_2 absorption spectrum in the 2.3 µm transparency window by high sensitivity CRDS: (I) Rovibrational lines

International Nuclear Information System (INIS)

Vasilchenko, S.; Konefal, M.; Mondelain, D.; Kassi, S.; Čermák, P.; Tashkun, S.A.; Perevalov, V.I.; Campargue, A.

2016-01-01

The absorption of carbon dioxide is very weak near 2.3 µm which makes this transparency window of particular interest for the study of Venus’ lower atmosphere. As a consequence of the weakness of the transitions located in this region, previous experimental data are very scarce and spectroscopic databases provide calculated line lists which should be tested and validated by experiment. In this work, we use the Cavity Ring Down Spectroscopy (CRDS) technique for a high sensitivity characterization of the CO_2 absorption spectrum in two spectral intervals of the 2.3 µm window: 4248–4257 and 4295–4380 cm"−"1 which were accessed using a Distributed Feed Back (DFB) diode laser and a Vertical External Cavity Surface Emitting Laser (VECSEL) as light sources, respectively. The achieved sensitivity (noise equivalent absorption, α_m_i_n, on the order of 5×10"−"1"0 cm"−"1) allowed detecting numerous new transitions with intensity values down to 5×10"−"3"0 cm/molecule. The rovibrational assignments were performed by comparison with available theoretical line lists in particular those obtained at IAO Tomsk using the global effective operator approach. Hot bands of the main isotopologue and "1"6O"1"2C"1"8O bands were found to be missing in the HITRAN database while they contribute importantly to the absorption in the region. Additional CRDS spectra of a CO_2 sample highly enriched in "1"8O were recorded in order to improve the spectroscopy of this isotopologue. As a result about 700 lines of "1"6O"1"2C"1"8O, "1"6O"1"2C"1"7O, "1"7O"1"2C"1"8O, "1"2C"1"8O_2 and "1"3C"1"8O_2 were newly measured. The status of the different databases (HITRAN, CDSD, variational calculations) in the important 2.3 µm transparency window is discussed. Possible improvements to correct evidenced deficiencies are suggested. - Highlights: • High sensitivity CRDS with a VECSEL in the 2.3 µm transparency window of CO_2. • Natural and "1"8O enriched CO_2 spectra recorded with

Increased conjugated bilirubin is sufficient to initiate screening for biliary atresia

DEFF Research Database (Denmark)

Madsen, Stine Skipper; Kvist, Nina; Thorup, Jørgen

2015-01-01

. This percentage value has caused diagnostic trouble over the years. The objective of the present study was to investigate the possibility of changing the recommendations. METHODS: This was a retrospective analysis of the medical records of children operated for biliary atresia in the 1993-2012 period. RESULTS......: mean 129.7 μmol/l (42-334 μmol/l) and 73% (28-97%), respectively. CONCLUSION: The total amount of conjugated bilirubin above 20 μmol/l is sufficient to require further evaluation for biliary atresia. The percentage value is unnecessary and may cause confusion. FUNDING: none. TRIAL REGISTRATION...

Anisotropy of exciton spectrum and spin-orbit interactions in quantum wells in tilted magnetic field

International Nuclear Information System (INIS)

Olendski, Oleg; Shahbazyan, Tigran V

2006-01-01

We study theoretically excitonic energy spectrum and optical absorption in narrowgap semiconductor quantum wells in strong magnetic field. We show that, in the presence of an in-plane field component, the absorption coefficient exhibit a double-peak structure due to hybridization of bright and dark excitons. If both Rashba and Dresselhaus spin-orbit terms are present, the spectrum is anisotropic in in-plane field orientation with respect to [100] axis. In particular, the magnitude of the splitting can be tuned in a wide interval by varying the azimuthal angle of the in-plane field. The absorption spectrrum anisotropy would allow simultaneous measurement Dresselhaus and Rashba spin-orbit coefficients

Development of Educational Simulation on Spectrum of HPGe Detector and Implementation of Education Program

International Nuclear Information System (INIS)

Seo, K. W.; Joo, Y. C.; Ji, Y. J.; Lee, M. O.; Lee, S. Y.; Jun, Y. K.

2005-12-01

In this development, characteristics of Aptec, Genie2000(Canberra Co, USA), GammaVision(Ortec Co, USA) which are usually used in Korea radioactive measure laboratory, such as peak search, peak fitting, central area position and area calculation, spectrum correction and method for radioactive calculation are included. And radioactive source geometry, absorption of sample itself, methods for correcting coincidence summing effect is developed and the result effected on spectrum analysis teaching material. Developed simulation HPGe detector spectrum are spectrum for correction, spectrum for correcting radio source-detection duration geometry, sample spectrum which need self absorption correction of radio source, peak search spectrum for optimizing peak search offset setting and background spectrum. These spectrum are made similar to real spectrum by processing peak and background which were measured from mix standard volume radio source. Spectrum analysis teaching material is developed more focus on practical thing than theoretical thing, simulation spectrum must be used in spectrum analysis practise. Optimal method for spectrum analysis condition, spectrum correction, Geometry correction and background spectrum analysis are included in teaching material and also ANSI N42 recommended 'Spectrum analysis program test' procedure is included too. Aptec, Genie2000, Gamma Vision software manuals are included in appendix. In order to check the text of developed simulation on spectrum of HPGe detector, in 2004 and 2005, these was implemented in the other regular course as a course for superviser of the handling with RI. And the text and practical procedure were reviewed through the course and were revised

Fine structure of the CCl3 UV absorption spectrum and CCl3 kinetics

DEFF Research Database (Denmark)

Ellermann, T.

1992-01-01

The UV gas-phase spectrum of CCl3 was recorded in the range 220-300 nm using pulse radiolysis of CHCl3/SF6 or CCl4/Ar gas mixtures. The UV spectrum exhibits a pronounced vibrational fine structure which is assigned to transition into the (C2A1'(3s)) Rydberg state. The vibronic progression has...

Bilirubin concentration is positively associated with haemoglobin concentration and inversely associated with albumin to creatinine ratio among Indigenous Australians: eGFR Study.

Science.gov (United States)

Hughes, J T; Barzi, F; Hoy, W E; Jones, G R D; Rathnayake, G; Majoni, S W; Thomas, M A B; Sinha, A; Cass, A; MacIsaac, R J; O'Dea, K; Maple-Brown, L J

2017-12-01

Low serum bilirubin concentrations are reported to be strongly associated with cardio-metabolic disease, but this relationship has not been reported among Indigenous Australian people who are known to be at high risk for diabetes and chronic kidney disease (CKD). serum bilirubin will be negatively associated with markers of chronic disease, including CKD and anaemia among Indigenous Australians. A cross-sectional analysis of 594 adult Aboriginal and Torres Strait Islander (TSI) people in good health or with diabetes and markers of CKD. Measures included urine albumin: creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), haemoglobin (Hb) and glycated haemoglobin (HbA1c). Diabetes was defined by medical history, medications or HbA1c≥6.5% or ≥48mmol/mol. Anaemia was defined as Hbbilirubin was performed. Participants mean (SD) age was 45.1 (14.5) years, and included 62.5% females, 71.7% Aboriginal, 41.1% with diabetes, 16.7% with anaemia, 41% with ACR>3mg/mmol and 18.2% with eGFRbilirubin concentration was lower in females than males (6 v 8μmol/L, pbilirubin; Hb and cholesterol (both positively related) and ACR, triglycerides, Aboriginal ethnicity and female gender (all inversely related). Serum bilirubin concentrations were positively associated with Hb and total cholesterol, and inversely associated with ACR. Further research to determine reasons explaining lower bilirubin concentrations among Aboriginal compared with TSI participants are needed. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Wavelet Space-Scale-Decomposition Analysis of QSO's Ly$\\alpha$ Absorption Lines: Spectrum of Density Perturbations

OpenAIRE

Pando, Jesus; Fang, Li-Zhi

1995-01-01

A method for measuring the spectrum of a density field by a discrete wavelet space-scale decomposition (SSD) has been studied. We show how the power spectrum can effectively be described by the father function coefficients (FFC) of the wavelet SSD. We demonstrate that the features of the spectrum, such as the magnitude, the index of a power law, and the typical scales, can be determined with high precision by the FFC reconstructed spectrum. This method does not require the mean density, which...

Calculated optical absorption of different perovskite phases

DEFF Research Database (Denmark)

Castelli, Ivano Eligio; Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

2015-01-01

We present calculations of the optical properties of a set of around 80 oxides, oxynitrides, and organometal halide cubic and layered perovskites (Ruddlesden-Popper and Dion-Jacobson phases) with a bandgap in the visible part of the solar spectrum. The calculations show that for different classes...... of perovskites the solar light absorption efficiency varies greatly depending not only on bandgap size and character (direct/indirect) but also on the dipole matrix elements. The oxides exhibit generally a fairly weak absorption efficiency due to indirect bandgaps while the most efficient absorbers are found...... in the classes of oxynitride and organometal halide perovskites with strong direct transitions....

Herbicidal Spectrum, Absorption and Transportation, and Physiological Effect on Bidens pilosa of the Natural Alkaloid Berberine.

Science.gov (United States)

Wu, Jiao; Ma, Jing-Jing; Liu, Bo; Huang, Lun; Sang, Xiao-Qing; Zhou, Li-Juan

2017-08-02

Berberine is a natural herbicidal alkaloid from Coptis chinensis Franch. Here we characterized its herbicidal spectrum and absorption and transportation in the plant, along with the possible mechanism. Berberine showed no effect on the germination of the 10 tested plants. The IC 50 values of berberine on the primary root length and fresh weight of the 10 tested plants ranged from 2.91 to 9.79 mg L -1 and 5.76 to 35.07 mg L -1 , respectively. Berberine showed a similar herbicidal effect on Bidens pilosa as the commercial naturally derived herbicide cinmethylin. HPLC and fluorescence analysis revealed that berberine was mainly absorbed by B. pilosa root and transported through vascular bundle acropetally. Enzyme activity studies, GC-MS analysis, and SEM and TEM observations indicated that berberine might first function on the cell membrane indicated by variation of the IUFA percent and then cause POD, PPO, and SOD activity changes and cellular structure deformity, which was eventually expressed as the decrease of cell adaptation ability and abnormal cell function and may even result in cell death. Environmental safety evaluation tests revealed that berberine was low in toxicity to Brachydanio rerio. These indicate that berberine has the potential to be a bioherbicide and/or a lead molecule for new herbicides.