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Christensen RD, Bahr TM, Wong RJ, Vreman HJ, Bhutani VK, Stevenson DK. A "Gold Standard" Test for Diagnosing and Quantifying Hemolysis in Neonates and Infants. J Perinatol 2023; 43:1541-1547. [PMID: 37468612 DOI: 10.1038/s41372-023-01730-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023]
Abstract
Identifying "gold standard" diagnostic tests can promote evidence-based neonatology practice. Hemolysis is a pathological shortening of the erythrocyte lifespan, differing from erythrocyte senescence in responsible mechanisms and clinical implications. Diagnosing hemolysis goes beyond a binary (yes vs. no) determination. It is characterized according to magnitude, and as acute vs. chronic, and genetically based vs. not. For neonates with significant hyperbilirubinemia or anemia, detecting hemolysis and quantifying its magnitude provides diagnostic clarity. The 2022 American Academy of Pediatrics (AAP) Clinical Practice Guideline on management of hyperbilirubinemia in the newborn states that hemolysis is a risk factor for developing significant hyperbilirubinemia and neurotoxicity. The guideline recommends identifying hemolysis from any cause, but specific guidance is not provided. A spectrum of laboratory tests has been endorsed as diagnostic methods for hemolysis. Herein we examine these laboratory tests and recommend one as the "gold standard" for diagnosing and quantifying hemolysis in neonates and infants.
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Affiliation(s)
- Robert D Christensen
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA.
- Obstetric and Neonatal Operations, Intermountain Health, Salt Lake City, UT, USA.
| | - Timothy M Bahr
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
- Obstetric and Neonatal Operations, Intermountain Health, Salt Lake City, UT, USA
| | - Ronald J Wong
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Hendrik J Vreman
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Vinod K Bhutani
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - David K Stevenson
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Stevenson DK, Vreman HJ, Wong RJ. Heme, Heme Oxygenase-1, Statins, and SARS-CoV-2. Antioxidants (Basel) 2023; 12:antiox12030614. [PMID: 36978862 PMCID: PMC10044896 DOI: 10.3390/antiox12030614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Heme, a metalloporphyrin, or more specifically, a tetrapyrrole containing ferrous iron, is an ancient molecule [...]
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Strauss KA, Ahlfors CE, Soltys K, Mazareigos GV, Young M, Bowser LE, Fox MD, Squires JE, McKiernan P, Brigatti KW, Puffenberger EG, Carson VJ, Vreman HJ. Crigler-Najjar Syndrome Type 1: Pathophysiology, Natural History, and Therapeutic Frontier. Hepatology 2020; 71:1923-1939. [PMID: 31553814 PMCID: PMC7909716 DOI: 10.1002/hep.30959] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/04/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS We describe the pathophysiology, treatment, and outcome of Crigler-Najjar type 1 syndrome (CN1) in 28 UGT1A1 c.222C>A homozygotes followed for 520 aggregate patient-years. APPROACH AND RESULTS Unbound ("free") bilirubin (Bf ) was measured in patient sera to characterize the binding of unconjugated bilirubin (BT ) to albumin (A) and validate their molar concentration ratio (BT /A) as an index of neurological risk. Two custom phototherapy systems were constructed from affordable materials to provide high irradiance in the outpatient setting; light dose was titrated to keep BT /A at least 30% below intravascular BT binding capacity (i.e., BT /A = 1.0). Categorical clinical outcomes were ascertained by chart review, and a measure (Lf ) was used to quantify liver fibrosis. Unbound bilirubin had a nonlinear relationship to BT (R2 = 0.71) and BT /A (R2 = 0.76), and Bf as a percentage of BT correlated inversely to the bilirubin-albumin equilibrium association binding constant (R2 = 0.69), which varied 10-fold among individuals. In newborns with CN1, unconjugated bilirubin increased 4.3 ± 1.1 mg/dL per day. Four (14%) neonates developed kernicterus between days 14 and 45 postnatal days of life; peak BT ≥ 30 mg/dL and BT /A ≥ 1.0 mol:mol were equally predictive of perinatal brain injury (sensitivity 100%, specificity 93.3%, positive predictive value 88.0%), and starting phototherapy after age 13 days increased this risk 3.5-fold. Consistent phototherapy with 33-103 µW/cm2 •nm for 9.2 ± 1.1 hours/day kept BT and BT /A within safe limits throughout childhood, but BT increased 0.46 mg/dL per year to reach dangerous concentrations by 18 years of age. Liver transplantation (n = 17) normalized BT and eliminated phototherapy dependence. Liver explants showed fibrosis ranging from mild to severe. CONCLUSION Seven decades after its discovery, CN1 remains a morbid and potentially fatal disorder.
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Affiliation(s)
- Kevin A. Strauss
- Clinic for Special Children, Strasburg, PA,Penn-Lancaster General Hospital, Lancaster, PA,Departments of Pediatrics and Molecular, Cell & Cancer Biology, University of Massachusetts School of Medicine, Worcester, MA
| | - Charles E. Ahlfors
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | - Kyle Soltys
- Department of Surgery, Division of Pediatric Transplantation, Hillman Center for Pediatric Transplantation, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - George V. Mazareigos
- Department of Surgery, Division of Pediatric Transplantation, Hillman Center for Pediatric Transplantation, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | | | | | - Michael D. Fox
- Clinic for Special Children, Strasburg, PA,Department of Pediatrics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA,Diagnostic Referral Division, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE
| | - James E. Squires
- Division of Gastroenterology and Hepatology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Patrick McKiernan
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, UPMC Children’s Hospital of Pittsburgh and Pittsburgh Liver Research Center, Pittsburgh, PA
| | | | | | | | - Hendrik J. Vreman
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
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Abstract
BACKGROUND The efficiency of a phototherapy (PT) device is a function of the irradiance delivered by the device at the surface of the skin. Because cost limits the ability of health care facilities in low- and middle-income countries to procure commercial PT devices, efforts have gone into local fabrication of devices for use in health care facilities in Nigeria. Evaluation of such fabricated devices is yet to be conducted. OBJECTIVE To identify and document essential features of locally fabricated phototherapy (FPT) devices in use in Nigeria. MATERIALS AND METHODS A cross sectional survey of locally FPT devices available in health facilities providing newborn health care services was conducted as part of evaluating neonatal jaundice management services in Kaduna State. Each FPT was characterized with respect to mobility/portability, adjustability, lamp type, number and color of lamps used. The irradiance of each device was measured using Model 22 Olympic BiliMeter™ at the facility's traditional PT distance and also at a distance at which optimum irradiance is delivered by the device. RESULTS A total of 54 PT devices were in use. Thirty-two (59.3%) of these devices were locally fabricated while others were obtained from commercial sources. Of the fabricated devices 22/32 (68.8%) were non-adjustable while the remaining 10 devices were adjustable but with limited adjustability. Only 5/32 (15.6%) of the FPT devices used special blue fluorescent lamps. The majority, 68.8% (22/32) of the FPT devices used ordinary low-intensity blue lamps while the remaining 5/32 (15.6%) devices used white light fluorescent lamps. None of the devices used light emitting diodes as a PT light source. Only three fabricated devices offered irradiance (9.4, 13.6 and 33 µW/cm2/nm) at the facilities' traditional distances for PT. CONCLUSIONS FPT devices in use in Kaduna, functioned sub-optimally because of technically inadequate designs. The devices will need to be designed to especially enable adjustability to vary distance between device and patient's skin and the use of lamps which offer high irradiance.
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Affiliation(s)
- Isa Abdulkadir
- Neonatal Unit, Department of Paediatrics, Faculty of Clinical Sciences College of Medicine, Ahmadu Bello University/Teaching Hospital, Zaria, Kaduna State 810107, Nigeria
| | - Sirajo Lawal
- Department of Chemical Engineering, Kaduna Polytechnic, Kaduna State 800262, Nigeria
| | - Mustapha N Adebiyi
- Neonatal Unit, Department of Paediatrics, Faculty of Clinical Sciences College of Medicine, Ahmadu Bello University/Teaching Hospital, Zaria, Kaduna State 810107, Nigeria
| | - Hendrik J Vreman
- Neonatal & Developmental Medicine Laboratory, Division of Neonatology, Department of Pediatrics, Stanford University Medical Center, Stanford, CA 94305-5208, USA
| | - Tina M Slusher
- Department of Pediatrics, University of Minnesota & Hennepin Healthcare, Minneapolis, MN 55415, USA
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Hansen TWR, Maisels MJ, Ebbesen F, Vreman HJ, Stevenson DK, Wong RJ, Bhutani VK. Sixty years of phototherapy for neonatal jaundice - from serendipitous observation to standardized treatment and rescue for millions. J Perinatol 2020; 40:180-193. [PMID: 31420582 DOI: 10.1038/s41372-019-0439-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/04/2019] [Accepted: 05/23/2019] [Indexed: 11/09/2022]
Abstract
A breakthrough discovery 60 years ago by Cremer et al. has since changed the way we treat infants with hyperbilirubinemia and saved the lives of millions from death and disabilities. "Photobiology" has evolved by inquiry of diverse light sources: fluorescent tubes (wavelength range of 400-520 nm; halogen spotlights that emit circular footprints of light; fiberoptic pads/blankets (mostly, 400-550 nm range) that can be placed in direct contact with skin; and the current narrow-band blue light-emitting diode (LED) light (450-470 nm), which overlaps the peak absorption wavelength (458 nm) for bilirubin photoisomerization. Excessive bombardment with photons has raised concerns for oxidative stress in very low birthweight versus term infants treated aggressively with phototherapy. Increased emphasis on prescribing phototherapy as a "drug" that is dosed cautiously and judiciously is needed. In this historical review, we chronicled the basic to the neurotoxic components of severe neonatal hyperbilirubinemia and the use of standardized interventions.
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Affiliation(s)
- Thor Willy Ruud Hansen
- Division of Paediatric and Adolescent Medicine, Department of Neonatal Intensive Care, Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - M Jeffrey Maisels
- Department of Pediatrics, Oakland University William Beaumont School of Medicine, Beaumont Children's Hospital, Royal Oak, MI, USA
| | - Finn Ebbesen
- Department of Pediatrics, Aalborg University Hospital, Aalborg, Denmark.,Institute of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Vinod K Bhutani
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
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Stevenson DK, Wong RJ, Ostrander CR, Maric I, Vreman HJ, Cohen RS. Increased Carbon Monoxide Washout Rates in Newborn Infants. Neonatology 2020; 117:118-122. [PMID: 31634890 DOI: 10.1159/000503635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 09/23/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Endogenous carbon monoxide (CO) production is primarily due to heme degradation, which also results in the equimolar production of bilirubin. Thus, estimates of total body CO production can serve as indices of total body bilirubin formation. The elimination rate of CO from a person's body (CO washout rate) after exposure to an elevated ambient CO concentration is determined by a variety of factors, and is very different between babies and adults. OBJECTIVE We determined CO washout rates for babies using a simplified technique to measure total body CO excretion rates (VeCO). METHODS Using a simplified technique, we measured the times to reach an approximate steady state after a change in ambient CO concentration (decay time constant) and CO washout rates in normal newborn infants using non-linear least squares curve fitting. RESULTS We found a mean CO washout time of 18.7 ± 4.2 min and a CO equilibration (decay time) constant of 0.12 ± 0.04/min (0.08-0.21) for newborn infants. CONCLUSIONS We confirm that CO washout rates for babies are much faster than those for adults. Therefore, measurements of carboxyhemoglobin (COHb) or end-tidal CO (ETCO), corrected for ambient CO, (COHbc and ETCOc, respectively) can be used as surrogates for VeCO and can provide accurate estimates of endogenous CO (VCO) and bilirubin production rates under normal environmental conditions. Such measurements can be used to identify infants with severe hyperbilirubinemia due to hemolysis and thus at high risk for bilirubin neurotoxicity.
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Affiliation(s)
- David K Stevenson
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Ronald J Wong
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA,
| | - Clint R Ostrander
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA.,Peak Laboratories, LLC, Mountain View, California, USA
| | - Ivana Maric
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Hendrik J Vreman
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Ronald S Cohen
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
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Vreman HJ, Kourula S, Jašprová J, Ludvíková L, Klán P, Muchová L, Vítek L, Cline BK, Wong RJ, Stevenson DK. The effect of light wavelength on in vitro bilirubin photodegradation and photoisomer production. Pediatr Res 2019; 85:865-873. [PMID: 30710116 DOI: 10.1038/s41390-019-0310-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 11/09/2022]
Abstract
BACKGROUND The action spectrum for bilirubin photodegradation has been intensively studied. However, questions still remain regarding which light wavelength most efficiently photodegrades bilirubin. In this study, we determined the in vitro effects of different irradiation wavelength ranges on bilirubin photodegradation. METHODS In our in vitro method, normalized absolute irradiance levels of 4.2 × 1015 photons/cm2/s from light-emitting diodes (ranging from 390-530 nm) and 10-nm band-pass filters were used to irradiate bilirubin solutions (25 mg/dL in 4% human serum albumin). Bilirubin and its major photoisomer concentrations were determined; the half-life time of bilirubin (t1/2) was calculated for each wavelength range, and the spectral characteristics for bilirubin photodegradation products were obtained for key wavelengths. RESULTS The in vitro photodegradation of bilirubin at 37 °C decreased linearly as the wavelength was increased from 390 to 500 nm with t1/2 decreasing from 63 to 17 min, respectively. At 460 ± 10 nm, a significantly lower rate of photodegradation and thus higher t1/2 (31 min) than that at 500 nm (17 min) was demonstrated. CONCLUSION In our system, the optimum bilirubin photodegradation and lumirubin production rates occurred between 490 and 500 nm. Spectra shapes were remarkably similar, suggesting that lumirubin production was the major process of bilirubin photodegradation.
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Affiliation(s)
- Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA.
| | - Stephanie Kourula
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Jana Jašprová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Lucie Ludvíková
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Petr Klán
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lucie Muchová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Libor Vítek
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic.
| | - Benjamin K Cline
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
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Vreman HJ, Kourula S, Jašprová J, Ludvíková L, Klán P, Muchová L, Vítek L, Cline BK, Wong RJ, Stevenson DK. Correction: The effect of light wavelength on in vitro bilirubin photodegradation and photoisomer production. Pediatr Res 2019; 85:905. [PMID: 30814644 DOI: 10.1038/s41390-019-0356-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Following publication of this article, the authors noticed that an incorrect affiliation was assigned to the author "Lucie Muchová". The original article has now been updated so that the author "Lucie Muchová" is associated with the "Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00 Prague, Czech Republic". This has been corrected in both the PDF and HTML versions of the article.
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Affiliation(s)
- Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA.
| | - Stephanie Kourula
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Jana Jašprová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Lucie Ludvíková
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Petr Klán
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lucie Muchová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Libor Vítek
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic.
| | - Benjamin K Cline
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
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Slusher TM, Vreman HJ, Brearley AM, Vaucher YE, Wong RJ, Stevenson DK, Adeleke OT, Ojo IP, Edowhorhu G, Lund TC, Gbadero DA. Filtered sunlight versus intensive electric powered phototherapy in moderate-to-severe neonatal hyperbilirubinaemia: a randomised controlled non-inferiority trial. Lancet Glob Health 2018; 6:e1122-e1131. [PMID: 30170894 DOI: 10.1016/s2214-109x(18)30373-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/22/2018] [Accepted: 07/30/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Kernicterus resulting from severe neonatal hyperbilirubinaemia is a leading cause of preventable deaths and disabilities in low-income and middle-income countries, partly because high-quality intensive phototherapy is unavailable. Previously, we showed that filtered-sunlight phototherapy (FSPT) was efficacious and safe for treatment of mild-to-moderate neonatal hyperbilirubinaemia. We aimed to extend these studies to infants with moderate-to-severe hyperbilirubinaemia. METHODS We did a prospective, randomised controlled non-inferiority trial in Ogbomoso, Nigeria-a simulated rural setting. Near-term or term infants aged 14 days or younger who were of 35 weeks or more gestational age and with total serum bilirubin concentrations at or above the recommended age-dependent treatment levels for high-risk neonates were randomly assigned (1:1) to either FSPT or intensive electric phototherapy (IEPT). Randomisation was computer-generated, and neither clinicians nor the parents or guardians of participants were masked to group allocation. FSPT was delivered in a transparent polycarbonate room lined with commercial tinting films that transmitted effective phototherapeutic light, blocked ultraviolet light, and reduced infrared radiation. The primary outcome was efficacy, which was based on assessable treatment days only (ie, those on which at least 4 h of phototherapy was delivered) and defined as a rate of increase in total serum bilirubin concentrations of less than 3·4 μmol/L/h in infants aged 72 h or younger, or a decrease in total serum bilirubin concentrations in those older than 72 h. Safety was defined as no sustained hypothermia, hyperthermia, dehydration, or sunburn and was based on all treatment days. Analysis was by intention to treat with a non-inferiority margin of 10%. FINDINGS Between July 31, 2015, and April 30, 2017, 174 neonates were enrolled and randomly assigned: 87 to FSPT and 87 to IEPT. Neonates in the FSPT group received 215 days of phototherapy, 82 (38%) of which were not assessable. Neonates in the IEPT group received 219 treatment days of phototherapy, 67 (31%) of which were not assessable. Median irradiance was 37·3 μW/cm2/nm (IQR 21·4-56·4) in the FSPT group and 50·4 μW/cm2/nm (44·5-66·2) in the IEPT group. FSPT was efficacious on 116 (87·2%) of 133 treatment days; IEPT was efficacious on 135 (88·8%) of 152 treatment days (mean difference -1·6%, 95% CI -9·9 to 6·7; p=0·8165). Because the CI did not extend below -10%, we concluded that FSPT was not inferior to IEPT. Treatment was safe for all neonates. INTERPRETATION FSPT is safe and no less efficacious than IEPT for treatment of moderate-to-severe neonatal hyperbilirubinaemia in near-term and term infants. FUNDING Thrasher Research Fund and National Center for Advancing Translational Sciences.
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Affiliation(s)
- Tina M Slusher
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA; Department of Pediatrics, Hennepin County Medical Center, Minneapolis, MN, USA; Bowen University Teaching Hospital, Ogbomosho, Oyo, Nigeria.
| | - Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Ann M Brearley
- Division of Biostatistics, University of Minnesota, Minneapolis, MN, USA
| | - Yvonne E Vaucher
- Department of Pediatrics, University of California San Diego, San Diego, CA, USA
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Ifelayo P Ojo
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | | | - Troy C Lund
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
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Borden AR, Satrom KM, Wratkowski P, George TN, Adkisson CA, Vreman HJ, Johnson AP, Nichols KJ, Slusher TM. Variation in the Phototherapy Practices and Irradiance of Devices in a Major Metropolitan Area. Neonatology 2018; 113:269-274. [PMID: 29393277 PMCID: PMC5860931 DOI: 10.1159/000485369] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/15/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Phototherapy (PT) is widely used to prevent and treat severe hyperbilirubinemia and its associated risks for both acute and chronic bilirubin encephalopathy. Intensive PT, recommended for inpatient treatment of hyperbilirubinemia in term and near-term infants, is defined as having a spectral irradiance of ≥30 μW/cm2/nm. OBJECTIVES We aimed to assess local PT practices by measuring the irradiance of PT devices in local neonatal intensive care units and newborn nurseries. METHODS The irradiance footprint, including maximum irradiance at the center of the footprint, of 39 PT devices in 7 area hospitals was measured according to current practice in these facilities. RESULTS The mean ± SD (range) footprint irradiance was 20.7 ± 5.8 (8.8-29.4) μW/cm2/nm. The mean ± SD maximum irradiance at the footprint center for all devices at a mean clinically used treatment distance of 33.1 ± 9.3 (25.5-60.0) cm was 27.8 ± 7.0 (14.7-42.0) μW/cm2/nm. Sixty-two percent of the devices did not meet the minimum recommended spectral irradiance for intensive PT. For the sites without irradiance-based protocols, the maximum irradiance of the devices (n = 33) at the treatment distances was 25.8 ± 6.1 μW/cm2/nm. CONCLUSIONS Despite established PT guidelines, local protocols and practices vary. Based on an assessment of 7 local hospitals, intensive PT was suboptimal for 62% of devices. Straightforward changes, such as decreasing the distance between an infant and the light source and establishing a consistent irradiance-based protocol, could substantially improve the quality of the intervention.
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Ebbesen F, Madsen PH, Vandborg PK, Jakobsen LH, Trydal T, Vreman HJ. Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue). Pediatr Res 2016; 80:511-5. [PMID: 27331354 DOI: 10.1038/pr.2016.115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 04/02/2016] [Indexed: 11/09/2022]
Abstract
BACKGROUND 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. MATERIALS 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. RESULTS 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. CONCLUSION 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.
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Affiliation(s)
- Finn Ebbesen
- Department of Pediatrics, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Poul H Madsen
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | | | - Lasse H Jakobsen
- Department of Statistics, Aalborg University Hospital, Aalborg, Denmark
| | - Torleif Trydal
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Hendrik J Vreman
- Neonatal and Developmental Medicine Laboratory, Division of Neonatology, Department of Pediatrics, Stanford University Medical Center, Stanford, California
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14
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van Bon L, Cossu M, Scharstuhl A, Pennings BWC, Vonk MC, Vreman HJ, Lafyatis RL, van den Berg W, Wagener FADTG, Radstake TRDJ. Low heme oxygenase-1 levels in patients with systemic sclerosis are associated with an altered Toll-like receptor response: another role for CXCL4? Rheumatology (Oxford) 2016; 55:2066-2073. [PMID: 27411481 DOI: 10.1093/rheumatology/kew251] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 05/19/2016] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE SSc is a disease characterized by inflammation and fibrosis. Heme Oxygenase-1 (HO-1) is a haem-degrading enzyme that mediates resolution of inflammation and is induced upon mediators abundantly present in SSc. We aimed to assess whether HO-1 expression/function is disturbed in SSc patients and could therefore be contributing to the ongoing inflammation. METHODS In total, 92 SSc patients and 48 healthy controls were included. By measuring total bilirubin in plasma in vivo, HO-activity was assessed. HO-1 expression levels were determined with western blot in monocytes before and after induction of HO-1 with cobalt protoporphyrin (CoPP) with or without CXCL4. Monocyte-derived dendritic cells (DCs) were stimulated with several Toll-like receptor (TLR) ligands with or without pre-stimulation with CoPP for 24 h. Cytokine levels were measured in the supernatants using the Luminex Bead Array. RESULTS SSc patients have lower plasma levels of bilirubin, suggestive of an aberrant HO-1 function. We demonstrated low HO-1 expression in immune cells from SSc patients, whereas induction with CoPP was able to restore HO-1 levels in DCs from SSc patients, almost normalizing the increased TLR response observed in SSc. Co-exposure to CXCL4 completely abrogated CoPP-induced HO-1 expression, suggesting that the high CXCL4 levels present in SSc patients block the normal induction of HO-1 and its function. CONCLUSION We demonstrate that HO activity in SSc patients is decreased and show its functional consequences. Since CXCL4 blocks the induction of HO-1 expression, neutralization of CXCL4 in SSc patients could have clinical benefits by diminishing overactivation of immune cells and other anti-inflammatory effects of HO-1.
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Affiliation(s)
- Lenny van Bon
- Department of Rheumatology & Clinical Immunology and Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht.,Department of Rheumatology
| | - Marta Cossu
- Department of Rheumatology & Clinical Immunology and Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht
| | - Alwin Scharstuhl
- Department of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Bas W C Pennings
- Department of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Hendrik J Vreman
- Neonatal and Developmental Medicine Laboratory, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | - Robert L Lafyatis
- Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC
| | | | - Frank A D T G Wagener
- Department of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Timothy R D J Radstake
- Department of Rheumatology & Clinical Immunology and Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht .,Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC
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15
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Linfield DT, Lamola AA, Mei E, Hwang AY, Vreman HJ, Wong RJ, Stevenson DK. The effect of hematocrit on in vitro bilirubin photoalteration. Pediatr Res 2016; 79:387-90. [PMID: 26571225 DOI: 10.1038/pr.2015.240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/31/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Phototherapy using light in the spectral range of 410-500 nm, which overlaps the absorption of bilirubin, is the common treatment for neonatal hyperbilirubinemia. Hemoglobin (Hb) absorbs light strongly throughout this same range and thus can compete with bilirubin for this light and consequently reduce the efficacy of phototherapy. Here, we determined the effect of hematocrit (Hct) on in vitro bilirubin photoalteration using narrow-band blue (450 nm) light-emitting diodes (LEDs). METHODS Suspensions with Hcts from 0 to 80% and 16 ± 1 mg/dl bilirubin were prepared by mixing red blood cells (RBCs), bilirubin (30 mg/dl) in 4% human serum albumin, and normal saline. Aliquots of each suspension were exposed to blue light at equal irradiances. Before and after 60 min of exposure, bilirubin levels in supernatants (n = 46) were measured using a diazo-dye method. RESULTS Bilirubin photoalteration steeply decreased by ~60% as Hct increased from 0 to 10%. Over the clinically relevant range of 30-70% Hct, the decrease was significant, but less drastic, exhibiting a quasi-linear dependence on Hct. CONCLUSION Bilirubin photoalteration under blue light in vitro is significantly reduced as Hct increases. Clinical studies are warranted to confirm these in vitro observations that Hct can affect the efficacy of phototherapy.
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Affiliation(s)
- Debra T Linfield
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Angelo A Lamola
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Edward Mei
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Alexander Y Hwang
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Hendrik J Vreman
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Ronald J Wong
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - David K Stevenson
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
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16
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Ebbesen F, Vandborg PK, Madsen PH, Trydal T, Jakobsen LH, Vreman HJ. Effect of phototherapy with turquoise vs. blue LED light of equal irradiance in jaundiced neonates. Pediatr Res 2016; 79:308-12. [PMID: 26484622 DOI: 10.1038/pr.2015.209] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/27/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Blue light with peak emission around 460 nm is the preferred treatment of neonatal hyperbilirubinemia. However, studies using fluorescent light tubes have suggested that turquoise light with peak emission at 490 nm may be more efficient. At present, the predominant light source for phototherapy is light emitting diodes (LEDs). Hence, the aim of this study was to compare the bilirubin-reducing effect in jaundiced neonates treated either with turquoise or with blue LED light with peak emission at 497 or 459 nm, respectively, with equal irradiance on the infants. METHODS Infants with gestational age ≥33 wk and uncomplicated hyperbilirubinemia were randomized to either turquoise or blue LED light and were treated for 24 h. The mean irradiance footprint at skin level was 5.2 × 10(15) and 5.1 × 10(15) photons/cm(2)/s, respectively. RESULTS Forty-six infants received turquoise light and 45 received blue light. The median (95% confidence interval) decrease of total serum bilirubin was 35.3% (32.5; 37.3) and 33.1% (27.1; 36.8) for infants treated with turquoise and blue lights, respectively. The difference was nonsignificant (P = 0.53). The decrease was positively correlated to postnatal age and negatively to birth weight. CONCLUSION Using LED light of equal irradiance, turquoise and blue lights had equal bilirubin-reducing effect on hyperbilirubinemia of neonates.
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Affiliation(s)
- Finn Ebbesen
- Department of Paediatrics, Aalborg University Hospital, Aalborg, Denmark.,Clinical Institute, Aalborg University, Aalborg, Denmark
| | | | - Poul H Madsen
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Torleif Trydal
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Lasse H Jakobsen
- Department of Statistics, Aalborg University Hospital, Aalborg, Denmark
| | - Hendrik J Vreman
- Neonatal and Development Medicine Laboratory, Division of Neonatology, Department of Pediatrics, Stanford University Medical Center, Stanford, California
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17
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Slusher TM, Olusanya BO, Vreman HJ, Brearley AM, Vaucher YE, Lund TC, Wong RJ, Emokpae AA, Stevenson DK. A Randomized Trial of Phototherapy with Filtered Sunlight in African Neonates. N Engl J Med 2015; 373:1115-24. [PMID: 26376136 DOI: 10.1056/nejmoa1501074] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Sequelae of severe neonatal hyperbilirubinemia constitute a substantial disease burden in areas where effective conventional phototherapy is unavailable. We previously found that the use of filtered sunlight for the purpose of phototherapy is a safe and efficacious method for reducing total bilirubin. However, its relative safety and efficacy as compared with conventional phototherapy are unknown. METHODS We conducted a randomized, controlled noninferiority trial in which filtered sunlight was compared with conventional phototherapy for the treatment of hyperbilirubinemia in term and late-preterm neonates in a large, urban Nigerian maternity hospital. The primary end point was efficacy, which was defined as a rate of increase in total serum bilirubin of less than 0.2 mg per deciliter per hour for infants up to 72 hours of age or a decrease in total serum bilirubin for infants older than 72 hours of age who received at least 5 hours of phototherapy; we prespecified a noninferiority margin of 10% for the difference in efficacy rates between groups. The need for an exchange transfusion was a secondary end point. We also assessed safety, which was defined as the absence of the need to withdraw therapy because of hyperthermia, hypothermia, dehydration, or sunburn. RESULTS We enrolled 447 infants and randomly assigned 224 to filtered sunlight and 223 to conventional phototherapy. Filtered sunlight was efficacious on 93% of treatment days that could be evaluated, as compared with 90% for conventional phototherapy, and had a higher mean level of irradiance (40 vs. 17 μW per square centimeter per nanometer, P<0.001). Temperatures higher than 38.0°C occurred in 5% of the infants receiving filtered sunlight and in 1% of those receiving conventional phototherapy (P<0.001), but no infant met the criteria for withdrawal from the study for reasons of safety or required an exchange transfusion. CONCLUSIONS Filtered sunlight was noninferior to conventional phototherapy for the treatment of neonatal hyperbilirubinemia and did not result in any study withdrawals for reasons of safety. (Funded by the Thrasher Research Fund, Salt Lake City, and the National Center for Advancing Translational Sciences of the National Institutes of Health; Clinical Trials.gov number, NCT01434810.).
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Affiliation(s)
- Tina M Slusher
- From the Department of Pediatrics (T.M.S., T.C.L.) and the Biostatistical Design and Analysis Center, Clinical and Translational Science Institute (A.M.B.), University of Minnesota, and Hennepin County Medical Center (T.M.S.) - both in Minneapolis; Center for Healthy Start Initiative (B.O.O.) and Massey Street Children's Hospital (A.A.E.), Lagos, Nigeria; and Department of Pediatrics, Stanford University, Stanford (H.J.V., R.J.W., D.K.S.), and the University of California, San Diego, San Diego (Y.E.V.) - both in California
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18
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Castillo Cuadrado ME, Bhutani VK, Aby JL, Vreman HJ, Wong RJ, Stevenson DK. Evaluation of a new end-tidal carbon monoxide monitor from the bench to the bedside. Acta Paediatr 2015; 104:e279-82. [PMID: 25640053 DOI: 10.1111/apa.12938] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 12/31/2014] [Accepted: 01/16/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Martin E. Castillo Cuadrado
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
| | - Vinod K. Bhutani
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
| | - Janelle L. Aby
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
| | - Hendrik J. Vreman
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
| | - Ronald J. Wong
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
| | - David K. Stevenson
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Lucile Packard Children's Hospital; Stanford CA USA
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19
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Muchova L, Vanova K, Suk J, Micuda S, Dolezelova E, Fuksa L, Cerny D, Farghali H, Zelenkova M, Lenicek M, Wong RJ, Vreman HJ, Vitek L. Protective effect of heme oxygenase induction in ethinylestradiol-induced cholestasis. J Cell Mol Med 2015; 19:924-33. [PMID: 25683492 PMCID: PMC4420596 DOI: 10.1111/jcmm.12401] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/21/2014] [Indexed: 01/20/2023] Open
Abstract
Estrogen-induced cholestasis is characterized by impaired hepatic uptake and biliary bile acids secretion because of changes in hepatocyte transporter expression. The induction of heme oxygenase-1 (HMOX1), the inducible isozyme in heme catabolism, is mediated via the Bach1/Nrf2 pathway, and protects livers from toxic, oxidative and inflammatory insults. However, its role in cholestasis remains unknown. Here, we investigated the effects of HMOX1 induction by heme on ethinylestradiol-induced cholestasis and possible underlying mechanisms. Wistar rats were given ethinylestradiol (5 mg/kg s.c.) for 5 days. HMOX1 was induced by heme (15 μmol/kg i.p.) 24 hrs prior to ethinylestradiol. Serum cholestatic markers, hepatocyte and renal membrane transporter expression, and biliary and urinary bile acids excretion were quantified. Ethinylestradiol significantly increased cholestatic markers (P ≤ 0.01), decreased biliary bile acid excretion (39%, P = 0.01), down-regulated hepatocyte transporters (Ntcp/Oatp1b2/Oatp1a4/Mrp2, P ≤ 0.05), and up-regulated Mrp3 (348%, P ≤ 0.05). Heme pre-treatment normalized cholestatic markers, increased biliary bile acid excretion (167%, P ≤ 0.05) and up-regulated hepatocyte transporter expression. Moreover, heme induced Mrp3 expression in control (319%, P ≤ 0.05) and ethinylestradiol-treated rats (512%, P ≤ 0.05). In primary rat hepatocytes, Nrf2 silencing completely abolished heme-induced Mrp3 expression. Additionally, heme significantly increased urinary bile acid clearance via up-regulation (Mrp2/Mrp4) or down-regulation (Mrp3) of renal transporters (P ≤ 0.05). We conclude that HMOX1 induction by heme increases hepatocyte transporter expression, subsequently stimulating bile flow in cholestasis. Also, heme stimulates hepatic Mrp3 expression via a Nrf2-dependent mechanism. Bile acids transported by Mrp3 to the plasma are highly cleared into the urine, resulting in normal plasma bile acid levels. Thus, HMOX1 induction may be a potential therapeutic strategy for the treatment of ethinylestradiol-induced cholestasis.
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Affiliation(s)
- Lucie Muchova
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
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20
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Abstract
BACKGROUND AND OBJECTIVES We recently demonstrated that direct antiglobulin titer (DAT) positive, blood group A or B newborns born to group O mothers had a high incidence of hyperbilirubinemia, attributable to increased hemolysis. We reanalyzed our data asking whether increasing DAT strength plays a modulating role in the pathophysiology of the hemolysis and hyperbilirubinemia. METHODS Data from previously published DAT-positive, ABO-heterospecific neonates were analyzed for hyperbilirubinemia and hemolysis according to strength of DAT. DAT was measured by using a gel agglutination technique and reported as values ranging from DAT ± to DAT ++++. Hemolysis was evaluated by blood carboxyhemoglobin corrected for inspired, ambient CO (COHbc), and expressed as percent total hemoglobin (tHb). Hyperbilirubinemia was defined as any plasma total bilirubin value >95th percentile on the hour-specific nomogram. RESULTS Hyperbilirubinemia was more prevalent in those with DAT ++ readings (16 of 20, 80%) than those both DAT ± (37 of 87 [42.5%], relative risk: 1.88, 95% confidence interval: 1.35-2.61) and DAT + (32 of 56 [57.1%], relative risk: 1.40, 95% confidence interval: 1.02-1.92). COHbc values were higher for those with DAT ++ (1.45 ± 0.49% tHb [mean ± SD]) than those DAT ± (1.20 ± 0.37% tHb, P = .01) or DAT + (1.22 ± 0.37% tHb, P = .02). CONCLUSIONS DAT ++ readings were associated with a higher incidence of hyperbilirubinemia and higher COHbc values than DAT ± or DAT + counterparts. Increasing DAT strength may be a modulator of hemolysis and hyperbilirubinemia in ABO-heterospecific neonates. DAT strength, and not merely DAT presence or absence, should be taken into consideration in the management of ABO-heterospecific newborns.
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Affiliation(s)
- Michael Kaplan
- Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel; Faculty of Medicine of The Hebrew University, Jerusalem, Israel; and
| | - Cathy Hammerman
- Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel; Faculty of Medicine of The Hebrew University, Jerusalem, Israel; and
| | - Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
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21
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Slusher TM, Vreman HJ, Olusanya BO, Wong RJ, Brearley AM, Vaucher YE, Stevenson DK. Safety and efficacy of filtered sunlight in treatment of jaundice in African neonates. Pediatrics 2014; 133:e1568-74. [PMID: 24864170 PMCID: PMC4531268 DOI: 10.1542/peds.2013-3500] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES Evaluate safety and efficacy of filtered-sunlight phototherapy (FS-PT). METHODS Term/late preterm infants #14 days old with clinically significant jaundice, assessed by total bilirubin (TB) levels, were recruited from a maternity hospital in Lagos, Nigeria. Sunlight was filtered with commercial window-tinting films that remove most UV and significant levels of infrared light and transmit effective levels of therapeutic blue light. After placing infants under an FS-PT canopy, hourly measurements of axillary temperatures, monitoring for sunburn, dehydration, and irradiances of filtered sunlight were performed. Treatment was deemed safe and efficacious if infants were able to stay in FS-PT for $5 hours and rate of rise of TB was ,0.2 mg/dL/h for infants #72 hours of age or TB decreased for infants .72 hours of age. RESULTS A total of 227 infants received 258 days of FS-PT. No infant developed sunburn or dehydration. On 85 (33%) of 258 treatment days, infants were removed briefly from FS-PT due to minor temperature-related adverse events. No infant met study exit criteria. FS-PT was efficacious in 92% (181/197) of evaluable treatment days. Mean 6 SD TB change was –0.06 6 0.19 mg/dL/h. The mean 6 SD (range) irradiance of FS-PT was 38 6 22 (2–115) mW/cm2/nm, measured by the BiliBlanket Meter II. CONCLUSIONS With appropriate monitoring, filtered sunlight is a novel, practical, and inexpensive method of PT that potentially offers safe and efficacious treatment strategy for management of neonatal jaundice in tropical countries where conventional PT treatment is not available.
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Affiliation(s)
- Tina M. Slusher
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota;,Hennepin County Medical Center, Minneapolis, Minnesota
| | | | | | - Ronald J. Wong
- Department of Pediatrics, Stanford University, Stanford, California
| | - Ann M. Brearley
- Biostatistical Design and Analysis Center, Clinical and Translational Science Institute, University of Minnesota, Minneapolis, Minnesota; and
| | - Yvonne E. Vaucher
- Department of Pediatrics, School of Medicine, University of California at San Diego, San Diego, California
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22
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Wong RJ, Schulz S, Espadas C, Vreman HJ, Rajadas J, Stevenson DK. Effects of light on metalloporphyrin-treated newborn mice. Acta Paediatr 2014; 103:474-9. [PMID: 24417721 DOI: 10.1111/apa.12554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/13/2013] [Accepted: 01/08/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED Zinc protoporphyrin (ZnPP) is a promising metalloporphyrin with sufficient potency, but has poor solubility and is not absorbed well orally. Intragastric administration of ZnPP microparticles (30 μmol/kg) to 3-day-old mice resulted in a twofold increase in potency and no signs of phototoxicity. CONCLUSION The use of polymeric particulate delivery systems can improve the stability and enhance intestinal absorption of ZnPP, while retaining HO inhibitory potency without photosensitising effects, and thus is potentially useful in treating neonatal hyperbilirubinemia.
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Affiliation(s)
- Ronald J. Wong
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Stanford CA USA
| | - Stephanie Schulz
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Stanford CA USA
| | - Cecilia Espadas
- Biomaterials and Advanced Drug Delivery (BioADD) Laboratory; Stanford University School of Medicine; Stanford CA USA
| | - Hendrik J. Vreman
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Stanford CA USA
| | - Jayakumar Rajadas
- Biomaterials and Advanced Drug Delivery (BioADD) Laboratory; Stanford University School of Medicine; Stanford CA USA
| | - David K. Stevenson
- Division of Neonatal and Developmental Medicine; Department of Pediatrics; Stanford University School of Medicine; Stanford CA USA
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Kaplan M, Renbaum P, Hammerman C, Vreman HJ, Wong RJ, Stevenson DK. Heme oxygenase-1 promoter polymorphisms and neonatal jaundice. Neonatology 2014; 106:323-9. [PMID: 25277974 DOI: 10.1159/000365744] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/03/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Heme oxygenase (HO) is the initial, rate-limiting enzyme in the conversion of heme to bilirubin. Dinucleotide (GT)n repeat length in the promoter region of the encoding gene modulates transcription: shorter alleles, in contrast with longer allele counterparts, are associated with greater gene expression and should result in increased heme catabolism. OBJECTIVE We compared the rates of heme catabolism and plasma total bilirubin (TB) between HO-1 promoter genotypes of varying (GT)n repeat lengths in glucose-6-phosphate dehydrogenase (G6PD)-normal and -deficient neonates. METHODS HO-1 promoter length was determined from genomic DNA from previous studies by size discrimination of fluorescently-labeled PCR products with capillary electrophoresis. Sizing was confirmed by sequencing homozygote samples. Alleles were categorized as: short (≤24 GT repeats), medium (25-33 GT repeats), and long (≥34 GT repeats). Previously determined values for blood carboxyhemoglobin, corrected for inspired carbon monoxide (COHbc), and TB were used to determine the rate of heme catabolism and 3rd day TB values for each HO-1 promoter length genotype, respectively. G6PD Mediterranean was determined by PCR analysis. RESULTS Neither COHbc nor TB values were significantly different between various HO-1 promoter genotypes for either G6PD-normal or -deficient neonates. CONCLUSIONS In the steady state, HO-1 promoter genotypes, based on the length of (GT)n repeats, do not modulate heme catabolism or 3rd day TB values in either G6PD-normal or -deficient neonates.
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Affiliation(s)
- Michael Kaplan
- Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel
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24
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Dix LML, Blok CA, Lemmers PMA, van der Aa N, Molenschot MC, Vreman HJ, Krediet T, van Bel F. Early end-tidal carbon monoxide levels, patency of the ductus arteriosus and regional cerebral oxygenation in preterm infants. Neonatology 2014; 105:161-5. [PMID: 24356407 DOI: 10.1159/000356167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 10/02/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Carbon monoxide (CO), a relaxant regulator of muscle tone and marker of oxidative stress and inflammation, can be measured in exhaled air by determination of end-tidal CO corrected for CO in ambient air (ETCOc). OBJECTIVE Increased endogenous production of CO may influence patency of the ductus arteriosus, cerebral perfusion and, subsequently, cerebral oxygenation. The aim was to study the relation between early ETCOc levels, hemodynamically significant patent ductus arteriosus (hsPDA) and cerebral oxygenation (rScO2) in preterm infants <32 weeks' gestational age and determine predictive values of ETCOc for hsPDA. METHODS ETCOc was measured in 91 infants within the first 24 h after birth. A hsPDA was diagnosed according to echocardiographic indices. In 78/91 infants, rScO2 was monitored with near-infrared spectroscopy to assess cerebral oxygenation. RESULTS ETCOc values were significantly higher in infants who subsequently developed hsPDA (2.3 ± 0.7 ppm) vs. no-hsPDA (1.7 ± 0.6 ppm), p < 0.001. With a cut-off value of 2.5 ppm, positive and negative predictive values of ETCOc for hsPDA were 55 and 88%, respectively. rScO2 values were not different between the two groups (64 ± 1 vs. 65 ± 3%, NS). CONCLUSIONS The higher ETCOc values in hsPDA infants early after birth reflect the early relaxant state of ductal muscular tone. ETCOc <2.5 ppm within 24 h after birth may predict the subsequent absence of hsPDA. ETCOc showed no correlation with cerebral oxygenation in both groups.
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Affiliation(s)
- Laura M L Dix
- Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht, The Netherlands
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Slusher TM, Olusanya BO, Vreman HJ, Wong RJ, Brearley AM, Vaucher YE, Stevenson DK. Treatment of neonatal jaundice with filtered sunlight in Nigerian neonates: study protocol of a non-inferiority, randomized controlled trial. Trials 2013; 14:446. [PMID: 24373547 PMCID: PMC3879162 DOI: 10.1186/1745-6215-14-446] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 12/16/2013] [Indexed: 11/29/2022] Open
Abstract
Background Severe neonatal jaundice and its progression to kernicterus is a leading cause of death and disability among newborns in poorly-resourced countries, particularly in sub-Saharan Africa. The standard treatment for jaundice using conventional phototherapy (CPT) with electric artificial blue light sources is often hampered by the lack of (functional) CPT devices due either to financial constraints or erratic electrical power. In an attempt to make phototherapy (PT) more readily available for the treatment of pathologic jaundice in underserved tropical regions, we set out to test the hypothesis that filtered sunlight phototherapy (FS-PT), in which potentially harmful ultraviolet and infrared rays are appropriately screened, will be as efficacious as CPT. Methods/design This prospective, non-blinded randomized controlled non-inferiority trial seeks to enroll infants with elevated total serum/plasma bilirubin (TSB, defined as 3 mg/dl below the level recommended by the American Academy of Pediatrics for high-risk infants requiring PT) who will be randomly and equally assigned to receive FS-PT or CPT for a total of 616 days at an inner-city maternity hospital in Lagos, Nigeria. Two FS-PT canopies with pre-tested films will be used. One canopy with a film that transmits roughly 33% blue light (wavelength range: 400 to 520 nm) will be used during sunny periods of a day. Another canopy with a film that transmits about 79% blue light will be used during overcast periods of the day. The infants will be moved from one canopy to the other as needed during the day with the goal of keeping the blue light irradiance level above 8 μW/cm2/nm. Primary outcome: FS-PT will be as efficacious as CPT in reducing the rate of rise in bilirubin levels. Secondary outcome: The number of infants requiring exchange transfusion under FS-PT will not be more than those under CPT. Conclusion This novel study offers the prospect of an effective treatment for infants at risk of severe neonatal jaundice and avoidable exchange transfusion in poorly-resourced settings without access to (reliable) CPT in the tropics. Trial registration ClinicalTrials.gov Identifier:
NCT01434810
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Affiliation(s)
- Tina M Slusher
- Center for Global Health, Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.
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26
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Abstract
We evaluated nine semi-transparent plastic window-tinting films for their ability to block ultraviolet A (UVA) and infrared (IR) radiation and transmit therapeutic blue light (400-520 nm) for treating jaundiced newborns. For indoor testing, three light sources (TL/52 special blue fluorescent, Black Light UVA and IR heat lamps) were positioned above each film and measured successively using a thermocouple thermometer, UVA radiometer and blue light irradiance meter, placed below each film. For outdoor testing, the same setup was used with the sun at zenith and a cloudless sky. Compared with unfiltered radiation, blue light transmission through films ranged from 24 to 83%, UVA transmission was 0.1-7.1% and reductions in IR heat were 6-12°C and 5-10°C for heat lamp and sun, respectively. The data suggest that most of the relatively low-cost window-tinting films tested can effectively reduce sunlight UV and IR and offer a range of significant attenuations of therapeutic blue light.
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Affiliation(s)
- Hendrik J Vreman
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA
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Vanova K, Suk J, Petr T, Cerny D, Slanar O, Vreman HJ, Wong RJ, Zima T, Vitek L, Muchova L. Protective effects of inhaled carbon monoxide in endotoxin-induced cholestasis is dependent on its kinetics. Biochimie 2013; 97:173-80. [PMID: 24148277 DOI: 10.1016/j.biochi.2013.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/11/2013] [Indexed: 10/26/2022]
Abstract
Carbon monoxide (CO), a product of heme oxygenase (HMOX), has many beneficial biological functions and is a promising therapeutic agent for many pathological conditions. However, the kinetics of inhaled CO and its protective role in endotoxin-induced cholestasis is not fully known. Thus, our objective was to characterize the kinetics of inhaled CO and then investigate its use in early phase experimental endotoxin-induced cholestasis. Female Wistar rats were randomly divided into 4 groups: CON (control), LPS (lipopolysaccharide, 6 mg/kg), CO (250 ppm COx1h), and CO + LPS. Rats were sacrificed at 0-12 h after LPS administration. Tissues and blood were collected for liver injury markers and tissue CO distribution measurements. Livers were harvested for measurements of Hmox activity, Hmox1 mRNA expression, cytokines (IL10, IL6, TNF), and bile lipid and pigment transporters. Half-lives of CO in spleen, blood, heart, brain, kidney, liver, and lungs were 2.4 ± 1.5, 2.3 ± 0.8, 1.8 ± 1.6, 1.5 ± 1.2, 1.1 ± 1.1, 0.6 ± 0.3, 0.6 ± 0.2 h, respectively. CO treatment increased liver IL10 mRNA and decreased TNF expression 1 h after LPS treatment and prevented the down-regulation of bile acid and bilirubin hepatic transporters (Slc10a1, Abcb11, and Abcc2, p < 0.05), an effect closely related to the kinetics. The protective effect of CO against cholestatic liver injury persisted even 12 h after CO exposure, as shown by attenuation of serum cholestatic markers in CO-treated animals. CO exposure substantially attenuated endotoxin-induced cholestatic liver injury and was directly related to the kinetics of inhaled CO. This data underscores the importance of the kinetics of inhaled CO for the proper design of experimental and clinical studies of using CO as a treatment strategy.
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Affiliation(s)
- K Vanova
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - J Suk
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - T Petr
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - D Cerny
- Institute of Pharmacology, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - O Slanar
- Institute of Pharmacology, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - H J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - R J Wong
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - T Zima
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - L Vitek
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; 4th Department of Internal Medicine, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - L Muchova
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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Cline BK, Vreman HJ, Faber K, Lou H, Donaldson KM, Amuabunosi E, Ofovwe G, Bhutani VK, Olusanya BO, Slusher TM. Phototherapy device effectiveness in Nigeria: irradiance assessment and potential for improvement. J Trop Pediatr 2013; 59:321-5. [PMID: 23666953 DOI: 10.1093/tropej/fmt027] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
This study investigated the effectiveness of simple-to-implement adjustments of phototherapy devices on irradiance levels in a cross-section of Nigerian hospitals. A total of 76 phototherapy devices were evaluated in 16 hospitals while adjustments were implemented for a subset of 25 devices for which consent was obtained. The mean irradiance level was 7.6 ± 5.9 µW/cm(2)/nm for all devices prior to adjustments. The average irradiance level improved from 9.0 µW/cm(2)/nm to 27.3 µW/cm(2)/nm for the adjusted group (n = 25) compared with 6.8 ± 5.4 µW/cm(2)/nm for the unadjusted group (n = 51). Simple, inexpensive adjustments to phototherapy devices with sub-optimal irradiance levels can significantly improve their effectiveness to acceptable international standards and should be widely promoted in resource-constrained settings.
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Schulz S, Wong RJ, Jang KY, Kalish F, Chisholm KM, Zhao H, Vreman HJ, Sylvester KG, Stevenson DK. Heme oxygenase-1 deficiency promotes the development of necrotizing enterocolitis-like intestinal injury in a newborn mouse model. Am J Physiol Gastrointest Liver Physiol 2013; 304:G991-G1001. [PMID: 23578787 PMCID: PMC3680684 DOI: 10.1152/ajpgi.00363.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 04/09/2013] [Indexed: 01/31/2023]
Abstract
Necrotizing enterocolitis (NEC) is typified by mucosal destruction, which subsequently can lead to intestinal necrosis. Prematurity, enteral feeding, and bacterial colonization are the main risk factors and, combined with other stressors, can cause increased intestinal permeability, injury, and an exaggerated inflammatory response. Heme oxygenase-1 (HO-1) mediates intestinal protection due to anti-inflammatory, antioxidative, and antiapoptotic effects of its products carbon monoxide, biliverdin, and bilirubin. This study investigates a possible role of HO-1 in the pathogenesis of NEC using a newborn mouse model. We induced NEC-like intestinal injury in 7-day-old HO-1 heterozygous (HO-1 Het, Hmox1(+/-)) and wild-type (Wt, Hmox1(+/+)) mice by gavage feeding and hypoxic exposures. Control (Con) pups of both genotypes were dam-fed. Intestines of HO-1 Het Con pups appeared predisposed to injury, with higher histological damage scores, more TUNEL-positive cells, and a significant reduction in muscularis externa thickness compared with Wt Con pups. The increase in HO activity after HO-1 induction by the substrate heme or by hypoxic stress was significantly impaired in HO-1 Het pups. After induction of intestinal injury, HO-1 Het pups displayed significantly higher NEC incidence (78 vs. 43%), mortality (83 vs. 54%), and median scores (2.5 vs. 1.5) than Wt NEC pups. PCR array analyses revealed increased expressions of IL-1β, P-selectin, matrix metallopeptidase 2, collagen type XVIII-α1, serpine 1, and others in NEC-induced HO-1 Het ileal and jejunal tissues. We conclude that a partial HO-1 deficiency promotes experimental NEC-like intestinal injury, possibly mediated by exaggerated inflammation and disruption in tissue repair.
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Affiliation(s)
- Stephanie Schulz
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
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30
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Subhanova I, Muchova L, Lenicek M, Vreman HJ, Luksan O, Kubickova K, Kreidlova M, Zima T, Vitek L, Urbanek P. Expression of Biliverdin Reductase A in peripheral blood leukocytes is associated with treatment response in HCV-infected patients. PLoS One 2013; 8:e57555. [PMID: 23536765 PMCID: PMC3594226 DOI: 10.1371/journal.pone.0057555] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 01/26/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND AIMS Hepatitis C virus (HCV) infection is associated with systemic oxidative stress. Since the heme catabolic pathway plays an important role in antioxidant protection, we attempted to assess the gene expression of key enzymes of heme catabolism, heme oxygenase 1 (HMOX1), heme oxygenase 2 (HMOX2), and biliverdin reductase A (BLVRA) in the liver and peripheral blood leukocytes (PBL) of patients chronically infected with HCV. METHODS Gene expressions (HMOX1, HMOX2, BLVRA) and HCV RNA were analyzed in PBL of HCV treatment naïve patients (n = 58) and controls (n = 55), with a subset of HCV patients having data on hepatic gene expression (n = 35). Based upon the therapeutic outcome, HCV patients were classified as either responders (n = 38) or treatment-failure patients (n = 20). Blood samples in HCV patients were collected at day 0, and week 12, 24, 36, and 48 after the initiation of standard antiviral therapy. RESULTS Compared to the controls, substantially increased BLVRA expression was detected in PBL (p<0.001) of therapeutically naïve HCV patients. mRNA levels of BLVRA in PBL closely correlated with those in liver tissue (r2 = 0.347,p = 0.03). A marked difference in BLVRA expression in PBL between the sustained responders and patients with treatment failure was detected at week 0 and during the follow-up (p<0.001). Multivariate analysis revealed that BLVRA basal expression in PBL was an independent predictor for sustained virological response (OR 15; 95% CI 1.05-214.2; P = 0.046). HMOX1/2 expression did not have any effect on the treatment outcome. CONCLUSION Our results suggest that patients with chronic HCV infection significantly upregulate BLVRA expression in PBL. The lack of BLVRA overexpression is associated with non-responsiveness to standard antiviral therapy; whereas, HMOX1/2 does not seem to have any predictive potential.
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Affiliation(s)
- Iva Subhanova
- Institute of Medical Biochemistry and Laboratory Diagnostics, General University Hospital and 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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31
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van Imhoff DE, Hulzebos CV, van der Heide M, van den Belt VW, Vreman HJ, Dijk PH. High variability and low irradiance of phototherapy devices in Dutch NICUs. Arch Dis Child Fetal Neonatal Ed 2013; 98:F112-6. [PMID: 22611115 DOI: 10.1136/archdischild-2011-301486] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To evaluate phototherapy practices by measuring the irradiance levels of phototherapy (PT) devices. DESIGN Prospective study. SETTING Tertiary neonatal intensive care units. PATIENTS None. INTERVENTIONS Irradiance levels of PT devices used in the 10 Dutch Neonatal Intensive Care Units (NICUs) were measured according to the local PT practice patterns. The irradiance levels of all overhead and fibre-optic PT devices were measured with a radiometer using an infant silhouette model. RESULTS Eight different PT devices were used in the 10 NICUs; five were overhead devices and three fibre-optic pads. The median (range) irradiance level for overhead PT devices was 9.7 (4.3-32.6) µW/cm(2)/nm and for fibre-optic pads 6.8 (0.8-15.6) µW/cm(2)/nm. Approximately 50% of PT devices failed to meet the minimal recommended irradiance level of 10 µW/cm(2)/nm. Maximal irradiance levels for overhead PT spot lights were inversely related to the distance between device and infant model (R2=0.33). The distances ranged from 37 cm to 65 cm. CONCLUSIONS PT devices in the Dutch NICUs show considerable variability with often too low irradiance levels. These results indicate that suboptimal PT is frequently applied and may even be ineffective towards reducing total serum bilirubin levels. These results underline the need for greater awareness among all healthcare workers towards the requirements for effective PT including measurements of irradiance and distance.
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Affiliation(s)
- Deirdre E van Imhoff
- Department of Neonatology, Beatrix Children’s Hospital, University Medical Center Groningen, The Netherlands
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Zelenka J, Muchova L, Zelenkova M, Vanova K, Vreman HJ, Wong RJ, Vitek L. Intracellular accumulation of bilirubin as a defense mechanism against increased oxidative stress. Biochimie 2012; 94:1821-7. [PMID: 22580386 DOI: 10.1016/j.biochi.2012.04.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 04/30/2012] [Indexed: 12/22/2022]
Abstract
Antioxidant, anti-inflammatory and anti-atherogenic effects have been associated with elevations of unconjugated bilirubin (UCB) in serum and with the induction of heme oxygenase-1 (HO-1), the rate-limiting enzyme in UCB synthesis. The aim of this study was to investigate the intracellular metabolism and antioxidant properties of UCB in human hepatoblastoma HepG2 cells and tissues of Wistar rats exposed to oxidative stressors and lipopolysaccharide (LPS), respectively. Intracellular UCB concentrations in HepG2 cells correlated with its levels in culture media (p < 0.001) and diminished lipid peroxidation in a dose-dependent manner (p < 0.001). Moreover, induction of HO-1 with sodium arsenite led to 2.4-fold (p = 0.01) accumulation of intracellular UCB over basal level while sodium azide-derived oxidative stress resulted in a 60% drop (p < 0.001). This decrease was ameliorated by UCB elevation in media or by simultaneous induction of HO-1. In addition, hyperbilirubinemia and liver HO-1 induction in LPS-treated rats resulted in a 2-fold accumulation of tissue UCB (p = 0.01) associated with enhanced protection against lipid peroxidation (p = 0.02). In conclusion, hyperbilirubinemia and HO-1 induction associated with inflammation and oxidative stress increase intracellular concentrations of UCB, thus enhancing the protection of cellular lipids against peroxidation. Therefore, the previously reported protective effects of hyperbilirubinemia and HO-1 induction are at least in part due to intracellular accumulation of UCB.
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Affiliation(s)
- Jaroslav Zelenka
- Institute of Physiology, Academy of Sciences, Dept. 75, Videnska 1083, Prague 142 20, Czech Republic.
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Abstract
Metalloporphyrins are structural analogs of heme and their potential use in the management of neonatal hyperbilirubinemia has been the subject of considerable research for more than three decades. The pharmacological basis for using this class of compounds to control bilirubin levels is the targeted blockade of bilirubin production through the competitive inhibition of heme oxygenase (HO), the rate-limiting enzyme in the bilirubin production pathway. Ongoing research continues in the pursuit of identifying ideal metalloporphyrins, which are safe and effective, by defining therapeutic windows and targeted interventions for the treatment of excessive neonatal hyperbilirubinemia.
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Affiliation(s)
- Stephanie Schulz
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine Stanford, CA, USA
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Blok CA, Krediet TG, Kavelaars A, Koopman-Esseboom C, Vreman HJ, Van Bel F. Early end-tidal carbon monoxide levels and neurodevelopmental outcome at 3 years 6 months of age in preterm infants. Dev Med Child Neurol 2011; 53:1113-8. [PMID: 21933176 PMCID: PMC3220782 DOI: 10.1111/j.1469-8749.2011.04110.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM Increased end-tidal carbon monoxide (ETCOc) and cytokines in preterm infants are related to bronchopulmonary dysplasia and intraventricular haemorrhages. The aim was to study the predictive value of ETCOc and cytokine levels for long-term outcome. METHODS This study comprised 105 very preterm infants (57 males, 48 females; gestational age range 25 wks 5d-31 wks 4d; birthweight 610-2100 g) who were admitted to a neonatal intensive care unit between 1 February and 31 December 2002. ETCOc, plasma tumour necrosis factor alpha (TNF-α) and interleukins (IL) 6 and 8, and malondialdehyde (MDA, a marker of lipid peroxidation), were measured at days 1, 3, and 5 of life and related to outcome at 3 years 6 months of age (Griffiths Mental Developmental Scales). RESULTS Of the 105 infants, 69 were eligible for follow-up (37 males; 32 females; bronchopulmonary dysplasia, n = 12). ETCOc at 0 to 24 hours was higher in infants with adverse outcome (Griffiths developmental quotient <85, n = 15) compared with favourable outcome (2.7SD 0.7 vs 2.0SD 0.5; p < 0.05). MDA and cytokines did not differ between groups. Regression analysis with bootstrapping of independent variables (gestational age, birthweight, ETCOc, TNF-α, IL-6, IL-8, and bronchopulmonary dysplasia) showed that ETCOc was the only parameter that correlated with outcome. The sensitivity and negative predictive value of ETCOc for adverse outcome were 93% and 85% respectively. INTERPRETATION Adverse neurodevelopmental outcome is associated with increased endogenous carbon monoxide. ETCOc less than 2.0 ppm during the first day indicates a favourable outcome.
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Affiliation(s)
- Cornelie A Blok
- Department of Neonatology, University Medical Center Utrecht, the Netherlands
| | - Tannette G Krediet
- Department of Neonatology, University Medical Center Utrecht, the Netherlands
| | - Annemiek Kavelaars
- Laboratory of NeuroImmunology and Developmental Origins of Disease (NIDOD), University Medical Center Utrecht, the Netherlands
| | | | - Hendrik J Vreman
- Neonatal and Developmental Medicine Laboratory, Stanford University School of Medicine, Stanford, CA, USA
| | - Frank Van Bel
- Department of Neonatology, University Medical Center Utrecht, the Netherlands
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Abstract
Infants with hemolytic diseases frequently develop hyperbilirubinemia and are treated with phototherapy, which only eliminates bilirubin after its production. A better strategy might be to directly inhibit heme oxygenase (HO), the rate-limiting enzyme in bilirubin production. Metalloporphyrins (Mps) are heme analogs that competitively inhibit HO activity in vitro and in vivo and suppress plasma bilirubin levels in vivo. A promising Mp, zinc deuteroporphyrin bis glycol (ZnBG), is orally absorbed and effectively inhibits HO activity at relatively low doses. We determined the I(50) (the dose needed to inhibit HO activity by 50%) of orally administered ZnBG in vivo and then evaluated ZnBG's effects on in vivo bilirubin production, HO activity, HO protein levels, and HO-1 gene expression in newborn mice after heme loading, a model analogous to a hemolytic infant. The I(50) of ZnBG was found to be 4.0 μmol/kg body weight (BW). At a dose of 15 μmol/kg BW, ZnBG reduced in vivo bilirubin production, inhibited heme-induced liver HO activity and spleen HO activity to and below baseline, respectively, transiently induced liver and spleen HO-1 gene transcription, and induced liver and spleen HO-1 protein levels. We conclude that ZnBG may be an attractive compound for treating severe neonatal hyperbilirubinemia caused by hemolytic disease.
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Affiliation(s)
- Cynthia X He
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA
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37
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Abstract
Neonatal jaundice usually occurs in the transitional period after birth, presenting as an elevation of circulating bilirubin. Bilirubin neurotoxicity can occur if the levels of bilirubin become excessive (hyperbilirubinemia). This pathologic phenotype of newborn jaundice can develop because of excessive bilirubin production or impaired conjugation, with the risk for developing bilirubin-induced neurologic dysfunction, depending on the degree of the resultant bilirubin load. The plasma bilirubin level thus can be used to assess an infant's risk for developing bilirubin neurotoxicity relative to an infant's age in hours. Because all infants have an impaired conjugation ability, infants at greatest risk are those who have increased bilirubin production rates, because of hemolysis, for example. Therefore, developing potential preventive strategies as well as noninvasive technologies to treat and to identify infants with increased bilirubin production rates, respectively, are tantamount to reducing the incidence of bilirubin-induced neurologic dysfunction.
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Affiliation(s)
- David K Stevenson
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
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38
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Abstract
Phototherapy is the treatment of choice to reduce the severity of neonatal unconjugated hyperbilirubinemia regardless of its etiology. Its implementation requires a technical framework that conforms to existing evidence-based guidelines that promote its safer and effective use worldwide. Optimal use of phototherapy has been defined by specific ranges of total serum bilirubin thresholds configured to an infant's postnatal age (in hours) and potential risk for bilirubin neurotoxicity. Effective phototherapy implies its use at specific blue light wavelengths (peak emission, 450 ± 20 nm) and emission spectrum (range, 400-520 nm), preferably in a narrow bandwidth that is delivered at an irradiance of ≥30 μW/cm(2)/nm to up to 80% of an infant's body surface area. However, this is often not feasible in clinical settings with limited or constrained resources. To identify and bridge implementation barriers, we propose minimum criteria for device performance for safe and practical use of phototherapy as a prophylactic intervention to prevent severe hyperbilirubinemia.
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Affiliation(s)
- Vinod K Bhutani
- Division of Neonatal-Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Lucile Packard Children's Hospital, Stanford, CA 94304, USA.
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39
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Abstract
OBJECTIVE Neonatal jaundice results from an increased bilirubin production and decreased hepatic bilirubin conjugation and excretion. Severe hyperbilirubinemia is currently treated with phototherapy or exchange transfusion; however, its prevention by inhibiting bilirubin formation is a more logical strategy. Heme oxygenase (HO), with inducible (HO-1) and constitutive (HO-2) isoenzymes, is the rate-limiting enzyme in heme catabolism, producing equimolar amounts of bilirubin and carbon monoxide (CO). Metalloporphyrins (Mps) are heme derivatives that competitively inhibit HO and thereby suppress hyperbilirubinemia. No systematic studies have been reported evaluating whether the HO isoenzymes are inhibited differentially by various Mps. Identification of Mps that selectively inhibit the inducible HO-1 without affecting the 'housekeeping' HO-2 isoenzyme might be desirable in the clinical setting of hemolytic disease, in which the Hmox1 gene is greatly induced. Although bilirubin production is due to the activity of both HO-1 and HO-2, the inhibition of HO-1 with a relative sparing of HO-2 activity might provide the most selective approach for the treatment of hemolytic disease. STUDY DESIGN We determined for the deutero-, proto-, meso- and bis-glycol porphyrins with zinc, tin and chromium as central atoms, respectively, the concentration needed for 50% inhibition (I(50)) of HO-1 and HO-2 activities in rat spleen and brain tissue. RESULT For a given Mp, HO-1 activity was less inhibited than that of HO-2. The order of inhibitor potency of each Mp was nearly identical for both isoenzymes. Tin mesoporphyrin was the most potent inhibitor for both isoenzymes. HO-2 selectivity was greatest for tin protoporphyrin. Conversely, the Zn compounds were least inhibitory toward HO-2. No Mp preferentially inhibited HO-1. CONCLUSION Mps that produce a less inhibitory effect on HO-2, while limiting the response of the inducible HO-1, such as ZnPP, may be a useful clinical tool.
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Affiliation(s)
- R J Wong
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
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Vreman HJ, Wong RJ, Stevenson DK. Quantitating carbon monoxide production from heme by vascular plant preparations in vitro. Plant Physiol Biochem 2011; 49:61-68. [PMID: 21055958 DOI: 10.1016/j.plaphy.2010.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 09/28/2010] [Accepted: 09/30/2010] [Indexed: 05/30/2023]
Abstract
Heme in animals is mainly degraded enzymatically, producing a predictable amount of carbon monoxide (CO). Under some conditions, alternative sources of CO production are important, such as lipid peroxidation and photo-oxidation. Less is known about CO production in plants as a reflection of enzymatic activity or coupled oxidation, but a sensitive assay for CO production in plants would be a valuable tool to explore the various sources in plants as the conditions of the reactions and mechanisms are defined. Using gas chromatography, we determined the requirements for heme-supported in vitro CO generation by exogenous reactants (NADPH, tissue supernatant, oxygen), optimum reaction conditions (time, temperature, pH, light), and effects of various cofactors and substrates using supernatants from Spinacia oleracea (spinach) leaf and Solanum tuberosa (potato) tuber homogenates. We then determined the CO production rate distribution between organ (root, stem, leaf, flower, fruit) supernatants in a number of commercially available plant species. CO production ranged from 4-65 nmol CO/h/g fresh weight and occurred in all vascular plant tissues examined, with the highest rates in chloroplast-containing tissues. In spinach leaves, CO production was concentrated (>2-fold) in the particulate fraction, whereas in potato tubers, the particulate fraction accounted for <50% of the rates in homogenates. We conclude that gas chromatography is uniquely suited for the determination of CO production in pigmented, heterogeneous plant tissue preparations.
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Affiliation(s)
- Hendrik J Vreman
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5208, USA.
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Kaplan M, Hammerman C, Vreman HJ, Wong RJ, Stevenson DK. Hemolysis and hyperbilirubinemia in antiglobulin positive, direct ABO blood group heterospecific neonates. J Pediatr 2010; 157:772-7. [PMID: 20598320 PMCID: PMC2951500 DOI: 10.1016/j.jpeds.2010.05.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2010] [Revised: 04/08/2010] [Accepted: 05/14/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE We quantified hemolysis and determined the incidence of hyperbilirubinemia in neonates who were direct antiglobulin titer (DAT)-positive, ABO heterospecific, and compared variables among O-A and O-B subgroups. STUDY DESIGN Plasma total bilirubin (PTB) was determined before the neonates were discharged from the hospital and more frequently when clinically warranted, in neonates who were DAT positive with blood group A or B and with mothers who had blood group O. Heme catabolism (and therefore bilirubin production) was indexed by blood carboxyhemoglobin corrected for inspired carbon monoxide (COHbc). Hyperbilirubinemia was defined as any PTB concentration >95th percentile on the hour-of-life-specific bilirubin nomogram. RESULTS Of 164 neonates, 111 were O-A and 53 O-B. Overall, hyperbilirubinemia developed 85 neonates (51.8%), and it tended to be more prevalent in the O-B neonates than O-A neonates (62.3% versus 46.8%; P = .053). Hyperbilirubinemia developed in more O-B newborns than O-A newborns at <24 hours (93.9% versus 48.1%; P< .0001). COHbc values were globally higher than our previously published newborn values. Babies in whom hyperbilirubinemia developed had higher COHbc values than the already high values of babies who were non-hyperbilirubinemic, and O-B newborns tended to have higher values than their O-A counterparts. CONCLUSIONS DAT-positive, ABO heterospecificity is associated with increased hemolysis and a high incidence of neonatal hyperbilirubinemia. O-B heterospecificity tends to confer even higher risk than O-A counterparts.
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Oh W, Stevenson DK, Tyson JE, Morris BH, Ahlfors CE, Bender GJ, Wong RJ, Perritt R, Vohr BR, Van Meurs KP, Vreman HJ, Das A, Phelps DL, O'Shea TM, Higgins RD. Influence of clinical status on the association between plasma total and unbound bilirubin and death or adverse neurodevelopmental outcomes in extremely low birth weight infants. Acta Paediatr 2010; 99:673-678. [PMID: 20105142 DOI: 10.1111/j.1651-2227.2010.01688.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18-22 months corrected age in extremely low birth weight infants. METHOD Total plasma bilirubin and unbound bilirubin were measured in 1101 extremely low birth weight infants at 5 +/- 1 days of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18-22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow-up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. RESULTS Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow-up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow-up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. CONCLUSIONS In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma bilirubin and death or adverse neurodevelopmental outcomes at 18-22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants.
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Affiliation(s)
- W Oh
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - D K Stevenson
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - J E Tyson
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - B H Morris
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - C E Ahlfors
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - G Jesse Bender
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - R J Wong
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - R Perritt
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - B R Vohr
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - K P Van Meurs
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - H J Vreman
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - A Das
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - D L Phelps
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - T Michael O'Shea
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
| | - R D Higgins
- Warren Alpert Medical School of Brown University, RI, USAStanford University, Palo Alto, CAUniversity of Texas, Houston, TX, USAZF Diagnostics Vashon, WA, USAResearch Triangle International, RTI, NC, USAUniversity of Rochester, Rochester, NY, USAWake Forest University Winston-Salem, NC, USANICHD, Bethesda, MD, USA
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James EB, Vreman HJ, Wong RJ, Stevenson DK, Vichinsky E, Schumacher L, Hall JY, Simon J, Golden DW, Harmatz P. Elevated exhaled carbon monoxide concentration in hemoglobinopathies and its relation to red blood cell transfusion therapy. Pediatr Hematol Oncol 2010; 27:112-21. [PMID: 20201692 DOI: 10.3109/08880010903536227] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In this study, the authors examined a possible role of measurements of end-tidal carbon monoxide (CO), corrected for inhaled CO (ETCOc), as a noninvasive screening tool for hemoglobinopathies and as an indicator for when transfusions would be required in patients receiving chronic transfusions. ETCOc measurements were obtained in subjects with sickle cell disease (n = 18), thalassemia (n = 21), and healthy controls (n = 62). ETCOc values less than 3 parts per million (ppm) yielded a positive predictive value of 93% and negative predictive value of 94% in identifying hemoglobinopathies. Subsequently, 7 subjects with thalassemia had laboratory parameters and ETCOc measured over 2 transfusion cycles. ETCOc values were 4.90 +/- 0.32 ppm (mean +/- SD), with 89% of values being above normal (>or=3 ppm). Pretransfusion ETCOc levels significantly correlated with pretransfusion reticulocyte count (r = .96, P <.001), but not with pretransfusion hemoglobin (r = .44, P = .16) or pretransfusion soluble transferrin receptors (sTfR, r = .52, P = .10). In conclusion, we found that patients with hemoglobinopathies have ETCOc values above the range for healthy controls and ETCOc measurements can be used as an adjunct to hemoglobin measurements to determine the proper timing of transfusions.
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Affiliation(s)
- Ellen Butensky James
- Department of Gastroenterology, Children's Hospital & Research Center Oakland, Oakland, California 94609, USA
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Abstract
Total body, head, and trunk carbon monoxide (CO) excretion rates were measured separately by gas chromatography in 1- to 7-d-old Wistar rat pups exposed to the dark and to mixed blue (one Special Blue-F20T12/BB) and white (two Cool White-F20T12/CW) fluorescent light or blue light emitting diode (LED) sources. During 48-min cycled exposures to the dark and to either light source, total body CO excretion rapidly increased 1.9- and 1.4-fold, respectively, over dark control levels. When CO excretion rates from the head and trunk were measured separately during exposure to either light source, CO excretion from the head did not change significantly; however, a large mean 4.4-fold increase in CO excretion from the trunk was observed. When light intensity delivered by the blue LED source was varied, we found that trunk CO excretion increased with increasing light intensities. In the presence of riboflavin (10 micromol/kg), total body CO excretion increased 2.8- and 2.1-fold during exposure to the mixed fluorescent light and blue LED sources, respectively. We conclude that light-induced elevations in total body CO excretion may be caused by transdermally excreted CO, which is most likely produced through endogenous photosensitizer-mediated photooxidation of dermal biomolecules.
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Affiliation(s)
- Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
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Ahlfors CE, Vreman HJ, Wong RJ, Bender GJ, Oh W, Morris BH, Stevenson DK. Corrigendum to “Effects of sample dilution, peroxidise concentration, and chloride ion on the measurement of unbound bilirubin in premature newborns” [Clinical Biochemistry 40 (2007) 261–267]. Clin Biochem 2009. [DOI: 10.1016/j.clinbiochem.2008.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Morisawa T, Wong RJ, Bhutani VK, Vreman HJ, Stevenson DK. Inhibition of heme oxygenase activity in newborn mice by azalanstat. Can J Physiol Pharmacol 2009; 86:651-9. [PMID: 18841169 DOI: 10.1139/y08-069] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inhibition of heme oxygenase (HO), the rate-limiting enzyme in heme catabolism, may be an ideal strategy for preventing neonatal jaundice. Although natural and synthetic heme analogs, called metalloporphyrins (Mps), have been extensively investigated for this purpose, some Mps are phototoxic, affect the activity of other enzymes, or induce HO-1 transcription-properties that may limit their clinical use. Another class of compounds, imidazole-dioxolanes, has been shown to selectively inhibit the inducible isozyme HO-1. Therefore, we investigated the efficacy of azalanstat (AZA), an imidazole-dioxolane, towards inhibiting HO activity in 7-day-old mice. We found that a single dose of AZA at 500 micromol.kg(-1) body mass (BM) administered i.p. significantly inhibited HO activity and reduced in vivo bilirubin production. In the spleen, HO inhibition (>50%) was observed within 0.25-3 h after administration. After 24 h, however, spleen HO activity, HO-1 protein, and HO-1 mRNA levels significantly increased 1.2-, 2.4-, and 4.0-fold, respectively. We conclude that AZA effectively inhibits in vivo HO activity only at a high dose and that it also induces spleen HO-1 gene transcription. Therefore, other imidazole-dioxolanes should be evaluated to determine whether they are more potent than AZA for use in treating neonatal jaundice.
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Affiliation(s)
- Takeshi Morisawa
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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Abstract
OBJECTIVES The objectives of the study were to measure the effect of 4Z,15E-bilirubin on peroxidase free bilirubin measurements and to review the literature on this topic. METHODS 4Z,15E-Bilirubin was generated in situ in serum or serum albumin solution through controlled irradiation of isomerically pure 4Z,15Z-bilirubin IXalpha, under conditions in which the total amount of bilirubin remained constant. Reactions were monitored by difference spectroscopy, to ensure that solutions were not irradiated beyond the initial photostationary state and that concentrations of other isomers were kept to a minimum. Prepared in this way, 10% to 25% of the total bilirubin in the final solutions was in the form of the 4Z,15E-isomer. Free bilirubin in the solutions was measured with a peroxidase method, before and after irradiation. The use of bovine serum albumin as a surrogate for human albumin in in vitro studies also was investigated. RESULTS The findings of previous studies are not altogether consistent, with a common flaw in several being the failure to measure photoisomer concentrations. For bilirubin in serum albumin solution, conversion of approximately 25% of the 4Z,15Z-isomer to 4Z,15E-bilirubin led to a much smaller decrease (<20%) in the apparent free bilirubin concentration; for bilirubin in serum, conversion of approximately 15% of the 4Z,15Z-isomer to photoisomers resulted in a much larger increase ( approximately 40%). Irradiation of bilirubin in bovine serum albumin solution generated a very different array of photoisomers than that observed in human albumin solutions. CONCLUSIONS The effect of photoisomers on the accuracy and specificity of free 4Z,15Z-bilirubin measurements remains uncertain. In a clinical setting, free bilirubin measurements need to be interpreted with caution when samples contain photoisomers. Irradiated bovine albumin solutions of isomerically impure bilirubin used in previous studies are poor models for investigating the effects of phototherapy in humans and the albumin binding of photoisomers.
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Affiliation(s)
- Antony F McDonagh
- Division of Gastroenterology, Department of Medicine, University of California, San Francisco, CA 94143-0538, USA.
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Kaplan M, Na'amad M, Kenan A, Rudensky B, Hammerman C, Vreman HJ, Wong RJ, Stevenson DK. Failure to predict hemolysis and hyperbilirubinemia by IgG subclass in blood group A or B infants born to group O mothers. Pediatrics 2009; 123:e132-7. [PMID: 19114458 DOI: 10.1542/peds.2008-2617] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Direct antibody titer-positive, blood group A or B neonates who are born to group O mothers may be at risk for hemolysis and hyperbilirubinemia. Immunoglobulin G1 and immunoglobulin G3 subclasses are associated with increased hemolysis relative to immunoglobulin G2 and immunoglobulin G4. We investigated whether identification of immunoglobulin G subclass 1 or 3 may be predictive of hemolysis and hyperbilirubinemia. METHODS Direct antibody titer-positive, blood group A and B neonates born to group O mothers were tested for the presence of immunoglobulin G subclasses 1 and 3 in umbilical cord blood by using a commercially available gel testing technology. By inference, neonates in whom neither immunoglobulin G1 nor immunoglobulin G3 were detected were designated immunoglobulin G2 and/or 4. Mandatory plasma total bilirubin was measured at discharge, and additional measurements performed as clinically indicated. Hyperbilirubinemia was defined as any plasma total bilirubin value >95th percentile for hour of life. Blood carboxyhemoglobin and total hemoglobin concentrations were also measured on the predischarge sample. Measured carboxyhemoglobin, expressed as percentage of total hemoglobin, was corrected for ambient carbon monoxide to derive "corrected carboxyhemoglobin," a sensitive index of heme catabolism. The corrected carboxyhemoglobin/total hemoglobin ratio was calculated to correct for any differences in total hemoglobin mass between groups. RESULTS Eighty-two infants were studied, 18 of whom were designated as immunoglobulin G1, 0 as immunoglobulin G3, and 64 as immunoglobulin G2 and/or 4. The incidence of plasma total bilirubin >95th percentile was similar between the subgroupings. Corrected carboxyhemoglobin values and corrected carboxyhemoglobin/total hemoglobin ratio were also similar between the subgroupings. CONCLUSIONS Immunoglobulin G1 was found in 22% of direct antibody titer-positive, group A and B neonates who were born to group O mothers, whereas immunoglobulin G3 was rare. Hemolysis and hyperbilirubinemia could not be predicted by this gel technique that enabled identification of these immunoglobulin G subclasses.
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Affiliation(s)
- Michael Kaplan
- Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel.
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Kaplan M, Hammerman C, Vreman HJ, Wong RJ, Stevenson DK. Severe hemolysis with normal blood count in a glucose-6-phosphate dehydrogenase deficient neonate. J Perinatol 2008; 28:306-9. [PMID: 18379570 DOI: 10.1038/sj.jp.7211919] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A premature glucose-6-phosphate dehydrogenase (G-6-PD) deficient neonate was readmitted for exponential rise in the plasma bilirubin concentration to 33.0 mg dl(-1). Blood carboxyhemoglobin (2.8% of total hemoglobin, >threefold normal value) confirmed the presence of hemolysis; however, hematological indices were unchanged from the birth hospitalization. Serum unbound bilirubin, although present, was probably at a concentration insufficient to cause bilirubin encephalopathy. In G-6-PD deficient neonates, severe hemolysis may occur in the absence of hematological changes typical of a hemolytic process.
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Affiliation(s)
- M Kaplan
- Department of Neonatology, Shaare Zedek Medical Center, Jerusalem, Israel.
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Abstract
AIM As phototherapy (PT) devices employ a variety of broadband light sources, we developed and tested a standardized bench method for evaluating the efficacy of some devices. METHODS To evaluate efficacy, we quantified the in vitro photodegradation rate (expressed as t1/2) of unconjugated bilirubin in solution at 37 degrees C during exposure to a given light source at its mean delivered irradiance to the 2D body surface area (BSA) of newborn models. Reproducibility (between-day variation) of the method was determined at irradiance levels from 10 to 70 microW/cm2/nm on three different days. RESULTS Between-day t1/2 measurements had coefficients of variation from 3% to 10%. When t1/2 values were normalized to the exposable 2D horizontal BSA, halogen lamp devices, without and with fiberoptics, were least effective (t1/2=60-108 min and 100-126 min for preterm and term models, respectively). Fluorescent tube devices had t1/2=19-78 min and 25-78 min, for preterm and term models, respectively. Light-emitting diode (LED)-based devices yielded the shortest t1/2 values (16-24 min) for preterm and term newborn models. CONCLUSIONS We demonstrated the applicability of the method through the determination of the efficacy of several commercially available PT devices. This standardized method is reproducible and effectively evaluates the relative in vitro efficacy of various devices and may guide further in vitro and in vivo evaluations of devices.
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Affiliation(s)
- H J Vreman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305-5208, USA.
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