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Sample records for hemoglobin

  1. Hemoglobin

    MedlinePlus

    ... Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hemoglobin Share this page: Was ...

  2. Hemoglobin derivatives

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  3. Hemoglobin electrophoresis

    MedlinePlus

    ... is an abnormal form of hemoglobin associated with sickle cell anemia . In people with this condition, the red blood ... symptoms are much milder than they are in sickle cell anemia. Other, less common, abnormal Hb molecules cause other ...

  4. Hemoglobin (image)

    MedlinePlus

    ... called heme, which binds oxygen. In the lungs, oxygen is exchanged for carbon dioxide. Abnormalities of an individual's hemoglobin value can indicate defects in the normal balance between red blood cell production and destruction. Both low and high values can ...

  5. Hemoglobin Test

    MedlinePlus

    ... thrombocythemia and polycythemia vera. Current Opinion in Hematology [Internet]. 2016 Mar [cited 2017 Feb 1]; 23(2): ... Function of Hemoglobin. New England Journal of Medicine [Internet]. 1998 Jan 22 [cited 2017 Feb 1]; 338: ...

  6. Hemoglobin C disease

    MedlinePlus

    Clinical hemoglobin C ... Hemoglobin C is an abnormal type of hemoglobin, the protein in red blood cells that carries oxygen. It is a type of hemoglobinopathy. The disease is caused by a problem with ...

  7. Human hemoglobin genetics

    SciTech Connect

    Honig, G.R.; Adams, J.G.

    1986-01-01

    This book contains the following 10 chapters: Introduction; The Human Hemoglobins; The Human Globin Genes; Hemoglobin Synthesis and Globin Gene Expression; The Globin Gene Mutations - A. Mechanisms and Classification; The Globin Gene Mutations - B. Their Phenotypes and Clinical Expression; The Genetics of the Human Globin Gene Loci: Formal Genetics and Gene Linkage; The Geographic Distribution of Globin Gene Variation; Labortory Identification, Screening, Education, and Counseling for Abnormal Hemoglobins and Thalassemias; and Approaches to the Treatment of the Hemoglobin Disorders.

  8. The Hemoglobin E Thalassemias

    PubMed Central

    Fucharoen, Suthat; Weatherall, David J.

    2012-01-01

    Hemoglobin E (HbE) is an extremely common structural hemoglobin variant that occurs at high frequencies throughout many Asian countries. It is a β-hemoglobin variant, which is produced at a slightly reduced rate and hence has the phenotype of a mild form of β thalassemia. Its interactions with different forms of α thalassemia result in a wide variety of clinical disorders, whereas its coinheritance with β thalassemia, a condition called hemoglobin E β thalassemia, is by far the most common severe form of β thalassemia in Asia and, globally, comprises approximately 50% of the clinically severe β-thalassemia disorders. PMID:22908199

  9. The hemoglobin E thalassemias.

    PubMed

    Fucharoen, Suthat; Weatherall, David J

    2012-08-01

    Hemoglobin E (HbE) is an extremely common structural hemoglobin variant that occurs at high frequencies throughout many Asian countries. It is a β-hemoglobin variant, which is produced at a slightly reduced rate and hence has the phenotype of a mild form of β thalassemia. Its interactions with different forms of α thalassemia result in a wide variety of clinical disorders, whereas its coinheritance with β thalassemia, a condition called hemoglobin E β thalassemia, is by far the most common severe form of β thalassemia in Asia and, globally, comprises approximately 50% of the clinically severe β-thalassemia disorders.

  10. The optimal target hemoglobin.

    PubMed

    Ritz, E; Schwenger, V

    2000-07-01

    There is still controversy concerning the optimal target hemoglobin during treatment with recombinant human erythropoietin (rHuEPO). Some evidence suggests that hemoglobin concentrations higher than currently recommended lead to improvements in cognitive function, physical performance, and rehabilitation. At least in patients with advanced cardiac disease, however, one controlled trial failed to show a benefit from normalizing predialysis hemoglobin concentrations. In contrast, preliminary observations in three additional studies (albeit with limited statistical power) failed to show adverse cardiovascular effects from normalization of hemoglobin, but definite benefit with respect to quality of life, physical performance, and cardiac geometry. These observations are consistent with the notion that hemoglobin concentrations higher than those recommended by the National Kidney Foundation Dialysis Outcomes Quality Initiative Anemia Work Group are beneficial, at least in patients without advanced cardiac disease.

  11. Phylogeny of Echinoderm Hemoglobins

    PubMed Central

    Christensen, Ana B.; Herman, Joseph L.; Elphick, Maurice R.; Kober, Kord M.; Janies, Daniel; Linchangco, Gregorio; Semmens, Dean C.; Bailly, Xavier; Vinogradov, Serge N.; Hoogewijs, David

    2015-01-01

    Background Recent genomic information has revealed that neuroglobin and cytoglobin are the two principal lineages of vertebrate hemoglobins, with the latter encompassing the familiar myoglobin and α-globin/β-globin tetramer hemoglobin, and several minor groups. In contrast, very little is known about hemoglobins in echinoderms, a phylum of exclusively marine organisms closely related to vertebrates, beyond the presence of coelomic hemoglobins in sea cucumbers and brittle stars. We identified about 50 hemoglobins in sea urchin, starfish and sea cucumber genomes and transcriptomes, and used Bayesian inference to carry out a molecular phylogenetic analysis of their relationship to vertebrate sequences, specifically, to assess the hypothesis that the neuroglobin and cytoglobin lineages are also present in echinoderms. Results The genome of the sea urchin Strongylocentrotus purpuratus encodes several hemoglobins, including a unique chimeric 14-domain globin, 2 androglobin isoforms and a unique single androglobin domain protein. Other strongylocentrotid genomes appear to have similar repertoires of globin genes. We carried out molecular phylogenetic analyses of 52 hemoglobins identified in sea urchin, brittle star and sea cucumber genomes and transcriptomes, using different multiple sequence alignment methods coupled with Bayesian and maximum likelihood approaches. The results demonstrate that there are two major globin lineages in echinoderms, which are related to the vertebrate neuroglobin and cytoglobin lineages. Furthermore, the brittle star and sea cucumber coelomic hemoglobins appear to have evolved independently from the cytoglobin lineage, similar to the evolution of erythroid oxygen binding globins in cyclostomes and vertebrates. Conclusion The presence of echinoderm globins related to the vertebrate neuroglobin and cytoglobin lineages suggests that the split between neuroglobins and cytoglobins occurred in the deuterostome ancestor shared by echinoderms and

  12. Amyloid Fibrils from Hemoglobin

    PubMed Central

    Jayawardena, Nadishka; Kaur, Manmeet; Nair, Smitha; Malmstrom, Jenny; Goldstone, David; Negron, Leonardo; Gerrard, Juliet A.; Domigan, Laura J.

    2017-01-01

    Amyloid fibrils are a class of insoluble protein nanofibers that are formed via the self-assembly of a wide range of peptides and proteins. They are increasingly exploited for a broad range of applications in bionanotechnology, such as biosensing and drug delivery, as nanowires, hydrogels, and thin films. Amyloid fibrils have been prepared from many proteins, but there has been no definitive characterization of amyloid fibrils from hemoglobin to date. Here, nanofiber formation was carried out under denaturing conditions using solutions of apo-hemoglobin extracted from bovine waste blood. A characteristic amyloid fibril morphology was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM), with mean fibril dimensions of approximately 5 nm diameter and up to several microns in length. The thioflavin T assay confirmed the presence of β-sheet structures in apo-hemoglobin fibrils, and X-ray fiber diffraction showed the characteristic amyloid cross-β quaternary structure. Apo-hemoglobin nanofibers demonstrated high stability over a range of temperatures (−20 to 80 °C) and pHs (2–10), and were stable in the presence of organic solvents and trypsin, confirming their potential as nanomaterials with versatile applications. This study conclusively demonstrates the formation of amyloid fibrils from hemoglobin for the first time, and also introduces a cost-effective method for amyloid fibril manufacture using meat industry by-products. PMID:28398221

  13. Rice (Oryza) hemoglobins

    USDA-ARS?s Scientific Manuscript database

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  14. High oxygen affinity hemoglobins.

    PubMed

    Mangin, O

    2017-02-01

    High oxygen affinity hemoglobins are responsible for rare and heterogeneous autosomic dominant genetic diseases. They cause pure erythrocytosis, sometimes accountable for hyperviscosity and thrombosis, or hemolysis. Differential diagnoses must be first ruled out. The diagnosis is based on the identification of a decreased P50, and their possible characterization by cation exchange-high performance liquid chromatography and capillary electrophoresis. Finally, genetic studies of the responsible globin chain gene will confirm the mutation. The prognosis mainly relies on the P50 decrease rate and on the hemoglobin cooperativity impairment. Disease management should be personalized, and it should primarily depend on smoking cessation and physical activity. Phlebotomy and platelet aggregation inhibitors' prescriptions can be discussed. There is no contraindication to flights, high-altitude conditions, or pregnancy. Nevertheless, blood donation must be prohibited. Copyright © 2016 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  15. Interaction between hypericin and hemoglobin.

    PubMed

    Vardapetyan, H R; Martirosyan, A S; Tiratsuyan, S G; Hovhannisyan, A A

    2010-10-05

    In the present work the hypericin interaction with hemoglobin was studied by absorption and fluorescence spectroscopy both under incubation in dark and visible light exposure. An absorption reduction in Soret band of hemoglobin (407 nm) was revealed under the photodynamic influence and incubation in dark with hypericin that had hypericin concentration and time dependent manner. Hypericin reduced the intensity of the hemoglobin emission peaks at 334 and 421 nm, correlating with hypericin concentration, incubation and irradiation time. An obvious increase in electrophoretic mobility of hemoglobin was observed under the incubation with hypericin. Simultaneously, a partial conversion of hemoglobin to met-hemoglobin and a pH decrease in hemoglobin solution were detected. Structural changes of hemoglobin caused by hypericin were accompanied by a change in peroxidase activity of the protein. Thus under the hypericin influence hemoglobin properties as a hydrogen peroxide detector could be improved and an effective determination of peroxide formation could be achieved. This makes hemoglobin an attractive 'recognition' element for construction of third-generation biosensors.

  16. Hemoglobin Drift after Cardiac Surgery

    PubMed Central

    George, Timothy J.; Beaty, Claude A.; Kilic, Arman; Haggerty, Kara A.; Frank, Steven M.; Savage, William J.; Whitman, Glenn J.

    2013-01-01

    Introduction Recent literature suggests that a restrictive approach to red blood cell transfusions is associated with improved outcomes in cardiac surgery (CS) patients. Even in the absence of bleeding, intravascular fluid shifts cause hemoglobin levels to drift postoperatively, possibly confounding the decision to transfuse. We undertook this study to define the natural progression of hemoglobin levels in postoperative CS patients. Methods We included all CS patients from 10/10-03/11 who did not receive a postoperative transfusion. Primary stratification was by intraoperative transfusion status. Change in hemoglobin was evaluated relative to the initial postoperative hemoglobin. Maximal drift was defined as the maximum minus the minimum hemoglobin for a given hospitalization. Final drift was defined as the difference between initial and discharge hemoglobin. Results Our final cohort included 199 patients, 71(36%) received an intraoperative transfusion while 128(64%) did not. The average initial and final hemoglobin for all patients were 11.0±1.4g/dL and 9.9±1.3g/dL, respectively, an final drift of 1.1±1.4g/dL. The maximal drift was 1.8±1.1g/dL and was similar regardless of intraoperative transfusion status(p=0.9). Although all patients’ hemoglobin initially dropped, 79% of patients reached a nadir and experienced a mean recovery of 0.7±0.7g/dL by discharge. On multivariable analysis, increasing CPB time was significantly associated with total hemoglobin drift(Coefficient/hour: 0.3[0.1–0.5]g/dL, p=0.02). Conclusions In this first report of hemoglobin drift following CS, although all postoperative patients experienced downward hemoglobin drift, 79% of patients exhibited hemoglobin recovery prior to discharge. Physicians should consider the eventual upward hemoglobin drift prior to administering red cell transfusions. PMID:22609121

  17. [Hemoglobin H: laboratory identification].

    PubMed

    Ribeiro, V S; de Araújo, J T

    1992-01-01

    Hemoglobin H (Hb H) disease is an alpha thalassemia form characterized by low synthesis of alpha chain and high beta chain concentration; this unbalance induces the beta chain tetramers formation. Hb H is relatively frequent in Thailand and Greece. Isolated cases have been reported in Chinese, Filipinos, Malaysians. In the Near East occasional cases were observed in Greek Cypriots and Jordanian Arabs. Hb H carriers were found in Italy, Spain, Canada, Indonesia and other countries. In Brazil there are descendants of Italians, Chinese and people of negro origin who are carriers of Hb H. We identified the Hb H by electrophoresis, instability and characteristic inclusion bodies.

  18. Disorders of Human Hemoglobin

    NASA Astrophysics Data System (ADS)

    Bank, Arthur; Mears, J. Gregory; Ramirez, Francesco

    1980-02-01

    Studies of the human hemoglobin system have provided new insights into the regulation of expression of a group of linked human genes, the γ -δ -β globin gene complex in man. In particular, the thalassemia syndromes and related disorders of man are inherited anemias that provide mutations for the study of the regulation of globin gene expression. New methods, including restriction enzyme analysis and cloning of cellular DNA, have made it feasible to define more precisely the structure and organization of the globin genes in cellular DNA. Deletions of specific globin gene fragments have already been found in certain of these disorders and have been applied in prenatal diagnosis.

  19. Hemoglobin senses body temperature.

    PubMed

    Artmann, G M; Digel, Ilya; Zerlin, K F; Maggakis-Kelemen, Ch; Linder, Pt; Porst, D; Kayser, P; Stadler, A M; Dikta, G; Temiz Artmann, A

    2009-06-01

    When aspirating human red blood cells (RBCs) into 1.3 mum pipettes (DeltaP = -2.3 kPa), a transition from blocking the pipette below a critical temperature T(c) = 36.3 +/- 0.3 degrees C to passing it above the T(c) occurred (micropipette passage transition). With a 1.1 mum pipette no passage was seen which enabled RBC volume measurements also above T(c). With increasing temperature RBCs lost volume significantly faster below than above a T(c) = 36.4 +/- 0.7 (volume transition). Colloid osmotic pressure (COP) measurements of RBCs in autologous plasma (25 degrees C < or = T < or = 39.5 degrees C) showed a T (c) at 37.1 +/- 0.2 degrees C above which the COP rapidly decreased (COP transition). In NMR T(1)-relaxation time measurements, the T(1) of RBCs in autologous plasma changed from a linear (r = 0.99) increment below T(c) = 37 +/- 1 degrees C at a rate of 0.023 s/K into zero slope above T(c) (RBC T(1) transition). An amorphous hemoglobin-water gel formed in the spherical trail, the residual partial sphere of the aspirated RBC. At T(c), a sudden fluidization of the gel occurs. All changes mentioned above happen at a distinct T(c) close to body temperature. The T(c) is moved +0.8 degrees C to higher temperatures when a D(2)O buffer is used. We suggest a mechanism similar to a "glass transition" or a "colloidal phase transition". At T(c), the stabilizing Hb bound water molecules reach a threshold number enabling a partial Hb unfolding. Thus, Hb senses body temperature which must be inscribed in the primary structure of hemoglobin and possibly other proteins.

  20. THE RENAL HANDLING OF HEMOGLOBIN

    PubMed Central

    Bunn, H. Franklin; Jandl, James H.

    1969-01-01

    The fate of small doses of isotopically labeled isologous hemoglobin was studied in the rat. When haptoglobin depleted animals were given 2.0 mg of 59Fe hemoglobin intravenously, nearly half was trapped by the kidneys. Kidney 59Fe activity disappeared slowly over several weeks. Whatever iron was lost from the kidneys was largely reutilized. In contrast, the porphyrin of hemoglobin absorbed by the kidneys appeared to be rapidly catabolized, since 5 hr after the injection of 14C or 59Fe heme-labeled hemoglobin only a small fraction was recovered as hematin. Likewise, after injection of globin-labeled hemoglobin, rapid disappearance of kidney protein activity indicated that the absorbed globin was readily catabolized in situ. PMID:5778790

  1. Delayed treatment of hemoglobin neurotoxicity.

    PubMed

    Regan, Raymond F; Rogers, Bret

    2003-01-01

    Hemoglobin is an oxidative neurotoxin that may contribute to cell injury after CNS trauma and hemorrhagic stroke. Prior studies have demonstrated that concomitant treatment with iron-chelating antioxidants prevents its neurotoxicity. However, the efficacy of these agents when applied hours after hemoglobin has not been determined, and is the subject of the present investigation. Consistent with prior observations, an increase in reactive oxygen species generation, detected by 2',7'-dichlorofluorescin oxidation, was observed when mixed neuronal/astrocyte cultures prepared from mouse cortex were exposed to hemoglobin alone. However, this oxidative stress developed slowly. A significant increase in the dichlorofluorescein signal compared with control, untreated cultures was not observed until four hours after addition of hemoglobin, and was followed by loss of membrane integrity and propidium iodide staining. Treating cultures with the 21-aminosteroid U74500A or the ferric iron chelator deferoxamine four hours after initiating hemoglobin treatment markedly attenuated reactive oxygen species production within 2 h. Continuous exposure to 5 micro M hemoglobin for 24 h resulted in death of about three-quarters of neurons, without injuring astrocytes. Most neuronal loss was prevented by concomitant treatment with U74500A; its effect was not significantly attenuated if treatment was delayed for 2-4 h, and it still prevented over half of neuronal death if treatment was delayed for 8 h. Similar neuroprotection was produced by delayed treatment with deferoxamine or the lipid-soluble iron chelator phenanthroline. None of these agents had any effect on neuronal death when added to cultures 12 h after hemoglobin. These results suggest that hemoglobin is a potent but slowly-acting neurotoxin. The delayed onset of hemoglobin neurotoxicity may make it an attractive target for therapeutic intervention.

  2. Non-invasive hemoglobin monitoring.

    PubMed

    Joseph, Bellal; Haider, Ansab; Rhee, Peter

    2016-09-01

    Technology has transformed the practice of medicine and surgery in particular over the last several decades. This change in practice has allowed diagnostic and therapeutic tests to be performed less invasively. Hemoglobin monitoring remains one of the most commonly performed diagnostic tests in the United States. Recently, non-invasive hemoglobin monitoring technology has gained popularity. The aim of this article is to review the principles of how this technology works, pros and cons, and the implications of non-invasive hemoglobin technology particularly in trauma surgery.

  3. More Refined Experiments with Hemoglobin.

    ERIC Educational Resources Information Center

    Morin, Phillippe

    1985-01-01

    Discusses materials needed, procedures used, and typical results obtained for experiments designed to make a numerical stepwise study of the oxygenation of hemoglobin, myoglobin, and other oxygen carriers. (JN)

  4. Nonlinear photoacoustic spectroscopy of hemoglobin

    SciTech Connect

    Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.; Xia, Jun; Wang, Lihong V.

    2015-05-18

    As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.

  5. Nonlinear photoacoustic spectroscopy of hemoglobin

    NASA Astrophysics Data System (ADS)

    Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.; Xia, Jun; Wang, Lihong V.

    2015-05-01

    As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.

  6. More Refined Experiments with Hemoglobin.

    ERIC Educational Resources Information Center

    Morin, Phillippe

    1985-01-01

    Discusses materials needed, procedures used, and typical results obtained for experiments designed to make a numerical stepwise study of the oxygenation of hemoglobin, myoglobin, and other oxygen carriers. (JN)

  7. Rice ( Oryza) hemoglobins

    PubMed Central

    Arredondo-Peter, Raúl; Moran, Jose F.; Sarath, Gautam

    2014-01-01

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs. PMID:25653837

  8. Rice ( Oryza) hemoglobins.

    PubMed

    Arredondo-Peter, Raúl; Moran, Jose F; Sarath, Gautam

    2014-01-01

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit a very high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs.

  9. Solid phase pegylation of hemoglobin.

    PubMed

    Suo, Xiaoyan; Zheng, Chunyang; Yu, Pengzhan; Lu, Xiuling; Ma, Guanghui; Su, Zhiguo

    2009-01-01

    A solid phase conjugation process was developed for attachment of polyethylene glycol to hemoglobin molecule. Bovine hemoglobin was loaded onto an ion exchange chromatography column and adsorbed by the solid medium. Succinimidyl carbonate mPEG was introduced in the mobile phase after the adsorption. Pegylation took place between the hemoglobin on the solid phase, and the pegylation reagent in the liquid phase. A further elution was carried out to separate the pegylated and the unpegylated protein. Analysis by HPSEC, SDS-PAGE, and MALLS demonstrated that the fractions eluted from the solid phase contained well-defined components. Pegylated hemoglobin with one PEG chain was obtained with the yield of 75%, in comparison to the yield of 30% in the liquid phase pegylation. The P(50) values of the mono-pegylated hemoglobin, prepared with SC-mPEG 5 kDa, 10 kDa and 20 kDa, were 19.97, 20.23 and 20.54 mmHg, which were much closer to the value of red blood cells than that of pegylated hemoglobin prepared with the conventional method.

  10. Reticulocyte hemoglobin equivalent to detect thalassemia and thalassemic hemoglobin variants.

    PubMed

    Sudmann, Å A; Piehler, A; Urdal, P

    2012-12-01

    Thalassemia and iron deficiency may both result in hypochromic microcytic anemia. Hematological algorithms that differentiate the two are mainly established in adult selected diagnostic groups. We aimed at creating an algorithm applicable in the presence of children, hemoglobin variants, and iron deficiency. Our study material constituted blood samples referred during 1 year for routine diagnostics of hemoglobinopathy. We included 443 samples, of which 37% were from children 3 months or older. We found β-thalassemia trait (n = 100), α-thalassemia (n = 75), combined α-/β-thalassemia (n = 14), hemoglobin variants (n = 42), and no-hemoglobinopathy (n = 207), of whom 107 had a ferritin at or below 20 μg/L. We included reticulocyte hemoglobin equivalent, ferritin, and erythrocyte count in our algorithm. Our algorithm differentiated β-thalassemia trait from no-hemoglobinopathy with a sensitivity of 99% at 83% specificity. It performed better than other published algorithms when applied to all patient samples, while equally or moderately better in the 63% adult samples. Our algorithm also detected the clinically significant α-thalassemias, and most of the combined α-/β-thalassemias and thalassemic hemoglobin variants. Our algorithm efficiently differentiated thalassemia and thalassemic hemoglobin variants from iron deficiency in children and adults. © 2012 Blackwell Publishing Ltd.

  11. Hemoglobin Wayne Trait with Incidental Polycythemia.

    PubMed

    Ambelil, Manju; Nguyen, Nghia; Dasgupta, Amitava; Risin, Semyon; Wahed, Amer

    2017-01-01

    Hemoglobinopathies, caused by mutations in the globin genes, are one of the most common inherited disorders. Many of the hemoglobin variants can be identified by hemoglobin analysis using conventional electrophoresis and high performance liquid chromatography; however hemoglobin DNA analysis may be necessary in other cases for confirmation. Here, we report a case of a rare alpha chain hemoglobin variant, hemoglobin Wayne, in a 47-year-old man who presented with secondary polycythemia. Capillary zone electrophoresis and high performance liquid chromatography revealed a significant amount of a hemoglobin variant, which was further confirmed by hemoglobin DNA sequencing as hemoglobin Wayne. Since the patient was not homozygous for hemoglobin Wayne, which is associated with secondary polycythemia, the laboratory diagnosis in this case was critical in ruling out hemoglobinopathy as the etiology of his polycythemia.

  12. Reactions of arsine with hemoglobin

    SciTech Connect

    Hatlelid, K.M.; Brailsford, C.; Carter, D.E.

    1996-02-09

    The mechanism of arsine (AsH{sub 3}) induced hemolysis was studied in vitro using isolated red blood cells (RBCs) from the rat or dog. AsH{sub 3}-induced hemolysis of dog red blood cells was completely blocked by carbon monoxide (CO) preincubation and was reduced by pure oxygen (O{sub 2}) compared to incubations in air. Since CO and O{sub 2} bind to heme and also reduced hemolysis, these results suggested a reaction between AsH{sub 3} and hemoglobin in the hemeligand binding pocket or with the heme iron. Further, sodium nitrite induction of methemoglobin (metHb) to 85% and 34% of total Hb in otherwise intact RBCs resulted in 56% and 16% decreases in hemolysis, respectively, after incubation for 4 h. This provided additional evidence for the involvement of hemoglobin in the AsH{sub 3}-induced hemolysis mechanism. Reactions between AsH{sub 3} and hemoglobin were studied in solutions of purified dog hemoglobin. Spectrophotometric studies of the reaction of AsH{sub 3} with various purified hemoglobin species revealed that AsH{sub 3} reacted with HbO{sub 2} to produce metHb and, eventually, degraded Hb characterized by gross precipitation of the protein. AsH{sub 3} did not alter the spectrum of deoxyHb and did not cause degradation of metHb in oxygen, but bound to and reduced metHb in the absence of oxygen. These data indicate that a reaction of AsH{sub 3} with oxygenated hemoglobin, HbO{sub 2}, may lead to hemolysis, but there are reactions between AsH{sub 3} and metHb that may not be directly involved in the hemolytic process. 17 refs., 6 figs.

  13. [Homozygous hemoglobin-E (Hb-EE) disease].

    PubMed

    Amendola, G; Danise, P; Di Palma, A; Franzese, M; Avino, D; D'Arco, A M

    2004-01-01

    The Authors report on a 16 year-old girl, of Cambodian descent, who was admitted to the hospital for hematuria. She showed a mild microcytic, hypochromic anemia with a normal iron balance; clinical examination was normal with neither pallor nor icterus nor splenomegaly; electrophoresis of hemoglobin yielded no hemoglobin A, a sligtly increased amount of HbF and a single band with a mobility similar to that of HbA2; the patient showed no evidence of overt increased hemolysis. With the DNA technology a final diagnosis of homozygous hemoglobin E was made. Hemoglobin E is the most common Hb variant among Southeast Asian populations. The Authors discuss on the benign nature of Hb-EE disease, pointing out that the presence of a single HbE gene in combination with that for beta-thalassemia leads generally to a disorder often comparable in severity to that of homozygous beta-thalassemia. With the recent migration of a high number of people from the countries, where HbE is extremely frequent, to the Western world (including Italy), this thalassemia syndrome is now a global health problem; therefore its knowledge is an important diagnostic challenge to all the experts involved in the care of thalassemic patients.

  14. Hemoglobin in a coacervate system.

    PubMed

    Ecanow, J; Ecanow, D; Ecanow, B

    1990-01-01

    Hemoglobin dissolved in a coacervate system shows the properties of a resuscitation fluid. In the coacervate system used, the equilibrium phase was the colloid rich phase. We propose a new definition of the coacervate phase to be that phase in a coacervate system which is most dissimilar to water in its physical chemical properties.

  15. Carboxyalkylated Hemoglobin as a Potential Blood Substitute

    DTIC Science & Technology

    1989-09-20

    chromatography to remove minor and glycosylated hemoglobin components. Carbox) methylation Reaction - Many of the procedures have been described in our early...hemoglobin by peptide mapping after treatment with radiolabeled methyl acetyl phosphate. These binding sites are Met-l(3) and Lys-81(f) for liganded...ABSTRACT (Continue on reverse if necesary andia entify by block number) Carbox,, methylated hemoglobin is more stable than oxy hemoglobin during some

  16. Recombinant Hemoglobins as Artificial Oxygen Carriers

    PubMed Central

    Fronticelli, Clara; Koehler, Raymond C.; Brinigar, William S.

    2008-01-01

    This paper describes the approaches we have taken to construct a) mutant hemoglobins with different oxygen affinities, and b) mutant hemoglobins and myoglobins that polymerize to high molecular weight aggregates in an effort to prevent extravasation and the associated vasoactivity. In vivo testing indicates that exchange transfusion of polymeric hemoglobins in mice does not result in vasoactivity and that polymeric hemoglobins are effective oxygen carriers to ischemic tissues irrespective of their oxygen affinity and cooperativity. PMID:17364470

  17. Blood Test: Hemoglobin A1C

    MedlinePlus

    ... TV, Video Games, and the Internet Blood Test: Hemoglobin A1c KidsHealth > For Parents > Blood Test: Hemoglobin A1c Print A A A What's in this ... de sangre: hemoglobina A1c What It Is A hemoglobin A1c (HbA1c) test is used to monitor long- ...

  18. Blood Test: Hemoglobin A1C

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Hemoglobin A1c KidsHealth > For Parents > Blood Test: Hemoglobin A1c A A A What's in this article? ... de sangre: hemoglobina A1c What It Is A hemoglobin A1c (HbA1c) test is used to monitor long- ...

  19. Hemoglobin

    MedlinePlus

    ... there may be some throbbing or a slight bruise. This soon goes away. Why the Test is ... of the heart ( cor pulmonale ) Severe chronic obstructive pulmonary disease (COPD) Scarring or thickening of the lungs ( ...

  20. Hemoglobin Labeled by Radioactive Lysine

    DOE R&D Accomplishments Database

    Bale, W. F.; Yuile, C. L.; DeLaVergne, L.; Miller, L. L.; Whipple, G. H.

    1949-12-08

    This paper reports on the utilization of tagged epsilon carbon of DL-lysine by a dog both anemic and hypoproteinemic due to repeated bleeding plus a diet low in protein. The experiment extended over period of 234 days, a time sufficient to indicate an erythrocyte life span of at least 115 days based upon the rate of replacement of labeled red cell proteins. The proteins of broken down red cells seem not to be used with any great preference for the synthesis of new hemoglobin.

  1. Hemoglobin Variants: Biochemical Properties and Clinical Correlates

    PubMed Central

    Thom, Christopher S.; Dickson, Claire F.; Gell, David A.; Weiss, Mitchell J.

    2013-01-01

    Diseases affecting hemoglobin synthesis and function are extremely common worldwide. More than 1000 naturally occurring human hemoglobin variants with single amino acid substitutions throughout the molecule have been discovered, mainly through their clinical and/or laboratory manifestations. These variants alter hemoglobin structure and biochemical properties with physiological effects ranging from insignificant to severe. Studies of these mutations in patients and in the laboratory have produced a wealth of information on hemoglobin biochemistry and biology with significant implications for hematology practice. More generally, landmark studies of hemoglobin performed over the past 60 years have established important paradigms for the disciplines of structural biology, genetics, biochemistry, and medicine. Here we review the major classes of hemoglobin variants, emphasizing general concepts and illustrative examples. PMID:23388674

  2. Determination Of Ph Including Hemoglobin Correction

    DOEpatents

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  3. Fetal hemoglobin silencing in humans

    PubMed Central

    Oneal, Patricia A.; Gantt, Nicole M.; Schwartz, Joseph D.; Bhanu, Natarajan V.; Lee, Y. Terry; Moroney, John W.; Reed, Christopher H.; Schechter, Alan N.; Luban, Naomi L. C.; Miller, Jeffery L.

    2006-01-01

    Interruption of the normal fetal-to-adult transition of hemoglobin expression should largely ameliorate sickle cell and beta-thalassemia syndromes. Achievement of this clinical goal requires a robust understanding of gamma-globin gene and protein silencing during human development. For this purpose, age-related changes in globin phenotypes of circulating human erythroid cells were examined from 5 umbilical cords, 99 infants, and 5 adult donors. Unexpectedly, an average of 95% of the cord blood erythrocytes and reticulocytes expressed HbA and the adult beta-globin gene, as well as HbF and the gamma-globin genes. The distribution of hemoglobin and globin gene expression then changed abruptly due to the expansion of cells lacking HbF or gamma-globin mRNA (silenced cells). In adult reticulocytes, less than 5% expressed gamma-globin mRNA. These data are consistent with a “switching” model in humans that initially results largely from gamma- and beta-globin gene coexpression and competition during fetal development. In contrast, early postnatal life is marked by the rapid accumulation of cells that possess undetectable gamma-globin mRNA and HbF. The silencing phenomenon is mediated by a mechanism of cellular replacement. This novel silencing pattern may be important for the development of HbF-enhancing therapies. PMID:16735596

  4. Hemoglobin Brigham (α2Aβ2100 Pro→Leu). HEMOGLOBIN VARIANT ASSOCIATED WITH FAMILIAL ERYTHROCYTOSIS

    PubMed Central

    Lokich, Jacob J.; Moloney, William C.; Bunn, H. Franklin; Bruckheimer, Sally M.; Ranney, Helen M.

    1973-01-01

    Erythrocytosis associated with the presence of a hemoglobin with increased oxygen affinity has been reported for 10 hemoglobin variants, most of which demonstrate altered electrophoretic mobility. Several members of a family were found to have erythrocytosis, and both the whole blood and the hemoglobin exhibited increased oxygen affinity. Phosphate-free hemoglobin solutions had a normal Bohr effect and reactivity to 2,3-diphosphoglycerate. The electrophoretic properties of the hemoglobin were normal, but on peptide mapping of a tryptic digest of the isolated β-chains, a normal βT11 peptide and an abnormal βT11 with greater Rf were seen. Analysis of the abnormal peptide showed the substitution of leucine for the normal proline at β100 (helical residue G2). The hemoglobin variant, designated Hb Brigham, serves to emphasize the necessity for detailed evaluation of the structure and function of hemoglobin in familial erythrocytosis even with electrophoretically “normal” hemoglobin. PMID:4719677

  5. Blood replacement with nanobiotechnologically engineered hemoglobin and hemoglobin nanocapsules

    PubMed Central

    Chang, Thomas Ming Swi

    2012-01-01

    Unlike donor red blood cells (RBCs), blood substitutes can be treated to remove infective agents and can be used on the spot or in the ambulance in emergency without the time-consuming typing and cross-matching. Donor RBC requires storage at 4° and is only good for 42 days, but blood substitutes can be stored for much longer time. For example, a bovine polyhemoglobin (PolyHb) can be stored at room temperature for more than 1 year. It has been shown as far back as 1957 that artificial RBC can be prepared with ultrathin polymer membranes of nanodimension thickness. To increase the circulation time, the first-generation engineered hemoglobin (Hb) is formed by using glutaraldehyde to crosslink Hb into soluble nanodimension PolyHb that has been tested clinically in patients. Further extension includes conjugated Hb, intramolecularly crosslinked Hb and recombinant Hb. For certain clinical uses, in addition to engineered Hb, we also need antioxidants to remove oxygen radicals to prevent injury from ischemia reperfusion. Thus, we use nanobiotechnology to prepare second-generation engineered Hb by assembling Hb together with superoxide dismutase (SOD) and catalase (CAT) to form a nanodimension soluble complex of polyhemoglobin (PolyHb)-CAT-SOD. A third generation system is to prepare nanodimension complete artificial RBCs that can circulate for sufficient length of time after infusion. One approach uses lipid vesicles to encapsulate hemoglobin (Hb). Another approach is to use biodegradable polymer-like polylactic acid or a copolymer of polyethylene glycol-polylactide (PEG-PLA) to form the membrane of nanodimension complete artificial RBC (www.artcell.mcgill.ca). PMID:20564467

  6. Determination of Human Hemoglobin Derivatives.

    PubMed

    Attia, Atef M M; Ibrahim, Fatma A A; Abd El-Latif, Noha A; Aziz, Samir W; Abdelmottaleb Moussa, Sherif A; Elalfy, Mohsen S

    2015-01-01

    The levels of the inactive hemoglobin (Hb) pigments [such as methemoglobin (metHb), carboxyhemoglobin (HbCO) and sulfohemoglobin (SHb)] and the active Hb [in the oxyhemoglobin (oxyHb) form] as well as the blood Hb concentration in healthy non pregnant female volunteers were determined using a newly developed multi-component spectrophotometric method. The results of this method revealed values of SHb% in the range (0.0727-0.370%), metHb% (0.43-1.0%), HbCO% (0.4-1.52%) and oxyHb% (97.06-98.62%). Furthermore, the results of this method revealed values of blood Hb concentration in the range (12.608-15.777 g/dL). The method is highly sensitive, accurate and reproducible.

  7. Spectrophotometric Properties of Hemoglobin: Classroom Applications.

    ERIC Educational Resources Information Center

    Frary, Roger

    1997-01-01

    Discusses simple and safe techniques that can be used in the educational laboratory to study hemoglobin. Discusses the spectral properties of hemoglobin, spectral-absorbence curves of oxyhemoglobin and carboxyhemoglobin, tracking the conversion of oxyhemoglobin to methemoglobin, and changing from the oxyhemoglobin to deoxyhemoglobin conformation.…

  8. Role of Noninvasive Hemoglobin Monitoring in Trauma

    DTIC Science & Technology

    2015-03-25

    neonatal units, and operating rooms [3-5], it is invasive, and the accuracy of these devices has been reported to vary with hemoglobin level, potentially... resuscitation , and improve patient outcomes. The specific aim of this prospective cohort study was to compare the accuracy of noninvasive hemoglobin

  9. Low hemoglobin deferral in blood donors

    PubMed Central

    Mast, Alan E.

    2013-01-01

    Low hemoglobin deferral occurs in about 10% of attempted whole blood donations and commonly is a consequence of iron deficiency anemia. Pre-menopausal women often have iron deficiency anemia caused by menstruation and pregnancy and have low hemoglobin deferral on their first donation attempt. Frequent donors also develop iron deficiency and iron deficiency anemia because blood donation removes a large amount of iron from the donor and the 56-day minimum inter-donation interval for donors in the United States is not sufficient for recovery of hemoglobin and iron stores. Other causes for low hemoglobin deferral range from a medically insignificant deferral of a woman with hemoglobin between 12.0 and 12.4 g/dL, which is within the normal reference range but below the 12.5 g/dL needed to donate blood, to anemia caused by an unrecognized malignancy in a “healthy” individual attempting to donate blood. The diverse causes of anemia in blood donors make it difficult to provide accurate information to donors about the cause of their low hemoglobin deferral and complicate implementation of programs to prevent them by blood collecting agencies. This article reviews how hemoglobin is measured and the demographics and causes of low hemoglobin deferral in blood donors. It provides recommendations for how blood collection agencies can provide donors with accurate information about the cause of their deferral and discusses programs that can be implemented to decrease these deferrals in regular donors. PMID:24332843

  10. Spectrophotometric Properties of Hemoglobin: Classroom Applications.

    ERIC Educational Resources Information Center

    Frary, Roger

    1997-01-01

    Discusses simple and safe techniques that can be used in the educational laboratory to study hemoglobin. Discusses the spectral properties of hemoglobin, spectral-absorbence curves of oxyhemoglobin and carboxyhemoglobin, tracking the conversion of oxyhemoglobin to methemoglobin, and changing from the oxyhemoglobin to deoxyhemoglobin conformation.…

  11. Nanoscale spectroscopy and imaging of hemoglobin.

    PubMed

    Kennedy, Eamonn; Yarrow, Fiona; Rice, James H

    2011-09-01

    Sub diffraction limited infrared absorption imaging of hemoglobin was performed by coupling IR optics with an atomic force microscope. Comparisons between the AFM topography and IR absorption images of micron sized hemoglobin features are presented, along with nanoscale IR spectroscopic analysis of the metalloprotein.

  12. Structure and reactivity of hexacoordinate hemoglobins

    PubMed Central

    Kakar, Smita; Hoffman, Federico G.; Storz, Jay F.; Fabian, Marian; Hargrove, Mark S.

    2015-01-01

    The heme prosthetic group in hemoglobins is most often attached to the globin through coordination of either one or two histidine side chains. Those proteins with one histidine coordinating the heme iron are called “pentacoordinate” hemoglobins, a group represented by red blood cell hemoglobin and most other oxygen transporters. Those with two histidines are called “hexacoordinate hemoglobins”, which have broad representation among eukaryotes. Coordination of the second histidine in hexacoordinate Hbs is reversible, allowing for binding of exogenous ligands like oxygen, carbon monoxide, and nitric oxide. Research over the past several years has produced a fairly detailed picture of the structure and biochemistry of hexacoordinate hemoglobins from several species including neuroglobin and cytoglobin in animals, and the nonsymbiotic hemoglobins in plants. However, a clear understanding of the physiological functions of these proteins remains an elusive goal. PMID:20933319

  13. Degradation of human hemoglobin by Prevotella intermedia.

    PubMed

    Guan, Su-Min; Nagata, Hideki; Shizukuishi, Satoshi; Wu, Jun-Zheng

    2006-01-01

    In this study, the ability of Prevotella intermedia, an obligate anaerobic rod, to degrade human hemoglobin was determined by SDS-PAGE and the degradation was quantified by scanning densitometry. Both bacterial cells and culture supernatants degraded hemoglobin. The hemoglobin degradation by P. intermedia was time-dependent, heat sensitive, pH related and was not influenced by iron restriction. Inhibition studies demonstrated that a cysteine protease might be involved in hemoglobin degradation and this protease might require metal ions for its activity and it might be thiol-requiring and trypsin-inducible. The results indicate that P. intermedia is capable to release heme from hemoglobin, hence provide a source of iron for its proliferation.

  14. Monoclonal antibodies specific for sickle cell hemoglobin

    SciTech Connect

    Jensen, R.H.; Vanderlaan, M.; Grabske, R.J.; Branscomb, E.W.; Bigbee, W.L.; Stanker, L.H.

    1985-01-01

    Two mouse hybridoma cell lines were isolated which produce monoclonal antibodies that bind hemoglobin S. The mice were immunized with peptide-protein conjugates to stimulate a response to the amino terminal peptide of the beta chain of hemoglobin S, where the single amino acid difference between A and S occurs. Immunocharacterization of the antibodies shows that they bind specifically to the immunogen peptide and to hemoglobin S. The specificity for S is high enough that one AS cell in a mixture with a million AA cells is labeled by antibody, and such cells can be analyzed by flow cytometry. Immunoblotting of electrophoretic gels allows definitive identification of hemoglobin S as compared with other hemoglobins with similar electrophoretic mobility. 12 references, 4 figures.

  15. Structure-function relations of human hemoglobins

    PubMed Central

    2006-01-01

    In 1949 Pauling and his associates showed that sickle cell hemoglobin (HbS) belonged to an abnormal molecular species. In 1958 Ingram, who used a two-dimensional system of electrophoresis and chromatography to break down the hemoglobin molecule into a mixture of smaller peptides, defined the molecular defect in HbS by showing that it differed from normal adult hemoglobin by only a single peptide. Since then, more than 200 variant and abnormal hemoglobins have been described. Furthermore, the construction of an atomic model of the hemoglobin molecule based on a high-resolution x-ray analysis by Dr. Max Perutz at Cambridge has permitted the study of the stereochemical part played by the amino acid residues, which were replaced, deleted, or added to in each of the hemoglobin variants. Some of the variants have been associated with clinical conditions. The demonstration of a molecular basis for a disease was a significant turning point in medicine. A new engineered hemoglobin derived from crocodile blood, with markedly reduced oxygen affinity and increased oxygen delivery to the tissues, points the way for future advances in medicine. PMID:17252042

  16. [Abnormal hemoglobins and thalassemias in Mexico].

    PubMed

    Ruiz-Reyes, G

    1998-01-01

    The distribution of abnormal hemoglobins in Mexico is derived from surveys and from the study of patients with hemolytic anemia. In aboriginal populations, more than 3,000 individuals have been studied: structural abnormal hemoglobins are virtually absent in Mexican Indians and the sporadic finding of hemoglobin S among them is due to admixture with Africans brought as slaves during the Spanish domination; two new variants of hemoglobin (Mexico and Chiapas) were found in aborigines. The surveys in hybrid groups in selected areas of the country show that in some West and East Coast communities there are different frequencies of Hb S heterozygous, and that a high prevalence of Hb S trait has been found in some communities similar to that in some African areas. In a group of 200 subjects of a town located along the Gulf of Mexico Coast, 6% of Hb S and 15% of thalassemia beta heterozygous is observed. In hospital surveys in two cities (Guadalajara and Puebla) several abnormalities of hemoglobin have been identified (C, SC, Riyadh, Baltimore, Tarrant, Fannin-Lubbock and Mexico). In the study of isolated cases, mainly of patients with hemolytic anemia, hemoglobins I-Philadelphia, G-San Jose and D-Los Angeles are seen. The thalassemias are the more frequent hemoglobin abnormalities in selected populations of our country. In a community of Italian ancestry a frequency of 1.3% of beta thalassemia trait is found. In our laboratory, 76% of the abnormalities are cases of beta thalassemia trait. Patients with Hb H disease, beta thalassemia (homozygous and heterozygous) and combinations of these abnormalities with hemoglobins S, Hb S + hereditary persistence of fetal hemoglobin (HPFH) and Hb E as well as families with delta-beta thalassemia, HPFH and Hb Lepore-Washington-Boston have been also detected.

  17. Mutational analysis of hemoglobin binding and heme utilization by a bacterial hemoglobin receptor.

    PubMed

    Fusco, W G; Choudhary, N R; Council, S E; Collins, E J; Leduc, I

    2013-07-01

    Iron is an essential nutrient for most living organisms. To acquire iron from their environment, Gram-negative bacteria use TonB-dependent transporters that bind host proteins at the bacterial surface and transport iron or heme to the periplasm via the Ton machinery. TonB-dependent transporters are barrel-shaped outer membrane proteins with 22 transmembrane domains, 11 surface-exposed loops, and a plug domain that occludes the pore. To identify key residues of TonB-dependent transporters involved in hemoglobin binding and heme transport and thereby locate putative protective epitopes, the hemoglobin receptor of Haemophilus ducreyi HgbA was used as a model of iron/heme acquisition from hemoglobin. Although all extracellular loops of HgbA are required by H. ducreyi to use hemoglobin as a source of iron/heme, we previously demonstrated that hemoglobin binding by HgbA only involves loops 5 and 7. Using deletion, substitution, and site-directed mutagenesis, we were able to differentiate hemoglobin binding and heme acquisition by HgbA. Deletion or substitution of the GYEAYNRQWWA region of loop 5 and alanine replacement of selected histidines affected hemoglobin binding by HgbA. Conversely, mutation of the phenylalanine in the loop 7 FRAP domain or substitution of the NRQWWA motif of loop 5 significantly abrogated utilization of heme from hemoglobin. Our findings show that hemoglobin binding and heme utilization by a bacterial hemoglobin receptor involve specific motifs of HgbA.

  18. Hemoglobin Philly (β35 tyrosine→phenylalanine): studies in the molecular pathology of hemoglobin

    PubMed Central

    Rieder, Ronald F.; Oski, Frank A.; Clegg, J. B.

    1969-01-01

    An abnormal unstable hemoglobin, hemoglobin Philly, was found in three members of a family, each of whom had evidence of a chronic hemolytic state. The presence of the mutant protein was suggested by the rapid appearance of inclusion bodies upon incubation of erythrocytes with brilliant cresyl blue and by the increased heat precipitability of the hemoglobin. However, no abnormal hemoglobin could be demonstrated by electrophoresis or column chromatography. Sulfhydryl titration of the hemolysates with p-mercuribenzoate indicated that there was an average of four reactive sulfhydryl groups per hemoglobin molecule instead of the usual two. The total number of hemoglobin sulfhydryl groups was normal; six groups were measured when denatured globin was reacted with 5,5′-dithiobis[2-nitrobenzoic acid]. This indicated that the increased sulfhydryl reactivity was due to an increased availability to p-mercuribenzoate of the usually unreactive hemoglobin cysteines at β112 and α104. After treatment for ½ hr with 4-5 moles of p-mercuribenzoate per mole of hemoglobin, electrophoresis revealed that 30-35% of the hemoglobin had been dissociated into α- and β-chains. Normal hemolysates revealed negligible splitting after 72 hr of similar treatment. The α- and β-chains of hemoglobin Philly were separated from the unsplit hemoglobin A by carboxymethyl cellulose chromatography. Fingerprint and amino acid analyses revealed that tyrosine β35 was replaced by phenylalanine. In hemoglobin Philly there is loss of the normal hydrogen bond between the tyrosine hydroxyl group and the carboxyl group of aspartic acid α126 at the α1β1 contact. This shifts the equilibrium from hemoglobin tetramers toward monomers, exposing the β112 and α104 cysteines. In the cell, precipitation of the unstable monomers may contribute to erythrocyte destruction. Images PMID:5822575

  19. Interaction of Human Hemoglobin with Methotrexate

    NASA Astrophysics Data System (ADS)

    Zaharia, M.; Gradinaru, R.

    2015-05-01

    This study focuses on the interaction between methotrexate and human hemoglobin using steady-state ultraviolet-visible and fluorescence quenching methods. Fluorescence quenching was found to be valuable in assessing drug binding to hemoglobin. The quenching of methotrexate is slightly smaller than the quenching observed with related analogs (dihydrofolate and tetrahydrofolate). The quenching studies were performed at four different temperatures and various pH values. The number of binding sites for tryptophan is ~1. Parameter-dependent assays revealed that electrostatic forces play an essential role in the methotrexate-hemoglobin interaction. Furthermore, the complex was easily eluted using gel filtration chromatography.

  20. Preparation of Hemoglobin-Containing Microcapsules.

    DTIC Science & Technology

    1982-04-01

    L -i2 801 PREPARRTION OF HEMOGLOBIN-CONTAINING MICROCAPSULES (U) i/i I SRI INTERNATIONAL MENLO PRK CA Z REYES APR 82 UNLSSFE SRI1-2254-2 DRMDi,7-8@-C...R oI• _ AD I PREPARATION OF HEMOGLOBIN- /2 o ) CONTAINING MICROCAPSULES . 00 ANNUAL AND FINAL REPORT ZOILA REYES, Ph.D. APRIL 1982 Supported by U.S...1/31/82) PREPARATION OF HEMOGLOBIN-CONTAINING MICROCAPSULES 6. PERFORMING ORG. REPOR’ NUMBER 2254-2 7. AUTHOR(s) 8. CONTRACT OR GRANT NUMBER(s) Zoila

  1. Detection of Sickle Cell Hemoglobin in Haiti by Genotyping and Hemoglobin Solubility Tests

    PubMed Central

    Carter, Tamar E.; von Fricken, Michael; Romain, Jean R.; Memnon, Gladys; St. Victor, Yves; Schick, Laura; Okech, Bernard A.; Mulligan, Connie J.

    2014-01-01

    Sickle cell disease is a growing global health concern because infants born with the disorder in developing countries are now surviving longer with little access to diagnostic and management options. In Haiti, the current state of sickle cell disease/trait in the population is unclear. To inform future screening efforts in Haiti, we assayed sickle hemoglobin mutations using traditional hemoglobin solubility tests (HST) and add-on techniques, which incorporated spectrophotometry and insoluble hemoglobin separation. We also generated genotype data as a metric for HST performance. We found 19 of 202 individuals screened with HST were positive for sickle hemoglobin, five of whom did not carry the HbS allele. We show that spectrophotometry and insoluble hemoglobin separation add-on techniques could resolve false positives associated with the traditional HST approach, with some limitations. We also discuss the incorporation of insoluble hemoglobin separation observation with HST in suboptimal screening settings like Haiti. PMID:24957539

  2. Methylation of hemoglobin to enhance flocculant performance

    USDA-ARS?s Scientific Manuscript database

    An inexpensive bioflocculant, bovine hemoglobin (Hb), has been covalently modified through methylation of the side chain carboxyl groups of aspartic and glutamic acid residues to improve its flocculation activity. Potentiometric titration of the recovered products showed approximately 28% degree of ...

  3. Low affinity PEGylated hemoglobin from Trematomus bernacchii, a model for hemoglobin-based blood substitutes

    PubMed Central

    2011-01-01

    Background Conjugation of human and animal hemoglobins with polyethylene glycol has been widely explored as a means to develop blood substitutes, a novel pharmaceutical class to be used in surgery or emergency medicine. However, PEGylation of human hemoglobin led to products with significantly different oxygen binding properties with respect to the unmodified tetramer and high NO dioxygenase reactivity, known causes of toxicity. These recent findings call for the biotechnological development of stable, low-affinity PEGylated hemoglobins with low NO dioxygenase reactivity. Results To investigate the effects of PEGylation on protein structure and function, we compared the PEGylation products of human hemoglobin and Trematomus bernacchii hemoglobin, a natural variant endowed with a remarkably low oxygen affinity and high tetramer stability. We show that extension arm facilitated PEGylation chemistry based on the reaction of T. bernacchii hemoglobin with 2-iminothiolane and maleimido-functionalyzed polyethylene glycol (MW 5000 Da) leads to a tetraPEGylated product, more homogeneous than the corresponding derivative of human hemoglobin. PEGylated T. bernacchii hemoglobin largely retains the low affinity of the unmodified tetramer, with a p50 50 times higher than PEGylated human hemoglobin. Moreover, it is still sensitive to protons and the allosteric effector ATP, indicating the retention of allosteric regulation. It is also 10-fold less reactive towards nitrogen monoxide than PEGylated human hemoglobin. Conclusions These results indicate that PEGylated hemoglobins, provided that a suitable starting hemoglobin variant is chosen, can cover a wide range of oxygen-binding properties, potentially meeting the functional requirements of blood substitutes in terms of oxygen affinity, tetramer stability and NO dioxygenase reactivity. PMID:22185675

  4. Cloned Hemoglobin Genes Enhance Growth Of Cells

    NASA Technical Reports Server (NTRS)

    Khosla, Chaitan; Bailey, James E.

    1991-01-01

    Experiments show that portable deoxyribonucleic acid (DNA) sequences incorporated into host cells make them produce hemoglobins - oxygen-binding proteins essential to function of red blood cells. Method useful in several biotechnological applications. One, enhancement of growth of cells at higher densities. Another, production of hemoglobin to enhance supplies of oxygen in cells, for use in chemical reactions requiring oxygen, as additive to serum to increase transport of oxygen, and for binding and separating oxygen from mixtures of gases.

  5. Hemoglobins, programmed cell death and somatic embryogenesis.

    PubMed

    Hill, Robert D; Huang, Shuanglong; Stasolla, Claudio

    2013-10-01

    Programmed cell death (PCD) is a universal process in all multicellular organisms. It is a critical component in a diverse number of processes ranging from growth and differentiation to response to stress. Somatic embryogenesis is one such process where PCD is significantly involved. Nitric oxide is increasingly being recognized as playing a significant role in regulating PCD in both mammalian and plant systems. Plant hemoglobins scavenge NO, and evidence is accumulating that events that modify NO levels in plants also affect hemoglobin expression. Here, we review the process of PCD, describing the involvement of NO and plant hemoglobins in the process. NO is an effector of cell death in both plants and vertebrates, triggering the cascade of events leading to targeted cell death that is a part of an organism's response to stress or to tissue differentiation and development. Expression of specific hemoglobins can alter this response in plants by scavenging the NO, thus, interrupting the death process. Somatic embryogenesis is used as a model system to demonstrate how cell-specific expression of different classes of hemoglobins can alter the embryogenic process, affecting hormone synthesis, cell metabolite levels and genes associated with PCD and embryogenic competence. We propose that plant hemoglobins influence somatic embryogenesis and PCD through cell-specific expression of a distinct plant hemoglobin. It is based on the premise that both embryogenic competence and PCD are strongly influenced by cellular NO levels. Increases in cellular NO levels result in elevated Zn(2+) and reactive-oxygen species associated with PCD, but they also result in decreased expression of MYC2, a transcription factor that is a negative effector of indoleacetic acid synthesis, a hormone that positively influences embryogenic competence. Cell-specific hemoglobin expression reduces NO levels as a result of NO scavenging, resulting in cell survival. Copyright © 2013 Elsevier Ireland Ltd

  6. Carboxyalkylated Hemoglobin as a Potential Blood Substitute.

    DTIC Science & Technology

    1991-11-19

    diisothiocyanatobenzene sulfonic acid. Collaborative studies with investigators at the Letterman Army Institute of Research indicated that carboxy - methylated hemoglobin... crosslinking agents so that we might find the one with the most desirable properties (2,3). In this annual report, we focus on the reagents studied in...can be considered as a mimic for both of these structures. Crosslinking of Hemoglobin A - In the past year we have sought a better crosslinking agent

  7. HEMOGLOBIN PRODUCTION FACTORS IN THE HUMAN LIVER

    PubMed Central

    Whipple, G. H.; Robscheit-Robbins, F. S.

    1942-01-01

    Human liver tissue has been assayed to determine the amount of hemoglobin production factors in normal and abnormal states. Standardized dogs made anemic by blood removal have been used in this biological assay. Normal animal liver as control is rated as 100 per cent. Normal human liver tissue as compared with the normal animal control contains more of these hemoglobin production factors—a biological assay ratio of 120 to 160 per cent. Infections, acute and chronic, do not appear to modify these values, the concentration of hemoglobin-producing factors falling within the normal range. Pernicious anemia and aplastic anemia both show large liver stores of hemoglobin-producing factors—a biological assay ratio of 200 to 240 per cent. Therapy in pernicious anemia reduces these liver stores as new red cells are formed. Secondary anemia presents a low normal or subnormal liver store of hemoglobin-producing factors—an assay of 60 to 130 per cent. Hemochromatosis, erythroblastic anemia, and hemolytic icterus in spite of large iron deposits in the liver usually show a biological assay which is normal or close to normal. Polycythemia shows low reserve stores of hemoglobin-producing factors. Leukemias present a wide range of values discussed above. Hypoproteinemia almost always is associated with low reserve stores of hemoglobin-producing factors in the liver—biological assays of 60 to 80 per cent. Hypoproteinemia means a depletion of body protein reserve stores including the labile protein liver reserves—a strong indication that the prehemoglobin material (or globin) is related to these liver stores. Pregnancy, eclampsia, and lactation all may present subnormal liver stores of hemoglobin-producing factors. Exhaustion of protein stores lowers the barrier to infection and renders the liver very susceptible to many toxic substances. It should not be difficult to correct hypoproteinemia under these conditions and thus relieve the patient of a real hazard. PMID:19871236

  8. Tangential flow filtration of hemoglobin.

    PubMed

    Palmer, Andre F; Sun, Guoyong; Harris, David R

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P(50)) and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (alpha) and beta (beta) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the alpha and beta globin chains agreed well with the calculated theoretical mass of the alpha- and beta- globin chains. Taken together, our results demonstrate that HPLC-grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers.

  9. Tangential Flow Filtration of Hemoglobin

    PubMed Central

    Sun, Guoyong; Harris, David R.

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells (bRBCs and hRBCs, respectively) via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P50), and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (α) and beta (β) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the α and β globin chains agreed well with the calculated theoretical mass of the α-and β-globin chains. Taken together, our results demonstrate that HPLC grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers (HBOCs). PMID:19224583

  10. Noninvasive hemoglobin monitoring: how accurate is enough?

    PubMed

    Rice, Mark J; Gravenstein, Nikolaus; Morey, Timothy E

    2013-10-01

    Evaluating the accuracy of medical devices has traditionally been a blend of statistical analyses, at times without contextualizing the clinical application. There have been a number of recent publications on the accuracy of a continuous noninvasive hemoglobin measurement device, the Masimo Radical-7 Pulse Co-oximeter, focusing on the traditional statistical metrics of bias and precision. In this review, which contains material presented at the Innovations and Applications of Monitoring Perfusion, Oxygenation, and Ventilation (IAMPOV) Symposium at Yale University in 2012, we critically investigated these metrics as applied to the new technology, exploring what is required of a noninvasive hemoglobin monitor and whether the conventional statistics adequately answer our questions about clinical accuracy. We discuss the glucose error grid, well known in the glucose monitoring literature, and describe an analogous version for hemoglobin monitoring. This hemoglobin error grid can be used to evaluate the required clinical accuracy (±g/dL) of a hemoglobin measurement device to provide more conclusive evidence on whether to transfuse an individual patient. The important decision to transfuse a patient usually requires both an accurate hemoglobin measurement and a physiologic reason to elect transfusion. It is our opinion that the published accuracy data of the Masimo Radical-7 is not good enough to make the transfusion decision.

  11. Hemoglobin levels in normal Filipino pregnant women.

    PubMed

    Kuizon, M D; Natera, M G; Ancheta, L P; Platon, T P; Reyes, G D; Macapinlac, M P

    1981-09-01

    The hemoglobin concentrations during pregnancy in Filipinos belonging to the upper income group, who were prescribed 105 mg elemental iron daily, and who had acceptable levels of transferrin saturation, were examined in an attempt to define normal levels. The hemoglobin concentrations for each trimester followed a Gaussian distribution. The hemoglobin values equal to the mean minus one standard deviation were 11.4 gm/dl for the first trimester and 10.4 gm/dl for the second and third trimesters. Using these values as the lower limits of normal, in one group of pregnant women the prevalence of anemia during the last two trimesters was found lower than that obtained when WHO levels for normal were used. Groups of women with hemoglobin of 10.4 to 10.9 gm/dl (classified anemic by WHO criteria but normal in the present study) and those with 11.0 gm/dl and above could not be distinguished on the basis of their serum ferritin levels nor on the degree of decrease in their hemoglobin concentration during pregnancy. Many subjects in both groups, however, had serum ferritin levels less than 12 ng/ml which indicate poor iron stores. It might be desirable in future studies to determine the hemoglobin cut-off point that will delineate subjects who are both non-anemic and adequate in iron stores using serum ferritin levels as criterion for the latter.

  12. Hemoglobin parameters from diffuse reflectance data.

    PubMed

    Mourant, Judith R; Marina, Oana C; Hebert, Tiffany M; Kaur, Gurpreet; Smith, Harriet O

    2014-03-01

    Tissue vasculature is altered when cancer develops. Consequently, noninvasive methods of monitoring blood vessel size, density, and oxygenation would be valuable. Simple spectroscopy employing fiber optic probes to measure backscattering can potentially determine hemoglobin parameters. However, heterogeneity of blood distribution, the dependence of the tissue-volume-sampled on scattering and absorption, and the potential compression of tissue all hinder the accurate determination of hemoglobin parameters. We address each of these issues. A simple derivation of a correction factor for the absorption coefficient, μa, is presented. This correction factor depends not only on the vessel size, as others have shown, but also on the density of blood vessels. Monte Carlo simulations were used to determine the dependence of an effective pathlength of light through tissue which is parameterized as a ninth-order polynomial function of μa. The hemoglobin bands of backscattering spectra of cervical tissue are fit using these expressions to obtain effective blood vessel size and density, tissue hemoglobin concentration, and oxygenation. Hemoglobin concentration and vessel density were found to depend on the pressure applied during in vivo acquisition of the spectra. It is also shown that determined vessel size depends on the blood hemoglobin concentration used.

  13. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards). ...

  14. 21 CFR 864.7400 - Hemoglobin A 2 assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hemoglobin A 2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A 2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  15. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glycosylated hemoglobin assay. 864.7470 Section... Glycosylated hemoglobin assay. (a) Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a, A1b, and A1c) in a patient's blood by a column chromatographic...

  16. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards). ...

  17. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids...

  18. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Glycosylated hemoglobin assay. 864.7470 Section... Glycosylated hemoglobin assay. (a) Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a, A1b, and A1c) in a patient's blood by a column chromatographic...

  19. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not include...

  20. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not include...

  1. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards). ...

  2. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass) due...

  3. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not include...

  4. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids...

  5. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass) due...

  6. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards). ...

  7. 21 CFR 864.7400 - Hemoglobin A2 assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hemoglobin A2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  8. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids...

  9. 21 CFR 864.7400 - Hemoglobin A2 assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hemoglobin A2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  10. 21 CFR 864.7400 - Hemoglobin A 2 assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hemoglobin A 2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A 2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  11. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards). [45 FR 60601, Sept...

  12. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass) due...

  13. 21 CFR 864.7400 - Hemoglobin A2 assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hemoglobin A2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  14. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass) due...

  15. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards). ...

  16. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not include...

  17. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids...

  18. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards). [45 FR 60618, Sept. 12, 1980] ...

  19. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrophoretic hemoglobin analysis system. 864....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin... hemoglobin types as an aid in the diagnosis of anemia or erythrocytosis (increased total red cell mass) due...

  20. 21 CFR 864.7500 - Whole blood hemoglobin assays.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Whole blood hemoglobin assays. 864.7500 Section... blood hemoglobin assays. (a) Identification. A whole blood hemoglobin assay is a device consisting or... hemoglobin content of whole blood for the detection of anemia. This generic device category does not include...

  1. 21 CFR 866.5470 - Hemoglobin immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hemoglobin immunological test system. 866.5470... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids...

  2. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards). ...

  3. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Glycosylated hemoglobin assay. 864.7470 Section... Glycosylated hemoglobin assay. (a) Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a, A1b, and A1c) in a patient's blood by a column chromatographic...

  4. 21 CFR 864.5620 - Automated hemoglobin system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated hemoglobin system. 864.5620 Section 864....5620 Automated hemoglobin system. (a) Identification. An automated hemoglobin system is a fully... hemoglobin content of human blood. (b) Classification. Class II (performance standards). ...

  5. 21 CFR 864.7415 - Abnormal hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Abnormal hemoglobin assay. 864.7415 Section 864... hemoglobin assay. (a) Identification. An abnormal hemoglobin assay is a device consisting of the reagents... hemoglobin types. (b) Classification. Class II (performance standards). ...

  6. Polyethylene Glycol Camouflaged Earthworm Hemoglobin

    PubMed Central

    Moges, Selamawit; Nacharaju, Parimala; Roche, Camille; Dantsker, David; Palmer, Andre; Friedman, Joel M.

    2017-01-01

    Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals’ systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the

  7. Anion Bohr effect of human hemoglobin.

    PubMed

    Bucci, E; Fronticelli, C

    1985-01-15

    The pH dependence of oxygen affinity of hemoglobin (Bohr effect) is due to ligand-linked pK shifts of ionizable groups. Attempt to identify these groups has produced controversial data and interpretations. In a further attempt to clarify the situation, we noticed that hemoglobin alkylated in its liganded form lost the Bohr effect while hemoglobin alkylated in its unliganded form showed the presence of a practically unmodified Bohr effect. In spite of this difference, analyses of the extent of alkylation of the two compounds failed to identify the presence of specific preferential alkylations. In particular, the alpha 1 valines and beta 146 histidines appeared to be alkylated to the same extent in the two proteins. Focusing our attention on the effect of the anions on the functional properties of hemoglobin, we measured the Bohr effect of untreated hemoglobin in buffers made with HEPES [N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid], MES [2-(N-morpholino)ethanesulfonic acid], and MOPS [3-(N-morpholino)propanesulfonic acid], which being zwitterions do not need addition of chlorides or other anions for reaching the desired pH. The shape acquired by the Bohr effect curves, either as pH dependence of oxygen affinity or as pH dependence of protons exchanged with the solution, was irreconcilable with that of the Bohr effect curves in usual buffers. This indicated the relevance of solvent components in determining the functional properties of hemoglobin. A new thermodynamic model is proposed for the Bohr effect that includes the interaction of hemoglobin with solvent components. The classic proton Bohr effect is a special case of the new theory.

  8. The Electrophoretic Pattern of Hemoglobin in Newborn Babies, and Abnormalities of Hemoglobin F Synthesis in Adults

    PubMed Central

    Vella, F.; Cunningham, T. A.

    1967-01-01

    On routine electrophoretic analyses on filter paper and starch gel in an alkaline or neutral medium, no abnormal hemoglobin fractions were found in the blood of 600 newborn infants or their mothers. Trace amounts of hemoglobin Barts were noted in many of the blood samples from newborns when the starch gels (phosphate buffer pH 7.0) were stained with a benzidine/H2O2 reagent. In one infant, precocious cessation of synthesis of hemoglobin F was postulated to account for the small amounts of this hemoglobin found in a cord-blood specimen. Analysis of 15,000 blood samples from adults revealed two instances in which the hemoglobin F level was 20 and 35%, respectively. The former was attributed to a hereditary persistence of hemoglobin F, while the latter was associated with acute leukemia. In an addendum, the finding of an infant with an abnormal hemoglobin variant, resembling in many of its properties hemoglobin F Texas, is reported. ImagesFig. 1Fig. 2 PMID:6019054

  9. Convergent evolution of hemoglobin switching in jawed and jawless vertebrates.

    PubMed

    Rohlfing, Kim; Stuhlmann, Friederike; Docker, Margaret F; Burmester, Thorsten

    2016-02-01

    During development, humans and other jawed vertebrates (Gnathostomata) express distinct hemoglobin genes, resulting in different hemoglobin tetramers. Embryonic and fetal hemoglobin have higher oxygen affinities than the adult hemoglobin, sustaining the oxygen demand of the developing organism. Little is known about the expression of hemoglobins during development of jawless vertebrates (Agnatha). We identified three hemoglobin switches in the life cycle of the sea lamprey. Three hemoglobin genes are specifically expressed in the embryo, four genes in the filter feeding larva (ammocoete), and nine genes correspond to the adult hemoglobin chains. During the development from the parasitic to the reproductive adult, the composition of hemoglobin changes again, with a massive increase of chain aHb1. A single hemoglobin chain is expressed constitutively in all stages. We further showed the differential expression of other globin genes: Myoglobin 1 is most highly expressed in the reproductive adult, myoglobin 2 expression peaks in the larva. Globin X1 is restricted to the embryo; globin X2 was only found in the reproductive adult. Cytoglobin is expressed at low levels throughout the life cycle. Because the hemoglobins of jawed and jawless vertebrates evolved independently from a common globin ancestor, hemoglobin switching must also have evolved convergently in these taxa. Notably, the ontogeny of sea lamprey hemoglobins essentially recapitulates their phylogeny, with the embryonic hemoglobins emerging first, followed by the evolution of larval and adult hemoglobins.

  10. Hemoglobin Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

    Schwartz, Kelly; Hernandez, Margarita; Boles, Blaise R.

    2011-01-01

    Staphylococcus aureus nasal colonization is an important risk factor for community and nosocomial infection. Despite the importance of S. aureus to human health, molecular mechanisms and host factors influencing nasal colonization are not well understood. To identify host factors contributing to nasal colonization, we collected human nasal secretions and analyzed their ability to promote S. aureus surface colonization. Some individuals produced secretions possessing the ability to significantly promote S. aureus surface colonization. Nasal secretions pretreated with protease no longer promoted S. aureus surface colonization, suggesting the involvement of protein factors. The major protein components of secretions were identified and subsequent analysis revealed that hemoglobin possessed the ability to promote S. aureus surface colonization. Immunoprecipitation of hemoglobin from nasal secretions resulted in reduced S. aureus surface colonization. Furthermore, exogenously added hemoglobin significantly decreased the inoculum necessary for nasal colonization in a rodent model. Finally, we found that hemoglobin prevented expression of the agr quorum sensing system and that aberrant constitutive expression of the agr effector molecule, RNAIII, resulted in reduced nasal colonization of S. aureus. Collectively our results suggest that the presence of hemoglobin in nasal secretions contributes to S. aureus nasal colonization. PMID:21750673

  11. Evolution of Hemoglobin and Its Genes

    PubMed Central

    Hardison, Ross C.

    2012-01-01

    Insights into the evolution of hemoglobins and their genes are an abundant source of ideas regarding hemoglobin function and regulation of globin gene expression. This article presents the multiple genes and gene families encoding human globins, summarizes major events in the evolution of the hemoglobin gene clusters, and discusses how these studies provide insights into regulation of globin genes. Although the genes in and around the α-like globin gene complex are relatively stable, the β-like globin gene clusters are more dynamic, showing evidence of transposition to a new locus and frequent lineage-specific expansions and deletions. The cis-regulatory modules controlling levels and timing of gene expression are a mix of conserved and lineage-specific DNA, perhaps reflecting evolutionary constraint on core regulatory functions shared broadly in mammals and adaptive fine-tuning in different orders of mammals. PMID:23209182

  12. A rare hemoglobin variant, Hb Belliard

    PubMed Central

    Benavides, Raul

    2017-01-01

    There are many documented variants of hemoglobin; however, other than a limited number (such as sickle cell disease), very few are known to have any clinical significance. As advances in detection and identification continue through gel electrophoresis, capillary electrophoresis, and DNA sequencing, more rare variants are identified. Without case reporting, the significance of these variants will remain unknown or continue to be thought of as insignificant. Here we report a rare hemoglobin variant, Hb Belliard, which was detected in a 68-year-old Indian immigrant to the United States. He presented with elevated hemoglobin and was found to have a unique peak on capillary electrophoresis. The specimen was sent for sequencing and was subsequently found to have Hb Belliard. Currently, Hb Belliard is thought to be insignificant.

  13. Oxygen binding constants for human hemoglobin tetramers.

    PubMed

    Gill, S J; Di Cera, E; Doyle, M L; Bishop, G A; Robert, C H

    1987-06-30

    High-precision studies of oxygen binding in hemoglobin (HbA0) solutions at near-physiological concentrations (2-12 mM heme; pHs 7.0-9.1; various buffers) have led to an unanticipated result: an unmeasurably low contribution from the triply ligated species. We have obtained this result from new differential oxygen-binding measurements for human hemoglobin through the use of a thin-layer apparatus, which enables study of solutions at high Hb concentrations. The effect of tetramer dissociation into dimers, which becomes significant at hemoglobin concentrations below 1 mM in heme, is avoided. The analysis of the binding reactions is thus cast in terms of tetramer-binding polynomial written with overall Adair equilibrium constants which directly reflect the contributions of intermediate ligated species. The unmeasurable contribution of the triply ligated species renders the equilibrium constants of the third and fourth stepwise reactions practically undeterminable.

  14. Classification of the Disorders of Hemoglobin

    PubMed Central

    Forget, Bernard G.; Bunn, H. Franklin

    2013-01-01

    Over the years, study of the disorders of hemoglobin has served as a paradigm for gaining insights into the cellular and molecular biology, as well as the pathophysiology, of inherited genetic disorders. To date, more than 1000 disorders of hemoglobin synthesis and/or structure have been identified and characterized. Study of these disorders has established the principle of how a mutant genotype can alter the function of the encoded protein, which in turn can lead to a distinct clinical phenotype. Genotype/phenotype correlations have provided important understanding of pathophysiological mechanisms of disease. Before presenting a brief overview of these disorders, we provide a summary of the structure and function of hemoglobin, along with the mechanism of assembly of its subunits, as background for the rationale and basis of the different categories of disorders in the classification. PMID:23378597

  15. PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION

    PubMed Central

    Hamilton, Paul B.; Farr, Lee E.; Hiller, Alma; Van Slyke, Donald D.

    1947-01-01

    A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma. Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed. Solutions stored at 4°C. showed no conversion of hemoglobin to methemoglobin over a period of 2½ months; over a 6 month period a small and variable amount of methemoglobin may be formed. PMID:19871690

  16. Hemoglobin D-Punjab: origin, distribution and laboratory diagnosis

    PubMed Central

    Torres, Lidiane de Souza; Okumura, Jéssika Viviani; Silva, Danilo Grünig Humberto da; Bonini-Domingos, Claudia Regina

    2015-01-01

    This review discusses hemoglobin D-Punjab, also known as hemoglobin D-Los Angeles, one of the most common hemoglobin variants worldwide. It is derived from a point mutation in the beta-globin gene (HBB: c.364G>C; rs33946267) prevalent in the Punjab region, Northwestern Indian. Hemoglobin D-Punjab can be inherited in heterozygosis with hemoglobin A causing no clinical or hematological alterations, or in homozygosis, the rarest form of inheritance, a condition that is commonly not related to clinical symptomatology. Moreover, this variant can exist in association with other hemoglobinopathies, such as thalassemias; the most noticeable clinical alterations occur when hemoglobin D-Punjab is associated to hemoglobin S. The clinical manifestations of this association can be similar to homozygosis for hemoglobin S. Although hemoglobin D-Punjab is a common variant globally with clinical importance especially in cases of double heterozygosis, hemoglobin S/D-Punjab is still understudied. In Brazil, for example, hemoglobin D-Punjab is the third most common hemoglobin variant. Thus, this paper summarizes information about the origin, geographic distribution, characterization and occurrence of hemoglobin D-Punjab haplotypes to try to improve our knowledge of this variant. Moreover, a list of the main techniques used in its identification is provided emphasizing the importance of complementary molecular analysis for accurate diagnosis. PMID:25818823

  17. Metastable Polymerization of Sickle Hemoglobin in Droplets

    PubMed Central

    Aprelev, Alexey; Weng, Weijun; Zakharov, Mikhail; Rotter, Maria; Yosmanovich, Donna; Kwong, Suzanna; Briehl, Robin W.; Ferrone, Frank A.

    2007-01-01

    Sickle cell disease arises from a genetic mutation of one amino acid in each of the two hemoglobin β chains, leading to the polymerization of hemoglobin in the red cell upon deoxygenation, and is characterized by vascular crises and tissue damage due to the obstruction of small vessels by sickled cells. It has been an untested assumption that, in red cells that sickle, the growing polymer mass would consume monomers until the thermodynamically well-described monomer solubility was reached. By photolyzing droplets of sickle hemoglobin suspended in oil we find that polymerization does not exhaust the available store of monomers, but stops prematurely, leaving the solutions in a supersaturated, metastable state typically 20% above solubility at 37°C, though the particular values depend on the details of the experiment. We propose that polymer growth stops because the growing ends reach the droplet edge, whereas new polymer formation is thwarted by long nucleation times, since the hemoglobin concentration is lowered by depletion of monomers into the polymers that have formed. This finding suggests a new aspect to the pathophysiology of sickle cell disease, namely, that cells deoxygenated in the microcirculation are not merely undeformable, but will actively wedge themselves tightly against the walls of the microvasculature by a ratchet-like mechanism driven by the supersaturated solution. PMID:17493634

  18. Comparative immunology of Galapagos iguana hemoglobins.

    PubMed

    Higgins, P J; Rand, C S

    1975-09-01

    The antigenic properties of the major hemoglobin component of the Galapgaos iguanas were studied using second-approximation qualitative and quantitative immunochemical techniques. Phylogenetic distances, relative to the Galapagos marine iguana. Amblyrhynchus cristatus, were established on the basis of immunological cross-reactions.

  19. RGB mapping of hemoglobin distribution in skin

    NASA Astrophysics Data System (ADS)

    Jakovels, Dainis; Spigulis, Janis; Rogule, Laura

    2011-07-01

    An experimental RGB imaging system based on commercial color camera was constructed, and its potential for mapping of hemoglobin distribution in skin was studied. Two types of LEDs (RGB and white "warm" LEDs) were compared as illuminators for acquiring images of vascular and pigmented skin malformations. A novel approach for studies of skin capillary refill by RGB analysis has been proposed and discussed.

  20. Hemoglobin: A Nitric-Oxide Dioxygenase

    PubMed Central

    Gardner, Paul R.

    2012-01-01

    Members of the hemoglobin superfamily efficiently catalyze nitric-oxide dioxygenation, and when paired with native electron donors, function as NO dioxygenases (NODs). Indeed, the NOD function has emerged as a more common and ancient function than the well-known role in O2 transport-storage. Novel hemoglobins possessing a NOD function continue to be discovered in diverse life forms. Unique hemoglobin structures evolved, in part, for catalysis with different electron donors. The mechanism of NOD catalysis by representative single domain hemoglobins and multidomain flavohemoglobin occurs through a multistep mechanism involving O2 migration to the heme pocket, O2 binding-reduction, NO migration, radical-radical coupling, O-atom rearrangement, nitrate release, and heme iron re-reduction. Unraveling the physiological functions of multiple NODs with varying expression in organisms and the complexity of NO as both a poison and signaling molecule remain grand challenges for the NO field. NOD knockout organisms and cells expressing recombinant NODs are helping to advance our understanding of NO actions in microbial infection, plant senescence, cancer, mitochondrial function, iron metabolism, and tissue O2 homeostasis. NOD inhibitors are being pursued for therapeutic applications as antibiotics and antitumor agents. Transgenic NOD-expressing plants, fish, algae, and microbes are being developed for agriculture, aquaculture, and industry. PMID:24278729

  1. Unrecognized hemoglobin SE disease as microcytosis

    PubMed Central

    Cooper, Barry; Guileyardo, Joseph; Mora, Adan

    2016-01-01

    Hemoglobin SE disease was first described during the 1950s as a relatively benign microcytosis, but increasing prevalence has revealed a predisposition towards vasoocclusive sickling. Recognition of SE hemoglobinopathies’ potential complications is crucial so medical measures can be utilized to avoid multiorgan injury. PMID:27365881

  2. Analysis of bicarbonate binding to crocodilian hemoglobin.

    PubMed

    Bauer, C; Forster, M; Gros, G; Mosca, A; Perrella, M; Rollema, H S; Vogel, D

    1981-08-25

    Crocodilian hemoglobin has a high intrinsic oxygen affinity but does not react with those organic phosphate esters that normally control the oxygen affinity of blood in higher vertebrates. Instead, its oxygen affinity is greatly lowered by CO2. The present study was undertaken to determine the nature of the CO2 binding to the hemoglobin of a crocodilian species, the Caiman, both qualitatively and quantitatively. The following parameters were measured: (a) carbamino compounds of deoxy- and oxyhemoglobin, (b) the effect of CO2 (at constant pH) on the oxygen affinity of Caiman hemoglobin, (c) total CO2 concentration of hemoglobin solutions at different pH and pCO2 values, and (d) the effect of CO2 on CD spectra of Caiman aquomethemoglobin. An analysis of the results of these measurements revealed that CO2 binding in the form of carbamate was not oxygen-linked and cannot, therefore, mediate the CO2 effect on the oxygen affinity. It was found, however, that 2 mol of bicarbonate can be bound/hemoglobin tetramer and that the association constant of the bicarbonate anion greatly depends upon the state of ligation. At pH 7.02 and 25 degrees C, a numerical value of 2.0 X 10(3) M-1 was obtained for deoxyhemoglobin, while for oxyhemoglobin no significant bicarbonate binding could be observed. At more alkaline pH (pH greater than or equal to 7.5), the association constant for deoxyhemoglobin decreases. Circular dichroism of Caiman aquomethemoglobin decreased considerably in the 287-nm region upon addition of CO2 at constant pH, an effect very similar to the one caused by inositol hexaphosphate in human aquomethemoglobin.

  3. Hemoglobin Hasharon (α247 his(CD5)β2): a hemoglobin found in low concentration

    PubMed Central

    Charache, S.; Mondzac, A. M.; Gessner, U.

    1969-01-01

    Hemoglobin Hasharon (α247 his(CD5)β2) was found to comprise only 16-19% of hemolysates of carriers. These heterozygotes appeared to have mild, compensated, hemolytic anemia. Hb Hasharon was more heat-labile than hemoglobins A, S, or C. Its specific activity was higher than that of Hb A after administration of 59Fe to two carriers. When hemoglobin synthesis by bone marrow cells was studied in vitro, about 18% of incorporated leucine appeared in the Hb Hasharon fraction. It is suggested that Hb Hasharon is unstable in vivo, and that mild hemolytic anemia and a relatively small decrease in its concentration in hemolysates result from its denaturation within red cells. Decreased synthesis, which appears to be the major cause of the small amount of abnormal hemoglobin, may protect heterozygotes from clinically significant hemolytic anemia. Images PMID:5780195

  4. Hemoglobin C, S-C, and E Diseases

    MedlinePlus

    ... Hemolytic Anemia Hemoglobin C, S-C, and E Diseases Iron Deficiency Anemia Sickle Cell Disease Thalassemias Vitamin Deficiency Anemia ( ... Hemolytic Anemia Hemoglobin C, S-C, and E Diseases Iron Deficiency Anemia Sickle Cell Disease Thalassemias Vitamin Deficiency Anemia ...

  5. Alpha chain hemoglobins with electrophoretic mobility similar to that of hemoglobin S in a newborn screening program.

    PubMed

    Silva, Marcilene Rezende; Sendin, Shimene Mascarenhas; Araujo, Isabela Couto de Oliveira; Pimentel, Fernanda Silva; Viana, Marcos Borato

    2013-01-01

    To characterize alpha-chain variant hemoglobins with electric mobility similar to that of hemoglobin S in a newborn screening program. β(S) allele and alpha-thalassemia deletions were investigated in 14 children who had undefined hemoglobin at birth and an electrophoretic profile similar to that of hemoglobin S when they were six months old. Gene sequencing and restriction enzymes (DdeI, BsaJI, NlaIV, Bsu36I and TaqI) were used to identify hemoglobins. Clinical and hematological data were obtained from children who attended scheduled medical visits. THE FOLLOWING ALPHA CHAIN VARIANTS WERE FOUND: seven children with hemoglobin Hasharon [alpha2 47(CE5) Asp>His, HbA2:c.142G>C], all associated with alpha-thalassemia, five with hemoglobin Ottawa [alpha1 15(A13) Gly>Arg, HBA1:c.46G>C], one with hemoglobin St Luke's [alpha1 95(G2) Pro>Arg, HBA1:c.287C>G] and another one with hemoglobin Etobicoke [alpha212 84(F5) Ser>Arg, HBA212:c.255C>G]. Two associations with hemoglobin S were found: one with hemoglobin Ottawa and one with hemoglobin St Luke's. The mutation underlying hemoglobin Etobicoke was located in a hybrid α212 allele in one child. There was no evidence of clinically relevant hemoglobins detected in this study. Apparently these are the first cases of hemoglobin Ottawa, St Luke's, Etobicoke and the α212 gene described in Brazil. The hemoglobins detected in this study may lead to false diagnosis of sickle cell trait or sickle cell disease when only isoelectric focusing is used in neonatal screening. Additional tests are necessary for the correct identification of hemoglobin variants.

  6. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  7. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  8. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the presence...

  9. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  10. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the presence...

  11. Relationship of Hemoglobin to Arterial Oxygen Desaturation during Aeromedical Evacuation

    DTIC Science & Technology

    2015-04-02

    AFRL-SA-WP-SR-2015-0007 Relationship of Hemoglobin to Arterial Oxygen Desaturation during Aeromedical Evacuation Jay...2. REPORT TYPE Special Report 3. DATES COVERED (From – To) September 2012 – September 2014 4. TITLE AND SUBTITLE Relationship of Hemoglobin to...oxygen carrying capability ( hemoglobin ). The incidence and severity of hypoxemia during AE of non- critically injured casualties have not been

  12. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  13. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  14. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the presence...

  15. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the presence...

  16. 21 CFR 864.7455 - Fetal hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin assay. (a) Identification. A fetal hemoglobin assay is a device that is used to determine the presence...

  17. Photopyroelectric Technique for Hemoglobin Assessment in Human Blood

    NASA Astrophysics Data System (ADS)

    Balderas-López, J. A.; Gómez y Gómez, Y. M.; Bautista-Ramírez, M. E.

    2015-06-01

    A new photopyroelectric (PPE) methodology, for optical characterization of general liquids, was used for the assessment of hemoglobin in human blood. The optical absorption coefficient of a hemoglobin reference was measured with this PPE methodology and its corresponding absorptivity, at 532 nm, was obtained. This last reference was used for hemoglobin quantification of blood from a healthy man.

  18. Sensitivity of Routine Tests for Urine Protein to Hemoglobin

    PubMed Central

    Jansen, Barbara S.; Lumsden, John H.

    1985-01-01

    Increasing concentrations of canine hemoglobin were added to aliquots of urine and saline to determine the relative sensitivity of several hemoglobin and protein detection methods including commercial reagent strips and sulfosalicylic acid. The hemoglobin detection pads of the reagent strips were 50 times more sensitive than the protein detection pads, indicating the presence of hemoglobin at a concentration of 0.001 g/L whereas the protein pads did not react positively unless the hemoglobin concentration exceeded 0.05 g/L. The sulfosalicylic acid test was the least sensitive, detecting hemoglobin only at concentrations of 0.4 g/L or higher. These results were similar for hemoglobin added either in the form of lysed red blood cells, intact red blood cells or associated with plasma proteins in whole blood. It was shown that a urine hemoglobin concentration eliciting less than the maximal score on the hemoglobin detection pad will not be detected as “protein” either with the commercial urinalysis strips or with sulfosalicylic acid. It was also seen that hemoglobin becomes visible as a red pigment when exceeding 0.3-0.5 g/L in a clear, light urine. It follows that a positive urine protein reading in the presence of a positive but less than maximal hemoglobin score or a protein reading exceeding 1.0 g/L in a nonpigmented urine indicates “true” proteinuria in excess of hemoglobin and plasma proteins associated with urinary tract hemorrhage. PMID:17422554

  19. Bioimaging techniques for subcellular localization of plant hemoglobins and measurement of hemoglobin-dependent nitric oxide scavenging in planta.

    PubMed

    Hebelstrup, Kim H; Østergaard-Jensen, Erik; Hill, Robert D

    2008-01-01

    Plant hemoglobins are ubiquitous in all plant families. They are expressed at low levels in specific tissues. Several studies have established that plant hemoglobins are scavengers of nitric oxide (NO) and that varying the endogenous level of hemoglobin in plant cells negatively modulates bioactivity of NO generated under hypoxic conditions or during cellular signaling. Earlier methods for determination of hemoglobin-dependent scavenging in planta were based on measuring activity in whole plants or organs. Plant hemoglobins do not contain specific organelle localization signals; however, earlier reports on plant hemoglobin have demonstrated either cytosolic or nuclear localization, depending on the method or cell type investigated. We have developed two bioimaging techniques: one for visualization of hemoglobin-catalyzed scavenging of NO in specific cells and another for visualization of subcellular localization of green fluorescent protein-tagged plant hemoglobins in transformed Arabidopsis thaliana plants.

  20. Self-Assembly of a Functional Triple Protein: Hemoglobin-Avidin-Hemoglobin via Biotin-Avidin Interactions.

    PubMed

    Singh, Serena; Kluger, Ronald

    2016-05-24

    Hypertension resulting from vasoconstriction in clinical trials of cross-linked tetrameric (α2β2) human hemoglobins implicates the extravasation of the hemoglobins into endothelia where they scavenge nitric oxide (NO), which is the signal for relaxation of the surrounding smooth muscle. Thus, we sought an efficient route to create a larger species that avoids extravasation while maintaining the oxygenation function of hemoglobin. Selectively formed cysteine-linked biotin conjugates of hemoglobin undergo self-assembly with avidin into a stable triple protein, hemoglobin-avidin-hemoglobin (HbAvHb), which binds and releases oxygen with moderate affinity and cooperativity. The triple protein is likely to be stabilized by interactions of each constituent hemoglobin (pI 6.9) with the oppositely charged avidin (pI 10.5) as well as the strong association of the biotin moieties on hemoglobin with avidin.

  1. Hemoglobin estimation by the HemoCue® portable hemoglobin photometer in a resource poor setting

    PubMed Central

    2011-01-01

    Background In resource poor settings where automated hematology analyzers are not available, the Cyanmethemoglobin method is often used. This method though cheaper, takes more time. In blood donations, the semi-quantitative gravimetric copper sulfate method which is very easy and inexpensive may be used but does not provide an acceptable degree of accuracy. The HemoCue® hemoglobin photometer has been used for these purposes. This study was conducted to generate data to support or refute its use as a point-of-care device for hemoglobin estimation in mobile blood donations and critical care areas in health facilities. Method EDTA blood was collected from study participants drawn from five groups: pre-school children, school children, pregnant women, non-pregnant women and men. Blood collected was immediately processed to estimate the hemoglobin concentration using three different methods (HemoCue®, Sysmex KX21N and Cyanmethemoglobin). Agreement between the test methods was assessed by the method of Bland and Altman. The Intraclass correlation coefficient (ICC) was used to determine the within subject variability of measured hemoglobin. Results Of 398 subjects, 42% were males with the overall mean age being 19.4 years. The overall mean hemoglobin as estimated by each method was 10.4 g/dl for HemoCue, 10.3 g/dl for Sysmex KX21N and 10.3 g/dl for Cyanmethemoglobin. Pairwise analysis revealed that the hemoglobin determined by the HemoCue method was higher than that measured by the KX21N and Cyanmethemoglobin. Comparing the hemoglobin determined by the HemoCue to Cyanmethemoglobin, the concordance correlation coefficient was 0.995 (95% CI: 0.994-0.996, p < 0.001). The Bland and Altman's limit of agreement was -0.389 - 0.644 g/dl with the mean difference being 0.127 (95% CI: 0.102-0.153) and a non-significant difference in variability between the two measurements (p = 0.843). After adjusting to assess the effect of other possible confounders such as sex, age and category

  2. [Abnormal hemoglobins in Negroid Ecuadorian populations].

    PubMed

    Jara, N O; Guevara Espinoza, A; Guderian, R H

    1989-02-01

    The prevalence of hemoglobinopathies was determined in the black race located in two distinct geographical areas in Ecuador; in the coastal province of Esmeraldas, particularly the Santiago basin (Rio Cayapas and Rio Onzoles) and in the province of Imbabura, particularly in the intermoutain valley, Valle de Chota. A total of 2038 blood samples were analyzed, 1734 in Esmeraldas and 304 in Inbabura, of which 23.2% (473 individuals) were found to be carriers of abnormal hemoglobins, 25.4% (441) in Esmeraldas and 10.5% (32) in Imbabura. The abnormal hemoglobins found in Esmeraldas were Hb AS (19.2%), Hb AC (5.0%), Hb SS (0.6%) and Hb SC (0.5%) while in Imbabura only Hb AS (9.5%) and Hb AC (0.9%) were found. The factors that could influence the difference in prevalence found in the two geographical areas are discussed.

  3. Universal metastability of sickle hemoglobin polymerization

    NASA Astrophysics Data System (ADS)

    Weng, Weijun

    Sickle hemoglobin (HbS) is a natural mutation of the normal hemoglobin (HbA) found in the red blood cells of human body. Polymerization of HbS occurs when the concentration of deoxyHbS exceeds a well-defined solubility, which is the underlying cause of the Sickle Cell Disease. It has long been assumed that thermodynamic equilibrium is reached when polymerization comes to an end. However, in this thesis we demonstrate that in confined volume as well as in bulk solution, HbS polymerization terminates prematurely, leaving the solution in a metastable state. A newly developed Reservoir method as well as modulated excitation method were adopted for the study. This discovery of universal metastability gives us new insights into understanding the mechanism of sickle cell disease.

  4. Hemoglobin-Based Nanoarchitectonic Assemblies as Oxygen Carriers.

    PubMed

    Jia, Yi; Duan, Li; Li, Junbai

    2016-02-10

    Safe and effective artificial oxygen carriers are the subject of great interest due to the problems of traditional blood transfusion and enormous demand in clinical use. In view of its unique oxygen-transport ability and normal metabolic pathways, hemoglobin is regarded as an ideal oxygen-carrying unit. With advances in nano-biotechnology, hemoglobin assemblies as artificial oxygen carriers achieve great development. Here, recent progress on hemoglobin-based oxygen carriers is highlighted in view of two aspects: acellular hemoglobin-based oxygen carriers and cellular hemoglobin-based oxygen carriers. These novel oxygen carriers exhibit advantages over traditional carriers and will greatly promote research on reliable and feasible oxygen carriers.

  5. Serum ferritin levels in hemoglobin H disease.

    PubMed

    Galanello, R; Melis, M A; Paglietti, E; Cornacchia, G; de Virgiliis, S; Cao, A

    1983-01-01

    This study shows that hemoglobin H disease patients aged between 0.5 and 44 years, usually (27 out of 30) have normal serum ferritin levels according to age. This reconfirms that in this disease there are usually normal iron stores. However, in a few patients (3 out of 30) increased levels were found. This may be due to inappropriate iron medication, transfusions or associated idiopathic hereditary hemocromatosis gene.

  6. Carboxyalkylated Hemoglobin as a Potential Blood Substitute.

    DTIC Science & Technology

    1987-01-24

    I- 1.8 MICROCOpy RESOLUTION TEST CHART NAT OWAI BURErAU Of STANDARDS 1963-A OliC FIE COPJ Alit D CARBOXYALKYLATED HEMOGLOBIN AS AN POTENTIAL BLOOD...valine derivatives as the monocarboxymethyl and dicarboxymethyl derivatives, respectively. These derivatives are ninhydrin -negative. The lysine...derivative, wLich was eluted in 1 M acetic acid, was applied to an amino acid analyzer since it is ninhydrin -positive. Its position coincided with that of

  7. Free heme and sickle hemoglobin polymerization

    NASA Astrophysics Data System (ADS)

    Uzunova, Veselina V.

    This work investigates further the mechanism of one of the most interesting of the protein self-assembly systems---the polymerization of sickle hemoglobin and the role of free heme in it. Polymerization of sickle hemoglobin is the primary event in the pathology of a chronic hemolytic condition called sickle cell anemia with complex pathogenesis, unexplained variability and symptomatic treatment. Auto-oxidation develops in hemoglobin solutions exposed to room temperature and causes release of ferriheme. The composition of such solutions is investigated by mass spectrometry. Heme dimers whose amount corresponds to the initial amounts of heme released from the protein are followed. Differences in the dimer peak height are established for hemoglobin variants A, S and C and depending on the exposure duration. The effects of free heme on polymerization kinetics are studied. Growth rates and two characteristic parameters of nucleation are measured for stored Hb S. After dialysis of polymerizing solutions, no spherulites are detected at moderately high supersaturation and prolonged exposure times. The addition of 0.16-0.26 mM amounts of heme to dialyzed solutions leads to restoration of polymerization. The measured kinetic parameters have higher values compared to the ones before dialysis. The amount of heme in non-dialyzed aged solution is characterized using spectrophotometry. Three methods are used: difference in absorbance of dialyzed and non-dialyzed solutions, characteristic absorbance of heme-albumin complex and absorbance of non-dialyzed solutions with added potassium cyanide. The various approaches suggest the presence of 0.12 to 0.18 mM of free ferriheme in such solutions. Open questions are whether the same amounts of free heme are present in vivo and whether the same mechanism operates intracellulary. If the answer to those questions is positive, then removal of free heme from erythrocytes can influence their readiness to sickle.

  8. Fetal hemoglobin in sickle cell anemia.

    PubMed

    Akinsheye, Idowu; Alsultan, Abdulrahman; Solovieff, Nadia; Ngo, Duyen; Baldwin, Clinton T; Sebastiani, Paola; Chui, David H K; Steinberg, Martin H

    2011-07-07

    Fetal hemoglobin (HbF) is the major genetic modulator of the hematologic and clinical features of sickle cell disease, an effect mediated by its exclusion from the sickle hemoglobin polymer. Fetal hemoglobin genes are genetically regulated, and the level of HbF and its distribution among sickle erythrocytes is highly variable. Some patients with sickle cell disease have exceptionally high levels of HbF that are associated with the Senegal and Saudi-Indian haplotype of the HBB-like gene cluster; some patients with different haplotypes can have similarly high HbF. In these patients, high HbF is associated with generally milder but not asymptomatic disease. Studying these persons might provide additional insights into HbF gene regulation. HbF appears to benefit some complications of disease more than others. This might be related to the premature destruction of erythrocytes that do not contain HbF, even though the total HbF concentration is high. Recent insights into HbF regulation have spurred new efforts to induce high HbF levels in sickle cell disease beyond those achievable with the current limited repertory of HbF inducers.

  9. Fetal hemoglobin in sickle cell anemia

    PubMed Central

    Akinsheye, Idowu; Alsultan, Abdulrahman; Solovieff, Nadia; Ngo, Duyen; Baldwin, Clinton T.; Sebastiani, Paola; Chui, David H. K.

    2011-01-01

    Fetal hemoglobin (HbF) is the major genetic modulator of the hematologic and clinical features of sickle cell disease, an effect mediated by its exclusion from the sickle hemoglobin polymer. Fetal hemoglobin genes are genetically regulated, and the level of HbF and its distribution among sickle erythrocytes is highly variable. Some patients with sickle cell disease have exceptionally high levels of HbF that are associated with the Senegal and Saudi-Indian haplotype of the HBB-like gene cluster; some patients with different haplotypes can have similarly high HbF. In these patients, high HbF is associated with generally milder but not asymptomatic disease. Studying these persons might provide additional insights into HbF gene regulation. HbF appears to benefit some complications of disease more than others. This might be related to the premature destruction of erythrocytes that do not contain HbF, even though the total HbF concentration is high. Recent insights into HbF regulation have spurred new efforts to induce high HbF levels in sickle cell disease beyond those achievable with the current limited repertory of HbF inducers. PMID:21490337

  10. Oxygen saturation in pulse oximetry in hemoglobin anomalies.

    PubMed

    Zur, B; Bagci, S; Ludwig, M; Stoffel-Wagner, B

    2012-07-01

    Pulse oximetry is an essential diagnostic method in pediatric emergency medicine and pediatric intensive care. However, if undetected hemoglobin anomalies are the underlying cause measurements of low oxygen saturation can be interpreted incorrectly or may lead to unnecessary examinations. In 2 recently discovered hemoglobin anomalies, Hb Bonn and Hb Venusberg, this resulted in extensive and repeat cardiopulmonary examinations. This review aims to provide an overview of hemoglobin anomalies causing low oxygen saturation.We describe the methods required for differential diagnosis of hemoglobin anomalies, such as hemoglobin electrophoresis, High Performance Liquid Chromatography, hemoglobin gene sequencing and spectral photometry, and the difficulties with the interpretation of results. Furthermore, with a review of the literature we provide an extensive overview of hemoglobin anomalies which result in low oxygen saturation measurement in pulse oximetry. With the examples of Hb Bonn, a novel hemoglobin mutation of the proximal α1-globin, which results in false low pulse oximetry measurements of oxygen saturation, and Hb Venusberg, a low oxygen-affine hemoglobin mutation of the β-globin, we highlight the difficulties arising from the respective case histories.In pediatric medicine, hemoglobin anomalies must be included in the diagnosis as a possible underlying cause of low oxygen saturation in case of ambiguous or conflicting pulse oximetry findings. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Maternal hemoglobin decline following 'uneventful' cesarean delivery.

    PubMed

    Ashwal, Eran; Wertheimer, Avital; Aviram, Amir; Orbach-Zinger, Sharon; Yogev, Yariv; Hiersch, Liran

    2016-09-01

    To assess hemoglobin (Hb) decline following elective and non-elective uneventful cesarean section (CS). A retrospective cohort study of all women with singleton pregnancy who underwent uneventful CS defined as clinical estimation of intra-operative bleeding < 1000 ml. Hemoglobin decline (pre- and post-CS levels difference) of women with non-elective CS (during labor/delivery process) were compared to those who underwent elective CS (no labor). Cases complicated by placenta previa/abruption were excluded. Overall 2767 women underwent uneventful CS, of them, 954 (34.5%) were non-elective and 1813 (65.5%) were elective. Hemoglobin decline was higher in the non-elective group (1.5 ± 1.3 versus 1.0 ± 1.2 g/dL, p < 0.001). This was also observed in the nulliparous patients as well as in those with previous single CS subgroups. The rate of Hb decline ≥3 g/dL and the rate of post-CS Hb < 7 g/dL were higher in the non-elective group (8.9% versus 3.1%, p < 0.001 and 2.3% versus 0.4%, p = 0.001, respectively). On multivariable analysis, non-elective CS was found to be significantly associated with Hb decline of  ≥3 g/dl after surgery (aOR = 2.10, 95% CI 1.36-3.23, p = 0.001) and need for blood products transfusion (aOR = 2.24, 95% CI 1.04-4.83, p = 0.03). Non-elective CS was associated with an increased risk of Hb decline and blood product transfusion even in an apparent uneventful operation.

  12. Universal Metastability of Sickle Hemoglobin Polymerization

    PubMed Central

    Weng, Weijun; Aprelev, Alexey; Briehl, Robin W.; Ferrone, Frank A.

    2008-01-01

    Summary Sickle hemoglobin (HbS) polymerization occurs when deoxy HbS concentration exceeds a well-defined solubility. In experiments using sickle hemoglobin droplets suspended in oil, it has been shown that when polymerization ceases the monomer concentration is above equilibrium solubility. We find that the final concentration in uniform bulk solutions (i.e. with negligible boundaries) agrees with the droplet measurements, and both exceed the expected solubility. To measure hemoglobin in uniform solutions we used modulated excitation of trace amounts of CO in gels of HbS. In this method, a small amount of CO is introduced to a spatially uniform deoxyHb sample, so that less than 2% of the sample is liganded. The liganded fraction is repeatedly photolyzed and the rate of recombination allows the concentration of deoxyHbS in the solution phase to be determined, even if polymers have formed. Both uniform and droplet samples exhibit the same quantitative behavior, exceeding solubility by an amount that depends on the initial concentration of the sample, as well as conditions under which the gel was formed. We hypothesize that the early termination of polymerization is due to the obstruction in polymer growth, which is consistent with the observation that pressing on slides lowers the final monomer concentration, making it closer to solubility. The thermodynamic solubility in free solution is thus only achieved in conditions with low polymer density or under external forces (such as found in sedimentation) that disrupt polymers. Since we find that only about 67% of the expected polymer mass forms, this result will impact any analysis predicated on predicting the polymer fraction in a given experiment. PMID:18308336

  13. Mini-hemoglobins from nemertean worms.

    PubMed

    Vandergon, Thomas L; Riggs, Austen F

    2008-01-01

    Hemoglobins (Hbs) found in members of the phylum Nemertea are smaller than any other known Hb molecules. These mini-Hbs have been of great interest because of their unique three-dimensional structure and their stable ligand-binding properties. Also of interest is the expression of mini-Hb in neural tissue, body wall muscle tissue, and red blood cells. This chapter outlines methods that may be used to isolate and purify functional mini-Hbs from all three tissue types in nemertean worms.

  14. Neutral changes during divergent evolution of hemoglobins

    NASA Technical Reports Server (NTRS)

    Jukes, T. H.

    1978-01-01

    A comparison of the mRNAs for rabbit and human beta-hemoglobins shows that synonymous changes in codons have accumulated three times as rapidly as nucleotide replacements that produced changes in amino acids. This agrees with predictions based on the so-called neutral theory. In addition, seven codon changes that appear to be single-base changes (according to maximum parsimony) are actually two-base changes. This indicates that the construction of primordial sequences is of limited significance when based on inferences that assume minimum base changes for amino acid replacements.

  15. Preparation of Hemoglobin-Containing Microcapsules.

    DTIC Science & Technology

    1981-06-01

    were suspended in saline for storage in a refrigerator. Although in these microencapsulation experiments, the Hb was not denatured, the microcapsules ... microencapsulated Hb, l.O-ml sample of the microcapsule suspension was diluted with 10 ml 0.9% NaCI. The absorption spectrum was taken immediately after dilution...AD A135 634 PREPARATION OF HEMOGLOBIN CONTA NING MICROCAPSULES (U) I/ ,R 224 AM OS NTERNATIDNAL MENOPARKO CA REYES AUNN8 SRI-2254-1 DAMD17-80-C-01?7

  16. Relationship of Baseline Hemoglobin Level with Serum Ferritin, Postphlebotomy Hemoglobin Changes, and Phlebotomy Requirements among HFE C282Y Homozygotes.

    PubMed

    Mousavi, Seyed Ali; Mahmood, Faiza; Aandahl, Astrid; Knutsen, Teresa Risopatron; Llohn, Abid Hussain

    2015-01-01

    Objectives. We aimed to examine whether baseline hemoglobin levels in C282Y-homozygous patients are related to the degree of serum ferritin (SF) elevation and whether patients with different baseline hemoglobin have different phlebotomy requirements. Methods. A total of 196 patients (124 males and 72 females) who had undergone therapeutic phlebotomy and had SF and both pre- and posttreatment hemoglobin values were included in the study. Results. Bivariate correlation analysis suggested that baseline SF explains approximately 6 to 7% of the variation in baseline hemoglobin. The results also showed that males who had higher (≥150 g/L) baseline hemoglobin levels had a significantly greater reduction in their posttreatment hemoglobin despite requiring fewer phlebotomies to achieve iron depletion than those who had lower (<150 g/L) baseline hemoglobin, regardless of whether baseline SF was below or above 1000 µg/L. There were no significant differences between hemoglobin subgroups regarding baseline and treatment characteristics, except for transferrin saturation between male subgroups with SF above 1000 µg/L. Similar differences were observed when females with higher (≥138 g/L) baseline hemoglobin were compared with those with lower (<138 g/L) baseline hemoglobin. Conclusion. Dividing C282Y-homozygous patients into just two subgroups according to the degree of baseline SF elevation may obscure important subgroup variations.

  17. [Evaluation of D10 hemoglobin testing system for hemoglobin A1C assay].

    PubMed

    Marzullo, C; Minery, M

    2008-01-01

    Bio-Rad D10 hemoglobin testing system with rack loader for hemoglobinA1C assay was evaluated. Analytical qualities were satisfactory. Imprecision was good (within-run cv was 0,5% for 4,5% of HBA(1C), 0,63% for 7,4% of HBA1C, 0,46% for 11,1% of HBA1C, between-run cv was 1,16% for 4,7% of HBA1C, 1,01% for 7,6% of HBA1C, 1,04% for 11,2% of HBA1C). Results were very well correlated with those obtained on Bio-Rad Variant II (r = 0,998). Bland and Altman graph showed good agreement between the two methods for HbA1C under 15%. The measuring range was up to 18,3% of HBA1C. There was no specimen related carry over. Triglycerides under 5,5 mmol/L and bilirubin under 734 mumol/L did not interfere. Carbamylation of HBA1C did not interfere for urea concentration under 14 mmol/L. Practicability was very good. Detection of common hemoglobin variants (HbS, C, D, E, O) is available. Fast and easy switching between short and long program allows to perform HBA1C determination for patients with hemoglobin variants. So, D10 is an interesting and easy to use small HPLC automate witch offers accurate HBA1C quantification certified by NGSP.

  18. Multiple hemoglobins of the cutthroat trout, Salmo clarki.

    PubMed

    Southard, J N; Berry, C R; Farley, T M

    1986-07-01

    Nine hemoglobins were purified from blood of Salmo clarki by ion-exchange chromatography and preparative isoelectric focusing. The subunit structures of eight of the purified hemoglobins were studied by electrophoresis of globins in the presence of urea. Six are alpha 2 beta 2 tetramers while two appear to be heterotetramers of the type alpha alpha' beta 2 and alpha alpha' beta beta'. The effects of pH, nucleotides, and temperature on the oxygen equilibria of the purified hemoglobins were studied. Five hemoglobins with isoelectric points from 9.1 to 7.1 and one minor hemoglobin with an isoelectric point of 5.9 appear to have essentially identical oxygen binding properties. All have similar oxygen equilibria which are independent of pH and temperature and not affected by saturating amounts of ATP. Another minor hemoglobin with an isoelectric point below 5.9 has similar oxygen equilibria except for a possible pH dependence. Two hemoglobins, with isoelectric points of 6.5 and 6.4, have oxygen binding properties which are strongly pH and temperature dependent. Addition of ATP or GTP causes a large decrease in the oxygen affinity without affecting the cooperativity of oxygen binding. The effect of GTP is slightly greater than that of ATP. No significant differences were observed in the oxygen equilibria of these two hemoglobins. The red blood cells of S. clarki were found to contain large amounts of both ATP and GTP, with an ATP:GTP ratio of 3:1. Both nucleotides may be important modulators of hemoglobin oxygen affinity in S. clarki, in contrast to the situation in S. gairdneri, in which red blood cell GTP concentrations are considerably lower. The presence of six or possibly seven hemoglobins with identical oxygen binding properties in S. clarki suggests that, to a large extent, the physiological role of multiple hemoglobins in this species involves phenomena not directly related to the oxygen binding properties of the hemoglobins.

  19. Hemoglobin level in older persons and incident Alzheimer disease

    PubMed Central

    Buchman, A.S.; Wilson, R.S.; Leurgans, S.E.; Bennett, D.A.

    2011-01-01

    Objective: To test the hypothesis that level of hemoglobin is associated with incident Alzheimer disease (AD). Methods: A total of 881 community-dwelling older persons participating in the Rush Memory and Aging Project without dementia and a measure of hemoglobin level underwent annual cognitive assessments and clinical evaluations for AD. Results: During an average of 3.3 years of follow-up, 113 persons developed AD. In a Cox proportional hazards model adjusted for age, sex, and education, there was a nonlinear relationship between baseline level of hemoglobin such that higher and lower levels of hemoglobin were associated with AD risk (hazard ratio [HR] for the quadratic of hemoglobin 1.06, 95% confidence interval [CI] 1.01–1.11). Findings were unchanged after controlling for multiple covariates. When compared to participants with clinically normal hemoglobin (n = 717), participants with anemia (n = 154) had a 60% increased hazard for developing AD (95% CI 1.02–2.52), as did participants with clinically high hemoglobin (n = 10, HR 3.39, 95% CI 1.25–9.20). Linear mixed-effects models showed that lower and higher hemoglobin levels were associated with a greater rate of global cognitive decline (parameter estimate for quadratic of hemoglobin = −0.008, SE −0.002, p < 0.001). Compared to participants with clinically normal hemoglobin, participants with anemia had a −0.061 z score unit annual decline in global cognitive function (SE 0.012, p < 0.001), as did participants with clinically high hemoglobin (−0.090 unit/year, SE 0.038, p = 0.018). Conclusions: In older persons without dementia, both lower and higher hemoglobin levels are associated with an increased hazard for developing AD and more rapid cognitive decline. PMID:21753176

  20. Medical Aspects of Sickle Hemoglobin in Military Personnel

    PubMed Central

    Brodine, C. E.; Uddin, D. E.

    1977-01-01

    The Department of Defense (DOD) will soon issue a directive to test all incoming military personnel for the presence of hemoglobin S. The military testing program for hemoglobin S is an occupational medicine program. This report includes a discussion of armed services physical standards, a description of the Navy effort to evaluate an automated system for detection of hemoglobin S, and the proposed DOD directive. PMID:833894

  1. Medical aspects of sickle hemoglobin in military personnel.

    PubMed

    Brodine, C E; Uddin, D E

    1977-01-01

    The Department of Defense (DOD) will soon issue a directive to test all incoming military personnel for the presence of hemoglobin S. The military testing program for hemoglobin S is an occupational medicine program. This report includes a discussion of armed services physical standards, a description of the Navy effort to evaluate an automated system for detection of hemoglobin S, and the proposed DOD directive.

  2. Hemoglobin alpha in the blood vessel wall

    PubMed Central

    Butcher, Joshua T.; Johnson, Tyler; Beers, Jody; Columbus, Linda; Isakson, Brant E

    2014-01-01

    Hemoglobin has been studied and well haracterized in red blood cells for over one hundred years. However, new work has indicated that the hemoglobin alpha subunit (Hbα) is also found within the blood vessel wall, where it appears to localize at the myoendothelial junction (MEJ) and plays a role in regulating nitric oxide (NO) signaling between endothelium and smooth muscle. This discovery has created a new paradigm for control of endothelial nitric oxide synthase activity, nitric oxide diffusion, and ultimately, control of vascular tone and blood pressure. This review will discuss the current knowledge of hemoglobin’s properties as a gas exchange molecule in the blood stream, and extrapolate the properties of Hbα biology to the MEJ signaling domain. Specifically, we propose that Hbα is present at the MEJ to regulate NO release and diffusion in a restricted physical space, which would have powerful implications for the regulation of blood flow in peripheral resistance arteries. PMID:24832680

  3. Multiple geminate ligand recombinations in human hemoglobin.

    PubMed Central

    Esquerra, R M; Goldbeck, R A; Reaney, S H; Batchelder, A M; Wen, Y; Lewis, J W; Kliger, D S

    2000-01-01

    The geminate ligand recombination reactions of photolyzed carbonmonoxyhemoglobin were studied in a nanosecond double-excitation-pulse time-resolved absorption experiment. The second laser pulse, delayed by intervals as long as 400 ns after the first, provided a measure of the geminate kinetics by rephotolyzing ligands that have recombined during the delay time. The peak-to-trough magnitude of the Soret band photolysis difference spectrum measured as a function of the delay between excitation pulses showed that the room temperature kinetics of geminate recombination in adult human hemoglobin are best described by two exponential processes, with lifetimes of 36 and 162 ns. The relative amounts of bimolecular recombination to T- and R-state hemoglobins and the temperature dependence of the submicrosecond kinetics between 283 and 323 K are also consistent with biexponential kinetics for geminate recombination. These results are discussed in terms of two models: geminate recombination kinetics modulated by concurrent protein relaxation and heterogeneous kinetics arising from alpha and beta chain differences. PMID:10827999

  4. A review of variant hemoglobins interfering with hemoglobin A1c measurement.

    PubMed

    Little, Randie R; Roberts, William L

    2009-05-01

    Hemoglobin A1c (HbA1c) is used routinely to monitor long-term glycemic control in people with diabetes mellitus, as HbA1c is related directly to risks for diabetic complications. The accuracy of HbA1c methods can be affected adversely by the presence of hemoglobin (Hb) variants or elevated levels of fetal hemoglobin (HbF). The effect of each variant or elevated HbF must be examined with each specific method. The most common Hb variants worldwide are HbS, HbE, HbC, and HbD. All of these Hb variants have single amino acid substitutions in the Hb beta chain. HbF is the major hemoglobin during intrauterine life; by the end of the first year, HbF falls to values close to adult levels of approximately 1%. However, elevated HbF levels can occur in certain pathologic conditions or with hereditary persistence of fetal hemoglobin. In a series of publications over the past several years, the effects of these four most common Hb variants and elevated HbF have been described. There are clinically significant interferences with some methods for each of these variants. A summary is given showing which methods are affected by the presence of the heterozygous variants S, E, C, and D and elevated HbF. Methods are divided by type (immunoassay, ion-exchange high-performance liquid chromatography, boronate affinity, other) with an indication of whether the result is artificially increased or decreased by the presence of a Hb variant. Laboratorians should be aware of the limitations of their method with respect to these interferences. 2009 Diabetes Technology Society.

  5. WAXS studies of the structural diversity of hemoglobin in solution.

    SciTech Connect

    Makowski, L.; Bardhan, J.; Gore, D.; Lal, J.; Mandava, S.; Park, S.; Rodi, D. J.; Ho, N. T.; Ho, C.; Fischetti, R. F.

    2011-01-01

    Specific ligation states of hemoglobin are, when crystallized, capable of taking on multiple quaternary structures. The relationship between these structures, captured in crystal lattices, and hemoglobin structure in solution remains uncertain. Wide-angle X-ray solution scattering (WAXS) is a sensitive probe of protein structure in solution that can distinguish among similar structures and has the potential to contribute to these issues. We used WAXS to assess the relationships among the structures of human and bovine hemoglobins in different liganded forms in solution. WAXS data readily distinguished among the various forms of hemoglobins. WAXS patterns confirm some of the relationships among hemoglobin structures that have been defined through crystallography and NMR and extend others. For instance, methemoglobin A in solution is, as expected, nearly indistinguishable from HbCO A. Interestingly, for bovine hemoglobin, the differences between deoxy-Hb, methemoglobin and HbCO are smaller than the corresponding differences in human hemoglobin. WAXS data were also used to assess the spatial extent of structural fluctuations of various hemoglobins in solution. Dynamics has been implicated in allosteric control of hemoglobin, and increased dynamics has been associated with lowered oxygen affinity. Consistent with that notion, WAXS patterns indicate that deoxy-Hb A exhibits substantially larger structural fluctuations than HbCO A. Comparisons between the observed WAXS patterns and those predicted on the basis of atomic coordinate sets suggest that the structures of Hb in different liganded forms exhibit clear differences from known crystal structure.

  6. Properties of Hemoglobin Decolorized with a Histidine-Specific Protease.

    PubMed

    Shi, Jing; de Roos, Andre; Schouten, Olaf; Zheng, Chaoya; Vink, Collin; Vonk, Brenda; Kliphuis, Annette; Schaap, Albert; Edens, Luppo

    2015-06-01

    This study investigated the application of Aspergilloglutamic peptidase (AGP) on porcine hemoglobin decolorization. AGP from fungus Aspergillus niger is identified to possess a high preference towards the histidine residues. As histidine residues in hemoglobin are known to coordinate the heme group within the globin molecule, we therefore hypothesized that incubating hemoglobin with a histidine-specific protease would efficiently separate the non-heme peptides from the heme-enriched peptides with a minimum degree of hydrolysis. AGP-decolored porcine hemoglobin hydrolysates were assessed on their functional (for example, color, emulsification, foaming, and water binding) and sensory properties. The results were compared with commercially available blood-derived proteins (subtilisin-decolored hemoglobin hydrolysates and plasma protein). It was observed that AGP is able to effectively decolor hemoglobin. The degree of hydrolysis (DH) increased less than 3% using AGP to achieve 90% color reduction of hemoglobin, whereas a DH increase of more than 20% is needed using subtilisin. The AGP-decolored hemoglobin hydrolysates (AGP-Hb) possess good emulsification, foaming, and water binding properties, which are better or comparable with the plasma protein, and much better than the subtilisin-decolored hemoglobin hydrolysates (subtilisin-Hb). The model canned meat with addition of AGP-Hb showed the highest value in hardness, springiness, and chewiness from the texture analysis. Furthermore, the canned meat with AGP-Hb was found to have a better sensory profile than the ones with addition of subtilisin-Hb and plasma protein.

  7. Sex differences and hemoglobin levels in relation to stroke outcomes.

    PubMed

    Kimberly, W Taylor; Lima, Fabricio O; O'Connor, Sydney; Furie, Karen L

    2013-02-19

    Women have worse outcomes after stroke compared to men. Since women have lower hemoglobin values, we examined whether hemoglobin levels may associate with worse stroke outcomes in women. We retrospectively studied 274 patients enrolled in a prospective multicenter study. We explored the relationship of hemoglobin with clinical outcome at 6 months, as measured by the modified Rankin Scale (mRS). Ordinal logistic regression was used to evaluate the independent effect of hemoglobin on clinical outcome, and to explore the influence of sex on that association. Women had a lower mean hemoglobin level (11.7 ± 1.8 g/dL) compared to men (13.3 ± 1.7 g/dL). Low hemoglobin was associated with worse 6-month mRS outcomes in univariate analysis (p < 0.001). Lower hemoglobin remained independently associated with poor outcome after adjustment for comorbid disease, stroke severity, age, and sex. The inclusion of hemoglobin in the model attenuated the independent effect of sex on outcome. Sex differences in stroke outcome are linked to lower hemoglobin level, which is more prevalent in women. Further examination of this potentially modifiable predictor is warranted.

  8. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... diabetes and to determine the proper insulin dosage for a patient. Elevated levels of glycosylated hemoglobin indicate uncontrolled diabetes in a patient. (b) Classification. Class II (performance standards). ...

  9. Characterization of the hemoglobin of the backswimmer Anisops deanei (Hemiptera).

    PubMed

    Wawrowski, Agnes; Matthews, Philip G D; Gleixner, Eva; Kiger, Laurent; Marden, Michael C; Hankeln, Thomas; Burmester, Thorsten

    2012-09-01

    While O(2)-binding hemoglobin-like proteins are present in many insects, prominent amounts of hemoglobin have only been found in a few species. Backswimmers of the genera Anisops and Buenoa (Notonectidae) have high concentrations of hemoglobin in the large tracheal cells of the abdomen. Oxygen from the hemoglobin is delivered to a gas bubble and controls the buoyant density, which enables the bugs to maintain their position without swimming and to remain stationary in the mid-water zone where they hunt for prey. We have obtained the cDNA sequences of three Anisops deanei hemoglobin chains by RT-PCR and RACE techniques. The deduced amino acid sequences show an unusual insertion of a single amino acid in the conserved helix E, but this does not affect protein stability or ligand binding kinetics. Recombinant A. deanei hemoglobin has an oxygen affinity of P(50) = 2.4 kPa (18 torr) and reveals the presence of a dimeric fraction or two different conformations. The absorption spectra demonstrate that the Anisops hemoglobin is a typical pentacoordinate globin. Phylogenetic analyses show that the backswimmer hemoglobins evolved within Heteroptera and most likely originated from an intracellular hemoglobin with divergent function.

  10. Rate of Nitric Oxide Scavenging by hemoglobin bound to haptoglobin

    PubMed Central

    Azarov, Ivan; He, Xiaojun; Jeffers, Anne; Basu, Swati; Ucer, Burak; Hantgan, Roy R.; Levy, Andrew; Kim-Shapiro, Daniel B.

    2008-01-01

    Cell-free hemoglobin, released from the red cell, may play a major role in regulating the bioavailability of nitric oxide. The abundant serum protein haptoglobin, rapidly binds to free hemoglobin forming a stable complex accelerating its clearance. The haptoglobin gene is polymorphic with two classes of alleles denoted 1 and 2. We have previously demonstrated that the haptoglobin 1 protein-hemoglobin complex is cleared twice as fast as the haptoglobin 2 protein-hemoglobin complex. In this report we explored whether haptoglobin binding to hemoglobin reduces the rate of nitric oxide scavenging using time-resolved absorption spectroscopy. We found that both the haptoglobin 1 and haptoglobin 2 protein complexes react with nitric oxide at the same rate as unbound cell-free hemoglobin. To confirm these results we developed a novel assay where free hemoglobin and hemoglobin bound to haptoglobin competed in the reaction with NO. The relative rate of the NO reaction was then determined by examining the amount of reacted species using analytical ultracentrifugation. Since complexation of hemoglobin with haptoglobin does not reduce NO scavenging, we propose that the haptoglobin genotype may influence nitric oxide bioavailability by determining the clearance rate of the haptoglobin-hemoglobin complex. We provide computer simulations showing that a two-fold difference in the rate of uptake of the haptoglobin hemoglobin complex by macrophages significantly affects nitric oxide bioavailability thereby providing a plausible explanation for why there is more vasospasm after subarachnoid hemorrhage in individuals and transgenic mice homozygous for the Hp 2 allele. PMID:18364244

  11. Hemosomegenesis and hemoglobin biosynthesis in vertebrates.

    PubMed

    Brunner Júnior, A; de Rizzo, E; Morena, D D; Cianciarullo, A M; Jared, C; Morena, P

    1992-08-01

    1. Ultrastructural observations on maturing rabbit embryo erythroid cells led to the finding of hemoglobinized organelles distinguishable from mitochondria due to their highly dense matrix, two or three longitudinally arranged double lamellae, and smaller diameters. Intraorganellar 50-60 A particles identical to those contained in the hemoglobinized cytoplasm were found. 2. Their hemoglobin (Hb) content was demonstrated by electrophoresis of the concentrated supernatant from the isolated, washed, and osmotically lysed organellar fraction. We have proposed that these organelles are the sites for heme integration into the globin (G) polypeptide chains and subunits assembly. The term hemosome has been suggested for such entities. 3. This hypothesis has been sustained by several analytical and experimental works based on the postulation that hemosomes should be found at higher frequencies where the Hb biosynthesis rate is more intensive, or where the induction of this biosynthesis is always dependent on the formation of hemosomes. 4. Maturing erythroid cells of the circulating embryo blood contain hemosomes in higher frequency than in liver erythroid cells, coinciding with the higher Hb biosynthesis rate in peripheral blood than in the liver. In bleeding anemia, the decay of Hb concentration parallels the reduction of the mean number of hemosomes per reticulocyte, in comparison with normal reticulocytes. 5. In HeLa cells and epithelial cultured cells induced to synthesize Hb, it was shown that this biosynthesis is ever concomitant with the formation of hemosomes and depends on the presence of erythropoietin, as occurs in erythroid cells. 6. Studies on hemosomegenesis and Hb biosynthesis experimentally effected in epithelial cultured cells, allowed the interpretation of the sequence of events leading to hemosome formation in maturing erythroid cells. Simultaneously with iron uptake, mitochondria differentiate to lamellated bodies and, successively, expansions rise for

  12. Stroma-free hemoglobin from bovine blood.

    PubMed

    Lima, Maria Celiana P; Andrade, Cristina T

    2007-01-01

    Isolation and purification of bovine hemoglobin (HbBv) was carried out after reaction of whole blood with carbon monoxide. Washing/centrifugation steps were used to eliminate leukocytes, platelets, and plasma proteins. Hypotonic media and ultrasound radiation were used to lyse red blood cells. Lyse by ultrasound was shown to lead to solutions at the highest concentrations in HbBv, and the least concentrations in major phospholipids contaminants. Additional purification procedures were performed to remove membrane proteins and phospholipids. In the first case, proteins were denatured by thermal treatment, and filtered. To eliminate phospholipids, liquid chromatography was used with strong anion exchangers. Purity of HbBv was evaluated by normal phase high performance liquid chromatography (HPLC), electrophoresis, and size-exclusion HPLC.

  13. Computation Of Facilitated Transport of O2 In Hemoglobin

    NASA Technical Reports Server (NTRS)

    Davis, Sanford

    1991-01-01

    Report describes computations of unsteady facilitated transport of oxygen through liquid membrane of hemoglobin. Used here, "facilitated transport" means diffusion of permeant through membrane in which that diffusion enhanced by reversible chemical reaction between permeant and membrane. In this case, reversible reactions between hemoglobin and oxygen.

  14. Hemoglobin Screening Independently Predicts All-Cause Mortality.

    PubMed

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

    2015-01-01

    Objective .- Determine if the addition of hemoglobin testing improves risk prediction for life insurance applicants. Method .- Hemoglobin results for insurance applicants tested from 1993 to 2007, with vital status determined by Social Security Death Master File follow-up in 2011, were analyzed by age and sex with and without accounting for the contribution of other test results. Results .- Hemoglobin values ≤12.0 g/dL (and possibly ≤13.0 g/dL) in females age 50+ (but not age <50) and hemoglobin values ≤13.0 g/dL in all males are associated with progressively increasing mortality risk independent of the contribution of other test values. Increased risk is also noted for hemoglobin values >15.0 g/dL (and possibly >14.0 g/dL) for all females and for hemoglobin values >16.0 g/dL for males. Conclusion .- Hemoglobin testing can add additional independent risk assessment to that obtained from other laboratory testing, BP and build in this relatively healthy insurance applicant population. Multiple studies support this finding at older ages, but data (and the prevalence of diseases impacting hemoglobin levels) are limited at younger ages.

  15. Direct measurement of equilibrium constants for high-affinity hemoglobins.

    PubMed

    Kundu, Suman; Premer, Scott A; Hoy, Julie A; Trent, James T; Hargrove, Mark S

    2003-06-01

    The biological functions of heme proteins are linked to their rate and affinity constants for ligand binding. Kinetic experiments are commonly used to measure equilibrium constants for traditional hemoglobins comprised of pentacoordinate ligand binding sites and simple bimolecular reaction schemes. However, kinetic methods do not always yield reliable equilibrium constants with more complex hemoglobins for which reaction mechanisms are not clearly understood. Furthermore, even where reaction mechanisms are clearly understood, it is very difficult to directly measure equilibrium constants for oxygen and carbon monoxide binding to high-affinity (K(D) < 1 micro M) hemoglobins. This work presents a method for direct measurement of equilibrium constants for high-affinity hemoglobins that utilizes a competition for ligands between the "target" protein and an array of "scavenger" hemoglobins with known affinities. This method is described for oxygen and carbon monoxide binding to two hexacoordinate hemoglobins: rice nonsymbiotic hemoglobin and Synechocystis hemoglobin. Our results demonstrate that although these proteins have different mechanisms for ligand binding, their affinities for oxygen and carbon monoxide are similar. Their large affinity constants for oxygen, 285 and approximately 100 micro M(-1) respectively, indicate that they are not capable of facilitating oxygen transport.

  16. Regulatory mechanisms of hemoglobin oxygen affinity in acidosis and alkalosis

    PubMed Central

    Bellingham, A. J.; Detter, J. C.; Lenfant, C.

    1971-01-01

    The recent reports of the effect of 2,3-diphosphoglycerate (2,3-DPG) on hemoglobin affinity for oxygen suggested that this substance may play a role in man's adaptation to acidosis and alkalosis. A study of the effect of induced acidosis and alkalosis on the oxyhemoglobin dissociation curve of normal man was therefore carried out, and the mechanisms involved in the physiological regulation of hemoglobin oxygen affinity examined. In acute changes of plasma pH there was no alteration in red cell 2,3-DPG content. However, there were changes in hemoglobin oxygen affinity and these correlated with changes in mean corpuscular hemoglobin concentration (MCHC). With maintained acidosis and alkalosis, red cell 2,3-DPG content was altered and correlated with the changes in hemoglobin oxygen affinity. Both of these mechanisms shift the hemoglobin oxygen dissociation curve opposite to the direct pH (Bohr) effect, and providing the rate of pH change is neither too rapid nor too large, they counteract the direct pH effect and the in vivo hemoglobin oxygen affinity remains unchanged. It is also shown that approximately 35% of the change in hemoglobin oxygen affinity resulting from an alteration in red cell 2,3-DPG, is explained by effect of 2,3-DPG on the red cell pH. PMID:5545127

  17. The effect of cationic starch on hemoglobin, and the primary attempt to encapsulate hemoglobin.

    PubMed

    Gao, Wei; Sha, Baoyong; Liu, Yongchun; Wu, Daocheng; Shen, Xin; Jing, Guixia

    2015-06-01

    Though starch has been a common material used for drug delivery, it has not been used as an encapsulation material for hemoglobin-based oxygen carriers. In this study, cationic amylose (CA) was synthesized by an etherification reaction. The interaction behaviors between CA and hemoglobin (Hb) were measured by zeta potential, size, and UV-Vis absorption spectra at different pH values. Cationic starch encapsulated Hb by electrostatic adhesion, reverse micelles, and cross-linking, and showed a core shell structure with a size of around 100 nm, when measured immediately after dispersing in PBS solution. However, we found that it was prone to swell, aggregate, and leak Hb with a longer duration of dispersal in PBS.

  18. INTRINSIC REGULATION OF HEMOGLOBIN EXPRESSION BY VARIABLE SUBUNIT INTERFACE STRENGTHS

    PubMed Central

    Manning, James M.; Popowicz, Anthony M.; Padovan, Julio C.; Chait, Brian T.; Manning, Lois R.

    2012-01-01

    SUMMARY The expression of the six types of human hemoglobin subunits over time is currently considered to be regulated mainly by transcription factors that bind to upstream control regions of the gene (the “extrinsic” component of regulation). Here we describe how subunit pairing and further assembly to tetramers in the liganded state is influenced by the affinity of subunits for one another (the “intrinsic” component of regulation). The adult hemoglobin dimers have the strongest subunit interfaces and the embryonic hemoglobins are the weakest with fetal hemoglobins of intermediate strength, corresponding to the temporal order of their expression. These variable subunit binding strengths and the attenuating effects of acetylation contribute to the differences with which these hemoglobin types form functional O2-binding tetramers consistent with gene switching. PMID:22129306

  19. NEPHRITIS AND ITS INFLUENCE UPON HEMOGLOBIN PRODUCTION IN EXPERIMENTAL ANEMIA

    PubMed Central

    Whipple, G. H.; Robscheit-Robbins, F. S.

    1939-01-01

    Spontaneous glomerulonephritis develops not infrequently (11 per cent incidence) in the anemia colony. The course of the nephritis is insidious and usually extends over several years but ends in uremia, often with terminal bronchopneumonia. Hemoglobin production in these standard anemic dogs is well established as related to various standard food factors. These tests are summarized in the tables above to show the changes that appear year by year in the life of each dog. Nephritis causes little or no change in hemoglobin production in anemic dogs in the early stages of the disease. In the late stages of nephritis there may be no change or moderate changes in hemoglobin production in these anemic dogs. The average is 70 per cent of normal hemoglobin production in advanced nephritis. It seems unlikely that this degree of impairment of hemoglobin production in nephritis would result in spontaneous anemia in the dog. PMID:19870858

  20. [Spectroscopic studies of guanidine hydrochloride-induced unfolding of hemoglobin].

    PubMed

    Li, Jin-Jing; Tang, Qian; Cao, Hong-Yu; Zhang, Yu-Jiao; Zhang, Tao; Zheng, Xue-Fang

    2012-09-01

    In the present paper, based on the ultraviolet-visible (UV-Vis) absorption spectroscopy, fluorescence spectroscopy, and stopped flow-fluorescence spectroscopy, the authors studied the protein unfolding process of hemoglobin induced by GdmHcl. The experiments result shows that there were two different procedures about GdmHcl inducing hemoglobin unfolding from the evidences of UV-Vis absorption spectrum and fluorescence phase diagrams. Namely, the hemoglobin subunit exhibits depolymerization, forming the intermediates when incubated with GdmHcl at the concentration of 1. 0 mol x L(-1). With the increase in the concentration, various subunit structure became loose gradually, and the protoheme collapsed eventually. UV-Vis absorption spectroscopy indicates that the addition of reductant can cooperate with the depolymerization of hemoglobin subunit and the disaggregation of protoheme. The reductant results in the unfolding procedure that hemoglobin from "three-state model" turns into "two-state model".

  1. Hemoglobin values: comparative survey of the 1976 Canadian Olympic team.

    PubMed Central

    Clement, D. B.; Asmundson, R. C.; Medhurst, C. W.

    1977-01-01

    In view of the role of hemoglobin in oxygen transport, the hemoglobin concentration in whole blood may indicate readiness for maximal physical performance. Hemoglobin concentrations were determined in members of the 1976 Canadian Olympic team and compared with those of the 1975 Canadian general population and with published data for the 1968 Australian and Dutch Olympic teams. The mean hemoglobin concentrations of the 123 male and 64 female Canadian Olympic athletes were 14.7 +/- 1.0 and 12.9 +/- 0.7 g/dL, respectively. Both male and female Canadian Olympic athletes had significantly lower (P less than 0.01) values than the other three groups. The suboptimal hemoglobin concentrations may be related to inadequate dietary intake of protein and iron. PMID:902207

  2. Insights into Hemoglobin Assembly through in Vivo Mutagenesis of α-Hemoglobin Stabilizing Protein*

    PubMed Central

    Khandros, Eugene; Mollan, Todd L.; Yu, Xiang; Wang, Xiaomei; Yao, Yu; D'Souza, Janine; Gell, David A.; Olson, John S.; Weiss, Mitchell J.

    2012-01-01

    α-Hemoglobin stabilizing protein (AHSP) is believed to facilitate adult Hemoglobin A assembly and protect against toxic free α-globin subunits. Recombinant AHSP binds multiple forms of free α-globin to stabilize their structures and inhibit precipitation. However, AHSP also stimulates autooxidation of αO2 subunit and its rapid conversion to a partially unfolded bishistidyl hemichrome structure. To investigate these biochemical properties, we altered the evolutionarily conserved AHSP proline 30 in recombinantly expressed proteins and introduced identical mutations into the endogenous murine Ahsp gene. In vitro, the P30W AHSP variant bound oxygenated α chains with 30-fold increased affinity. Both P30W and P30A mutant proteins also caused decreased rates of αO2 autooxidation as compared with wild-type AHSP. Despite these abnormalities, mice harboring P30A or P30W Ahsp mutations exhibited no detectable defects in erythropoiesis at steady state or during induced stresses. Further biochemical studies revealed that the AHSP P30A and P30W substitutions had minimal effects on AHSP interactions with ferric α subunits. Together, our findings indicate that the ability of AHSP to stabilize nascent α chain folding intermediates prior to hemin reduction and incorporation into adult Hemoglobin A is physiologically more important than AHSP interactions with ferrous αO2 subunits. PMID:22287545

  3. Interference of the Hope Hemoglobin With Hemoglobin A1c Results.

    PubMed

    Chakraborty, Sutirtha; Chanda, Dalia; Gain, Mithun; Krishnan, Prasad

    2015-01-01

    Hemoglobin A1c (HbA1c) is now considered to be the marker of choice in diagnosis and management of diabetes mellitus, based on the results of certain landmark clinical trials. Herein, we report the case of a 52-year-old ethnic Southeast Asian Indian man with impaired glucose tolerance whose glycated hemoglobin (ie, HbA1c) levels, as measured via Bio-Rad D10 high-performance liquid chromatography (HPLC) and Roche Tina-quant immunoassay were 47.8% and 44.0%, respectively. No variant hemoglobin (Hb) peak was observed via the D10 chromatogram. We assayed the patient specimen on the Sebia MINICAP capillary electrophoresis platform; the HbA1c level was 6.8%, with a large variant Hb peak of 42.0%. This finding suggested the possible presence of the heterozygous Hb Hope, which can result in spuriously elevated HbA1c results on HPLC and turbidimetric immunoassays. Although the capillary electrophoresis system was able to identify the variant, the A1c results should not be considered accurate due to overlapping of the variant and adult Hb peaks on the electrophoretogram reading. Hb Hope is usually clinically silent but can present such analytical challenges. Through this case study, we critically discuss the limitations of various HbA1c assay methods, highlighting the fact that laboratory professionals need to be aware of occurrences of Hb Hope, to help ensure patient safety.

  4. Bohr effect of hemoglobins: Accounting for differences in magnitude.

    PubMed

    Okonjo, Kehinde O

    2015-09-07

    The basis of the difference in the Bohr effect of various hemoglobins has remained enigmatic for decades. Fourteen amino acid residues, identical in pairs and located at specific 'Bohr group positions' in human hemoglobin, are implicated in the Bohr effect. All 14 are present in mouse, 11 in dog, eight in pigeon and 13 in guinea pig hemoglobin. The Bohr data for human and mouse hemoglobin are identical: the 14 Bohr groups appear at identical positions in both molecules. The dog data are different from the human because three Bohr group positions are occupied by non-ionizable groups in dog hemoglobin; the pigeon data are vastly different from the human because six Bohr group positions are occupied by non-ionizable groups in pigeon hemoglobin. The guinea pig data are quite complex. Quantitative analyses showed that only the pigeon data could be fitted with the Wyman equation for the Bohr effect. We demonstrate that, apart from guinea pig hemoglobin, the difference between the Bohr effect of each of the other hemoglobins and of pigeon hemoglobin can be accounted for quantitatively on the basis of the occupation of some of their Bohr group positions by non-ionizable groups in pigeon hemoglobin. We attribute the anomalous guinea pig result to a new salt-bridge formed in its R2 quaternary structure between the terminal NH3(+) group of one β-chain and the COO(-) terminal group of the partner β-chain in the same molecule. The pKas of this NH3(+) group are 6.33 in the R2 and 4.59 in the T state. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Propofol Enhances Hemoglobin-Induced Cytotoxicity in Neurons

    PubMed Central

    Yuan, Jing; Cui, Guiyun; Li, Wenlu; Zhang, Xiaoli; Wang, Xiaoying; Zheng, Hui; Zhang, Jian; Xiang, Shuanglin; Xie, Zhongcong

    2016-01-01

    BACKGROUND It has been increasingly suggested that propofol protects against hypoxic-/ischemic-induced neuronal injury. As evidenced by hemorrhage-induced stroke, hemorrhage into the brain may also cause brain damage. Whether propofol protects against hemorrhage-induced brain damage remains unknown. Therefore, in this study, we investigated the effects of propofol on hemoglobin-induced cytotoxicity in cultured mouse cortical neurons. METHODS Neurons were prepared from the cortex of embryonic 15-day-old mice. Hemoglobin was used to induce cytotoxicity in the neurons. The neurons were then treated with propofol for 4 hours. Cytotoxicity was determined by lactate dehydrogenase release assay. Caspase-3 activation was examined by Western blot analysis. Finally, the free radical scavenger U83836E was used to examine the potential involvement of oxidative stress in propofol’s effects on hemoglobin-induced cytotoxicity. RESULTS We found that treatment with hemoglobin induced cytotoxicity in the neurons. Propofol enhanced hemoglobin-induced cytotoxicity. Specifically, there was a significant difference in the amount of lactate dehydrogenase release between hemoglobin plus saline (19.84% ± 5.38%) and hemoglobin plus propofol (35.79% ± 4.41%) in mouse cortical neurons (P = 0.00058, Wilcoxon Mann-Whitney U test, n = 8 in the control group or the treatment group). U83836E did not attenuate the enhancing effects of propofol on hemoglobin-induced cytotoxicity in the neurons, and propofol did not significantly affect caspase-3 activation induced by hemoglobin. These data suggested that caspase-3 activation and oxidative stress might not be the underlying mechanisms by which propofol enhanced hemoglobin-induced cytotoxicity. Moreover, these data suggested that the neuroprotective effects of propofol would be dependent on the condition of the brain injury, which will need to be confirmed in future studies. CONCLUSIONS These results from our current proof-of-concept study should

  6. Hemoglobin Ypsilanti: a high-oxygen-affinity hemoglobin demonstrated by two automated high-pressure liquid chromatography systems.

    PubMed

    Mais, Daniel D; Boxer, Laurence A; Gulbranson, Ronald D; Keren, David F

    2007-11-01

    Hemoglobin (Hb) Ypsilanti is a rare high-oxygen-affinity hemoglobin. Like other high-oxygen-affinity hemoglobins, Hb Ypsilanti manifests as erythrocytosis. Because the migration of many high-oxygen-affinity variants on alkaline and acid gels does not differ from that of HbA, oxygen-hemoglobin dissociation studies are often used to document their presence. Hb Ypsilanti is a notable exception because its electrophoresis pattern on alkaline gel is highly characteristic, exemplifying the phenomenon of hybrid formation in variant hemoglobins. In the past few years, several laboratories have begun to use high-pressure liquid chromatography (HPLC) as a screen for hemoglobinopathies. We demonstrate the elution profile of Hb Ypsilanti on the 2 most widely used HPLC methods.

  7. Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

    PubMed Central

    2010-01-01

    Background The genomes of salmonids are considered pseudo-tetraploid undergoing reversion to a stable diploid state. Given the genome duplication and extensive biological data available for salmonids, they are excellent model organisms for studying comparative genomics, evolutionary processes, fates of duplicated genes and the genetic and physiological processes associated with complex behavioral phenotypes. The evolution of the tetrapod hemoglobin genes is well studied; however, little is known about the genomic organization and evolution of teleost hemoglobin genes, particularly those of salmonids. The Atlantic salmon serves as a representative salmonid species for genomics studies. Given the well documented role of hemoglobin in adaptation to varied environmental conditions as well as its use as a model protein for evolutionary analyses, an understanding of the genomic structure and organization of the Atlantic salmon α and β hemoglobin genes is of great interest. Results We identified four bacterial artificial chromosomes (BACs) comprising two hemoglobin gene clusters spanning the entire α and β hemoglobin gene repertoire of the Atlantic salmon genome. Their chromosomal locations were established using fluorescence in situ hybridization (FISH) analysis and linkage mapping, demonstrating that the two clusters are located on separate chromosomes. The BACs were sequenced and assembled into scaffolds, which were annotated for putatively functional and pseudogenized hemoglobin-like genes. This revealed that the tail-to-tail organization and alternating pattern of the α and β hemoglobin genes are well conserved in both clusters, as well as that the Atlantic salmon genome houses substantially more hemoglobin genes, including non-Bohr β globin genes, than the genomes of other teleosts that have been sequenced. Conclusions We suggest that the most parsimonious evolutionary path leading to the present organization of the Atlantic salmon hemoglobin genes involves

  8. The primary structure of genetic variants of mouse hemoglobin

    SciTech Connect

    Popp, R.A.; Bailiff, E.G.; Skow, L.C.; Whitney, J.B. III

    1982-01-01

    The primary structures of the ..cap alpha.. globins from CE/J, DBA/2J, and a stock of Potter's mice were determined to identify the amino acid substitutions associated with the unique isoelectric focusing patterns of these hemoglobins. In addition, the primary structures of the ..cap alpha.. globins from MOL III and PERU mice were studied in search of amino acid substitutions that may not be detected by isoelectric focusing. CE/J hemoglobin contains a unique kind of ..cap alpha.. globin called chain 5. It differs from the single kind of ..cap alpha.. globin (chain 1) in C57BL/6 by having alanine rather than glycine at position 78. DBA/2J hemoglobin has two kinds of ..cap alpha.. globins: one half is like chain 5 and the other half is like chain 1. The hemoglobin from Potter's stock of Mus musculus molossinus also contains chains 1 and 5, but they are expressed at different levels (i.e., 80% chain 1 and 20% chain 5). MOL III hemoglobin has a single kind of ..cap alpha.. globin identical to that in C57BL/6, and PERU hemoglobin contains approximately 40% chain 1 and 60% chain 4. Chains 1 and 4 have different amino acids at positions 25, 62, and 68. These studies confirm that mouse hemoglobins separable by isoelectric focusing, but not by other means of electrophoresis, have substitutions of neutrally charged amino acids in their ..cap alpha.. chains.

  9. Two-photon excited fluorescence emission from hemoglobin

    NASA Astrophysics Data System (ADS)

    Sun, Qiqi; Zeng, Yan; Zhang, Wei; Zheng, Wei; Luo, Yi; Qu, Jianan Y.

    2015-03-01

    Hemoglobin, one of the most important proteins in blood, is responsible for oxygen transportation in almost all vertebrates. Recently, we discovered two-photon excited hemoglobin fluorescence and achieved label-free microvascular imaging based on the hemoglobin fluorescence. However, the mechanism of its fluorescence emission still remains unknown. In this work, we studied the two-photon excited fluorescence properties of the hemoglobin subunits, heme/hemin (iron (II)/(III) protoporphyrin IX) and globin. We first studied the properties of heme and the similar spectral and temporal characteristics of heme and hemoglobin fluorescence provide strong evidence that heme is the fluorophore in hemoglobin. Then we studied the fluorescence properties of hemin, globin and methemoglobin, and found that the hemin may have the main effect on the methemoglobin fluorescence and that globin has tryptophan fluorescence like other proteins. Finally, since heme is a centrosymmetric molecule, that the Soret band fluorescence of heme and hemoglobin was not observed in the single photon process in the previous study may be due to the parity selection rule. The discovery of heme two-photon excited fluorescence may open a new window for heme biology research, since heme as a cofactor of hemoprotein has many functions, including chemical catalysis, electron transfer and diatomic gases transportation.

  10. [Beta globin haplotypes in hemoglobin S carriers in Colombia].

    PubMed

    Durán, Claudia Liliana; Morales, Olga Lucía; Echeverri, Sandra Johanna; Isaza, Mario

    2012-01-01

    The hemoglobin S (HbS) mutation is accompanied by other mutations in the region of chromosome 11 known as "beta globin cluster". The pattern of combination of these polymorphisms giving rise to the haplotypes that co-inherit the HbS mutation, are called haplotypes bs, and are of great epidemiological and clinical significance. The frequencies of major haplotypes associated with S beta-globin gene was determined in Colombian patients heterozygous for hemoglobin S. As part of the national neonatal screening program at Clínica Colsanitas, located in major cities of Colombia, nearly 1,200 children from different areas of the country were examined for hemoglobinopathies. The sickle cell trait was identified as the most common. S beta-globin gene haplotypes were determined by PCR and restriction enzymes in 33 children with AS hemoglobin electrophoretic patterns (carrier state). In addition, electrophoretic patterns of hemoglobin, fetal hemoglobin levels and hematologic parameters of each individual were identified. The most frequent haplotypes in Colombia were the Bantú haplotype (36.4 %), followed by Senegal (30.3 %), Benin (21.2 %) and Cameroon (12.1 %) haplotypes. Hemoglobin electrophoresis confirmed the AS phenotype in all patients, and fetal hemoglobin levels below 1%. Other hematological parameters were normal in all cases. The HbS haplotypes found more frequently in the sample were of African origin, and their distribution varied according to the place of origin of the individual. The most frequent corresponded to the Bantu haplotype.

  11. Development of an immunoassay to detect benzene adducts in hemoglobin

    SciTech Connect

    Grassman, J.A.

    1993-01-01

    The purpose of this project was to develop an immunoassay to detect the adducts formed in hemoglobin after exposure to benzene, which is known to cause bone marrow degeneration and acute myelogenous leukemia. The use of benzene-adduct detection as a biological monitoring method would permit measurement of low exposures and exposures sustained weeks earlier. The reactivity of hydroquinone, an important benzene metabolite, with blood proteins and amino acids was investigated in order to decide which antigens and analytes were likely to be suitable for immunoassay development. The second section determined the combination of benzene-metabolite and antigen need to produce an immunoassay with the requisite low detection limit and specificity. The immunoassays with the best performance were tested on hemoglobin from benzene-exposed mice. In vitro studies showed that hydroquinone efficiently formed adducts with erythrocyte membranes and hemoglobin but not with albumin. Adduction efficiency was greater in incubations using purified hemoglobin than whole blood. Cysteine accounted for 15 to 27% of the adducts formed by hydroquinone. The site of the other adducts were not identified although there was evidence that the hemoglobin heme was adducted. Adducts were found on only 1 of the 2 globin chains. Tryptic digestion of the globin failed to associate the adducts with a specific peptide. Antigens made from hydroquinone-adducted hemoglobin but not hydroquinone-adducted cysteines coupled to carrier proteins effectively elicited adduct-specific antibodies. Interference due to reactivity to hemoglobin was controlled by using uniform quantities of hemoglobin in all wells. The mid-range of the best assays were approximately 12 pmoles HQ per well. Antibodies directed toward hemoglobin adducted with the benzene metabolites phenol, catechol and 1,2,4-trihydroxybenzene were also made. The performance of the anti-1,2,4-trihydroxybenzene were suitable for quantitative immunoassays.

  12. [Analysis of clinical phenotype and genotype of unstable Hemoglobin Rush].

    PubMed

    Ge, Shijun; Yang, Biqing; Yi, Wei; Huang, Kai; Liu, Hongxian; Huang, Xiaoqin; Chu, Jiayou; Yang, Zhaoqing

    2017-02-10

    To analyze the hematological and genetic characteristics of unstable hemoglobin Rush (Hb Rush) and compound heterozygote of Hb Rush and thalassemia. Peripheral blood samples and genomic DNA from three patients (including two ethnic Dai and one Han Chinese) with anemia of undetermined origin were collected. Hematological phenotypes of these patients were determined through red blood cell analysis and hemoglobin electrophoresis. Genotypes of alpha- and beta-globin genes, -158 XmnⅠ polymorphic site of (G)γ promoter region, and haplotypes of 7 polymorphic restriction sites in the beta-globin gene cluster were determined using PCR-based methods and DNA sequencing. All patients have presented hypochromic microcytic anemia and hemoglobin fraction with significant increased measurement (30.5%-59.2%) in the region of fetal hemoglobin during alkaline medium electrophoresis. DNA analysis suggested that all patients have carried mutations leading to the unstable hemoglobin Rush (HBB codon 101, GAG>CAG, Glu>Gln). Two of them were compound heterozygotes of Hb Rush and thalassemia mutations of -α (3.7),CD17 and Hb E, respectively. Hb Rush mutation was associated with various haplotypes of the β-globin gene cluster. No significant association was found between increased abnormal hemoglobin fraction in the region of Hb F and the polymorphism of (G)γ promoter or large deletion of the beta-globin gene cluster. This study has confirmed the distribution of Hb Rush among various Chinese populations and is the third report of its kind. Hb Rush can result in increased measurement of hemoglobin fraction in the region of fetal hemoglobin (Hb F) during routine hemoglobin electrophoresis under alkaline condition. Hb Rush heterozygote alone can lead to hypochromic microcytic anemia and thalassemia-like phenotype. Prenatal diagnosis of Hb Rush is necessary for carriers.

  13. Sickle Cell Trait, Hemoglobin C Trait and Invasive Pneumococcal Disease

    PubMed Central

    Poehling, Katherine A.; Light, Laney S; Rhodes, Melissa; Snively, Beverly M.; Halasa, Natasha B.; Mitchel, Ed; Schaffner, William; Craig, Allen S.; Griffin, Marie R.

    2013-01-01

    Background The cause of historically higher rates of invasive pneumococcal disease among blacks than whites has remained unknown. We tested the hypothesis that sickle cell trait or hemoglobin C trait is an independent risk factor for invasive pneumococcal disease. Methods Eligible children were born in Tennessee (1996–2003), had a newborn screen, enrolled in TennCare aged <1 year, and resided in a Tennessee county with laboratory-confirmed, pneumococcal surveillance. Race/ethnicity was ascertained from birth certificates. Children were followed through 2005 until loss of enrollment, pneumococcal disease episode, 5th birthday or death. We calculated incidence rates by race/ethnicity and hemoglobin type before and after pneumococcal conjugate vaccine (PCV7) introduction. Poisson regression analyses compared IPD rates among blacks with sickle cell trait or hemoglobin C trait to whites and blacks with normal hemoglobin, controlling for age, gender, time (pre-PCV7, transition year or post-PCV7) and high-risk conditions (i.e. heart disease). Results Over 10 years, 415 invasive pneumococcal disease episodes occurred during 451,594 observed child-years. Before PCV7 introduction, disease rates/100,000 child-years were 2941 for blacks with sickle cell disease, 258 for blacks with sickle cell trait or hemoglobin C trait and 188, 172, and 125 for blacks, whites, and Hispanics with normal hemoglobin. Post-PCV7, rates declined for all groups. Blacks with sickle cell trait or hemoglobin C trait had 77% (95% CI 22%–155%) and 42% (95% CI 1%–100%) higher rates than whites and blacks with normal hemoglobin. Conclusion Black children with sickle cell trait or hemoglobin C trait have an increased risk of invasive pneumococcal disease. PMID:20220521

  14. Hemoglobin stability: observations on the denaturation of normal and abnormal hemoglobins by oxidant dyes, heat, and alkali

    PubMed Central

    Rieder, Ronald F.

    1970-01-01

    Several unstable mutant hemoglobins have alterations which affect areas of the molecule involved in the attachment of heme to globin. Loss of heme from globin has been demonstrated during the denaturation of some of these unstable mutants. The importance of heme ligands for the stability of hemoglobin was illustrated in the present experiments on the denaturation of several hemoglobins and hemoglobin derivatives by heat, oxidative dyes, and alkali. Heating of normal hemolysates diluted to 4 g of hemoglobin per 100 ml at 50°C for 20 hr in 0.05 M sodium phosphate, pH 7.4, caused precipitation of 23-54% of the hemoglobin. Dialysis against water or dilution of the sample decreased denaturation to 12-20%. Precipitation was decreased to less than 3.5% by the presence of 0.015 M potassium cyanide. Increasing the ionic strength of the medium increased precipitation. Cyanide prevented the formation of inclusion bodies when red cells containing unstable hemoglobin Philly, β35 tyr → phe, were incubated with the redox dye new methylene blue. Conversion to methemoglobin increased the rate of alkali denaturation of hemoglobin but the presence of potassium cyanide returned the denaturation rate to that of ferrohemoglobin. The ability of cyanide to decrease heat precipitation of hemoglobin may depend on a dimeric or tetrameric state of the hemoglobin molecule. Purified β-chains, which exist as tetramers, were stabilized but purified monomeric α-chains were not rendered more heat resistant by the ligand. Stabilization of hemoglobin by cyanide required binding of the ligand to only one heme of an αβ-dimer. Hemoglobin Gun Hill, an unstable molecule with heme groups present only on the α-chains was quite heat stable in the presence of cyanide. The binding of cyanide to the iron atom in methemoglobin is thought to be associated with increased planarity of the heme group and increased stability of the heme-globin complex. The stabilizing effect of cyanide in the above

  15. Biophysical basis of hypoxic radioprotection by deoxygenated dextran-hemoglobin

    SciTech Connect

    Wong, J.T.; Hill, R.P.

    1986-08-01

    Perfusion with deoxygenated dextran-hemoglobin provides an effective method for inducing hypoxic radioprotection of normal tissues during radiation treatment of tumors. In this study, the dependence of P50, the half-saturation pressure of oxygen binding to dextran-hemoglobin, was analyzed as a function of solution temperature and pH. The variation of attainable radioprotection with P50, and with the amount of collateral blood entering into the perfused region, was calculated. Upon perfusion of canine gracilis muscle with deoxygenated dextran-hemoglobin, a rapid onset of extensive venous hypoxia was observed.

  16. [Hemoglobin O Arab in Ivory Coast and western Africa].

    PubMed

    Sangare, A; Sanogo, I; Meite, M; Ambofo, Y; Abesopie, V; Segbena, A; Tolo, A

    1992-01-01

    The authors report 44 cases of hemoglobin O Arab share out in 3 phenotypes (A O Arab, C O Arab and S O Arab). The study of this abnormal hemoglobin has allowed the following conclusions: The Hb O Arab is a rare mutant of hemoglobin. The heterozygote form A O Arab and the association Hb C--Hb O Arab do not present any clinical and hematological manifestations. The associations Hb S--Hb O Arab brings about a serious hemoglobinopathy which has clinical and hematological features like the sickle-cell disease (SSFA2).

  17. Examining and mitigating acellular hemoglobin vasoactivity.

    PubMed

    Cabrales, Pedro

    2013-06-10

    There has been a striking advancement in our understanding of red cell substitutes over the past decade. Although regulatory oversight has influenced many aspects of product development in this period, those who have approached the demonstration of efficacy of red cell substitutes have failed to understand their implication at the level of the microcirculation, where blood interacts closely with tissue. The understanding of the adverse effects of acellular hemoglobin (Hb)-based oxygen carriers (HBOCs) has fortunately expanded from Hb-induced renal toxicity to a more complete list of biochemical mechanism. In addition, various unexpected adverse reactions were seen in early clinical studies. The effects of the presence of acellular Hb in plasma are relatively unique because of the convergence of mechanical and biochemical natures. Controlling the variables using genetic engineering and chemical modification to change specific characteristics of the Hb molecule may allow for solving the complex multivariate problems of acellular Hb vasoactivity. HBOCs may never be rendered free of negative effects; however, quantifying the nature and extent of microvascular complications establishes a platform for designing new ameliorative therapies. It is time to leave behind the study of vasoactivity and toxicity based on bench-top measurements of biochemical changes and those based solely on systemic parameters in vivo, and move to a more holistic analysis of the mechanisms creating the problems, complemented with meaningful studies of efficacy.

  18. MP4, a vasodilatory PEGylated hemoglobin.

    PubMed

    Cole, Russell H; Vandegriff, Kim D

    2011-01-01

    A vasodilatory hemoglobin (Hb)-based O(2) carrier (HBOC) has been developed by surface conjugation polyethylene glycol to tetrameric human Hb (MP4, Sangart, San Diego). Because the NO-binding kinetics of MP4 are similar to vasoconstrictive HBOCs, we propose that the decoupling of NO scavenging from vascular response is a consequence of MP4's high O(2) affinity (p50 = 5 mmHg) and unique surface chemistry. The release of ATP from erythrocytes is vasodilatory and the application of a high O(2) affinity HBOC minimizes ATP interference with intravascular ATP signaling. A second potential mechanism of action for MP4 involves the surface conjugation of polyethylene glycol (PEG) to tetrameric human Hb. It has been shown that the addition of unconjugated high molecular weight (Mw) PEG to cultured lung endothelial cells causes an immediate and significant reduction in endothelial permeability; an effect opposite to that of endothelial agonists such as cell-free Hb. It appears that some of the benefits of the PEG-endothelium interaction are carried onto molecules such as PEGylated Hb and PEGylated albumin, as demonstrated by favorable hemodynamic responses in vivo. PEGylation of ß93 cysteine residues, as in MP4, has also been reported to increase the nitrite reductase activity of Hb and enhance conversion of endogenous nitrite to bioactive NO.

  19. NITRO MUSK BOUND TO CARP HEMOGLOBIN ...

    EPA Pesticide Factsheets

    Nitroaromatic compounds including synthetic nitro musks are important raw materials and intermediates in the synthesis of explosives, dyes, and pesticides, pharmaceutical and personal care-products (PPCPs). The nitro musks such as musk xylene (MX) and musk ketone (MK) are extensively used as fragrance ingredients in PPCPs and other commercial toiletries. Identification and quantification of a bound 4-amino-MX (4-AMX) metabolite as well as a 2- amino-MK (2-AMK) metabolite were carried out by gas chromatography-mass spectrometry' (GC/MS), with selected ion monitoring (SIM) in both the electron ionization (ElMS) and electron capture (EC) negative ion chemical ionization (NICIMS) modes. Detection of 4-AMX and 2-AMK occurred after the cysteine adducts in carp hemoglobin, derived from the nitroso metabolites, were released by alkaline hydrolysis. The released metabolites were extracted into n-hexane. The extract was preconcentrated by evaporation, and analyzed by GC-SIM-MS. A comparison between the El and EC approaches was made. EC NICIMS detected both metabolites whereas only 4-AMX was detected by ElMS. The EC NICIMS approach exhibited fewer matrix responses and provided a lower detection limit. Quantitation in both approaches was based on internal standard and a calibration plot. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Q

  20. Does Hemoglobin Predict Proliferative Diabetic Retinopathy?

    PubMed Central

    Conway, Baqiyyah N; Miller, Rachel G; Klein, Ronald; Orchard, Trevor J

    2009-01-01

    Objective As an elevated erythropoietin has been observed in diabetic retinopathy, we sought to investigate the role of hemoglobin (HGB) in predicting proliferative diabetic retinopathy (PDR). Research Design and Methods We assessed 426 individuals without PDR at baseline (213 men; 213 women) from the Pittsburgh Epidemiology of Diabetes Complications Study, an 18-year prospective cohort study of childhood onset type 1 diabetes. PDR was determined by stereo fundus photography. Cox proportional hazards modeling with stepwise regression was used to determine the independent association of HGB with PDR. Analyses were conducted gender-specifically. Results There were 206 events. Although the incidence of PDR did not vary by gender (48 % in both men and women), in men, HGB exhibited a positive linear relationship with the 18-year incidence of PDR (HR=1.33, 1.10–1.60, p=0.003) while in women HGB exhibited a quadratic relationship with PDR (p=0.0008). After multivariable adjustment for univariately significant covariates, HGB remained significantly predictive of PDR in both men (p=0.004) and women (p=0.04). Conclusion Higher HGB predicts the incidence of PDR in Type 1 diabetes, though the association varies by gender, being linear and positive in men and quadratic in women. PMID:19901215

  1. High-altitude adaptations in vertebrate hemoglobins.

    PubMed

    Weber, Roy E

    2007-09-30

    Vertebrates at high altitude are subjected to hypoxic conditions that challenge aerobic metabolism. O(2) transport from the respiratory surfaces to tissues requires matching between the O(2) loading and unloading tensions and the O(2)-affinity of blood, which is an integrated function of hemoglobin's intrinsic O(2)-affinity and its allosteric interaction with cellular effectors (organic phosphates, protons and chloride). Whereas short-term altitudinal adaptations predominantly involve adjustments in allosteric interactions, long-term, genetically-coded adaptations typically involve changes in the structure of the haemoglobin molecules. The latter commonly comprise substitutions of amino acid residues at the effector binding sites, the heme-protein contacts, or at intersubunit contacts that stabilize either the low-affinity ('Tense') or the high-affinity ('Relaxed') structures of the molecules. Molecular heterogeneity (multiple isoHbs with differentiated oxygenation properties) can further broaden the range of physico-chemical conditions where Hb functions under altitudinal hypoxia. This treatise reviews the molecular and cellular mechanisms that adapt haemoglobin-oxygen affinities in mammals, birds and ectothermic vertebrates at high altitude.

  2. Hyperspectral imaging for dermal hemoglobin spectroscopy

    NASA Astrophysics Data System (ADS)

    Dwyer, Peter J.; DiMarzio, Charles A.

    1999-10-01

    It has been shown previously that images collected at selected wavelengths in a sufficiently narrow bandwidth can be used to produce maps of the oxygen saturation of hemoglobin in the dermis. A four-wavelength algorithm has been developed based on a two-layer model of the skin, in which the blood is contained in the lower layer (dermis), while the upper layer attenuates some of the reflection and adds a clutter term. In the present work, the algorithm is compared analytically to simpler algorithms using three wavelengths and based on a single-layer model. It is shown through Monte-Carlo models that, for typical skin, the single-layer model is adequate to analyze data from fiber-optical reflectance spectroscopy, but the two-layer model produces better results for imaging systems. Although the model does not address the full complexity of reflectance of a two-layer skin, it has proven to be sufficient to recover the oxygen saturation, and perhaps other medically relevant information. The algorithm is demonstrated on a suction blister, where the epidermis is removed to reveal the underlying dermis. Applications for this imaging modality exist in dermatology, in surgery, and in developing treatment plans for various diseases.

  3. Hemoglobin Variant Profiles among Brazilian Quilombola Communities.

    PubMed

    Santiago, Rayra P; Oliveira, Rodrigo M; Soares, Leonardo F; Figueiredo, Camylla V B; Silva, Denise Oliveira; Hurtado-Guerrero, Ana F; Fiuza, Luciana M; Guarda, Caroline C; Adorno, Elisângela V; Barbosa, Cynara G; Gonçalves, Marilda S

    2017-03-01

    Brazilian Quilombolas are communities composed of African-derived populations that have their territories guaranteed by the Brazilian Constitution. The present study investigated the hemoglobin (Hb) variants among these population groups. This study was conducted in a total of 2843 individuals of Brazilian Quilombola communities of the Bahia, Pará, and Piauí states. All the participants had their Hb profiles evaluated. The Hb S (HBB: c.20A>T) variant was described in all the studied localities. However, the individuals in Bahia State had the highest frequency of the Hb C (HBB: c.19G>A) variant; individuals from Piauí State had a higher frequency of the Hb D-Punjab (HBB: c.364G>C) variant compared to the other states, and individuals from Pará State only carried the Hb S variant. The present study revealed a specific distribution of Hb variants that could represent different waves of African influence in these Brazilian populations.

  4. Noninvasive hemoglobin measurement using dynamic spectrum

    NASA Astrophysics Data System (ADS)

    Yi, Xiaoqing; Li, Gang; Lin, Ling

    2017-08-01

    Spectroscopy methods for noninvasive hemoglobin (Hgb) measurement are interfered by individual difference and particular weak signal. In order to address these problems, we have put forward a series of improvement methods based on dynamic spectrum (DS), including instrument design, spectrum extraction algorithm, and modeling approach. The instrument adopts light sources composed of eight laser diodes with the wavelength range from 600 nm to 1100 nm and records photoplethysmography signals at eight wavelengths synchronously. In order to simplify the optical design, we modulate the light sources with orthogonal square waves and design the corresponding demodulation algorithm, instead of adopting a beam-splitting system. A newly designed algorithm named difference accumulation has been proved to be effective in improving the accuracy of dynamic spectrum extraction. 220 subjects are involved in the clinical experiment. An extreme learning machine calibration model between the DS data and the Hgb levels is established. Correlation coefficient and root-mean-square error of prediction sets are 0.8645 and 8.48 g/l, respectively. The results indicate that the Hgb level can be derived by this approach noninvasively with acceptable precision and accuracy. It is expected to achieve a clinic application in the future.

  5. PARALLEL ASSAY OF OXYGEN EQUILIBRIA OF HEMOGLOBIN

    PubMed Central

    Lilly, Laura E.; Blinebry, Sara K.; Viscardi, Chelsea M.; Perez, Luis; Bonaventura, Joe; McMahon, Tim J.

    2013-01-01

    Methods to systematically analyze in parallel the function of multiple protein or cell samples in vivo or ex vivo (i.e. functional proteomics) in a controlled gaseous environment have thus far been limited. Here we describe an apparatus and procedure that enables, for the first time, parallel assay of oxygen equilibria in multiple samples. Using this apparatus, numerous simultaneous oxygen equilibrium curves (OECs) can be obtained under truly identical conditions from blood cell samples or purified hemoglobins (Hbs). We suggest that the ability to obtain these parallel datasets under identical conditions can be of immense value, both to biomedical researchers and clinicians who wish to monitor blood health, and to physiologists studying non-human organisms and the effects of climate change on these organisms. Parallel monitoring techniques are essential in order to better understand the functions of critical cellular proteins. The procedure can be applied to human studies, wherein an OEC can be analyzed in light of an individual’s entire genome. Here, we analyzed intraerythrocytic Hb, a protein that operates at the organism’s environmental interface and then comes into close contact with virtually all of the organism’s cells. The apparatus is theoretically scalable, and establishes a functional proteomic screen that can be correlated with genomic information on the same individuals. This new method is expected to accelerate our general understanding of protein function, an increasingly challenging objective as advances in proteomic and genomic throughput outpace the ability to study proteins’ functional properties. PMID:23827235

  6. The Growth of Sickle Hemoglobin Polymers

    PubMed Central

    Aprelev, Alexey; Liu, Zenghui; Ferrone, Frank A.

    2011-01-01

    The measurement of polymer growth is an essential element in characterization of assembly. We have developed a precise method of measuring the growth of sickle hemoglobin polymers by observing the time required for polymers to traverse a photolytically produced channel between a region in which polymers are created and a detection region. The presence of the polymer is functionally detected by observing its ability to create new polymers through the well-established process of heterogeneous nucleation. Using this method, we have determined the rate constants for monomer addition to and release from polymer ends, as well as their temperature dependences. At 25°C we find k+ = 84 ± 2 mM−1 s−1 and k− = 790 ± 80 molecules/s from each end. These numbers are in accord with differential interference contrast measurements, and their ratio gives a solubility measured on individual fibers. The single-fiber solubility agrees with that measured in sedimentation experiments. The concentration dependence of the monomer addition rate is consistent with monomer addition, but not oligomer addition, to growing polymers. The concentration dependence suggests the presence of an activation enthalpy barrier, and the rate of monomer addition is not diffusion-limited. Analysis of the temperature dependence of the monomer addition rate reveals an apparent activation energy of 9.1 ± 0.6 kcal/mol. PMID:21843479

  7. Selenium binding to human hemoglobin via selenotrisulfide.

    PubMed

    Haratake, Mamoru; Fujimoto, Katsuyoshi; Ono, Masahiro; Nakayama, Morio

    2005-05-25

    Selenotrisulfide (e.g., glutathione selenotrisulfide (GSSeSG)) is an important intermediate in the metabolism of selenite. However, its reactivity with biological substances such as peptides and proteins in the subsequent metabolism is still far from clearly understood, because of its chemical instability under physiological conditions. Penicillamine (Pen) is capable of generating a chemically stable and isolatable selenotrisulfide, PenSSeSPen. To explore the metabolic fate of selenite in red blood cells (RBC), we investigated the reaction of selenotrisulfide with human hemoglobin (Hb) using PenSSeSPen as a model. PenSSeSPen rapidly reacted with Hb under physiological conditions. From the analysis of selenium binding using the Langmuir type binding equation, the apparent binding number of selenium per Hb tetramer almost corresponded to the number of reactive thiol groups of Hb. The thiol group blockade of Hb by iodoacetamide treatment completely inhibited the reaction of PenSSeSPen with Hb. In addition, MALDI-TOF mass spectrometric analysis of the selenium-bound Hb revealed that PenSSe moiety binds to the beta subunits of Hb. Overall, the reaction of PenSSeSPen with Hb appears to involve the thiol exchange between Pen and the cysteine residues on the beta subunit of Hb.

  8. Erythropoiesis in the Absence of Adult Hemoglobin

    PubMed Central

    Liu, Shanrun; McConnell, Sean C.

    2013-01-01

    During erythropoiesis, hemoglobin (Hb) synthesis increases from early progenitors to mature enucleated erythrocytes. Although Hb is one of the most extensively studied proteins, the role of Hb in erythroid lineage commitment, differentiation, and maturation remains unclear. In this study, we generate mouse embryos and embryonic stem (ES) cells with all of the adult α and β globin genes deleted (Hb Null). While Hb Null embryos die in midgestation, adult globin genes are not required for primitive or definitive erythroid lineage commitment. In vitro differentiation of Hb Null ES cells generates viable definitive proerythroblasts that undergo apoptosis upon terminal differentiation. Surprisingly, all stages of Hb Null-derived definitive erythroblasts develop normally in vivo in chimeric mice, and Hb Null erythroid cells undergo enucleation to form reticulocytes. Free heme toxicity is not observed in Hb Null-derived erythroblasts. Transplantation of Hb Null-derived bone marrow cells provides short-term radioprotection of lethally irradiated recipients, whose progressive anemia results in an erythroid hyperplasia composed entirely of Hb Null-derived erythroblasts. This novel experimental model system enables the role played by Hb in erythroid cell enucleation, cytoskeleton maturation, and heme and iron regulation to be studied. PMID:23530053

  9. Noninvasive hemoglobin measurement using dynamic spectrum.

    PubMed

    Yi, Xiaoqing; Li, Gang; Lin, Ling

    2017-08-01

    Spectroscopy methods for noninvasive hemoglobin (Hgb) measurement are interfered by individual difference and particular weak signal. In order to address these problems, we have put forward a series of improvement methods based on dynamic spectrum (DS), including instrument design, spectrum extraction algorithm, and modeling approach. The instrument adopts light sources composed of eight laser diodes with the wavelength range from 600 nm to 1100 nm and records photoplethysmography signals at eight wavelengths synchronously. In order to simplify the optical design, we modulate the light sources with orthogonal square waves and design the corresponding demodulation algorithm, instead of adopting a beam-splitting system. A newly designed algorithm named difference accumulation has been proved to be effective in improving the accuracy of dynamic spectrum extraction. 220 subjects are involved in the clinical experiment. An extreme learning machine calibration model between the DS data and the Hgb levels is established. Correlation coefficient and root-mean-square error of prediction sets are 0.8645 and 8.48 g/l, respectively. The results indicate that the Hgb level can be derived by this approach noninvasively with acceptable precision and accuracy. It is expected to achieve a clinic application in the future.

  10. Polychelated cryogels: hemoglobin adsorption from human blood.

    PubMed

    Erol, Kadir

    2017-02-01

    The separation and purification methods are extremely important for the hemoglobin (Hb) which is a crucial biomolecule. The adsorption technique is popular among these methods and the cryogels have been used quite much due to their macropores and interconnected flow channels. In this study, the Hb adsorption onto the Cu(II) immobilized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA)-Cu(II), cryogels was investigated under different conditions (pH, interaction time, initial Hb concentration, temperature and ionic strength) to optimize adsorption conditions. The swelling test, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), surface area (BET), elemental and ICP-OES analysis were performed for the characterization of cryogels. Polyethyleneimine (PEI) molecule was used as a Cu(II)-chelating ligand. The Hb adsorption capacity of cryogels was determined as 193.8 mg Hb/g cryogel. The isolation of Hb from human blood was also studied under optimum adsorption conditions determined and the Hb (124.5 mg/g cryogel) was isolated. The adsorption model was investigated in the light of Langmuir and Freundlich adsorption isotherm models and it was determined to be more appropriate to the Langmuir adsorption isotherm model.

  11. Accuracy of noninvasive hemoglobin and invasive point-of-care hemoglobin testing compared with a laboratory analyzer

    PubMed Central

    Shah, N; Osea, E A; Martinez, G J

    2014-01-01

    Introduction Hemoglobin concentration is assessed to detect anemia and its associated morbidities. Hemoglobin is usually determined from venous or capillary blood samples run on a laboratory analyzer. However, this method requires a needle stick and results can be delayed. It also exposes caregivers to risks associated with needle sticks and blood exposure. Noninvasive hemoglobin determination would be of benefit to patients and caregivers because it would allow for quick and painless point-of-care assessment. Methods Hemoglobin determination from a noninvasive spot check hemoglobin device (Pronto-7 with SpHb, Masimo) and an invasive point-of-care device (HemoCue) was compared with venous blood samples run on a laboratory hematology analyzer. Results A total of 440 outpatients and healthy volunteers were included (mean age 36 years, 62% female). Compared with the hematology analyzer, the bias ± standard deviation of was −0.1 ± 1.1 g/dL for SpHb and −0.1 ± 1.6 g/dL for HemoCue. Conclusion Noninvasive hemoglobin testing with SpHb provided similar accuracy as invasive point-of-care hemoglobin testing and may enable more efficient and effective patient care. PMID:23809685

  12. A molecular study on the role of alpha-hemoglobin-stabilizing protein in hemoglobin H disease.

    PubMed

    Surapolchai, Pacharapan; Chuansumrit, Ampaiwan; Sirachainan, Nongnuch; Kadegasem, Praguywan; Leung, Ka-Chun; So, Chi-Chiu

    2017-06-01

    The clinical course of hemoglobin H (HbH) disease is remarkably variable. It is not completely clear how genetic and environmental factors interplay to modify clinical severity in affected individuals. Previous studies suggested that altered structure or function of alpha-hemoglobin-stabilizing protein (AHSP) could modify the clinical phenotypes of thalassemias. The present study attempted to explore the potential role of AHSP in the pathophysiology of HbH disease in 95 Chinese and Thai/Sino-Thai patients with deletional and non-deletional form of this disease. We identified six polymorphic sites in AHSP which were subgrouped into major haplotype clades. No association between AHSP genotypes or haplotypes and clinical phenotypes was observed. Instead, multiple linear regression analysis indicated that expression of AHSP correlated negatively with age (P < 0.001) and hemoglobin (P = 0.007), but positively with reticulocyte count (P = 0.003) and severity score (P = 0.003). Subgroup analysis showed that AHSP expression was higher in the non-deletional form than in the deletional form (P < 0.001). Moreover, specific types of non-deletional HbH disease with production of mutant alpha-globin chains that do not bind to AHSP (Hb Constant Spring and Hb Pakse) showed the highest AHSP expression. The present findings demonstrate that AHSP expression is a biomarker of HbH disease severity and infer an important role of AHSP in modulating the pathophysiology of this disease. Pharmacological or genetic means to alter AHSP expression may be a novel approach for amelioration of disease severity in HbH disease.

  13. Identification of hemoglobin AC heterozygote status in a Malay family: a decision between hemoglobin electrophoresis and high performance liquid chromotography.

    PubMed

    Rosline, H; Roshan, T M; Ahmed, S A; Ilunihayati, I

    2007-05-01

    Thalassemia is a common public health problem among Malays. Hemoglobin C (Hb C) is a hemoglobin beta variant resulting from a single base mutation at the 6th position of the beta-globin gene leading to the substitution of glycine for glutamic acid. Hb C is commonly detected in West Africans and in African American but has not been reported in Malaysia. It can be falsely diagnosed as HbE trait in the Malaysian Thalassemia Screening Program which utilizes cellulose acetate hemoglobin electrophoresis. This is the first reported case of Hb AC heterozygote status in a Malay family, with unusual splenomegaly in one of the family members.

  14. IR Spectra of Different O2-Content Hemoglobin from Computational Study: Promising Detector of Hemoglobin Variant in Medical Diagnosis.

    PubMed

    Zhou, Su-Qin; Chen, Tu-Nan; Ji, Guang-Fu; Wang, En-Ren

    2017-06-01

    IR spectra of heme and different O2-content hemoglobin were studied by the quantum computation method at the molecule level. IR spectra of heme and different O2-content hemoglobin were quantificationally characterized from 0 to 100 THz. The IR spectra of oxy-heme and de-oxy-heme are obviously different at the frequency regions of 9.08-9.48, 38.38-39.78, 50.46-50.82, and 89.04-91.00 THz. At 24.72 THz, there exists the absorption peak for oxy-heme, whereas there is not the absorption peak for de-oxy-heme. Whether the heme contains Fe-O-O bond or not has the great influence on its IR spectra and vibration intensities of functional groups in the mid-infrared area. The IR adsorption peak shape changes hardly for different O2-content hemoglobin. However, there exist three frequency regions corresponding to the large change of IR adsorption intensities for containing-O2 hemoglobin in comparison with de-oxy-hemoglobin, which are 11.08-15.93, 44.70-50.22, and 88.00-96.68 THz regions, respectively. The most differential values with IR intensity of different O2-content hemoglobin all exceed 1.0 × 10(4) L mol(-1) cm(-1). With the increase of oxygen content, the absorption peak appears in the high-frequency region for the containing-O2 hemoglobin in comparison with de-oxy-hemoglobin. The more the O2-content is, the greater the absorption peak is at the high-frequency region. The IR spectra of different O2-content hemoglobin are so obviously different in the mid-infrared region that it is very easy to distinguish the hemoglobin variant by means of IR spectra detector. IR spectra of hemoglobin from quantum computation can provide scientific basis and specific identification of hemoglobin variant resulting from different O2 contents in medical diagnosis.

  15. Vitreoscilla hemoglobin renders Enterobacter aerogenes highly susceptible to heavy metals.

    PubMed

    Geckil, Hikmet; Arman, Ahmet; Gencer, Salih; Ates, Burhan; Yilmaz, H Ramazan

    2004-12-01

    When expressed in heterologous microorganisms Vitreoscilla hemoglobin (VHb) acts as oxygen storage and causes a higher oxygen uptake. In this study, the effect of this protein on growth, sensitivity and antioxidant properties of Enterobacter aerogenes exposed to metal stress was investigated. The strain expressing VHb was more sensitive to mercury and cadmium as the minimal inhibitory concentration (MIC) for these metals was up to 2-fold lower in this strain than the host and the recombinant strain carrying a comparable plasmid. At lower concentrations than MIC, the metals partially limited growth and caused an inhibition proportional to metal concentration applied. The growth pattern of VHb expressing strain was also distinctly different from other two non-hemoglobin strains. The hemoglobin containing strain showed substantially higher superoxide dismuates (SOD) activity than the non-hemoglobin strains, while catalase levels were similar in all strains. All strains exposed to copper, however, showed similar MIC values, growth patterns, and SOD and catalase levels.

  16. Quality control of hemoglobin-based blood substitutes.

    PubMed

    Hsia, J C; Er, S S

    1988-01-01

    Preparation and use of hemoglobin-based blood substitutes, from stroma-free hemoglobin (SFH or Hb) and its DPG analogue-modified derivatives (PLP-Hb, ATP-Hb etc.) without thorough characterization and quality control in animal or human testing have produced, and may continue to produce, artifacts in the finished product. Thus the development of such a natural substitute for the volume expansion and oxygen delivery functions of the blood will be impeded. A case is made for the use of affinity purified hemoglobin and modified hemoglobin as standard starting materials for the preparation of Hb-based blood substitute(s) in general, and in particular poly PLP-Hb. Development of a commercial scale blood-substitute is only possible after the safety and toxicity issues of substitutes have been resolved by applying rigorous quality control.

  17. Solid hemoglobin-polymer phantoms for evaluation of biophotonic systems.

    PubMed

    Jang, Hyounguk; Pfefer, T Joshua; Chen, Yu

    2015-09-15

    Stable tissue phantoms that incorporate the spectral absorption properties of hemoglobin would benefit a wide range of biophotonic technologies. Toward this end, we have developed and validated a novel polymer material incorporating hemoglobin. Our solid hemoglobin-polymer (SHP) material is fabricated by mixing liquid silicone base with a hemoglobin solution, followed by sonication and low temperature curing. The optical properties of samples were determined over 450-1000 nm using the inverse adding-doubling method and the Beer-Lambert law. Measurements indicated SHP optical stability over four months. Near-infrared spectroscopy and hyperspectral imaging measurements of SHP samples were performed to demonstrate the utility of this approach. SHP materials have the potential to improve tissue-simulating phantoms used for development, evaluation, and standardization of optical devices for oximetry and other applications.

  18. Weak binding gases as modulators of hemoglobin function

    SciTech Connect

    Schoenborn, B P; Saxena, A; North, B E

    1980-01-01

    Studies are reported in which the mechanisms of binding of inert gaseous agents to hemoglobin and myoglobin are investigated. Specific binding sites are mapped. Possible effects on sickle cell formation and oxygen binding are discussed. (ACR)

  19. Co-oximetry interference by hemoglobin-based blood substitutes.

    PubMed

    Ali, A A; Ali, G S; Steinke, J M; Shepherd, A P

    2001-04-01

    The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-Oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-Oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments' measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes. We investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different cooximeters. Some blood substitutes caused obvious interference, such as negative carboxyhemoglobin readings; however, the findings indicate that cooximeters will generally give less accurate but

  20. Neohemoglobins and Cross-Linked Hemoglobins as Blood Substitute.

    DTIC Science & Technology

    1982-12-01

    normal SFH. For bovine hemoglobi, cross-linking of the oxy and carboxy derivatives increased substantially the oxygen affinity and eliminated the oxygen...hemoglobins were prepared by the filtration method. The respective heme-free proteins (apohemoglobins) were prepared by extraction with methyl ...protein. Recombined neohemoglogins and cross-linked hemoglobins were purified by chromatography on CM cellulose using a linear gradient formed by equal

  1. The Manufacture and Study of Hemoglobin-Saline Solution.

    DTIC Science & Technology

    1981-02-25

    The saturation, as measured with the Co-oximeter, was corrected for the proportion of methemoglobin and carboxyhemoglobin , to reflect the per... measurements of the chemical characteristics of the solution during total-exchange transfusion in baboons. These included the monitoring of plasma and...methemoglobin values studied was 7 to 53% of total hemoglobin. 4 A plot of hemoglobin values obtained with the IL 282 (y) vs those measured by the

  2. Increased Vascular Resistance with Hemoglobin-Based Oxygen Carriers

    DTIC Science & Technology

    1993-01-01

    vascular resistance. Swine resuscitated with otofHb exhibited the rapid onset of marked systemic hypertension . The blood pressure rose within seconds...virtual absence of red blood cells (3), hemoglobin solutions have produced hypertension irn animals or have not supported an increase in cardiac output...with blood volume expansion. Half of all the humans administered hemoglobin in published trials demonstrated hypertension (4), and a recent human

  3. RENAL EFFECTS OF HEMOGLOBIN INFUSIONS IN DOGS IN HEMORRHAGIC SHOCK

    PubMed Central

    Hamilton, Paul B.; Hiller, Alma; Van Slyke, Donald D.

    1947-01-01

    The immediate effects of treating hemorrhagic shock in dogs by replacing lost blood with 7 per cent hemoglobin solution were favorable, both on renal function and on general condition. However, subsequent transitory depression of the urea clearance for several days, shown by some of the treated animals, but not by untreated bled controls, indicates sufficient possibility of renal damage by the hemoglobin solution to prevent its recommendation at present as a blood substitute. PMID:19871692

  4. Monoclonal antibodies recognizing single amino acid substitutions in hemoglobin

    SciTech Connect

    Stanker, L.H.; Branscomb, E.; Vanderlaan, M.; Jensen, R.H.

    1986-06-01

    Four monoclonal antibodies (mAb) to non-human primate hemoglobin referred to as Cap-4, Cap-5, Rh-2, and Rh-4, and two mAb to human hemoglobin, referred to as H-1 and H-3 were isolated and were partially characterized. Binding studies with these mAb on a panel of hemoglobins and isolated ..cap alpha.. and ..beta.. globin chains revealed a unique reactivity pattern for each mAb. Amino acid sequence analysis of the antigens used to generate the binding data suggests that the specific recognition of certain hemoglobin antigens by each mAb is controlled by the presence of a particular amino acid at a specific position within the epitope. The use of synthetic peptides as antigens confirmed this observation for five of the mAb. No synthetic peptides were tested with the sixth mAb, Rh-2. The amino acids required for binding of mAb Cap-4, Cap-5, Rh-4, and Rh-2 to hemoglobin are alanine at ..beta..5, threonine at ..beta..13, glutamine at ..beta..125, and leucine at ..cap alpha..68. The non-human primate hemoglobin antibodies require a specific amino acid that is not present in human hemoglobin. The amino acid required for binding of Cap-4, Cap-5, and Rh-4 could arise by a single base change in the ..beta.. globin gene, whereas the amino acid required for Rh-2 binding could only occur if two base changes occurred. Thus these mAb are candidate probes for a somatic cell mutation assay on the basis of the detection of peripheral blood red cells that possess single amino acid substituted hemoglobin as a result of single base substitutions in the globin genes of precursor cells.

  5. Generating S-Nitrosothiols from Hemoglobin

    PubMed Central

    Roche, Camille J.; Cassera, Maria B.; Dantsker, David; Hirsch, Rhoda Elison; Friedman, Joel M.

    2013-01-01

    In vitro, ferrous deoxy-hemes in hemoglobin (Hb) react with nitrite to generate nitric oxide (NO) through a nitrite reductase reaction. In vivo studies indicate Hb with nitrite can be a source of NO bioactivity. The nitrite reductase reaction does not appear to account fully for this activity because free NO is short lived especially within the red blood cell. Thus, the exporting of NO bioactivity both out of the RBC and over a large distance requires an additional mechanism. A nitrite anhydrase (NA) reaction in which N2O3, a potent S-nitrosating agent, is produced through the reaction of NO with ferric heme-bound nitrite has been proposed (Basu, S., Grubina, R., Huang, J., Conradie, J., Huang, Z., Jeffers, A., Jiang, A., He, X., Azarov, I., Seibert, R., Mehta, A., Patel, R., King, S. B., Hogg, N., Ghosh, A., Gladwin, M. T., and Kim-Shapiro, D. B. (2007) Nat. Chem. Biol. 3, 785–794) as a possible mechanism. Legitimate concerns, including physiological relevance and the nature of the mechanism, have been raised concerning the NA reaction. This study addresses these concerns demonstrating NO and nitrite with ferric hemes under near physiological conditions yield an intermediate having the properties of the purported NA heme-bound N2O3 intermediate. The results indicate that ferric heme sites, traditionally viewed as a source of potential toxicity, can be functionally significant, especially for partially oxygenated/partially met-R state Hb that arises from the NO dioxygenation reaction. In the presence of low levels of nitrite and either NO or a suitable reductant such as l-cysteine, these ferric heme sites can function as a generator for the formation of S-nitrosothiols such as S-nitrosoglutathione and, as such, should be considered as a source of RBC-derived and exportable bioactive NO. PMID:23775069

  6. Effects of thyroid status on glycated hemoglobin

    PubMed Central

    Bhattacharjee, Rana; Thukral, Anubhav; Chakraborty, Partha Pratim; Roy, Ajitesh; Goswami, Soumik; Ghosh, Sujoy; Mukhopadhyay, Pradip; Mukhopadhyay, Satinath; Chowdhury, Subhankar

    2017-01-01

    Introduction: Glycated hemoglobin (HbA1c) can be altered in different conditions. We hypothesize that HbA1c levels may change due to altered thyroid status, possibly due to changes in red blood cell (RBC) turnover. Objectives: The objective of this study was to determine the effects of altered thyroid status on HbA1c levels in individuals without diabetes, with overt hyper- and hypo-thyroidism, and if present, whether such changes in HbA1c are reversed after achieving euthyroid state. Methods: Euglycemic individuals with overt hypo- or hyper-thyroidism were selected. Age- and sex-matched controls were recruited. Baseline HbA1c and reticulocyte counts (for estimation of RBC turnover) were estimated in all the patients and compared. Thereafter, stable euthyroidism was achieved in a randomly selected subgroup and HbA1c and reticulocyte count was reassessed. HbA1c values and reticulocyte counts were compared with baseline in both the groups. Results: Hb A1c in patients initially selected was found to be significantly higher in hypothyroid group. HbA1c values in hyperthyroid patients were not significantly different from controls. HbA1c reduction and rise in reticulocyte count were significant in hypothyroid group following treatment without significant change in glucose level. Hb A1c did not change significantly following treatment in hyperthyroid group. The reticulocyte count, however, decreased significantly. Conclusion: Baseline HbA1c levels were found to be significantly higher in hypothyroid patients, which reduced significantly after achievement of euthyroidism without any change in glucose levels. Significant baseline or posttreatment change was not observed in hyperthyroid patients. Our study suggests that we should be cautious while interpreting HbA1c data in patients with hypothyroidism. PMID:28217494

  7. Novel hemoglobin particles--promising new-generation hemoglobin-based oxygen carriers.

    PubMed

    Bäumler, Hans; Xiong, Yu; Liu, Zhi Zhao; Patzak, Andreas; Georgieva, Radostina

    2014-08-01

    During the last 30 years, artificial oxygen carriers have been investigated intensively with the aim to develop universal blood substitutes. Favorably, hemoglobin-based oxygen carriers (HBOCs) are expected to meet the sophisticated requirements. However, the HBOCs tested until now show serious side effects, which resulted in failure of clinical trials and Food and Drug Administration disapproval. The main problem consists in vasoconstriction triggered by nitric oxide (NO) scavenging or/and oxygen oversupply in the pre-capillary arterioles. HBOCs with a size between 100 nm and 1 µm and high oxygen affinity are needed. Here we present a highly effective and simple fabrication procedure, which can provide hemoglobin particles (HbPs) with a narrow size distribution of around 700 nm, nearly uniform morphology, high oxygen affinity, and low immunogenicity. Isolated mouse glomeruli are successfully perfused with concentrated HbP suspensions without any observable vasoconstriction of the afferent arterioles. The results suggest no oxygen oversupply and limited NO scavenging by these particles, featuring them as a highly promising blood substitute. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  8. Relative phase of oscillations of cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations during sleep

    NASA Astrophysics Data System (ADS)

    Pierro, Michele L.; Sassaroli, Angelo; Bergethon, Peter R.; Fantini, Sergio

    2012-02-01

    We present a near-infrared spectroscopy study of the instantaneous phase difference between spontaneous oscillations of cerebral deoxy-hemoglobin and oxy-hemoglobin concentrations ([Hb] and [HbO], respectively) in the low-frequency range, namely 0.04-0.12 Hz. We report phase measurements during the transitions between different sleep stages in a whole-night study of a human subject. We have found that the phase difference between [Hb] and [HbO] low-frequency oscillations tends to be greater in deep sleep (by ~96° on average) and REM sleep (by ~77° on average) compared to the awake state. In particular, we have observed progressive phase increases as the subject transitions from awake conditions into non-REM sleep stages N1, N2, and N3. Corresponding phase decreases were recorded in the reversed transitions from sleep stages N3 to N2, and N2 to awake. These results illustrate the physiological information content of phase measurements of [Hb] and [HbO] oscillations that reflect the different cerebral hemodynamic conditions of the different sleep stages, and that can find broader applicability in a wide range of near-infrared spectroscopy brain studies.

  9. Iron nitrosyl hemoglobin formation from the reaction of hydroxylamine and hemoglobin under physiological conditions.

    PubMed

    Lockamy, Virginia L; Shields, Howard; Kim-Shapiro, Daniel B; King, S Bruce

    2004-11-01

    Sickle cell disease patients receiving hydroxyurea (HU) therapy have shown increases in the production of nitric oxide (NO) metabolites, which include iron nitrosyl hemoglobin (HbNO), nitrite, and nitrate. However, the exact mechanism by which HU forms HbNO in vivo is not understood. Previous studies indicate that the reaction of oxyhemoglobin (oxyHb) or deoxyhemoglobin (deoxyHb) with HU are too slow to account for in vivo HbNO production. In this study, we show that the reaction of methemoglobin (metHb) with HU to form HbNO could potentially be fast enough to account for in vivo HbNO formation but competing reactions of either excess oxyHb or deoxyHb during the reaction reduces the likelihood that HbNO will be produced from the metHb-HU reaction. Using electron paramagnetic resonance (EPR) spectroscopy we have detected measurable amounts of HbNO and metHb during the reactions of oxyHb, deoxyHb, and metHb with excess hydroxylamine (HA). We also demonstrate HbNO and metHb formation from the reactions of excess oxyHb, deoxyHb, or metHb and HA, conditions that are more likely to mimic those in vivo. These results indicate that the reaction of hydroxylamine with hemoglobin produces HbNO and lend chemical support for a potential role for hydroxylamine in the in vivo metabolism of hydroxyurea.

  10. Nitric oxide in plants: the roles of ascorbate and hemoglobin.

    PubMed

    Wang, Xiaoguang; Hargrove, Mark S

    2013-01-01

    Ascorbic acid and hemoglobins have been linked to nitric oxide metabolism in plants. It has been hypothesized that ascorbic acid directly reduces plant hemoglobin in support of NO scavenging, producing nitrate and monodehydroascorbate. In this scenario, monodehydroascorbate reductase uses NADH to reduce monodehydroascorbate back to ascorbate to sustain the cycle. To test this hypothesis, rates of rice nonsymbiotic hemoglobin reduction by ascorbate were measured directly, in the presence and absence of purified rice monodehydroascorbate reductase and NADH. Solution NO scavenging was also measured methodically in the presence and absence of rice nonsymbiotic hemoglobin and monodehydroascorbate reductase, under hypoxic and normoxic conditions, in an effort to gauge the likelihood of these proteins affecting NO metabolism in plant tissues. Our results indicate that ascorbic acid slowly reduces rice nonsymbiotic hemoglobin at a rate identical to myoglobin reduction. The product of the reaction is monodehydroascorbate, which can be efficiently reduced back to ascorbate in the presence of monodehydroascorbate reductase and NADH. However, our NO scavenging results suggest that the direct reduction of plant hemoglobin by ascorbic acid is unlikely to serve as a significant factor in NO metabolism, even in the presence of monodehydroascorbate reductase. Finally, the possibility that the direct reaction of nitrite/nitrous acid and ascorbic acid produces NO was measured at various pH values mimicking hypoxic plant cells. Our results suggest that this reaction is a likely source of NO as the plant cell pH drops below 7, and as nitrite concentrations rise to mM levels during hypoxia.

  11. Hemoglobin from a deep-sea hydrothermal-vent copepod.

    PubMed

    Hourdez, S; Lamontagne, J; Peterson, P; Weber, R E; Fisher, C R

    2000-10-01

    Deep-sea hydrothermal-vent fauna live in a highly variable environment where oxygen levels can be very low, and carbon dioxide and sulfide can reach high concentrations (1). These conditions are harsh for most aerobic metazoans, yet copepods can be abundant at hydrothermal vents. Here we report the structure and functional properties of hemoglobin extracted from the copepod Benthoxynus spiculifer, which was found in large numbers in a paralvinellid/gastropod community collection made during a cruise to the Juan de Fuca Ridge in 1998. Although hemoglobin has been reported in some littoral copepods (2), this is the first study of the structure and functional properties of copepod hemoglobin. Hemoglobin represents about 60% of the total soluble proteins extracted from B. spiculifer, and although it imparts a red color to the copepod, it does not provide a significant storage pool of oxygen. It is a 208-kDa protein, composed of 14 globin chains--7 of 14.3 kDa and 7 of 15.2 kDa. The hemoglobin has a very high and temperature-sensitive oxygen affinity, with no cooperativity or Bohr effect. These properties are adaptive for an animal living in a low-oxygen environment in which the primary function of the hemoglobin is most likely oxygen acquisition to support aerobic respiration.

  12. Increased nitrite reductase activity of fetal versus adult ovine hemoglobin

    PubMed Central

    Blood, Arlin B.; Tiso, Mauro; Verma, Shilpa T.; Lo, Jennifer; Joshi, Mahesh S.; Azarov, Ivan; Longo, Lawrence D.; Gladwin, Mark T.; Kim-Shapiro, Daniel B.; Power, Gordon G.

    2009-01-01

    Growing evidence indicates that nitrite, NO2−, serves as a circulating reservoir of nitric oxide (NO) bioactivity that is activated during physiological and pathological hypoxia. One of the intravascular mechanisms for nitrite conversion to NO is a chemical nitrite reductase activity of deoxyhemoglobin. The rate of NO production from this reaction is increased when hemoglobin is in the R conformation. Because the mammalian fetus exists in a low-oxygen environment compared with the adult and is exposed to episodes of severe ischemia during the normal birthing process, and because fetal hemoglobin assumes the R conformation more readily than adult hemoglobin, we hypothesized that nitrite reduction to NO may be enhanced in the fetal circulation. We found that the reaction was faster for fetal than maternal hemoglobin or blood and that the reactions were fastest at 50–80% oxygen saturation, consistent with an R-state catalysis that is predominant for fetal hemoglobin. Nitrite concentrations were similar in blood taken from chronically instrumented normoxic ewes and their fetuses but were elevated in response to chronic hypoxia. The findings suggest an augmented nitrite reductase activity of fetal hemoglobin and that the production of nitrite may participate in the regulation of vascular NO homeostasis in the fetus. PMID:19028797

  13. [Acquired hemoglobin H disease in the early stage of erythroleukemia].

    PubMed

    Bürgi, W; Schlup, P; Deubelbeiss, K A; Fischer, S; Killer, D

    1992-03-07

    At the onset of erythroleukemia, the patient, a 74-year-old Swiss male, was also found to have microcytic-hypochromic anemia (Hb: 82 g/l, MCV: 69 fl, MCH: 21 pg). Further laboratory examinations revealed reduced hemoglobin stability, a hemoglobin H fraction of 3.0% on cellulose acetate-electrophoresis, and an abundance of hemoglobin H inclusion bodies in red cells. These findings, as well as the Swiss origin of the patient and his age at the onset of the disease, were consistent with acquired hemoglobin H disease. In addition to genetic hemoglobin H disease, acquired hemoglobin H disease was reported to be associated with myelodysplastic and myeloproliferative syndrome, or erythroleukemia and acute myelogenous leukemia. The literature contains fewer than 50 cases. It is suggested that the molecular basis of this rare disease involves a gene in trans to the alpha-globin genes reducing the expression of all four alpha-globin genes to approximately 10% of normal activity.

  14. Hemoglobin Uptake by Paracoccidioides spp. Is Receptor-Mediated

    PubMed Central

    Bailão, Elisa Flávia Luiz Cardoso; Parente, Juliana Alves; Pigosso, Laurine Lacerda; de Castro, Kelly Pacheco; Fonseca, Fernanda Lopes; Silva-Bailão, Mirelle Garcia; Báo, Sônia Nair; Bailão, Alexandre Melo; Rodrigues, Marcio L.; Hernandez, Orville; McEwen, Juan G.; Soares, Célia Maria de Almeida

    2014-01-01

    Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciens-mediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms. PMID:24831516

  15. [Clinical and hematological profile of Lepore Hemoglobin in Ivory Coast].

    PubMed

    Sangare, A; Sanogo, I; Meite, M; Segbena, A; Toure, A H; Elenga, J P; Siransy, L; Allangba, O

    1994-01-01

    Out of 97320 hemoglobin electrophoreses performed in Abidjan between January 1976 and January 1991, all subjects with hemoglobin Lepore were isolated. This trait was identified by three techniques, i.e., alkaline pH electrophoresis, acid pH electrophoresis, and isoelectric focusing. Seventy-nine cases of hemoglobin Lepore were observed. All were heterozygotes with type HbA-Lepore (n = 54), HbC-Lepore (n = 8) or HbS Lepore (n = 17). Where heterozygosis A and C had clinically silent, heterozygosis Hb-S Lepore resulted in a moderate chronic hemolytic anemia and, in all cases, painful episodes similar to those observed during homozygote sickle-cell disease. However the onset of episodes was later and their occurrence was less frequent. On hemograms, the Lepore trait (HbA Lepore) appeared as a pseudo-polyglobulia with microcytosis; similar features were observed for heterozygosis HbC Lepore. Heterozygosis HbS Lepore caused moderate anemia (mean hemoglobin level: 10.66 g/dl) and microcytosis (MGV = 68.8 fl). The characteristics show that the clinical and hematological behavior of hemoglobin Lepore, a rare hemoglobin, is similar to heterozygous beta-thalassemia.

  16. Cell volume regulation in hemoglobin CC and AA erythrocytes

    SciTech Connect

    Berkowitz, L.R.; Orringer, E.P.

    1987-03-01

    Swelling hemoglobin CC erythrocytes stimulates a ouabain-insensitive K flux that restores original cell volume. Studies were performed with the K analog, /sup 86/Rb. This volume regulatory pathway was characterized for its anion dependence, sensitivity to loop diuretics, and requirement for Na. The swelling-induced K flux was eliminated if intracellular chloride was replaced by nitrate and both swelling-activated K influx and efflux were partially inhibited by 1 mM furosemide or bumetanide. K influx in swollen hemoglobin CC cells was not diminished when Na in the incubation medium was replaced with choline, indicating Na independence of the swelling-induced flux. Identical experiments with hemoglobin AA cells also demonstrated a swelling-induced increase in K flux, but the magnitude and duration of this increase were considerably less than that seen with hemoglobin CC cells. The increased K flux in hemoglobin AA cells was likewise sensitive to anion replacement and to loop diuretics and did not require the presence of Na. These data indicate that a volume-activated K pathway with similar transport characteristics exists in both hemoglobin CC and AA red cells.

  17. Hemoglobin uptake by Paracoccidioides spp. is receptor-mediated.

    PubMed

    Bailão, Elisa Flávia Luiz Cardoso; Parente, Juliana Alves; Pigosso, Laurine Lacerda; de Castro, Kelly Pacheco; Fonseca, Fernanda Lopes; Silva-Bailão, Mirelle Garcia; Báo, Sônia Nair; Bailão, Alexandre Melo; Rodrigues, Marcio L; Hernandez, Orville; McEwen, Juan G; Soares, Célia Maria de Almeida

    2014-05-01

    Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciens-mediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms.

  18. Chemical modification of hemoglobin improves biocatalytic oxidation of PAHs.

    PubMed

    Torres, E; Vazquez-Duhalt, R

    2000-07-14

    Chemical modifications on human hemoglobin were performed with the aim to change both surface and active-site hydrophobicities. The modifications included covalent coupling of poly(ethylene)glycol (5000 MW) on free amino groups and the methyl esterification of free carboxylic groups. The modified hemoglobin was assayed for the oxidation of 11 polycyclic aromatic hydrocarbons (PAHs) and 2 organosulfur aromatic compounds. Acenaphthene, anthracene, azulene, benzo(a)pyrene, fluoranthene, fluorene, phenanthrene, and pyrene were transformed to their respective quinones, while for chrysene and biphenyl no biocatalytic reaction could be detected. Dibenzothiophene and thianthrene were oxidized to form sulfoxides. The doubly modified hemoglobin, PEG-Met-hemoglobin, showed up to 10 times higher activity than the unmodified protein. The kinetic constants show that the PEG-Met-hemoglobin has a significantly higher catalytic efficiency. The equilibrium substrate binding constants for unmodified and PEG-Met-modified hemoglobis and hemoglobin show that this catalytic enhancement could be attributed to the affinity increase for hydrophobic substrates in the modified protein. Copyright 2000 Academic Press.

  19. IPR and technological issues regarding a biopharmaceutical formulation hemoglobin.

    PubMed

    Honrao, Chandrashekhar; Banerjee, Uttam C; Bansal, Parikshit

    2008-01-01

    Hemoglobin, the protein responsible for the red color of blood plays a very important part in 'life'- it transports oxygen, without which humans cannot survive. The idea of using purified Hemoglobin as a possible universal substitute for red blood cells has been around for almost a century. Hemoglobin formulations have important therapeutic applications, especially in case of trauma and war when requirements for blood may be very large. Manufacture of hemoglobin for use as a biopharmaceutical poses practical challenges, owing to dependence on human expired blood and fragility of the protein molecule. Biotechnology can play a critical role in breaking these barriers, by not only ensuring recombinant production of hemoglobin, but also enhancing stability of the molecule. The present article, based on a review of patents and available literature gives an insight into the IPR and technological issues involved in the commercial production of this 'life-saving' protein. There are more than 250 patents worldwide related to hemoglobin formulation, cross-linking and determination.

  20. Dithionite Tube Test - A Rapid, Inexpensive Technique for the Detection of Hemoglobin S and Non-S Sickling Hemoglobin.

    DTIC Science & Technology

    hemoglobinopathies of low solubility such as Kings County and Stanleyville II. The dithionite and urea-dithionite tests, however, will provide rapid, accurate, reliable, and inexpensive screening for hemoglobin S. (Author)

  1. Lyophilized bovine hemoglobin as a possible reference material for the determination of hemoglobin derivatives in human blood.

    PubMed

    Maas, B H; Buursma, A; Ernst, R A; Maas, A H; Zijlstra, W G

    1998-11-01

    We investigated the suitability of a lyophilized bovine hemoglobin (LBH) preparation containing various fractions of oxyhemoglobin (O2Hb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) for quality assessment in multicomponent analysis (MCA) of hemoglobin derivatives. It was demonstrated that a stable preparation of these components after reconstitution yields a hemoglobin solution that is spectrophotometrically equivalent with a fresh bovine hemoglobin solution. The preparation was found to be stable for at least 1 year when it is kept at 2-8 degrees C and for 1 h after reconstitution. We determined the fractions of O2Hb, COHb, and MetHb of several LBH preparations, using the complete spectra of 480-650 nm with 2-nm intervals and absorptivities as determined for pure LBH solutions. A field trial involving various types of multiwavelength hemoglobin photometers showed the suitability of LBH as a quality-control material. Computer models of the various common multiwavelength hemoglobin photometers may be useful for establishing more accurate target values of LBH preparations for each type of photometer and for studying the importance of the influence of specific factors such as wavelength selection, absorptivity values, and interfering dyes.

  2. Identification of a haptoglobin-hemoglobin complex in the Alaskan Least Cisco (Coregonus sardinella).

    PubMed

    Wahl, S M; Boger, J K; Michael, V; Duffy, L K

    1992-01-01

    The hemoglobin and a hemoglobin binding protein have been characterized in the Arctic fish (Coregonus sardinella). The evolutionary significance of the hemoglobin and plasma protein differences between fish and mammals is still unresolved. Blood samples from the Alaskan Least Cisco were separated into plasma and hemoglobin fractions and the proteins in these fractions were analyzed both by alkaline agarose gel electrophoresis, by isolelectric focusing, and by capillary electrophoresis. Staining the plasma proteins gels with o-dianisidine revealed hemoglobin containing protein complexes. A hemoglobin-containing band was observed in hemolyzed plasma which did not migrate with free hemoglobin, and is believed to be hemoglobin-haptoglobin complex. Size exclusion chromatography further characterized the hemoglobin as disassociating freely into dimers, and hemoglobin-haptoglobin complex having a molecular weight greater then 200,000 daltons.

  3. Structural transition temperature of hemoglobins correlates with species' body temperature.

    PubMed

    Zerlin, Kay Frank Thorsten; Kasischke, Nicole; Digel, Ilya; Maggakis-Kelemen, Christina; Temiz Artmann, Aysegül; Porst, Dariusz; Kayser, Peter; Linder, Peter; Artmann, Gerhard Michael

    2007-12-01

    Human red blood cells (RBCs) exhibit sudden changes in their biophysical properties at body temperature (T (B)). RBCs were seen to undergo a spontaneous transition from blockage to passage at T (C) = 36.4 +/- 0.3 degrees C, when the temperature dependency of RBC-passages through 1.3 mum narrow micropipettes was observed. Moreover, concentrated hemoglobin solutions (45 g/dl) showed a viscosity breakdown between 36 and 37 degrees C. With human hemoglobin, a structural transition was observed at T (B) as circular dichroism (CD) experiments revealed. This leads to the assumption that a species' body temperature occupies a unique position on the temperature scale and may even be imprinted in the structure of certain proteins. In this study, it was investigated whether hemoglobins of species with a T (B) different from those of human show temperature transitions and whether those were also linked to the species' T (B). The main conclusion was drawn from dynamic light scattering (DLS) and CD experiments. It was observed that such structural temperature transitions did occur in hemoglobins from all studied species and were correlated linearly (slope 0.81, r = 0.95) with the species' body temperature. We presumed that alpha-helices of hemoglobin were able to unfold more readily around T (B). alpha-helical unfolding would initiate molecular aggregation causing RBC passage and viscosity breakdown as mentioned above. Thus, structural molecular changes of hemoglobin could determine biophysical effects visible on a macroscopic scale. It is hypothesized that the species' body temperature was imprinted into the structure of hemoglobins.

  4. Hemoglobin Wood beta97(FG4) His replaced by Leu. A new high-oxygen-affinity hemoglobin associated with familial erythrocytosis.

    PubMed

    Taketa, F; Huang, Y P; Libnoch, J A; Dessel, B H

    1975-08-19

    The characterization of hemoglobin Wood (beta97(FG4) His replaced by Leu), a high oxygen affinity hemoglobin with reduced Hill constant is described. The amino acid substitution occurs at the alpha1beta2 interface, in the same position as in hemoglobin Malmö (beta97(FG4) His replaced by Gln) and in an homologous position when compared with hemoglobins Chesapeake (alpha92(FG4) Arg replaced by Leu) and J. Capetown (alpha92(fg4) arg replaced by Gln).

  5. A PEGylated bovine hemoglobin as a potent hemoglobin-based oxygen carrier.

    PubMed

    Wang, Ying; Wang, Linli; Yu, Weili; Gao, Dawei; You, Guoxing; Li, Penglong; Zhang, Shan; Zhang, Jun; Hu, Tao; Zhao, Lian; Zhou, Hong

    2017-01-01

    Hemoglobin (Hb)-based oxygen carriers (HBOCs) have been used as blood substitutes in surgery medicine and oxygen therapeutics for ischemic stroke. As a potent HBOC, the PEGylated Hb has received much attention for its oxygen delivery and plasma expanding ability. Two PEGylated Hbs, Euro-Hb, and MP4 have been developed for clinical trials, using human adult hemoglobin (HbA) as the original substrate. However, HbA was obtained from outdated human blood and its quantity available from this source may not be sufficient for mass production of PEGylated HbA. In contrast, bovine Hb (bHb) has no quantity constraints for its ample resource. Thus, bHb is of potential to function as an alternative substrate to obtain a PEGylated bHb (bHb-PEG). bHb-PEG was prepared under the same reaction condition as HbA-PEG, using maleimide chemistry. The structural, functional, solution and physiological properties of bHb-PEG were determined and compared with those of HbA-PEG. bHb-PEG showed higher hydrodynamic volume, colloidal osmotic pressure, viscosity and P50 than HbA-PEG. The high P50 of bHb can partially compensate the PEGylation-induced perturbation in the R to T state transition of HbA. bHb-PEG was non-vasoactive and could efficiently recover the mean arterial pressure of mice suffering from hemorrhagic shock. Thus, bHb-PEG is expected to function as a potent HBOC for its high oxygen delivery and strong plasma expanding ability. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:252-260, 2017.

  6. Selection of aptamers specific for glycated hemoglobin and total hemoglobin using on-chip SELEX.

    PubMed

    Lin, Hsin-I; Wu, Ching-Chu; Yang, Ching-Hsuan; Chang, Ko-Wei; Lee, Gwo-Bin; Shiesh, Shu-Chu

    2015-01-21

    Blood glycated hemoglobin (HbA1c) levels reflecting average glucose concentrations over the past three months are fundamental for the diagnosis, monitoring, and risk assessment of diabetes. It has been hypothesized that aptamers, which are single-stranded DNAs or RNAs that demonstrate high affinity to a large variety of molecules ranging from small drugs, metabolites, or proteins, could be used for the measurement of HbA1c. Aptamers are selected through an in vitro process called systematic evolution of ligands by exponential enrichment (SELEX), and they can be chemically synthesized with high reproducibility at relatively low costs. This study therefore aimed to select HbA1c- and hemoglobin (Hb)-specific single-stranded DNA aptamers using an on-chip SELEX protocol. A microfluidic SELEX chip was developed to continuously and automatically carry out multiple rounds of SELEX to screen specific aptamers for HbA1c and Hb. HbA1c and Hb were first coated onto magnetic beads. Following several rounds of selection and enrichment with a randomized 40-mer DNA library, specific oligonucleotides were selected. The binding specificity and affinity were assessed by competitive and binding assays. Using the developed microfluidic system, the incubation and partitioning times were greatly decreased, and the entire process was shortened dramatically. Both HbA1c- and Hb-specific aptamers selected by the microfluidic system showed high specificity and affinity (dissociation constant, Kd = 7.6 ± 3.0 nM and 7.3 ± 2.2 nM for HbA1c and Hb, respectively). With further refinements in the assay, these aptamers may replace the conventional antibodies for in vitro diagnostics applications in the near future.

  7. Pattern of cavities in globins: the case of human hemoglobin.

    PubMed

    Savino, Carmelinda; Miele, Adriana E; Draghi, Federica; Johnson, Kenneth A; Sciara, Giuliano; Brunori, Maurizio; Vallone, Beatrice

    2009-12-01

    Our aim is to shed light on the conservation of potential ligand docking sites that play an important role in ligand dynamics of globins by using the technique of filling internal cavities naturally present in hemoglobin and myoglobin with xenon atoms. In particular, we present the high resolution structures of the Xe-adduct of deoxygenated wild type human hemoglobin and a quadruple mutant (L(B10)Y and H(E7)Q in alpha and beta chains). For the sake of comparison we also determined under the same experimental conditions the xenon complex of wild type sperm whale myoglobin. The analysis revealed that the number and position of Xe binding cavities are different in the alpha and beta subunits, the latter being more similar to myoglobin. Notably, no proximal Xe docking site was detected in hemoglobin, at variance with myoglobin. The pattern of internal cavities accessibility and affinity for xenon suggests a different role for the dynamics of ligand migration in the two types of hemoglobin chains as compared to myoglobin. The number and position of hydrophobic cavities in hemoglobin are briefly discussed also in comparison with the data available for other members of the globin superfamily.

  8. Hemoglobin research and the origins of molecular medicine

    PubMed Central

    2008-01-01

    Much of our understanding of human physiology, and of many aspects of pathology, has its antecedents in laboratory and clinical studies of hemoglobin. Over the last century, knowledge of the genetics, functions, and diseases of the hemoglobin proteins has been refined to the molecular level by analyses of their crystallographic structures and by cloning and sequencing of their genes and surrounding DNA. In the last few decades, research has opened up new paradigms for hemoglobin related to processes such as its role in the transport of nitric oxide and the complex developmental control of the α-like and β-like globin gene clusters. It is noteworthy that this recent work has had implications for understanding and treating the prevalent diseases of hemoglobin, especially the use of hydroxyurea to elevate fetal hemoglobin in sickle cell disease. It is likely that current research will also have significant clinical implications, as well as lessons for other aspects of molecular medicine, the origin of which can be largely traced to this research tradition. PMID:18988877

  9. Electrospray ionization mass spectrometric characterization of acrylamide adducts to hemoglobin

    SciTech Connect

    Springer, D.L.; Goheen, S.C.; Edmonds, C.G. ); Bull, R.J.; Sylvester, D.M. )

    1993-01-01

    The most common procedure to identify hemoglobin adducts has been to cleave the adducts from the protein and characterize the adducting species, by, for example, derivatization and gas chromatography/mass spectrometry. To extend these approaches we used electrospray ionization mass spectrometry (ESI-MS) to characterize adducted hemoglobin. For this we incubated [[sup 14]C]acrylamide with the purified human hemoglobin (type A[sub 0]) under conditions that yielded high adduct levels. When the hemoglobin was separated by reversed-phase high-performance liquid chromatography (HPLC), 65% of the radioactivity copurified with the [beta]-subunit. Three adducted species were prominent in the ESI mass spectrum of the intact [beta]-subunit, indicating acrylamide adduction (i.e., mass increase of 71 Da) and two addition unidentified moieties with mass increments of 102 and 135 Da. Endoproteinase Glu-C digestion of the adducted [beta]-subunit resulted in a peptide mixture that, upon reversed-phase HPLC separation, provided several radiolabeled peptides. Using ESI-MS we identified these as the V[sub 91-101] and V[sub 102-122] peptides that represent the cysteine-containing peptides of the [beta]-subunit. These results provide definitive information on acrylamide-modified human hemoglobin and demonstrate that ESI-MS provides valuable structure information on chemically adducted proteins. 30 refs., 9 figs., 3 tabs.

  10. Relationship between maternal hemoglobin concentration and neonatal birth weight.

    PubMed

    Sekhavat, Leila; Davar, Robab; Hosseinidezoki, Somaiasadat

    2011-11-01

    Pregnancy considerably increases iron needs in a mother and her fetus. The purpose of this study was to assess the relationship between maternal hemoglobin concentration in labor with neonatal birth weight. A population-based study in Shahid Sadughi Hospital in Yazd, Iran, was performed by comparing 1842 singleton term pregnancies of patients with and without anemia and their newborns. Maternal characteristics, including hemoglobin values, were recorded at the labor visit. Maternal anemia was defined as hemoglobin concentration lower than 10 g/dl during pregnancy. Main outcome measures included birth weight and Apgar score. Linear and logistic regression models were used to analyze data. Anemia (Hb < 10 g/dl) was associated with a significantly increased risk of low birth weight (< 2500 g). High hemoglobin (> 13 g/dl) increased the risk of low birth weight but it was not significant. The risk of a low Apgar score was significantly increased in women with anemia. The minimum incidence of low birth weight occurs in association with a hemoglobin concentration of 10-13 g/dl. Maternal anemia was significantly associated with effect on birth weight. Also Hb > 13 g/dl was also associated with an increased risk of low birth weight.

  11. Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

    PubMed Central

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Berhanu, Getenesh; Thomas, David G.; Schrader, Sarah E.; Eldridge, Devon; Kennedy, Tay; Hambidge, Michael

    2011-01-01

    Researchers tested male and female infants from rural Ethiopia to investigate relations among hemoglobin, anthropometry, and attention. They utilized a longitudinal design to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron status and growth delays. Stunting (length-for-age z-scores < −2.0) and attention performance [t(30) = −2.42, p = .022] worsened over time. Growth and hemoglobin predicted attention at 9 months [R2 = .15, p < .05], but not at 6. The use of the attention task at 9 months was supported. The study contributes to the knowledge base of hemoglobin, growth, and attention. PMID:21545582

  12. Mastomys (rodentia: muridae) species distinguished by hemoglobin pattern differences.

    PubMed

    Robbins, C B; Krebs, J W; Johnson, K M

    1983-05-01

    Hemoglobin electrophoresis patterns were found to be reliable markers for distinguishing two species of Mastomys in Sierra Leone having 32 and 38 chromosomes. All 32-chromosome animals exhibited a single hemoglobin pattern, whereas those with 38-chromosomes had four distinguishable patterns. Both karyotypes were present throughout Sierra Leone. The 38-chromosome species was more prevalent in the Guinea savanna zone to the north, while the 32-chromosome species was most dominant in human-modified high forest areas of the eastern and southern parts of the country. In almost all situations the 32-chromosome species was more common in houses than in bush habitats; the reverse was true for Mastomys having 38 chromosomes. Analysis of hemoglobin patterns thus becomes useful for species identification, and is necessary to understand the roles of the different Mastomys forms as reservoirs of human diseases, such as Lassa fever in West Africa.

  13. A Hemoglobin Variant Associated with Neonatal Cyanosis and Anemia

    PubMed Central

    Crowley, Moira A.; Mollan, Todd L.; Abdulmalik, Osheisa Y.; Butler, Andrew D.; Goodwin, Emily F.; Sarkar, Arindam; Stolle, Catherine A.; Gow, Andrew J.; Olson, John S.; Weiss, Mitchell J.

    2013-01-01

    SUMMARY Globin-gene mutations are a rare but important cause of cyanosis. We identified a missense mutation in the fetal G γ-globin gene (HBG2) in a father and daughter with transient neonatal cyanosis and anemia. This new mutation modifies the ligand-binding pocket of fetal hemoglobin by means of two mechanisms. First, the relatively large side chain of methionine decreases both the affinity of oxygen for binding to the mutant hemoglobin subunit and the rate at which it does so. Second, the mutant methionine is converted to aspartic acid post-translationally, probably through oxidative mechanisms. The presence of this polar amino acid in the heme pocket is predicted to enhance hemoglobin denaturation, causing anemia. PMID:21561349

  14. Hemoglobin Koya Dora: high frequency of a chain termination mutant.

    PubMed Central

    De Jong, W W; Meera Khan, P; Bernini, L F

    1975-01-01

    Approximately 10% of the members of the Koya Dora tribe from Andhra Pradesh (India) carry an alpha chain hemoglobin variant, Hb Koya Dora (Hb KD), usually in amounts of 0.5%-2% of total hemoglobin. In four presumed homozygotes for Hb KD, up to 10% of the abnormal hemoglobin was present. The alpha chain of Hb KD was found to be elongated by at least 16 residues, possibly as a result of a mutation of the normal alpha chain termination codon UAA TO UCA, coding for serine. A pedigree in which two individuals possess Hb KD as well as the alpha chain variant Hb Rampa and normal Hb A proves the existence of two alpha chain loci in this population. Hb DK resembles the previously described Hb Constant Spring [6, 7] in many aspects, probably also in its alpha thalassemia-like expression. Images Fig. 1 Fig. 2 PMID:1155453

  15. Plant hemoglobins: important players at the crossroads between oxygen and nitric oxide.

    PubMed

    Gupta, Kapuganti J; Hebelstrup, Kim H; Mur, Luis A J; Igamberdiev, Abir U

    2011-12-15

    Plant hemoglobins constitute a diverse group of hemeproteins and evolutionarily belong to three different classes. Class 1 hemoglobins possess an extremely high affinity to oxygen and their main function consists in scavenging of nitric oxide (NO) at very low oxygen levels. Class 2 hemoglobins have a lower oxygen affinity and they facilitate oxygen supply to developing tissues. Symbiotic hemoglobins in nodules have mostly evolved from class 2 hemoglobins. Class 3 hemoglobins are truncated and represent a clade with a very low similarity to class 1 and 2 hemoglobins. They may regulate oxygen delivery at high O(2) concentrations. Depending on their physical properties, hemoglobins belong either to hexacoordinate non-symbiotic or pentacoordinate symbiotic groups. Plant hemoglobins are plausible targets for improving resistance to multiple stresses.

  16. Membrane-associated sickle hemoglobin: a major determinant of sickle erythrocyte rigidity.

    PubMed

    Evans, E A; Mohandas, N

    1987-11-01

    Micropipette aspiration tests on single erythrocytes have previously shown that the static rigidity (membrane shear modulus) of oxygenated sickle cells increased with increasing hemoglobin concentration, whereas the rigidity of normal cells was independent of hemoglobin concentration. Moreover, it was observed that after mechanical extension, sickle cells exhibited persistent deformation more frequently and to a greater extent than normal cells. To ascertain if differences in association of normal and sickle hemoglobin with the membrane could account for these observations, we measured rheologic properties of normal membranes reconstituted with sickle hemoglobin and sickle membranes reconstituted with normal hemoglobin. The static rigidity of normal ghosts reloaded with sickle hemoglobin was higher than those of either normal ghosts reloaded with normal hemoglobin or native normal cells. On the other hand, the increased rigidity of native sickle cells decreased to near-normal values following reconstitution with normal hemoglobin. Furthermore, we observed that normal ghosts reconstituted with sickle hemoglobin exhibited persistent bumps after mechanical extension, but no bumps formed on normal ghosts reconstituted with normal hemoglobin. Moreover residual bumps were not produced on sickle cells reloaded with normal hemoglobin. Since mechanical characteristics peculiar to sickle cells could be induced in normal cells by incorporation of sickle hemoglobin, and since normal characteristics could be restored to sickle cells by incorporation of normal hemoglobin, we suggest that the interaction of sickle hemoglobin with the cell membrane is responsible for augmented static rigidity of oxygenated sickle erythrocytes.

  17. Nitric Oxide in Plants: The Roles of Ascorbate and Hemoglobin

    PubMed Central

    Wang, Xiaoguang; Hargrove, Mark S.

    2013-01-01

    Ascorbic acid and hemoglobins have been linked to nitric oxide metabolism in plants. It has been hypothesized that ascorbic acid directly reduces plant hemoglobin in support of NO scavenging, producing nitrate and monodehydroascorbate. In this scenario, monodehydroascorbate reductase uses NADH to reduce monodehydroascorbate back to ascorbate to sustain the cycle. To test this hypothesis, rates of rice nonsymbiotic hemoglobin reduction by ascorbate were measured directly, in the presence and absence of purified rice monodehydroascorbate reductase and NADH. Solution NO scavenging was also measured methodically in the presence and absence of rice nonsymbiotic hemoglobin and monodehydroascorbate reductase, under hypoxic and normoxic conditions, in an effort to gauge the likelihood of these proteins affecting NO metabolism in plant tissues. Our results indicate that ascorbic acid slowly reduces rice nonsymbiotic hemoglobin at a rate identical to myoglobin reduction. The product of the reaction is monodehydroascorbate, which can be efficiently reduced back to ascorbate in the presence of monodehydroascorbate reductase and NADH. However, our NO scavenging results suggest that the direct reduction of plant hemoglobin by ascorbic acid is unlikely to serve as a significant factor in NO metabolism, even in the presence of monodehydroascorbate reductase. Finally, the possibility that the direct reaction of nitrite/nitrous acid and ascorbic acid produces NO was measured at various pH values mimicking hypoxic plant cells. Our results suggest that this reaction is a likely source of NO as the plant cell pH drops below 7, and as nitrite concentrations rise to mM levels during hypoxia. PMID:24376554

  18. Electrochemical behavior of immobilized hemoglobin in alkaline solution

    NASA Astrophysics Data System (ADS)

    Jović-Jovičić, Nataša; Mojović, Zorica; Mojović, Miloš; Banković, Predrag; Ajduković, Marija; Milutinović-Nikolić, Aleksandra; Jovanović, Dušan

    2017-04-01

    Glassy carbon electrode was modified with different synthesized hybrid clay-based materials and tested in alkaline solution with and without H2O2. The hybrid materials were obtained by immobilizing hemoglobin (Hb) on acid activated (AA) clay, or on AA clay modified with different sodium dodecyl sulfate (SDS) loadings. The obtained materials were characterized using DR UV-vis and ESR spectroscopy, elemental analysis, and SEM. The characterization confirmed higher degree of hemoglobin incorporation in the presence of SDS. The presence of SDS on the surface of clay particles resulted in the partial oxidation/denaturation of hemoglobin and formation of hemichrome. Cyclic voltammetry was used for the investigation of the electrochemical behavior of immobilized hemoglobin in alkaline solution. Two cathodic peaks at -0.45 V and -0.70 V were recorded and ascribed to the reduction of heme Fe(III)/Fe(II), and formation of HbFe(I) - highly reduced form of hemoglobin - respectively. The latter peak reflects hemoglobin denaturation. The presence of H2O2 in the alkaline solution increased current intensities corresponding to both peaks (-0.45 V and -0.7 V). Linear response of peak current intensity vs. H2O2 concentration was monitored for all investigated samples within different H2O2 concentration ranges. The AA-SDS1.0-Hb electrode exhibited the highest current response with linear regression equation in the following form: I(μA) = 7.99 + 1.056 × [H2O2] (mM) (R = 0.996). The limit of detection of 28 μM was estimated using the 3 sigma method. Different modified electrodes exhibited different degrees of denaturation resistance. The obtained values of Michaelis-Menten constant indicated that prolonged cycling in the presence of SDS increases protein denaturation.

  19. A hemoglobin A1C immunoassay method not affected by carbamylated hemoglobin.

    PubMed

    Rose, A M; Tongate, C; Valdes, R

    1995-01-01

    Hemoglobin A1C (HbA1C) methods based on charge separation of Hb species are subject to interference from carbamylated Hb (carb Hb). Carb Hb adducts are formed via interaction of terminal amino groups of HbA with isocyanic acid, after the spontaneous dissociation of urea to cyanate. It is hypothesized that a new immunoassay method, using a monoclonal antibody that recognizes the N-terminus of the Hb beta-chain and its sugar moiety, should be refractory to cross-reactive interference from carb Hb. To test this hypothesis, Hb was carbamylated in vitro and co-migration of carb Hb assessed with HbA1C using an electrophoretic method. Densitometric scans - post sodium cyanate incubation and electrophoretic separation - showed a 5 to 7 fold elevation of the HbA1C peak only, while HbA1C values obtained using immunoassay were unaffected. Also assessed was carbamylation interference in vivo, and a positive proportional bias with the electrophoretic system (Y) was observed compared to the immunoassay system (X) (y = 1.2x - 0.21 percent). Others have shown that carb Hb may cause a clinically significant false elevation in patient HbA1C values, when methods based on charge separation of Hb species are used. It is our conclusion, however, that while carb Hb may play a role, the differences observed in this study are largely due to calibration.

  20. [Association between hemoglobin Groene Hart and hemoglobin J-Paris-I: first case in Spain].

    PubMed

    de la Fuente-Gonzalo, Félix; Ropero, Paloma; Martínez-Nieto, Jorge; Villegas, Ana; González, Fernando A; Díaz-Mediavilla, Joaquín

    2015-03-09

    Thalassemias are the most frequent monogenic disorder around the world. α-thalassemias are due to a deficiency of synthesis in the alpha-globin chain of the hemoglobin (Hb). Hb Groene Hart is a hyperunstable variant. In this work, we have studied 24 cases affected by Hb Groene Hart, one of them associated with Hb J-Paris-I. Twenty-four patients from 17 unrelated families were included in this study. The characterization was done by sequencing. α1 gene sequencing showed the mutation CCT→TCT (Pro→Ser) at codon 119 (Hb Groene Hart) in all patients. In one case, there was an association with Hb J-Paris-I. In the Hb Groene Hart, the residue 119 of alpha-globin chain is affected. This amino acid has a key role in preserving the stability of alpha-globin chain. It is also remarkable the presence of this variant in both the immigrant and native population. Thus, the identification of Hb Groene Hart carriers should be considered in the screening of α-thalassemia in Spain, as it is done in Northern Africa. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  1. Modulation of oxygen binding to insect hemoglobins: The structure of hemoglobin from the botfly Gasterophilus intestinalis

    PubMed Central

    Pesce, Alessandra; Nardini, Marco; Dewilde, Sylvia; Hoogewijs, David; Ascenzi, Paolo; Moens, Luc; Bolognesi, Martino

    2005-01-01

    Hemoglobins (Hbs) reversibly bind gaseous diatomic ligands (e.g., O2) as the sixth heme axial ligand of the penta-coordinate deoxygenated form. Selected members of the Hb superfamily, however, display a functionally relevant hexa-coordinate heme Fe atom in their deoxygenated state. Endogenous heme hexa-coordination is generally provided in these Hbs by the E7 residue (often His), which thus modulates accessibility to the heme distal pocket and reactivity of the heme toward exogenous ligands. Such a pivotal role of the E7 residue is prominently shown by analysis of the functional and structural properties of insect Hbs. Here, we report the 2.6 Å crystal structure of oxygenated Gasterophilus intestinalis Hb1, a Hb known to display a penta-coordinate heme in the deoxygenated form. The structure is analyzed in comparison with those of Drosophila melanogaster Hb, exhibiting a hexa-coordinate heme in its deoxygenated derivative, and of Chironomus thummi thummi HbIII, which displays a penta-coordinate heme in the deoxygenated form. Despite evident structural differences in the heme distal pockets, the distinct molecular mechanisms regulating O2 binding to the three insect Hbs result in similar O2 affinities (P50 values ranging between 0.12 torr and 0.46 torr). PMID:16260762

  2. Modulation of oxygen binding to insect hemoglobins: the structure of hemoglobin from the botfly Gasterophilus intestinalis.

    PubMed

    Pesce, Alessandra; Nardini, Marco; Dewilde, Sylvia; Hoogewijs, David; Ascenzi, Paolo; Moens, Luc; Bolognesi, Martino

    2005-12-01

    Hemoglobins (Hbs) reversibly bind gaseous diatomic ligands (e.g., O2) as the sixth heme axial ligand of the penta-coordinate deoxygenated form. Selected members of the Hb superfamily, however, display a functionally relevant hexa-coordinate heme Fe atom in their deoxygenated state. Endogenous heme hexa-coordination is generally provided in these Hbs by the E7 residue (often His), which thus modulates accessibility to the heme distal pocket and reactivity of the heme toward exogenous ligands. Such a pivotal role of the E7 residue is prominently shown by analysis of the functional and structural properties of insect Hbs. Here, we report the 2.6 A crystal structure of oxygenated Gasterophilus intestinalis Hb1, a Hb known to display a penta-coordinate heme in the deoxygenated form. The structure is analyzed in comparison with those of Drosophila melanogaster Hb, exhibiting a hexa-coordinate heme in its deoxygenated derivative, and of Chironomus thummi thummi HbIII, which displays a penta-coordinate heme in the deoxygenated form. Despite evident structural differences in the heme distal pockets, the distinct molecular mechanisms regulating O2 binding to the three insect Hbs result in similar O(2 affinities (P50 values ranging between 0.12 torr and 0.46 torr).

  3. Using a Poetry Reading on Hemoglobin to Enhance Subject Matter

    ERIC Educational Resources Information Center

    Herrick, Richard S.; Cording, Robert K.

    2013-01-01

    student interest in the beauty and mystery of chemistry. A reading of the poem "Jerry-Built Forever" (on various aspects of hemoglobin) is used as an example; the poem is included in the article. Details of how the reading was performed and reactions of the…

  4. MP4, a new nonvasoactive polyethylene glycol-hemoglobin conjugate.

    PubMed

    Winslow, Robert M

    2004-09-01

    A new hemoglobin derivative, MP4, for use as a temporary oxygen-carrying plasma expander, has been prepared. The design of the molecule is based on novel criteria for optimized efficacy and safety, which include increased molecular radius, increased viscosity, increased oncotic pressure, and reduced p50. The chemical entity, MalPEG-Hb, is formulated at 4.2 g/dL in lactated Ringer's solution (MP4). It has a p50 of 5-6 mm Hg, oncotic pressure of 49 mm Hg and viscosity of 2.2 cPs. After 50% exchange transfusion with MP4, rats survive a 60% controlled hemorrhage in spite of total hemoglobin of 7.8 g/dL and plasma hemoglobin concentration of 1.6 g/dL. Although its binding affinity for NO is not different from that of purified hemoglobin A, it does not produce hypertension in a number of animal models and does not cause vasoconstriction in hamster microcirculation. Oxygen supply to tissue has been confirmed by direct observation in the hamster skinfold model, in which O2 release in precapillary and capillary vessels was quantified. The data demonstrate that the effectiveness of MP4 results from its ability to conserve O2 in precapillary vessels and release O2 in capillaries, thereby "targeting" O2 to hypoxic tissue. Preservation of functional capillary density and prevention of vasoconstriction further contribute to the effectiveness of this new formulation. MP4 is currently being tested in humans.

  5. Effect of Some High Consumption Spices on Hemoglobin Glycation

    PubMed Central

    Naderi, G. H.; Dinani, Narges J.; Asgary, S.; Taher, M.; Nikkhoo, N.; Boshtam, M.

    2014-01-01

    Formation of glycation products is major factor responsible in complications of diabetes. Worldwide trend is toward the use of natural additives in reducing the complications of diseases. Therefore, there is a growing interest in natural antiglycation found in plants. Herbs and spices are one of the most important targets to search for natural antiglycation from the point of view of safety. This study investigated the ability of some of the spices to inhibit glycation process in a hemoglobin/glucose model system and compared their potency with each other. For this subject the best concentration and time to incubate glucose with hemoglobin was investigated. Then the glycosylation degree of hemoglobin in the presence of extracts by the three concentrations 0.25, 0.5 and 1 μg/ml was measured colorimetrically at 520 nm. Results represent that some of extracts such as wild caraway, turmeric, cardamom and black pepper have inhibitory effects on hemoglobin glycation. But some of the extracts such as anise and saffron have not only inhibitory effects but also aggravated this event and have proglycation properties. In accordance with the results obtained we can conclude that wild caraway, turmeric, cardamom and black pepper especially wild caraway extracts are potent antiglycation agents, which can be of great value in the preventive glycation-associated complications in diabetes. PMID:25593391

  6. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glycosylated hemoglobin assay. 864.7470 Section 864.7470 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  7. Ultrasonic processing for recovery of chicken erythrocyte hemoglobin

    USDA-ARS?s Scientific Manuscript database

    Hemoglobin from chicken blood has been shown to be a good substitute for synthetic polymeric flocculants. One stage of processing the blood entails breaking open the cells and releasing the cytoplasmic contents; in the present study, we investigate the use of ultrasonic processing at this stage. Was...

  8. Correlations between oxygen affinity and sequence classifications of plant hemoglobins

    USDA-ARS?s Scientific Manuscript database

    Plants express three phylogenetic classes of hemoglobins (Hb) based on sequence analyses. Class 1 and 2 Hbs are full length globins with the classical 8 helix Mb-like fold, whereas Class 3 plant Hbs resemble the truncated globins found in bacteria. With the exception of the specialized leghemoglobin...

  9. The Relationship Between Hemoglobin Level and Intellectual Function.

    ERIC Educational Resources Information Center

    Munro, Nancy

    In a study to learn whether or not poor nutrition, as indicated by low hemoglobin levels, affects intelligence and behavior, 113 Head Start children in Missoula, Montana took part. Group testing with the Lorge Thorndike Intelligence Test and individual testing with the Wechsler and Primary Scale of Intelligence or Wechsler Intelligence Scale for…

  10. Using a Poetry Reading on Hemoglobin to Enhance Subject Matter

    ERIC Educational Resources Information Center

    Herrick, Richard S.; Cording, Robert K.

    2013-01-01

    student interest in the beauty and mystery of chemistry. A reading of the poem "Jerry-Built Forever" (on various aspects of hemoglobin) is used as an example; the poem is included in the article. Details of how the reading was performed and reactions of the…

  11. Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

    ERIC Educational Resources Information Center

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Berhanu, Getenesh; Thomas, David G.; Schrader, Sarah E.; Eldridge, Devon; Kennedy, Tay; Hambidge, Michael

    2011-01-01

    Male and female infants from rural Ethiopia were tested to investigate relations among hemoglobin (Hb), anthropometry, and attention. A longitudinal design was used to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron…

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  13. Occult hemoglobin as an indicator of impingement stress in fishes

    SciTech Connect

    Not Available

    1980-01-01

    During the process of impingement on cooling system intake screens, fish may be subject to different types of stress, the total of which often results in the death of individual fish. This report assesses the use of occult hemoglobin in fish demand mucus as an indicator of impingement stress. (ACR)

  14. A new colorimetric method for the estimation of glycosylated hemoglobin.

    PubMed

    Nayak, S S; Pattabiraman, T N

    1981-02-05

    A new colorimetric method, based on the phenol sulphuric acid reaction of carbohydrates, is described for the determination of glycosylated hemoglobin. Hemolyzates were treated with 1 mol/l oxalic acid in 2 mol/l Hcl for 4 h at 100 degrees C, the protein was precipitated with trichloroacetic acid, and the free sugars and hydroxymethyl furfural in the protein free supernatant were treated with phenol and sulphuric acid to form the color. The new method is compared to the thiobarbituric acid method and the ion-exchange chromatographic method for the estimation of glycosylated hemoglobin in normals and diabetics. The increase in glycosylated hemoglobin in diabetic patients as estimated by the phenol-sulphuric acid method was more significant (P less than 0.001) than the increase observed by the thiobarbituric acid method (P less than 0.01). The correlation between the phenol-sulphuric acid method and the column method was better (r = 0.91) than the correlation between the thiobarbituric acid method and the column method (r = 0.84). No significant correlation between fasting and postprandial blood sugar level and glycosylated hemoglobin level as determined by the two colorimetric methods was observed in diabetic patients.

  15. CO cage recombination in hemoglobin : Picosecond photolysis and nanosecond observation

    NASA Astrophysics Data System (ADS)

    Pin, S.; Valat, P.; Tourbez, H.; Alpert, B.

    1986-07-01

    Carboxy hemoglobin in aqueous solution was photodissociated by laser pulses of 30 ps at 532 nm. Kinetic studies show that only upon complete photodissociation can the pure CO geminate binding process be revealed. The protein region of the iron cage, where the geminate ligand diffuses before reaching the heme, is smaller than a single subunit and larger than the heme pocket.

  16. [Neonatal cyanosis due to fetal hemoglobin M-Osaka].

    PubMed

    Charon, A; Henrion, E; Delpire, S; Redondi, A; Lecart, C

    2011-10-01

    The case of a newborn with isolated neonatal cyanosis on day 1 is reported. The basic investigations were sufficient to reach the diagnosis. A rare abnormal fetal hemoglobin was isolated. The prognosis of this disease is excellent and self-resolving. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  17. Membrane alterations in irreversibly sickled cells: hemoglobin--membrane interaction.

    PubMed

    Lessin, L S; Kurantsin-Mills, J; Wallas, C; Weems, H

    1978-01-01

    Irreversibly sickled cells (ISCs) are sickle erythrocytes which retain bipolar elongated shapes despite reoxygenation and owe their biophysical abnormalities to acquired membrane alterations. Freeze-etched membranes both of ISCs produced in vitro and ISCs isolated in vivo reveal microbodies fixed to the internal (PS) surface which obscure spectrin filaments. Intramembranous particles (IMPs) on the intramembrane (PF) surface aggregate over regions of subsurface microbodies. Electron microscopy of diaminobenzidine-treated of ISC ghosts show the microbodies to contain hemoglobin and/or hemoglobin derivatives. Scanning electron microscopy and freeze-etching demonstrate that membrane--hemoglobin S interaction in ISCs enhances the membrane loss by microspherulation. Membrane-bound hemoglobin is five times greater in in vivo ISCs than non-ISCs, and increases during ISC production, parallelling depletion of adenosine triphosphate. Polyacrylamide gel electrophoresis of ISC membranes shows the presence of high-molecular-weight heteropolymers in the pre--band 1 region, a decrease in band 4.1 and an increase in bands 7, 8, and globin. The role of cross-linked membrane protein polymers in the generation of ISCs is discussed and is synthesized in terms of a unified concept for the determinants of the genesis of ISCs.

  18. Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

    ERIC Educational Resources Information Center

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Berhanu, Getenesh; Thomas, David G.; Schrader, Sarah E.; Eldridge, Devon; Kennedy, Tay; Hambidge, Michael

    2011-01-01

    Male and female infants from rural Ethiopia were tested to investigate relations among hemoglobin (Hb), anthropometry, and attention. A longitudinal design was used to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron…

  19. Human macrophage hemoglobin-iron metabolism in vitro

    SciTech Connect

    Custer, G.; Balcerzak, S.; Rinehart, J.

    1982-01-01

    An entirely in vitro technique was employed to characterize hemoglobin-iron metabolism by human macrophages obtained by culture of blood monocytes and pulmonary alveolar macrophages. Macrophages phagocytized about three times as many erythrocytes as monocytes and six times as many erythrocytes as pulmonary alveolar macrophages. The rate of subsequent release of /sup 59/Fe to the extracellular transferrin pool was two- to fourfold greater for macrophages as compared to the other two cell types. The kinetics of /sup 59/Fe-transferrin release were characterized by a relatively rapid early phase (hours 1-4) followed by a slow phase (hours 4-72) for all three cell types. Intracellular movement of iron was characterized by a rapid shift from hemoglobin to ferritin that was complete with the onset of the slow phase of extracellular release. A transient increase in /sup 59/Fe associated with an intracellular protein eluting with transferrin was also observed within 1 hour after phagocytosis. The process of hemoglobin-iron release to extracellular transferrin was inhibited at 4 degrees C but was unaffected by inhibitory of protein synthesis, glycolysis, microtubule function, and microfilament function. These data emphasize the rapidity of macrophage hemoglobin iron metabolism, provide a model for characterization of this process in vitro, and in general confirm data obtained utilizing in vivo animal models.

  20. Carbon monoxide binding to human hemoglobin A0.

    PubMed

    Di Cera, E; Doyle, M L; Connelly, P R; Gill, S J

    1987-10-06

    The carbon monoxide binding curve to human hemoglobin A0 has been measured to high precision in experimental conditions of 600 microM heme, 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid, 0.1 M NaCl, 10 mM inositol hexaphosphate, 1 mM disodium ethylenediaminetetraacetic acid, pH 6.94, and 25 degrees C. Comparison to the oxygen binding curve in the same experimental conditions demonstrates that the two curves are not parallel. This result invalidates Haldane's two laws for the partitioning between carbon monoxide and oxygen to human hemoglobin. The partition coefficient is found to be 263 +/- 27 at high saturation, in agreement with previous studies, but is lowered substantially at low saturation. Although the oxygen and carbon monoxide binding curves are not parallel, both show the population of the triply ligated species to be negligible. The molecular mechanism underlying carbon monoxide binding to hemoglobin is consistent with the allosteric model [Di Cera, E., Robert, C. H., & Gill, S. J. (1987) Biochemistry 26, 4003-4008], which accounts for the negligible contribution of the triply ligated species in the oxygen binding reaction to hemoglobin [Gill, S. J., Di Cera, E., Doyle, M. L., Bishop, G. A., & Robert, C. H. (1987) Biochemistry 26, 3995-4002]. The nature of the different binding properties of carbon monoxide stems largely from the lower partition coefficient of the T state (123 +/- 34), relative to the R state (241 +/- 19).(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Anemia and hemoglobin levels among Indigenous Xavante children, Central Brazil.

    PubMed

    Ferreira, Aline Alves; Santos, Ricardo Ventura; Souza, July Anne Mendonça de; Welch, James R; Coimbra, Carlos E A

    2017-01-01

    To evaluate the prevalence of anemia, mean hemoglobin levels, and the main nutritional, demographic, and socioeconomic factors among Xavante children in Mato Grosso State, Brazil. A survey was conducted with children under 10 years of age in two indigenous Xavante communities within the Pimentel Barbosa Indigenous Reserve. Hemoglobin concentration levels, anthropometric measurements, and socioeconomic/demographic data were collected by means of clinical measurements and structured interviews. The cut-off points recommended by the World Health Organization were used for anemia classification. Linear regression analyses with hemoglobin as the outcome and Poisson regression with robust variance and with the presence or absence of anemia as outcomes were performed (95%CI). Lower mean hemoglobin values were observed in children under 2 years of age, without a significant difference between sexes. Anemia was observed among 50.8% of children overall, with the highest prevalence among children under 2 years of age (77.8%). Age of the child was inversely associated with the occurrence of anemia (adjusted PR = 0.60; 95%CI 0.38-0.95) and mean hemoglobin values increased significantly with age. Greater height-for-age z-score values reduced the probability of having anemia by 1.8 times (adjusted PR = 0.59; 95%CI 0.34-1.00). Presence of another child with anemia within the household increased the probability of the occurrence of anemia by 52.9% (adjusted PR = 1.89; 95%CI 1.16-3.09). Elevated levels of anemia among Xavante children reveal a disparity between this Indigenous population and the national Brazilian population. Results suggest that anemia is determined by complex and variable relationships between socioeconomic, sociodemographic, and biological factors.

  2. Purification of diverse hemoglobins by metal salt precipitation.

    PubMed

    Zimmerman, Devon; Dienes, Jack; Abdulmalik, Osheiza; Elmer, Jacob J

    2016-09-01

    Although donated blood is the preferred material for transfusion, its limited availability and stringent storage requirements have motivated the development of blood substitutes. The giant extracellular hemoglobin (aka erythrocruorin) of the earthworm Lumbricus terrestris (LtEc) has shown promise as a blood substitute, but an efficient purification method for LtEc must be developed to meet the potential large demand for blood substitutes. In this work, an optimized purification process that uses divalent and trivalent metal salts to selectively precipitate human, earthworm, and bloodworm hemoglobin (HbA, LtEc, and GdHb, respectively) from crude solutions was developed. Although several metal ions were able to selectively precipitate LtEc, Zn(2+) and Ni(2+) provided the lowest heme oxidation and highest overall yield of LtEc. In contrast, Zn(2+) was the only metal ion that completely precipitated HbA and GdHb. Polyacrylamide gel electrophoresis (PAGE) analysis shows that metal precipitation removes several impurities to provide highly pure hemoglobin samples. Heme oxidation levels were relatively low for Zn(2+)-purified HbA and LtEc (2.4±1.3% and 5.3±2.1%, respectively), but slightly higher for Ni(2+)-purified LtEc (8.4±1.2%). The oxygen affinity and cooperativity of the precipitated samples are also identical to samples purified with tangential flow filtration (TFF) alone, indicating the metal precipitation does not significantly affect the function of the hemoglobins. Overall, these results show that hemoglobins from several different species can be highly purified using a combination of metal (Zn(2+)) precipitation and tangential flow filtration. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Manipulation of hemoglobin expression affects Arabidopsis shoot organogenesis.

    PubMed

    Wang, Yaping; Elhiti, Mohamed; Hebelstrup, Kim H; Hill, Robert D; Stasolla, Claudio

    2011-10-01

    Over the past few years non-symbiotic plant hemoglobins have been described in a variety of plant species where they fulfill several functions ranging from detoxification processes to basic aspects of plant growth and post-embryonic development. To date no information is available on the role of hemoglobins during in vitro morphogenesis. Shoot organogenesis was induced in Arabidopsis lines constitutively expressing class 1, 2 and 3 hemoglobins (GLB1, 2 and 3) and lines in which the respective genes were either downregulated by RNAi (GLB1) or knocked out (GLB2 and GLB3). The process was executed by culturing root explants on an initial auxin-rich callus induction medium (CIM) followed by a transfer onto a cytokinin-containing shoot induction medium (SIM). While the repression of GLB2 inhibited organogenesis the over-expression of GLB1 or GLB2 enhanced the number of shoots produced in culture, and altered the transcript levels of genes participating in cytokinin perception and signalling. The up-regulation of GLB1 or GLB2 activated CKI1 and AHK3, genes encoding cytokinin receptors and affected the transcript levels of cytokinin responsive regulators (ARRs). The expression of Type-A ARRs (ARR4, 5, 7, 15, and 16), feed-back repressors of the cytokinin pathway, was repressed in both hemoglobin over-expressors whereas that of several Type-B ARRs (ARR2, 12, and 13), transcription activators of cytokinin-responsive genes, was induced. Such changes enhanced the sensitivity of the root explants to cytokinin allowing the 35S::GLB1 and 35S::GLB2 lines to produce shoots at low cytokinin concentrations which did not promote organogenesis in the WT line. These results show that manipulation of hemoglobin can modify shoot organogenesis in Arabidopsis and possibly in those systems partially or completely unresponsive to applications of exogenous cytokinins.

  4. Low NO Concentration Dependence of Reductive Nitrosylation Reaction of Hemoglobin*

    PubMed Central

    Tejero, Jesús; Basu, Swati; Helms, Christine; Hogg, Neil; King, S. Bruce; Kim-Shapiro, Daniel B.; Gladwin, Mark T.

    2012-01-01

    The reductive nitrosylation of ferric (met)hemoglobin is of considerable interest and remains incompletely explained. We have previously observed that at low NO concentrations the reaction with tetrameric hemoglobin occurs with an observed rate constant that is at least 5 times faster than that observed at higher concentrations. This was ascribed to a faster reaction of NO with a methemoglobin-nitrite complex. We now report detailed studies of this reaction of low NO with methemoglobin. Nitric oxide paradoxically reacts with ferric hemoglobin with faster observed rate constants at the lower NO concentration in a manner that is not affected by changes in nitrite concentration, suggesting that it is not a competition between NO and nitrite, as we previously hypothesized. By evaluation of the fast reaction in the presence of allosteric effectors and isolated β- and α-chains of hemoglobin, it appears that NO reacts with a subpopulation of β-subunit ferric hemes whose population is influenced by quaternary state, redox potential, and hemoglobin dimerization. To further characterize the role of nitrite, we developed a system that oxidizes nitrite to nitrate to eliminate nitrite contamination. Removal of nitrite does not alter reaction kinetics, but modulates reaction products, with a decrease in the formation of S-nitrosothiols. These results are consistent with the formation of NO2/N2O3 in the presence of nitrite. The observed fast reductive nitrosylation observed at low NO concentrations may function to preserve NO bioactivity via primary oxidation of NO to form nitrite or in the presence of nitrite to form N2O3 and S-nitrosothiols. PMID:22493289

  5. Hemoglobin Kinetics and Long-term Prognosis in Heart Failure.

    PubMed

    Díez-López, Carles; Lupón, Josep; de Antonio, Marta; Zamora, Elisabet; Domingo, Mar; Santesmases, Javier; Troya, Maria-Isabel; Boldó, Maria; Bayes-Genis, Antoni

    2016-09-01

    The influence of hemoglobin kinetics on outcomes in heart failure has been incompletely established. Hemoglobin was determined at the first visit and at 6 months. Anemia was defined according to World Health Organization criteria (hemoglobin < 13g/dL for men and hemoglobin < 12g/dL for women). Patients were classified relative to their hemoglobin values as nonanemic (both measurements normal), transiently anemic (anemic at the first visit but not at 6 months), newly anemic (nonanemic initially but anemic at 6 months), or permanently anemic (anemic in both measurements). A total of 1173 consecutive patients (71.9% men, mean age 66.8±12.2 years) were included in the study. In all, 476 patients (40.6%) were considered nonanemic, 170 (14.5%) had transient anemia, 147 (12.5%) developed new-onset anemia, and 380 (32.4%) were persistently anemic. During a follow-up of 3.7±2.8 years after the 6-month visit, 494 patients died. On comprehensive multivariable analyses, anemia (P < .001) and the type of anemia (P < .001) remained as independent predictors of all-cause mortality. Compared with patients without anemia, patients with persistent anemia (hazard ratio [HR] = 1.62; 95% confidence interval [95%CI], 1.30-2.03; P < .001) and new-onset anemia (HR = 1.39; 95%CI, 1.04-1.87, P = .03) had higher mortality, and even transient anemia showed a similar trend, although without reaching statistical significance (HR = 1.31; 95%CI, 0.97-1.77, P = .075). Anemia, especially persistent and of new-onset, and to a lesser degree, transient anemia, is deleterious in heart failure. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  6. [Hemoglobin adducts as biomarkers of human exposure to selected xenobiotics].

    PubMed

    Bukowska, Bożena

    2015-06-12

    In the living and working environments more and more new substances of anthropogenic origin exerting toxic properties appear. Simultaneously, the evaluation of human exposure is assessed. For many years adducts of hemoglobin (Hb) have been useful markers of the exposure of humans to various xenobiotics. These adducts are also termed biologically effective dose biomarkers. This paper focuses on a review of literature, mainly from the years 2010-2014, which refers to the hemoglobin adducts of toxic compounds with electrophilic properties. In the interactions of xenobiotics with hemoglobin, groups such as thiol, amino, carboxyl and hydroxyl of this hemoprotein are involved. These combinations occur most often in the reaction of xenobiotics with an N-terminal amino group of valine in Hb, imidazole nitrogen of histidine and cysteine sulfhydryl β93. Hb adducts are characterized by high availability, a long period of occurrence (up to 120 days) in the circulatory system, and high durability, and they have contact with all cells of the body. The measurement of hemoglobin adducts can be potentially used in the assessment of exposure to many xenobiotics such as acrylamide; substances present in tobacco smoke, e.g. benzo(α)pyrene and benzanthracene, ethylene oxide, aryl amines; and substances used on a large scale in industry such as glycidol and naphthalene and its derivatives. Recently the possibility of determination of hemoglobin adducts with estrogen metabolites has been postulated as indicators informing about heightened risk of breast cancer. Protein adducts are used as an alternative to DNA adducts for different classes of electrophilic substances.

  7. Plant hemoglobins: a molecular fossil record for the evolution of oxygen transport.

    PubMed

    Hoy, Julie A; Robinson, Howard; Trent, James T; Kakar, Smita; Smagghe, Benoit J; Hargrove, Mark S

    2007-08-03

    The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport "leghemoglobins" evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins.

  8. Genetic Differences in Hemoglobin as Markers for Bone Marrow Transplantation in Mice

    DTIC Science & Technology

    1959-03-01

    derived. Thus, genetic differences in hemoglobin can be used as markers for bone marrow transplantation in irradiated mice. Hemoglobin typing may be particularly useful where the H-2 markers cannot be used.

  9. Plant Hemoglobins: A Molecular Fossil Record for the Evolutin of Oxygen Transport

    SciTech Connect

    Hoy,J.; Robinson, H.; Trent, lll, J.; Kakar, S.; Smagghe, B.; Hargrove, M.

    2007-01-01

    The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport 'leghemoglobins' evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins.

  10. Phenotypic expression of hemoglobins A₂, E and F in various hemoglobin E related disorders.

    PubMed

    Sae-ung, Nattaya; Srivorakun, Hataichanok; Fucharoen, Goonnapa; Yamsri, Supawadee; Sanchaisuriya, Kanokwan; Fucharoen, Supan

    2012-01-15

    Study on the phenotypic expression of hemoglobin (Hb) A(2) and Hb E in Hb E disorders has been difficult due to the co-separation of Hb A(2) and Hb E in most Hb analysis assays. Because these two Hbs are separated on capillary electrophoresis, we studied phenotypic expression of Hbs A(2), E and F in various Hb E disorders using this system. This was done on 362 subjects with several Hb E disorders including heterozygous Hb E, homozygous Hb E, β-thalassemia/Hb E, δβ-thalassemia/Hb E, and Hb Lepore/Hb E and those of these disorders with several forms of α-thalassemia. Normal controls showed Hb A(2) of 2.7 ± 0.3%. Heterozygous Hb E and homozygous Hb E had elevated Hb A(2) i.e. 3.8 ± 0.3% and 4.8 ± 0.5%, respectively. Further elevations were observed for β(0)-thalassemia/Hb E (6.1 ± 1.9%) and β(+)-thalassemia/Hb E (7.1 ± 1.2%). Interestingly, no elevation of Hb A(2) was found in the δβ-thalassemia/Hb E, and Hb Lepore/Hb E (2.3 ± 0.3%) but higher Hb F levels were noted which could be useful diagnostic markers. The levels of Hb E were variable. Co-inheritance of these Hb E disorders with α-thalassemia were associated with lower outputs of Hb E and Hb F but the levels of Hb A(2) were not altered. Different phenotypic expression of Hb A(2), Hb E and Hb F could help in differential diagnosis of these Hb E related disorders commonly encountered in the regions where access to molecular techniques is limited. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Variability of hemoglobin F expression in hemoglobin EE disease: hematological and molecular analysis.

    PubMed

    Pakdee, Naruwat; Yamsri, Supawadee; Fucharoen, Goonnapa; Sanchaisuriya, Kanokwan; Pissard, Serge; Fucharoen, Supan

    2014-01-01

    Although the molecular basis of variability of hemoglobin (Hb) F has been extensively examined in β-thalassemia and sickle cell diseases, less study has been done on Hb E disorder. To address the variability of Hb F expression in Hb EE disease, we have examined multiple single nucleotide polymorphisms (SNPs) in the β-globin gene cluster, BCL11A and HBS1L-MYB genes and determined their associations with Hb F levels in this syndrome. Study was done on 141 adult Thai individuals with homozygous Hb E. Hematological parameters were recorded and Hb F measured using Hb-HPLC analyzer. It was found in 26 cases that co-inheritance of α-thalassemia could lead to significant lower production of Hb F. Association of Hb F expression with the (G)γ-Xmn I polymorphism and other SNPs including rs2297339, rs2838513, rs4895441 and rs9399137 in HBS1L-MYB gene and rs4671393 and rs11886868 in BCL11A gene was therefore analyzed in the remaining 115 cases without α-thalassemia. It was found that 4 of these 7 SNPs including (G)γ-XmnI polymorphism (rs7482144), HBS1L-MYB (rs4895441) and (rs9399137) and BCL11A (rs4671393) were significantly associated with higher proportions of subjects with high Hb F (Hb F≥5%). The result demonstrated that multiple genetic modifying factors including T allele of (G)γ-XmnI polymorphism (rs7482144), G allele of HBS1L-MYB (rs489441), C allele of HBS1L-MYB (rs9399137) and C allele of BCL11A (rs4671393) are associated with increased Hb F and in combination could explain approximately 80% of the variation of Hb F in Hb EE disease in Thai population. Other genetic factors regulating Hb F expression in this common genetic disorder remains to be elucidated. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Targeted O2 delivery by low-p50 hemoglobin: a new basis for hemoglobin-based oxygen carriers.

    PubMed

    Winslow, Robert M

    2005-01-01

    We have proposed new criteria for a successful cell-free, hemoglobin-based O2 carrier. These include increased molecular radius, increased viscosity, increased oncotic pressure, and reduced p50. A new molecule, MalPEG-Hb, formulated at 4.2g/dL in lactated Ringer's solution (MP4), has been produced according to these new criteria. MP4 has a p50 of 5-6 mm Hg, oncotic pressure of 49mm Hg and viscosity of 2.2cPs. After 50% exchange transfusion with MP4, rats survive a 60% controlled hemorrhage in spite of total hemoglobin of 7.8 g/dL and plasma hemoglobin concentration of 1.6 g/dL. This model results in 50% mortality in control animals and 100% mortality in animals exchange-transfused with either crosslinked or polymerized hemoglobin. Oxygen supply to tissue was measured directly in the hamster skinfold model, in which O2 release in precapillary and capillary vessels can be quantified. The data demonstrate that the effectiveness of MP4 results from its ability to conserve O2 in precapillary vessels and release O2 in capillaries, thereby "targeting" O2 to hypoxic tissue. Preservation of functional capillary density and prevention of vasoconstriction further contribute to the effectiveness of this new formulation.

  13. Phase characterization of oscillatory components of the cerebral concentrations of oxy-hemoglobin and deoxy-hemoglobin

    NASA Astrophysics Data System (ADS)

    Pierro, Michele; Sassaroli, Angelo; Zheng, Feng; Fantini, Sergio

    2011-02-01

    We present a study of the relative phase of oscillations of cerebral oxy- and deoxy-hemoglobin concentrations in the low-frequency range, namely 0.04-0.12 Hz. We have characterized the potential contributions of noise to the measured phase distributions, and we have performed phase measurements on the brain of a human subject at rest, and on the brain of a human subject during stage I sleep. While phase distributions of pseudo hemodynamic oscillations generated from noise (obtained by applying to two independent sets of random numbers the same linear transformation that converts absorption coefficients at 690 and 830 nm into concentrations of oxy- and deoxy-hemoglobin) are peaked at 180º, those associated with real hemodynamic changes can be peaked around any value depending on the underlying physiology and hemodynamics. In particular, preliminary results reported here indicate a greater phase lead of deoxy-hemoglobin vs. oxy-hemoglobin low-frequency oscillations during stage I sleep (82º +/- 55º) than while the subject is awake (19º +/- 58º).

  14. Near-infrared absorbance measurements of hemoglobin solutions incubated with glucose

    NASA Astrophysics Data System (ADS)

    Zhernovaya, Olga S.; Tuchin, Valery V.; Meglinski, Igor; Ritchie, Laurie

    2007-02-01

    It is known that glucose influences on spectral properties of blood and hemoglobin and interacts with plasma proteins and hemoglobin in erythrocytes. Changes of optical properties of blood and hemoglobin at glucose concentration within physiological level are important for diagnosis and monitoring of diabetes. The purpose of this study is to investigate the effect of presence of glucose and glycation of hemoglobin on absorbance of aqueous hemoglobin solutions with different glucose concentrations. Measurements were taken using spectrophotometer EQUINOX 55 (Bruker Optic GmbH) in a range 1000-1800 nm. Water has absorption bands in the near-infrared region which may be influenced by glucose presence. We have hypothesized that glucose and hemoglobin, especially glycated hemoglobin, may influence the absorption band of water in solution. The hemoglobin solutions with different amount of glucose (from 0 to 1000 mg/dl with a step 100 mg/dl) were incubated up to 28 days. Our measurements show that presence of glucose affects the spectra of aqueous hemoglobin solutions. The magnitude of absorbance depends on glucose concentration. At the beginning of incubation hemoglobin solution without glucose has the lowest absorbance magnitude, but after a rather long time of incubation (28 days) the absorbance of hemoglobin solutions with glucose become smaller compared to the absorbance of hemoglobin solution without glucose. This fact may be explained by assumption of hemoglobin glycation, when glucose molecules chemically bind to hemoglobin, and water binding to hemoglobin. In the case of water binding to hemoglobin molecules the amount of free water molecules in solution decreases, so the water aborbance is excepted to decrease.

  15. Induction of Hemoglobin Accumulation in Human K562 Cells by Hemin is Reversible

    NASA Astrophysics Data System (ADS)

    Dean, Ann; Erard, Francois; Schneider, Arthur B.; Schechter, Alan N.

    1981-04-01

    Twenty micromolar hemin causes no change in the rate of division of K562 cells but results in accumulation of 11 to 14 picograms of embryonic and fetal hemoglobins per cell. This effect is reversible, and hemoglobin induction in response to hemin, and loss of hemoglobin upon removal of hemin, can be cyclically repeated. The cells can be indefinitely subcultured in the presence of the inducer. Thus, the control of hemoglobin levels in K562 cells does not depend on irreversible differentiation.

  16. Error in noninvasive spectrophotometric measurement of blood hemoglobin concentration under conditions of blood loss.

    PubMed

    Naftalovich, Rotem; Naftalovich, Daniel

    2011-10-01

    This paper discusses a current misinterpretation between different parameters of hemoglobin concentration measurement and its amplification under conditions of blood loss. The paper details the distinction between microcirculatory hematocrit and the hematocrit of the macrocirculation to analyze clinical use of real-time patient hemoglobin concentration measurement by noninvasive point-of-care devices such as the Rainbow Pulse CO-Oximetry™ (Masimo Corp., Irvine, CA). The hemoglobin concentration or hematocrit values have clinical significance such as for diagnosing anemia or as indicators to when a blood transfusion is needed. The device infers hemoglobin concentration from spectrophotometry of the fingertip and therefore the measured absorption is due to hemoglobin present in capillaries as well as in larger vessels, and the device accordingly reports the hemoglobin concentration as 'total hemoglobin' in a proprietary SpHb parameter. SpHb and macro hemoglobin concentration are different parameters. However, the numerical resemblance of SpHb values to values of macro hemoglobin concentrations, combined with the widely used unspecified term "Hb" in the medical setting, suggests that SpHb values are often interpreted by the clinician as macro hematocrit values. The claim of this paper is that under conditions of blood loss the portion of the SpHb total hemoglobin measure that is contributed from microcirculation increases, due to the decrease of macro hematocrit while microcirculatory hematocrit remains constant when above a critical value. The device is calibrated from phlembotomy drawn blood (from a vein in the arm), which is the gold standard in blood collection, and hence this changing contribution of microcirculatory hemoglobin to the SpHb value would distort the gap between macro hemoglobin and total hemoglobin, SpHb. The hypothesis is that if clinicians indeed interpret the SpHb values as macro hemoglobin values then there is an unreported discrepancy between

  17. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  18. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  19. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  20. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  1. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  2. Two-dimensional analysis of glycated hemoglobin heterogeneity in pediatric type 1 diabetes patients.

    PubMed

    Hempe, James M; McGehee, Amanda M; Chalew, Stuart A

    2013-11-15

    Interindividual and ethnic variation in glycated hemoglobin levels, unrelated to blood glucose variation, complicates the clinical use of glycated hemoglobin assays for the diagnosis and management of diabetes. Assessing the types and amounts of glycated hemoglobins present in erythrocytes could provide insight into the mechanism. Blood samples and self-monitored mean blood glucose (MBG) levels were obtained from 85 pediatric type 1 diabetes patients. Glycated hemoglobin levels were measured using three primary assays (boronate-affinity chromatography, capillary isoelectric focusing (CIEF), and standardized DCA2000+ immunoassay) and a two-dimensional (2D) analytical system consisting of boronate-affinity chromatography followed by CIEF. The 2D system separated hemoglobin into five subfractions, four of which contained glycated hemoglobins. Glycated hemoglobin measurements were compared in patients with low, moderate, or high hemoglobin glycation index (HGI), a measure of glycated hemoglobin controlled for blood glucose variation. MBG was not significantly different between HGI groups. Glycated hemoglobin levels measured by all three primary assays and in all four glycated 2D subfractions were significantly different between HGI groups and highest in high HGI patients. These results show that interindividual variation in glycated hemoglobin levels was evident in diabetes patients with similar blood glucose levels regardless of which glycated hemoglobins were measured.

  3. Crystal structure of hemoglobin from the maned wolf (Chrysocyon brachyurus) using synchrotron radiation.

    PubMed

    Fadel, Valmir; Canduri, Fernanda; Olivieri, Johnny R; Smarra, André L S; Colombo, Marcio F; Bonilla-Rodriguez, Gustavo O; de Azevedo, Walter F

    2003-12-01

    Crystal structure of hemoglobin isolated from the Brazilian maned wolf (Chrysocyon brachyurus) was determined using standard molecular replacement technique and refined using maximum-likelihood and simulated annealing protocols to 1.87A resolution. Structural and functional comparisons between hemoglobins from the Chrysocyon brachyurus and Homo sapiens are discussed, in order to provide further insights in the comparative biochemistry of vertebrate hemoglobins.

  4. Mass spectrometric analysis of tobacco-specific hemoglobin adducts.

    PubMed Central

    Schäffler, G; Betz, C; Richter, E

    1993-01-01

    Hemoglobin adducts of the common metabolite of the tobacco-specific nitrosamine (TSNA) 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) and of 4-aminobiphenyl (4-ABP) were quantified in blood samples from smokers and nonsmokers to test their suitability for biomonitoring tobacco smoke exposure. Additionally, TSNA adducts were measured in nasal snuff users. Mild alkaline treatment of hemoglobin releases 4-ABP and HPB, which were analyzed in parallel by capillary gas chromatography with electronic impact or negative ion chemical-ionization mass spectrometry (EI- or NICI-GC-MS). Samples of snuff users showed high levels of HPB adducts not correlated with the amount or type of snuff used. HPB concentrations in smokers and nonsmokers, however, were much lower, with no group-specific differences detectable. In contrast, 4-ABP adduct levels were much higher in smokers than in nonsmokers, confirming the significant difference between these two groups reported by others. PMID:8319620

  5. Predictable convergence in hemoglobin function has unpredictable molecular underpinnings.

    PubMed

    Natarajan, Chandrasekhar; Hoffmann, Federico G; Weber, Roy E; Fago, Angela; Witt, Christopher C; Storz, Jay F

    2016-10-21

    To investigate the predictability of genetic adaptation, we examined the molecular basis of convergence in hemoglobin function in comparisons involving 56 avian taxa that have contrasting altitudinal range limits. Convergent increases in hemoglobin-oxygen affinity were pervasive among high-altitude taxa, but few such changes were attributable to parallel amino acid substitutions at key residues. Thus, predictable changes in biochemical phenotype do not have a predictable molecular basis. Experiments involving resurrected ancestral proteins revealed that historical substitutions have context-dependent effects, indicating that possible adaptive solutions are contingent on prior history. Mutations that produce an adaptive change in one species may represent precluded possibilities in other species because of differences in genetic background. Copyright © 2016, American Association for the Advancement of Science.

  6. A thermodynamic model of hemoglobin suitable for physiological applications.

    PubMed

    Yoshida, T; Dembo, M

    1990-03-01

    We propose a quantitative model of the thermodynamics of hemoglobin in contact with its five major ligands (O2, CO2, Cl-, 2,3-bisphosphoglycerate, and H+). Our model incorporates the two-state formalism of J. Monod, J. Wyman, and J.P. Changeux (J. Mol. Biol. 12: 88-118, 1965) for treatment of quanternary transitions and also the mean field formalism of K. Linderstrom-Lang (C. R. Trav. Lab. Carlsberg Ser. Chim. 15: 1-30, 1924) for treatment of electrostatic interactions. On the basis of this approach, we develop an algorithm for the efficient computation of observable quantities, such as the occupancy of various ligand binding sites, and an objective statistical procedure for determining both maximum likelihood values and confidence limits of all the intrinsic thermodynamic parameters of hemoglobin. Finally, we show that the predictions of our theory are in good agreement with independent experimental observations.

  7. Virucidal levels of ozone induce hemolysis and hemoglobin degradation

    SciTech Connect

    Wagner, S.J.; Wagner, K.F.; Friedman, L.I.; Benade, L.F. )

    1991-10-01

    The animal virus, vesicular stomatitis virus (VSV), and the bacterial virus, phi 6, were inactivated by greater than 4 log10 in response to incubation with 13 to 14 mL of 1.4 mmol per L (65 micrograms/mL) to 1.6 mmol per L (75 micrograms/mL) of overlaid ozone in virus-spiked, dilute, red cell suspensions. Virus inactivation was greatly inhibited when ozone was overlaid in the presence of high-hematocrit red cells or, to a lesser degree, high levels of plasma. At hematocrits at which 5 to 6 log10 of VSV were inactivated, ozone caused 30-percent hemolysis, as measured by the loss of total cellular hemoglobin. Unexpectedly, this level of hemolysis could not be observed in supernatants because of the ozone-induced destruction (bleaching) of extracellular hemoglobin. These results suggest that ozone may have little biological specificity for damaging viruses over red cells.

  8. Liposomes surface conjugated with human hemoglobin target delivery to macrophages

    PubMed Central

    Zhang, Ning; Palmer, Andre F.

    2012-01-01

    Current strategies to deliver therapeutic molecules to specific cell and tissue types rely on conjugation of antibodies and other targeting ligands directly to the therapeutic molecule itself or its carrier. This work describes a novel strategy to deliver therapeutic molecules into macrophages that takes advantage of the native hemoglobin (Hb) scavenging activity of plasma haptoglobin (Hp) and the subsequent uptake of the Hb-Hp complex into macrophages via CD163 receptor mediated endocytosis. The drug delivery system described in this work consists of hemoglobin decorated liposomes that can encapsulate any therapeutic molecule of interest, in this case the model fluorescent dye calcein was used in this study. The results of this study clearly demonstrate that this delivery system is specific towards macrophages and demonstrates the feasibility of using this approach in targeted drug delivery. PMID:22012493

  9. Neonatal Cyanosis Due to Hemoglobin Variant: Hb F-Sarajevo.

    PubMed

    Lozar-Krivec, Jana; Stepic, Maja; Hovnik, Tinka; Krsnik, Mladen; Paro-Panjan, Darja

    2016-10-01

    Neonatal cyanosis is rarely due to hemoglobin variants with low oxygen affinity. We describe the clinical course and results of molecular genetic analysis of a boy who presented after birth with severe cyanosis. Arterial blood-gas analysis demonstrated a pronounced shift of the oxygen-hemoglobin dissociation curve to the right and molecular genetic analysis revealed a γ-globin variant, Hb F-Sarajevo. The patient presented is the second reported case of neonatal cyanosis due to this mutation, which was first described in 2012 by Zimmermann-Baer and coauthors. With the introduction of universal screening for congenital heart disease, the finding of low oxygen saturation will uncover more neonates with hemoglobinopathies with low oxygen affinity.

  10. Hemoglobin C trait accentuates erythrocyte dehydration in hereditary xerocytosis.

    PubMed

    Yang, Elizabeth; Voelkel, Erin B; Lezon-Geyda, Kimberly; Schulz, Vincent P; Gallagher, Patrick G

    2017-08-01

    A 17-year-old male presented with acute hemolysis with stomatocytosis, elevated mean corpuscular hemoglobin concentration (MCHC), and osmotic gradient ektacytometry consistent with marked erythrocyte dehydration. Erythrocytes from both parents also demonstrated evidence of dehydration with elevated MCHC and abnormal ektacytometry, but neither to the degree of the patient. Genetic studies revealed the patient had hereditary xerocytosis (HX) due to a novel PIEZO1 mutation inherited from his mother and hemoglobin C (HbC) trait inherited from his father. HbC trait accentuated the erythrocyte dehydration of HX. Coinheritance of interrelated disorders and/or modifier alleles should be considered whenever severe erythrocyte dehydration is observed. © 2017 Wiley Periodicals, Inc.

  11. Double filaments in fibers and crystals of deoxygenated hemoglobin S

    SciTech Connect

    Magdoff-Fairchild, B.; Chiu, C.C.

    1980-10-01

    Sickle cell hemoglobin (HbS) molecules in solution or in SS erythrocytes (those from individuals homozygous for the sickle hemoglobin gene), when deoxygenated, aggregate to form fibers that pack into paracrystalline arrays. The diminished oxygen affinity of HbS is produced by the polymerization, and the distortion of the pliant erythrocyte membrane is produced by the polymerization, and the distortion of the pliant erythrocyte membrane in sickle cell disease results from the elongation of polymers and their subsequent alignment. One of the important problems to be solved in sickle cell disease is the definition of the intermolecular interactions that stabilize the fiber structure. Knowledge of these interactions might lead to the design of stereospecific antisickling agents for clinical use that could inhibit polymerization or could at least destabilize the fiber.

  12. [The critical hemoglobin/hematocrit value in obstetrics].

    PubMed

    Huch, R

    1992-01-01

    During pregnancy, there are characteristics changes in the hemoglobin and hematocrit values. Compared with the norm for nonpregnant women, there is an increase in the total number of erythrocytes and in the plasma volume. An overproportional increase of the latter results in hydremia. The normal physiologic range for hemoglobin during pregnancy is 11.5-13.0 (13.5) g/dl; anemia is, by definition, present when the values are under 11 g/dl and is quite common in pregnancy. Since it is caused almost exclusively (95%) by iron deficiency, iron therapy or routine iron supplementation can influence its incidence. Values outside the norm range are associated with complications during pregnancy and with growth retardation of the fetus.

  13. [The effect of peroxynitrite on the affinity of hemoglobin for oxygen in vitro].

    PubMed

    2006-01-01

    The aim of the study was to estimate the influence of peroxynitrite on the affinity of hemoglobin for oxygen in vitro. It was shown that the incubation of venous blood with peroxynitrite resulted in a rise of affinity of hemoglobin for oxygen. Presumably, this effect is realized through the generation of various forms of hemoglobin: heme-oxidized and modified at the amino acid residues of the protein. The dependence of the results of hemoglobin-peroxynitrite reaction on the carbon dioxide tension and the saturation of hemoglobin by oxygen is discussed.

  14. Noninvasive investigation of skin local hypothermia influence upon local oxygenation and hemoglobin concentration

    NASA Astrophysics Data System (ADS)

    Douplik, Alexandre Y.; Kessler, Manfred D.; Kakihana, Yasuyuki; Krug, Alfons

    1997-08-01

    Functional evaluation of local hemoglobin concentration and hemoglobin oxygenation based on back scattering spectra from human skin in vivo have been obtained in visible range (502 - 628 nm) by a rapid microlightguide spectrometer (EMPHO II) with step 250 micrometer. Analysis of received results has shown that during local cooling there is two nearly simultaneous reactions: reduction of hemoglobin concentration and increase of hemoglobin oxygenation level. In a case when one has used previous heating of planning place for cooling, reduction of hemoglobin concentration is expressed higher by 22 - 33%.

  15. Hemoglobin Status and Externalizing Behavioral Problems in Children

    PubMed Central

    Su, Jianhua; Cui, Naixue; Zhou, Guoping; Ai, Yuexian; Sun, Guiju; Zhao, Sophie R.; Liu, Jianghong

    2016-01-01

    Background: Still considered one of the most prevalent nutritional problems in the world, anemia has been shown in many studies to have deleterious effects on neurobehavioral development. While most research efforts have focused on investigating the effects of anemia on social and emotional development of infants by using a cross-sectional design, research is still needed to investigate whether early childhood anemia, beyond infantile years, is linked with behavioral problems. Objective: This study assessed whether (1) hemoglobin (Hb) levels in early childhood are associated with externalizing behavior; and (2) this relationship is confounded by social adversity. Methods: Hemoglobin levels were taken from children (N = 98) of the China Jintan Cohort Study at age 4 years, and externalizing behaviors (attention and aggression) were assessed with the Child Behavior Checklist (ASEBA-CBCL) at age 6 years (mean age 5.77 ± 0.39 years old). Results: Compared with other children in the sample, children with relatively lower Hb levels at age 4 had more behavioral problems in both attention and aggression at age 6, independent of social adversity. For boys, this association was significant for attention problems, which did not interact with social adversity. For girls, the association was significant for aggression, which interacted with social adversity. While girls on average exhibited higher social adversity than boys, the main effect of Hb was only significant in girls with low social adversity. Conclusions: These results indicate that there is an inverse association between hemoglobin levels and later behavioral problems. Findings of this study suggest that regular monitoring of children’s hemoglobin levels and appropriate intervention may help with early identification of behavioral problems. PMID:27472352

  16. Site-specific semisynthetic variant of human hemoglobin

    SciTech Connect

    Hefta, S.A.; Lyle, S.B.; Busch, M.R.; Harris, D.E.; Matthew, J.B.; Gurd, F.R.N.

    1988-02-01

    A single round of Edman degradation was employed to remove the NH/sub 2/-terminal valine from isolated ..cap alpha.. chains of human hemoglobin. Reconstitution of normal ..beta.. chains with truncated or substituted ..cap alpha.. chains was used to form truncated (des-Val/sup 1/-..cap alpha..1) and substituted (((1-/sup 13/C)Gly/sup 1/)..cap alpha..1) tetrameric hemoglobin analogs. Structural homology of the analogs with untreated native hemoglobin was established by using several spectroscopic and physical methods. Functional studies indicate that the reconstituted tetrameric protein containing des-Val/sup 1/-..cap alpha.. chains has a higher affinity for oxygen, is less influenced by chloride ions or 2,3-biphosphoglycerate, and shows lower cooperativity than native hemoglobin. These results confirm the key functional role of the ..cap alpha..-chain NH/sub 2/ terminus in mediating cooperative oxygen binding across the dimer interface. The NH/sub 2/-terminal pK/sub 1/2/ value was determined for the (/sup 13/C)glycine-substituted analog to be 7.46 +/- 0.09 at 15/sup 0/C in the carbon monoxide-liganded form. This value, measured directly by /sup 13/C NMR, agrees with the determination made by the less-direct /sup 13/CO/sub 2/ method and confirms the role of this residue as a contributor to the alkaline Bohr effect; however, it is consistent with the presence of an NH/sub 2/-terminal salt bridge to the carboxylate of Arg-141 of the ..cap alpha.. chain in the liganded form.

  17. Hepcidin level predicts hemoglobin concentration in individuals undergoing repeated phlebotomy.

    PubMed

    Mast, Alan E; Schlumpf, Karen S; Wright, David J; Johnson, Bryce; Glynn, Simone A; Busch, Michael P; Olbina, Gordana; Westerman, Mark; Nemeth, Elizabeta; Ganz, Tomas

    2013-08-01

    Dietary iron absorption is regulated by hepcidin, an iron regulatory protein produced by the liver. Hepcidin production is regulated by iron stores, erythropoiesis and inflammation, but its physiology when repeated blood loss occurs has not been characterized. Hepcidin was assayed in plasma samples obtained from 114 first-time/reactivated (no blood donations in preceding 2 years) female donors and 34 frequent (≥3 red blood cell donations in preceding 12 months) male donors as they were phlebotomized ≥4 times over 18-24 months. Hepcidin levels were compared to ferritin and hemoglobin levels using multivariable repeated measures regression models. Hepcidin, ferritin and hemoglobin levels declined with increasing frequency of donation in the first-time/reactivated females. Hepcidin and ferritin levels correlated well with each other (Spearman's correlation of 0.74), but on average hepcidin varied more between donations for a given donor relative to ferritin. In a multivariable repeated measures regression model the predicted inter-donation decline in hemoglobin varied as a function of hepcidin and ferritin; hemoglobin was 0.51 g/dL lower for subjects with low (>45.7 ng/mL) or decreasing hepcidin and low ferritin (>26 ng/mL), and was essentially zero for other subjects including those with high (>45.7 ng/mL) or increasing hepcidin and low ferritin (>26 ng/mL) levels (P<0.001). In conclusion, hepcidin levels change rapidly in response to dietary iron needed for erythropoiesis. The dynamic regulation of hepcidin in the presence of a low levels of ferritin suggests that plasma hepcidin concentration may provide clinically useful information about an individual's iron status (and hence capacity to tolerate repeated blood donations) beyond that of ferritin alone. Clinicaltrials.gov identifier: NCT00097006.

  18. A model for ligand binding to hexacoordinate hemoglobins.

    PubMed

    Trent, J T; Hvitved, A N; Hargrove, M S

    2001-05-22

    Hexacoordinate hemoglobins are heme proteins capable of reversible intramolecular coordination of the ligand binding site by an amino acid side chain from within the heme pocket. Examples of these proteins are found in many living organisms ranging from prokaryotes to humans. The nonsymbiotic hemoglobins (nsHbs) are a class of hexacoordinate heme proteins present in all plants. The nsHb from rice (rHb1) has been used as a model system to develop methods for determining rate constants characterizing binding and dissociation of the His residue responsible for hexacoordination. Measurement of these reactions exploits laser flash photolysis to initiate the reaction from the unligated, pentacoordinate form of the heme protein. A model for ligand binding is presented that incorporates the reaction following rapid mixing with the reaction starting from the pentacoordinate hemoglobin (Hb). This model is based on results indicating that ligand binding to hexacoordinate Hbs is not a simple combination of competing first order (hexacoordination) and second order (exogenous ligand binding) reactions. Ligand binding following rapid mixing is a multiphasic reaction displaying time courses ranging from milliseconds to minutes. The new model incorporates a "closed", slow reacting form of the protein that is not at rapid equilibrium with the reactive conformation. It is also demonstrated that formation of the closed protein species is not dependent on hexacoordination.

  19. Vibrational modes of hemoglobin in red blood cells.

    PubMed

    Martel, P; Calmettes, P; Hennion, B

    1991-02-01

    Equine red blood cells were washed in saline heavy water (2H2O) to exchange the hydrogen atoms of the non-hemoglobin components with deuterons. This led to novel neutron scattering measurements of protein vibrations within a cellular system and permitted a comparison with inelastic neutron scattering measurements on purified horse hemoglobin, either dry or wetted with 2H2O. As a function of wavevector transfer Q and the frequency transfer v the neutron response typified by the dynamic structure factor S(Q, v) was found to be similar for extracted and cellular hemoglobin at low and high temperatures. At 77 K, in the cells, a peak in S(Q, v) due to the protein was found near 0.7 THz, approximately half the frequency of a strong peak in the aqueous medium. Measurements at higher temperatures (170 and 230 K) indicated similar small shifts downwards in the peak frequencies of both components. At 260 K the low frequency component became predominantly quasielastic, but a significant inelastic component could still be ascribed to the aqueous scattering. Near 295 K the frequency responses of both components were similar and centered near zero. When scattering due to water is taken into account it appears that the protein neutron response in, or out of, red blood cells is little affected by hydration in the low frequency regime where Van der Waals forces are thought to be effective.

  20. Vibrational modes of hemoglobin in red blood cells.

    PubMed Central

    Martel, P; Calmettes, P; Hennion, B

    1991-01-01

    Equine red blood cells were washed in saline heavy water (2H2O) to exchange the hydrogen atoms of the non-hemoglobin components with deuterons. This led to novel neutron scattering measurements of protein vibrations within a cellular system and permitted a comparison with inelastic neutron scattering measurements on purified horse hemoglobin, either dry or wetted with 2H2O. As a function of wavevector transfer Q and the frequency transfer v the neutron response typified by the dynamic structure factor S(Q, v) was found to be similar for extracted and cellular hemoglobin at low and high temperatures. At 77 K, in the cells, a peak in S(Q, v) due to the protein was found near 0.7 THz, approximately half the frequency of a strong peak in the aqueous medium. Measurements at higher temperatures (170 and 230 K) indicated similar small shifts downwards in the peak frequencies of both components. At 260 K the low frequency component became predominantly quasielastic, but a significant inelastic component could still be ascribed to the aqueous scattering. Near 295 K the frequency responses of both components were similar and centered near zero. When scattering due to water is taken into account it appears that the protein neutron response in, or out of, red blood cells is little affected by hydration in the low frequency regime where Van der Waals forces are thought to be effective. PMID:1849028

  1. Hemoglobin dynamics in red blood cells: correlation to body temperature.

    PubMed

    Stadler, A M; Digel, I; Artmann, G M; Embs, J P; Zaccai, G; Büldt, G

    2008-12-01

    A transition in hemoglobin behavior at close to body temperature has been discovered recently by micropipette aspiration experiments on single red blood cells (RBCs) and circular dichroism spectroscopy on hemoglobin solutions. The transition temperature was directly correlated to the body temperatures of a variety of species. In an exploration of the molecular basis for the transition, we present neutron scattering measurements of the temperature dependence of hemoglobin dynamics in whole human RBCs in vivo. The data reveal a change in the geometry of internal protein motions at 36.9 degrees C, at human body temperature. Above that temperature, amino acid side-chain motions occupy larger volumes than expected from normal temperature dependence, indicating partial unfolding of the protein. Global protein diffusion in RBCs was also measured and the findings compared favorably with theoretical predictions for short-time self-diffusion of noncharged hard-sphere colloids. The results demonstrated that changes in molecular dynamics in the picosecond time range and angstrom length scale might well be connected to a macroscopic effect on whole RBCs that occurs at body temperature.

  2. Chronic mountain sickness, optimal hemoglobin, and heart disease.

    PubMed

    Vargas, Enrique; Spielvogel, Hilde

    2006-01-01

    For the male inhabitants of La Paz, Bolivia (3200-4100 m), and other high altitude regions in America and Asia, chronic mountain sickness (CMS) is a major health problem. Since CMS was first described by Carlos Monge in the Peruvian Andes in 1925, numerous research papers have been devoted to this topic, but many unanswered questions still exist with respect to the beginning of the disease and its cause(s). The experience with CMS has shown that an excessively high hemoglobin concentration is not favorable for high altitude acclimatization, and the hypothesis of theoretically "optimal" hematocrit and "optimal" hemoglobin has been made. The calculated optimal hemoglobin concentration of 14.7 g/dL for resting men in the Andes is discussed as theoretical and not applicable in real life. The most frequent congenital and acquired heart diseases are discussed, such as patent ductus, atrial septum defect, ventricle septum defect among congenital heart diseases and the still very frequent rheumatic valve cardiopathies and Chagas disease as acquired cardiopathies. Among the typical acquired heart diseases of the high altitude dweller, special attention is given to chronic cor pulmonale as a consequence of severe CMS with pulmonary hypertension.

  3. Electro-enzymatic degradation of chlorpyrifos by immobilized hemoglobin.

    PubMed

    Tang, Tiantian; Dong, Jing; Ai, Shiyun; Qiu, Yanyan; Han, Ruixia

    2011-04-15

    Electro-enzymatic processes, which are enzyme catalysis combined with electrochemical reactions, have been used in the degradation of many environment pollutants. For some pollutants, the catalytic mechanisms of the electrochemical-enzyme reaction are still poorly understood. In this paper, the degradation of chlorpyrifos by a combination of immobilized hemoglobin and in situ generated hydrogen peroxide is reported for the first time. Hemoglobin was immobilized on graphite felts to catalyze the removal of chlorpyrifos in an electrochemical-enzyme system. Under the optimal conditions, more than 98% of the chlorpyrifos was degraded. Furthermore, the degradation products of chlorpyrifos were also studied and identified using liquid chromatography-mass spectrometry analysis. The results suggest a possible degradation mechanism for chlorpyrifos with low power and high efficiency, reveal the feasibility of hemoglobin as a substitute for some expensive natural enzymes, and demonstrate the application of an electro-enzymatic process in the treatment of organophosphorus compounds in wastewater. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Fetal hemoglobin accumulation in vitro. Effect of adherent mononuclear cells.

    PubMed Central

    Javid, J; Pettis, P K

    1983-01-01

    In clonal cultures of erythroid burst-forming units (BFU-E) obtained from blood, the accumulation of fetal and adult hemoglobins (Hb F and Hb A) was measured by radioligand immunoassay. Inclusion of adherent mononuclear cells in the culture promoted a striking increase in the relative amount of Hb F in each of 44 experiments with 14 donors. In two-thirds of the instances, this was accounted for by a selective increase in the absolute amount of Hb F. The differential effect on Hb F and Hb A accumulation was achieved without altering the maturity of the erythroid cells, their mean hemoglobin content, or the asynchrony of the production of the two hemoglobins. Virtually all bursts produced Hb F, and the population of BFU-E as a whole, rather than a selected subset, appeared to be the target of adherent cell action. When the adherent cells were excluded from the culture input, the base-line value of Hb F was reproducible for each donor over a period of several months, and correlated with the number of in vivo circulating F cells. PMID:6189860

  5. Direct estimation of evoked hemoglobin changes by multimodality fusion imaging

    PubMed Central

    Huppert, Theodore J.; Diamond, Solomon G.; Boas, David A.

    2009-01-01

    In the last two decades, both diffuse optical tomography (DOT) and blood oxygen level dependent (BOLD)-based functional magnetic resonance imaging (fMRI) methods have been developed as noninvasive tools for imaging evoked cerebral hemodynamic changes in studies of brain activity. Although these two technologies measure functional contrast from similar physiological sources, i.e., changes in hemoglobin levels, these two modalities are based on distinct physical and biophysical principles leading to both limitations and strengths to each method. In this work, we describe a unified linear model to combine the complimentary spatial, temporal, and spectroscopic resolutions of concurrently measured optical tomography and fMRI signals. Using numerical simulations, we demonstrate that concurrent optical and BOLD measurements can be used to create cross-calibrated estimates of absolute micromolar deoxyhemoglobin changes. We apply this new analysis tool to experimental data acquired simultaneously with both DOT and BOLD imaging during a motor task, demonstrate the ability to more robustly estimate hemoglobin changes in comparison to DOT alone, and show how this approach can provide cross-calibrated estimates of hemoglobin changes. Using this multimodal method, we estimate the calibration of the 3 tesla BOLD signal to be −0.55% ± 0.40% signal change per micromolar change of deoxyhemoglobin. PMID:19021411

  6. Regulation of the fetal hemoglobin silencing factor BCL11A

    PubMed Central

    Basak, Anindita; Sankaran, Vijay G.

    2016-01-01

    The clinical severity of sickle cell disease and β-thalassemia, the major disorders of β-globin, can be ameliorated by increased production of fetal hemoglobin (HbF). Here, we provide a brief overview of the fetal-to-adult hemoglobin switch that occurs in humans shortly after birth and review our current understanding of one of the most potent known regulators of this switching process, the multiple zinc finger–containing transcription factor BCL11A. Originally identified in genome-wide association studies, multiple orthogonal lines of evidence have validated BCL11A as a key regulator of hemoglobin switching and as a promising therapeutic target for HbF induction. We discuss recent studies that have highlighted its importance in silencing the HbF-encoding genes and discuss opportunities that exist to further understand the regulation of BCL11A and its mechanism of action, which could provide new insight into opportunities to induce HbF for therapeutic purposes. PMID:26963603

  7. Geminate combination of oxygen with iron-cobalt hybrid hemoglobins.

    PubMed

    Morris, R J; Gibson, Q H; Ikeda-Saito, M; Yonetani, T

    1984-06-10

    Photodissociation of oxygen from the ferrous subunits of hybrid hemoglobins in which the heme of either the alpha or the beta chain has been replaced by cobalt protoporphyrin IX shows large differences between the subunits. With a 25-ns light pulse, the apparent quantum yield at the end of the flash is greater for the beta-iron hybrid than for the alpha-iron hybrid. With the beta-iron hybrid, the yield is greater when solution conditions favor the T-state. After the flash, a part of the oxygen which has been dissociated recombines with a half-time of the order of tens of nanoseconds. The proportion is greatest in the R-state at low temperature and least in the T-state. With the alpha-iron hybrid, oxygen is much less readily removed, and the rapid recombination is slight or absent. It is seen most clearly at low temperatures in conditions which favor the T-state. The long term (greater than 100 ns) effect is that oxygen is much more readily removed from the beta-iron hybrid in the T-state than under any other condition. Analogous flash experiments performed with human hemoglobin A may be closely simulated by superposition of the results obtained with the two hybrid hemoglobins under the same conditions. Isolated human alpha and beta--SH chains show differences similar to, but less marked than, those of the iron-cobalt hybrids.

  8. Methylation of cysteine in hemoglobin following exposure to methylating agents

    SciTech Connect

    Bailey, E.; Connors, T.A.; Farmer, P.B.; Gorf, S.M.; Rickard, J.

    1981-06-01

    In addition to reacting with biologically important nucleophilic sites in DNA, alkylating agents also interact with amino acids in proteins. Measurements of the extent of formation of these alkyl amino acids may be used as a means of determining exposure to these compounds. The degree of S-methylation of cysteine in hemoglobin was studied following in vivo exposure of rats to methyl methanesulfonate, dimethylnitrosamine, and 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide. A linear dose-response curve was observed for methyl methanesulfonate over a 100-fold dose range. For dimethylnitrosamine, there was a threshold of doses where no methylation could be detected, and a curved dose-response curve was obtained. At high doses, the degree of methylation of hemoglobin cysteine was 7-fold lower than that with methyl methanesulfonate. In vivo, no alkylation could be observed with 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide; however, the existence of naturally occurring S-methylcysteine in the rat hemoglobin may have overshadowed small increases in alkylation arising from exposure to this compound. The natural occurrence of S-methylcysteine was studied in 13 species, and amounts ranging from 5.6 nmol/g globin (hamster) to 481 nmol/g globin (partridge) were observed. The reason for its occurrence is unknown but is under investigation.

  9. Methodologies for detection of hemoglobin-based oxygen carriers.

    PubMed

    Goebel, Catrin; Alma, Chris; Howe, Chris; Kazlauskas, Rymantas; Trout, Graham

    2005-01-01

    Blood substitutes based on hemoglobin or hemoglobin-based oxygen carriers (HBOCs) are oxygen-carrying therapeutic agents developed for use in operations and emergencies in place of donated blood. Increased oxygen-carrying capacity through the use of blood substitutes could help elite athletes to lengthen endurance capacity and improve their performance. As blood substitutes become more readily available, it is essential that a qualitative detection method for their abuse in sport is available. Ideally, such a method would be simple and inexpensive. This study investigates methods that could be used as screening procedures to easily detect HBOCs in plasma and develops tests that can unequivocally confirm their presence. The investigation into the screening method indicates that the direct visual screening of plasma discoloration is the most appropriate with detection limits of less than 1% HBOC in plasma. Two methods are shown to confirm the presence of exogenous hemoglobin in plasma samples, size-exclusion chromatography with photodiode array detection and high-performance liquid chromatography analysis of enzymatic digests with detection by electrospray mass spectrometry. This work emphasizes the need for cooperation between drug developers and sports testing laboratories to ensure that methods for the detection of putative doping agents are available prior to product release.

  10. Evolutionary and Functional Relationships in the Truncated Hemoglobin Family.

    PubMed

    Bustamante, Juan P; Radusky, Leandro; Boechi, Leonardo; Estrin, Darío A; Ten Have, Arjen; Martí, Marcelo A

    2016-01-01

    Predicting function from sequence is an important goal in current biological research, and although, broad functional assignment is possible when a protein is assigned to a family, predicting functional specificity with accuracy is not straightforward. If function is provided by key structural properties and the relevant properties can be computed using the sequence as the starting point, it should in principle be possible to predict function in detail. The truncated hemoglobin family presents an interesting benchmark study due to their ubiquity, sequence diversity in the context of a conserved fold and the number of characterized members. Their functions are tightly related to O2 affinity and reactivity, as determined by the association and dissociation rate constants, both of which can be predicted and analyzed using in-silico based tools. In the present work we have applied a strategy, which combines homology modeling with molecular based energy calculations, to predict and analyze function of all known truncated hemoglobins in an evolutionary context. Our results show that truncated hemoglobins present conserved family features, but that its structure is flexible enough to allow the switch from high to low affinity in a few evolutionary steps. Most proteins display moderate to high oxygen affinities and multiple ligand migration paths, which, besides some minor trends, show heterogeneous distributions throughout the phylogenetic tree, again suggesting fast functional adaptation. Our data not only deepens our comprehension of the structural basis governing ligand affinity, but they also highlight some interesting functional evolutionary trends.

  11. Relationship of Hemoglobin Concentration in Adult Asthmatic Patients.

    PubMed

    Nasreen, S; Nessa, A; Islam, M F; Husain, M F; Khatun, N; Wahed, F; Zannat, M R; Tajkia, T

    2016-10-01

    Asthma is a chronic inflammatory disorder of the airways, in which many cells and cellular elements play a role. Asthma is one of the most common diseases globally and currently affects 300 million people. The epidemic rise in anemia, asthma, and related allergic disease is a common major public health problem worldwide. Asthma and anemia associated with acute infections occur both in children and adults. This descriptive type of cross sectional study was done to find out the levels of hemoglobin concentration in adult asthmatic patients and carried out in the Department of Physiology, Mymensingh Medical College, Mymensingh, Bangladesh from July 2014 to January 2016. Fifty (50) male and 50 (fifty) female adult asthmatic patients aged 18-60 years were included in the study group. They are enrolled from the Department of Medicine, Mymensingh Medical College, Mymensingh, Bangladesh and also from locality. For comparison age matched 50 male and 50 female apparently healthy persons were also studied as control. Hemoglobin concentration was estimated by Cyanmethemoglobin method. For statistical analysis unpaired student's 't' test was used. Mean hemoglobin concentration was significantly decreased in study group in comparison to control group and the result was statistically significant (p<0.001). The study findings showed a high prevalence of anemia among asthmatic patients than non asthmatic healthy persons.

  12. Evolutionary and Functional Relationships in the Truncated Hemoglobin Family

    PubMed Central

    Bustamante, Juan P.; Radusky, Leandro; Boechi, Leonardo; Estrin, Darío A.; ten Have, Arjen; Martí, Marcelo A.

    2016-01-01

    Predicting function from sequence is an important goal in current biological research, and although, broad functional assignment is possible when a protein is assigned to a family, predicting functional specificity with accuracy is not straightforward. If function is provided by key structural properties and the relevant properties can be computed using the sequence as the starting point, it should in principle be possible to predict function in detail. The truncated hemoglobin family presents an interesting benchmark study due to their ubiquity, sequence diversity in the context of a conserved fold and the number of characterized members. Their functions are tightly related to O2 affinity and reactivity, as determined by the association and dissociation rate constants, both of which can be predicted and analyzed using in-silico based tools. In the present work we have applied a strategy, which combines homology modeling with molecular based energy calculations, to predict and analyze function of all known truncated hemoglobins in an evolutionary context. Our results show that truncated hemoglobins present conserved family features, but that its structure is flexible enough to allow the switch from high to low affinity in a few evolutionary steps. Most proteins display moderate to high oxygen affinities and multiple ligand migration paths, which, besides some minor trends, show heterogeneous distributions throughout the phylogenetic tree, again suggesting fast functional adaptation. Our data not only deepens our comprehension of the structural basis governing ligand affinity, but they also highlight some interesting functional evolutionary trends. PMID:26788940

  13. Application of glycated hemoglobin in the perinatal period

    PubMed Central

    Yu, Haiyan; Qi, Xiaorong; Wang, Xiaodong

    2014-01-01

    Glycated hemoglobin (HbA1c) is a special fragment formed by the binding of glucose to the C chain or D chain of hemoglobin A and as a result of non-enzymatic catalysis of mature hemoglobin and glucose, which is an indicator used to evaluate the blood glucose control in diabetes mellitus (DM) patients. Recent researches indicated that HbA1c could be applied in gestational diabetes mellitus (GDM) and pregnancy combined DM, and increasing of HbA1c was close associated with adverse outcomes of women with pregnancy combined DM and GDM. HbA1c was reported to have a significant importance in monitoring congenital malformation, abortion, perinatal mortality, preeclampsia, postpartum abnormal glucose metabolism, vascular complications and so on, which could be a test item during the second trimester. Sensitivity of HbA1c in diagnoses of DM is lower than oral glucose tolerance test (OGTT), thus OGTT is still the golden standard of GDM. Emphasis should be put on standardization of detection and threshold of HbA1c and establishment of HbA1c normal ranges of different trimesters, when HbA1c is used to diagnose pregnancy combined DM and GDM, and evaluate effects of treatments. PMID:25663962

  14. Hemoglobin Dynamics in Red Blood Cells: Correlation to Body Temperature

    PubMed Central

    Stadler, A. M.; Digel, I.; Artmann, G. M.; Embs, J. P.; Zaccai, G.; Büldt, G.

    2008-01-01

    A transition in hemoglobin behavior at close to body temperature has been discovered recently by micropipette aspiration experiments on single red blood cells (RBCs) and circular dichroism spectroscopy on hemoglobin solutions. The transition temperature was directly correlated to the body temperatures of a variety of species. In an exploration of the molecular basis for the transition, we present neutron scattering measurements of the temperature dependence of hemoglobin dynamics in whole human RBCs in vivo. The data reveal a change in the geometry of internal protein motions at 36.9°C, at human body temperature. Above that temperature, amino acid side-chain motions occupy larger volumes than expected from normal temperature dependence, indicating partial unfolding of the protein. Global protein diffusion in RBCs was also measured and the findings compared favorably with theoretical predictions for short-time self-diffusion of noncharged hard-sphere colloids. The results demonstrated that changes in molecular dynamics in the picosecond time range and angstrom length scale might well be connected to a macroscopic effect on whole RBCs that occurs at body temperature. PMID:18708462

  15. A Membrane-bound Hemoglobin from Gills of the Green Shore Crab Carcinus maenas*

    PubMed Central

    Ertas, Beyhan; Kiger, Laurent; Blank, Miriam; Marden, Michael C.; Burmester, Thorsten

    2011-01-01

    Most hemoglobins serve for the transport or storage of O2. Although hemoglobins are widespread in “entomostracan” Crustacea, malacostracans harbor the copper-containing hemocyanin in their hemolymph. Usually, only one type of respiratory protein occurs within a single species. Here, we report the identification of a hemoglobin of the shore crab Carcinus maenas (Malacostraca, Brachyura). In contrast to the dodecameric hemocyanin of this species, C. maenas hemoglobin does not reside in the hemolymph but is restricted to the gills. Immunofluorescence studies and cell fractioning showed that C. maenas hemoglobin resides in the membrane of the chief cells of the gill. To the best of our knowledge, this is the first time that a membrane-bound hemoglobin has been identified in eukaryotes. Bioinformatic evaluation suggests that C. maenas hemoglobin is anchored in the membrane by N-myristoylation. Recombinant C. maenas hemoglobin has a hexacoordinate binding scheme at the Fe2+ and an oxygen affinity of P50 = 0.5 Torr. A rapid autoxidation rate precludes a function as oxygen carrier. We rather speculate that, analogous to prokaryotic membrane-globins, C. maenas hemoglobin carries out enzymatic functions to protect the lipids in cell membrane from reactive oxygen species. Sequence comparisons and phylogenetic studies suggested that the ancestral arthropod hemoglobin was most likely an N-myristoylated protein that did not have an O2 supply function. True respiratory hemoglobins of arthropods, however, evolved independently in chironomid midges and branchiopod crustaceans. PMID:21118803

  16. Effects of porcine hemoglobin on serum lipid content and fecal lipid excretion in rats.

    PubMed

    Hosomi, Ryota; Fukunaga, Kenji; Nishiyama, Toshimasa; Yoshida, Munehiro

    2014-03-01

    The purpose of this study was to elucidate the effects of dietary hemoglobin on serum and liver lipid contents in rats, and the ability of hemoglobin hydrolysates to disrupt lipid absorption. After rats had been fed on casein- or porcine hemoglobin-containing diets for 4 weeks, their serum and liver lipid contents and fecal cholesterol, bile acid, and nitrogen excretion were measured. To elucidate the mechanism of lipid absorption by dietary hemoglobin, we also examined lipase activity, micellar solubility of cholesterol, and bile acid binding activity in the presence of hemoglobin hydrolysates. Dietary hemoglobin decreased serum and liver triglyceride and cholesterol contents and increased fecal fatty acid, cholesterol, and bile acid excretion. In addition, hemoglobin hydrolysates inhibited lipase activity compared with casein hydrolysates in an in vitro study. These results suggested that the hypolipidemic effect of hemoglobin is mediated by increased fecal lipid excretion, and that decreased lipase activity by hemoglobin is at least partially responsible for this result. The observed effects were documented with an 8 g/kg hemoglobin diet, which is lower than in other studies; therefore. hemoglobin may be useful in the prevention of lifestyle-related diseases.

  17. Hemoglobin is present as a canonical α2β2 tetramer in dopaminergic neurons.

    PubMed

    Russo, Roberta; Zucchelli, Silvia; Codrich, Marta; Marcuzzi, Federica; Verde, Cinzia; Gustincich, Stefano

    2013-09-01

    Hemoglobin is the oxygen carrier in blood erythrocytes. Oxygen coordination is mediated by α2β2 tetrameric structure via binding of the ligand to the heme iron atom. This structure is essential for hemoglobin function in the blood. In the last few years, expression of hemoglobin has been found in atypical sites, including the brain. Transcripts for α and β chains of hemoglobin as well as hemoglobin immunoreactivity have been shown in mesencephalic A9 dopaminergic neurons, whose selective degeneration leads to Parkinson's disease. To gain further insights into the roles of hemoglobin in the brain, we examined its quaternary structure in dopaminergic neurons in vitro and in vivo. Our results indicate that (i) in mouse dopaminergic cell line stably over-expressing α and β chains, hemoglobin exists as an α2β2 tetramer; (ii) similarly to the over-expressed protein, endogenous hemoglobin forms a tetramer of 64kDa; (iii) hemoglobin also forms high molecular weight insoluble aggregates; and (iv) endogenous hemoglobin retains its tetrameric structure in mouse mesencephalon in vivo. In conclusion, these results suggest that neuronal hemoglobin may be endowed with some of the biochemical activities and biological function associated to its role in erythroid cells. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.

  18. 13C Nuclear magnetic resonance studies to the binding of isocyanides to various hemoglobins and myoglobins.

    PubMed

    Dill, K; Satterlee, J D; Richards, J H

    1978-10-03

    Interactions between ethyl and isopropyl isocyanides and various hemoglobins and myoglobins have been studied by 13C nuclear magnetic resonance. The results indicate that the chemical shift of the bound isocyanide depends on the structure of the hemoglobin subunit or myoglobin. The resonances exhibited by isocyanides bound to myoglobin are sensitive to pH in contrast to the situation with rabbit and human hemoglobins. beta subunits of opossum, rabbit, and human hemoglobins show a significantly greater preferential affinity for CO relative to EIC than do alpha subunits which have allowed the assignment of resonances. Rabbit, human, and opossum hemoglobin subunits bind ethyl isocyanide without observable preferences and an excess of DPG does not appear to affect this random order of ligation. In contrast, an excess of IHP seems to cause preferential ligation of the alpha subunits in these hemoglobins. The results have been used to gain insights into the differing characteristics of the ligand binding pockets of these various hemoglobins.

  19. Pancreatic ascites hemoglobin contributes to the systemic response in acute pancreatitis.

    PubMed

    Pérez, Salvador; Pereda, Javier; Sabater, Luis; Sastre, Juan

    2015-04-01

    Upon hemolysis extracellular hemoglobin causes oxidative stress and cytotoxicity due to its peroxidase activity. Extracellular hemoglobin may release free hemin, which increases vascular permeability, leukocyte recruitment, and adhesion molecule expression. Pancreatitis-associated ascitic fluid is reddish and may contain extracellular hemoglobin. Our aim has been to determine the role of extracellular hemoglobin in the local and systemic inflammatory response during severe acute pancreatitis in rats. To this end we studied taurocholate-induced necrotizing pancreatitis in rats. First, extracellular hemoglobin in ascites and plasma was quantified and the hemolytic action of ascitic fluid was tested. Second, we assessed whether peritoneal lavage prevented the increase in extracellular hemoglobin in plasma during pancreatitis. Third, hemoglobin was purified from rat erythrocytes and administered intraperitoneally to assess the local and systemic effects of ascitic-associated extracellular hemoglobin during acute pancreatitis. Extracellular hemoglobin and hemin levels markedly increased in ascitic fluid and plasma during necrotizing pancreatitis. Peroxidase activity was very high in ascites. The peritoneal lavage abrogated the increase in extracellular hemoglobin in plasma. The administration of extracellular hemoglobin enhanced ascites; dramatically increased abdominal fat necrosis; upregulated tumor necrosis factor-α, interleukin-1β, and interleukin-6 gene expression; and decreased expression of interleukin-10 in abdominal adipose tissue during pancreatitis. Extracellular hemoglobin enhanced the gene expression and protein levels of vascular endothelial growth factor (VEGF) and other hypoxia-inducible factor-related genes in the lung. Extracellular hemoglobin also increased myeloperoxidase activity in the lung. In conclusion, extracellular hemoglobin contributes to the inflammatory response in severe acute pancreatitis through abdominal fat necrosis and inflammation

  20. Hemoglobin redux: combining neutron and X-ray diffraction with mass spectrometry to analyse the quaternary state of oxidized hemoglobins.

    PubMed

    Mueser, Timothy C; Griffith, Wendell P; Kovalevsky, Andrey Y; Guo, Jingshu; Seaver, Sean; Langan, Paul; Hanson, B Leif

    2010-11-01

    Improvements in neutron diffraction instrumentation are affording the opportunity to re-examine the structures of vertebrate hemoglobins and to interrogate proton and solvent position changes between the different quaternary states of the protein. For hemoglobins of unknown primary sequence, structural studies of cyanomethemoglobin (CNmetHb) are being used to help to resolve sequence ambiguity in the mass spectra. These studies have also provided additional structural evidence for the involvement of oxidized hemoglobin in the process of erythrocyte senescence. X-ray crystal studies of Tibetan snow leopard CNmetHb have shown that this protein crystallizes in the B state, a structure with a more open dyad, which possibly has relevance to RBC band 3 protein binding and erythrocyte senescence. R-state equine CNmetHb crystal studies elaborate the solvent differences in the switch and hinge region compared with a human deoxyhemoglobin T-state neutron structure. Lastly, comparison of histidine protonation between the T and R state should enumerate the Bohr-effect protons.

  1. Hemoglobin redux: combining neutron and X-ray diffraction with mass spectrometry to analyse the quaternary state of oxidized hemoglobins

    SciTech Connect

    Mueser, Timothy C. Griffith, Wendell P.; Kovalevsky, Andrey Y.; Guo, Jingshu; Seaver, Sean; Langan, Paul; Hanson, B. Leif

    2010-11-01

    X-ray and neutron diffraction studies of cyanomethemoglobin are being used to evaluate the structural waters within the dimer–dimer interface involved in quaternary-state transitions. Improvements in neutron diffraction instrumentation are affording the opportunity to re-examine the structures of vertebrate hemoglobins and to interrogate proton and solvent position changes between the different quaternary states of the protein. For hemoglobins of unknown primary sequence, structural studies of cyanomethemoglobin (CNmetHb) are being used to help to resolve sequence ambiguity in the mass spectra. These studies have also provided additional structural evidence for the involvement of oxidized hemoglobin in the process of erythrocyte senescence. X-ray crystal studies of Tibetan snow leopard CNmetHb have shown that this protein crystallizes in the B state, a structure with a more open dyad, which possibly has relevance to RBC band 3 protein binding and erythrocyte senescence. R-state equine CNmetHb crystal studies elaborate the solvent differences in the switch and hinge region compared with a human deoxyhemoglobin T-state neutron structure. Lastly, comparison of histidine protonation between the T and R state should enumerate the Bohr-effect protons.

  2. Reaction rates of oxygen with hemoglobin measured by non-equilibrium facilitated oxygen diffusion through hemoglobin solutions.

    PubMed

    Bouwer, S T; Hoofd, L; Kreuzer, F

    2001-02-16

    The purpose of this study was to verify the concept of non-equilibrium facilitated oxygen diffusion. This work succeeds our previous study, where facilitated oxygen diffusion by hemoglobin was measured at conditions of chemical equilibrium, and which yielded diffusion coefficients of hemoglobin and of oxygen. In the present work chemical non-equilibrium was induced using very thin diffusion layers. As a result, facilitation was decreased as predicted by theory. Thus, this work presents the first experimental demonstration of non-equilibrium facilitated oxygen diffusion. In addition, association and dissociation rate parameters of the reaction between oxygen and bovine and human hemoglobin were calculated and the effect of the homotropic and heterotropic interactions on each rate parameter was demonstrated. The results indicate that the homotropic interaction--which leads to increasing oxygen affinity with increasing oxygenation--is predominantly due to an increase in the association rate. The heterotropic interaction--which leads to decreasing oxygen affinity by anionic ligands--appears to be effected in two ways. Cl- increases the dissociation rate. In contrast, 2,3-diphosphoglycerate decreases the association rate.

  3. Proton nuclear magnetic resonance studies of hemoglobin M Milwaukee and their implications concerning the mechanism of cooperative oxygenation of hemoglobin.

    PubMed

    Fung, L W; Minton, A P; Lindstrom, T R; Pisciotta, A V; Ho, C

    1977-04-05

    Hemoglobin M Milwaukee (beta67E11 Val leads to Glu) is a naturally occurring valency hybrid containing two permanently oxidized hemes on the beta chains. In this mutant, the two abnormal beta chains cannot combine with ligands whereas the two alpha chains are normal and can combine with oxygen with a Hill coefficient varying from 1.1 to 1.3 [Udem et al. (1970), J Mol. Biol. 48, 489]. High-resolution proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate the exchangeable, ring-current shifted, ferrous and ferric hyperfine shifted resonances of Hb M Milwaukee in the absence and presence of organic phosphates. The alpha-heme environment, as manifested by the ring-current shifted resonances in the liganded form as well as the ferrous hyperfine shifted resonances in unliganded form, and subunit interactions, as manifested by the exchangeable resonances, are similar in Hb M Milwaukee to those in normal adult human hemoglobin. Organic phosphates can partially or completely inhibit the structural transformation which normally accompanies the binding of oxygen or carbon monoxide to Hb M Milwaukee. Upon stepwise addition of oxygen to deoxy Hb M Milwaukee, the hyperfine shifted resonance spectra of ferric beta chains show features which cannot be attributed to either fully deoxy or oxy species. However, the spectra for partially oxygenated Hb M Milwaukee can be described as an appropriately weighted average of the spectra of sero, singly, and doubly oxygenated species. The ferric hyperfine shifted resonance spectrum of the singly oxygenated intermediate has been calculated by a method employing least-squares analysis of the spectra of partially oxygenated Hb M Milwaukee at several values of oxygen saturation. The spectrum of this intermediate exhibits features which cannot be accounted for by a two-structure model. The present results are consistent with a sequential model for the oxygenation of this mutant hemoglobin. In view of the

  4. Hemoglobin variants detected by hemoglobin A1c (HbA1c) analysis and the effects on HbA1c measurements.

    PubMed

    Nasir, Nadzimah Mohd; Thevarajah, M; Yean, Chew Yee

    2010-04-01

    Hemoglobin (Hb) A1c is a tool widely used to monitor long-term glycemic control in diabetic patients. The objective of our study is to compare the HbA1c values measured on high performance liquid chromatography (HPLC) and immunoassay in patients who were detected to have hemoglobin variant after HbA1c analysis. We compared the HbA1c values measured using the Arkray Adams A1c HA-8160 (HPLC method) and Roche Cobas Integra (immunoturbidimetric method) from diabetic patients who were diagnosed with hemoglobin variants. Forty-three diabetic patients were diagnosed with hemoglobin variants: 13 elevated Hb F, 12 Hb E trait, seven Hb S trait, seven Hb D trait, two Hb E / beta-Thalassemia, one Hb C trait, and one homozygous Hb S. Knowledge of hemoglobin variants affecting HbA1c measurements is essential, in order to avoid mismanagement of diabetic patients.

  5. Identification of a Small Molecule that Increases Hemoglobin Oxygen Affinity and Reduces SS Erythrocyte Sickling

    PubMed Central

    2015-01-01

    Small molecules that increase the oxygen affinity of human hemoglobin may reduce sickling of red blood cells in patients with sickle cell disease. We screened 38 700 compounds using small molecule microarrays and identified 427 molecules that bind to hemoglobin. We developed a high-throughput assay for evaluating the ability of the 427 small molecules to modulate the oxygen affinity of hemoglobin. We identified a novel allosteric effector of hemoglobin, di(5-(2,3-dihydro-1,4-benzodioxin-2-yl)-4H-1,2,4-triazol-3-yl)disulfide (TD-1). TD-1 induced a greater increase in oxygen affinity of human hemoglobin in solution and in red blood cells than did 5-hydroxymethyl-2-furfural (5-HMF), N-ethylmaleimide (NEM), or diformamidine disulfide. The three-dimensional structure of hemoglobin complexed with TD-1 revealed that monomeric units of TD-1 bound covalently to β-Cys93 and β-Cys112, as well as noncovalently to the central water cavity of the hemoglobin tetramer. The binding of TD-1 to hemoglobin stabilized the relaxed state (R3-state) of hemoglobin. TD-1 increased the oxygen affinity of sickle hemoglobin and inhibited in vitro hypoxia-induced sickling of red blood cells in patients with sickle cell disease without causing hemolysis. Our study indicates that TD-1 represents a novel lead molecule for the treatment of patients with sickle cell disease. PMID:25061917

  6. Hemoglobin C Trait Provides Protection From Clinical Falciparum Malaria in Malian Children

    PubMed Central

    Travassos, Mark A.; Coulibaly, Drissa; Laurens, Matthew B.; Dembélé, Ahmadou; Tolo, Youssouf; Koné, Abdoulaye K.; Traoré, Karim; Niangaly, Amadou; Guindo, Aldiouma; Wu, Yukun; Berry, Andrea A.; Jacob, Christopher G.; Takala-Harrison, Shannon; Adams, Matthew; Shrestha, Biraj; Mu, Amy Z.; Kouriba, Bourema; Lyke, Kirsten E.; Diallo, Dapa A.; Doumbo, Ogobara K.; Plowe, Christopher V.; Thera, Mahamadou A.

    2015-01-01

    Background. Hemoglobin C trait, like hemoglobin S trait, protects against severe malaria in children, but it is unclear whether hemoglobin C trait also protects against uncomplicated malaria. We hypothesized that Malian children with hemoglobin C trait would have a lower risk of clinical malaria than children with hemoglobin AA. Methods. Three hundred children aged 0–6 years were enrolled in a cohort study of malaria incidence in Bandiagara, Mali, with continuous passive and monthly active follow-up from June 2009 to June 2010. Results. Compared to hemoglobin AA children (n = 242), hemoglobin AC children (n = 39) had a longer time to first clinical malaria episode (hazard ratio [HR], 0.19; P = .001; 364 median malaria-free days vs 181 days), fewer episodes of clinical malaria, and a lower cumulative parasite burden. Similarly, hemoglobin AS children (n = 14) had a longer time to first clinical malaria episode than hemoglobin AA children (HR, 0.15; P = .015; 364 median malaria-free days vs 181 days), but experienced the most asymptomatic malaria infections of any group. Conclusions. Both hemoglobin C and S traits exerted a protective effect against clinical malaria episodes, but appeared to do so by mechanisms that differentially affect the response to infecting malaria parasites. PMID:26019283

  7. Mössbauer Effect in Hemoglobin and Some Iron-Containing Biological Compounds

    PubMed Central

    Gonser, U.; Grant, R. W.

    1965-01-01

    The Mössbauer effect in Fe57 has been used to study the molecules, hemoglobin, O2-hemoglobin, CO2-hemoglobin, and CO-hemoglobin (within red cells) and the molecules, hemin and hematin (in the crystalline state). Quadrupole splittings and isomeric shifts observed in the Mössbauer spectra of these molecules are tabulated. The temperature dependence of the quadrupole splitting and relative recoil-free fraction for hemoglobin with different ligands has been investigated. An estimate of the Debye-Waller factor in O2-hemoglobin at 5°K is 0.83. An asymmetry in the quadrupole splitting observed in hemoglobin is attributed to a directional dependence of the recoil-free fraction which establishes the sign of the electric field gradient in the molecule and indicates that the lowest lying d orbital of the Fe atoms is |xy>. This asymmetry indicates that the iron atoms in hemoglobin are vibrating farther perpendicular to the heme planes than parallel to them, and, in fact, the ratio of the mean square displacements perpendicular and parallel to the heme planes in hemoglobin is ≈5.5 at 5°K. The temperature dependence of the quadrupole splitting in hemoglobin has been used to estimate a splitting between the lowest lying iron atom d orbitals of ≈420 cm-1. PMID:5884013

  8. Unexpectedly low pulse oximetry measurements associated with variant hemoglobins: a systematic review.

    PubMed

    Verhovsek, Madeleine; Henderson, Matthew P A; Cox, Gerard; Luo, Hong-yuan; Steinberg, Martin H; Chui, David H K

    2010-11-01

    Pulse oximetry estimates arterial blood oxygen saturation based on light absorbance of oxy- and deoxy-hemoglobin at 660 and 940 nm wavelengths. Patients with unexpectedly low SpO₂ often undergo cardio-pulmonary testing to ascertain the cause of their hypoxemia. However, in a subset of patients, a variant hemoglobin is responsible for low SpO₂ measurements. The extent of this problem is unclear. We performed a systematic literature review for reports of low SpO₂ associated with variant hemoglobins. We also reviewed unpublished cases from an academic hemoglobin diagnostic reference laboratory. Twenty-five publications and four unpublished cases were identified, representing 45 patients with low SpO₂ and confirmed variant hemoglobin. Fifty-seven family members of patients had confirmed or suspected variant hemoglobin. Three low oxygen affinity variant hemoglobins had concordantly low SpO₂ and SaO₂. Eleven variant hemoglobins were associated with unexpectedly low SpO₂ measurements but normal SaO₂. Hemoglobin light absorbance testing was reported in three cases, all of which showed abnormal absorption spectra between 600 and 900 nm. Seven other variant hemoglobins had decreased SpO₂, with unreported or uncertain SaO₂. Twenty-one variant hemoglobins were found to be associated with low SpO₂. Most variant hemoglobins were associated with spuriously low SpO₂. Abnormal absorption spectra explain the discrepancy between SpO₂ and SaO(2) for some variants. The differential diagnosis of possible variant hemoglobin ought to be considered in asymptomatic patients found to have unexpectedly low SpO₂. The correct diagnosis will help to spare patients from unnecessary investigations and anxiety.

  9. Hemoglobin correction for near-infrared pH determination in lysed blood solutions.

    PubMed

    Alam, M Kathleen; Franke, James E; Rohrscheib, Mark R; Nunez, David; Abate, Vincent; Maynard, John D; Kemeny, Gabor J

    2003-09-01

    The near-infrared (NIR) measurement of blood pH relies on the spectral signature of histidine residing on the hemoglobin molecule. If the amount of hemoglobin in solution varies, the size of the histidine signal can vary depending on changes in either the pH or hemoglobin concentration. Multivariate calibration models developed using the NIR spectra collected from blood at a single hemoglobin concentration are shown to predict data from different hemoglobin levels with a bias and slope. A simple, scalar path length correction of the spectral data does not correct this problem. However, global partial least-square (PLS) models built with data encompassing a range of hemoglobin concentration have a cross-validated standard error of prediction (CVSEP) similar to the CVSEP of data obtained from a single hemoglobin level. It will be shown that the prediction of pH of an unknown sample using a global PLS model requires that the unknown have a hemoglobin concentration falling within the range encompassed by the global model. An alternative method for correcting the predicted pH for hemoglobin levels is also presented. The alternative method updates the single-hemoglobin-level models with slope and intercept estimates from the pH predictions of data collected at alternate hemoglobin levels. The slope and intercept correction method gave SEP values averaging to 0.034 pH units. Since both methods require some knowledge of the hemoglobin concentration in order for a pH prediction to be made, a model for hemoglobin concentration is developed using spectral data and is used for pH correction.

  10. THE ENZYMATIC DEGRADATION OF HEMOGLOBIN TO BILE PIGMENTS BY MACROPHAGES

    PubMed Central

    Pimstone, Neville R.; Tenhunen, Raimo; Seitz, Paul T.; Marver, Harvey S.; Schmid, Rudi

    1971-01-01

    Recent studies have identified and characterized the enzymatic mechanism by which hemoglobin-heme is converted to bilirubin. Under physiologic conditions the enzyme system, microsomal heme-oxygenase, is most active in the spleen followed by the liver and bone marrow, all of which are tissues that normally are involved in the sequestration and metabolism of red cells. Indirect evidence suggested that the reticuloendothelial system is important in this process. To test this hypothesis, conversion of heme to bilirubin was studied in macrophages obtained by chemical or immunological means from the peritoneal cavity or from the lungs of rodents. Homogenates of pure populations of these cells were devoid of heme-oxygenase activity, unless before harvesting the macrophages had been exposed to methemalbumin, microcrystalline hemin, or hemoglobin in vivo. In macrophages exposed to heme pigments, the specific activity of heme-oxygenase was far in excess of that in the spleen or liver. Enzyme activity was also present in the granulomatous tissue surrounding subcutaneous hematomas. The heme-oxygenase system in macrophages resembles that in the spleen and liver in that it is localized in the microsomal fraction, has an absolute requirement for molecular oxygen and NADPH, is inhibited by carbon monoxide, and has a similar Km. These findings indicate that cells of the reticuloendothelial system, presumably including the Kupffer cells of the liver and the macrophages of the spleen, possess the enzymatic machinery for converting hemoglobin-heme to bilirubin. The reaction is a mixed function oxidation, probably involving cytochrome P450 as the terminal oxidase. Enzyme activity in macrophages is capable of regulatory adaptation in response to substrate loads. In the standard assay system for the enzyme, disappearance of heme always was in excess of the amount of bilirubin formed, suggesting the simultaneous presence of alternate routes of heme degradation not involving bilirubin as

  11. New-old hemoglobin-like proteins of symbiotic dinoflagellates

    PubMed Central

    Rosic, Nedeljka N; Leggat, William; Kaniewska, Paulina; Dove, Sophie; Hoegh-Guldberg, Ove

    2013-01-01

    Symbiotic dinoflagellates are unicellular photosynthetic algae that live in mutualistic symbioses with many marine organisms. Within the transcriptome of coral endosymbionts Symbiodinium sp. (type C3), we discovered the sequences of two novel and highly polymorphic hemoglobin-like genes and proposed their 3D protein structures. At the protein level, four isoforms shared between 87 and 97% sequence identity for Hb-1 and 78–99% for Hb-2, whereas between Hb-1 and Hb-2 proteins, only 15–21% sequence homology has been preserved. Phylogenetic analyses of the dinoflagellate encoding Hb sequences have revealed a separate evolutionary origin of the discovered globin genes and indicated the possibility of horizontal gene transfer. Transcriptional regulation of the Hb-like genes was studied in the reef-building coral Acropora aspera exposed to elevated temperatures (6–7°C above average sea temperature) over a 24-h period and a 72-h period, as well as to nutrient stress. Exposure to elevated temperatures resulted in an increased Hb-1 gene expression of 31% after 72 h only, whereas transcript abundance of the Hb-2 gene was enhanced by up to 59% by both 1-day and 3-day thermal stress conditions. Nutrient stress also increased gene expression of Hb-2 gene by 70%. Our findings describe the differential expression patterns of two novel Hb genes from symbiotic dinoflagellates and their polymorphic nature. Furthermore, the inducible nature of Hb-2 gene by both thermal and nutrient stressors indicates a prospective role of this form of hemoglobin in the initial coral–algal responses to changes in environmental conditions. This novel hemoglobin has potential use as a stress biomarker. PMID:23610627

  12. Early diagnosis of sepsis using serum hemoglobin subunit Beta.

    PubMed

    Yoo, Hayoung; Ku, Sae-Kwang; Kim, Shin-Woo; Bae, Jong-Sup

    2015-02-01

    The development of new sepsis-specific biomarkers is mandatory to improve the detection and monitoring of the disease. Hemoglobin is the main oxygen and carbon dioxide carrier in cells of the erythroid lineage and is responsible for oxygen delivery to the respiring tissues of the body. Hemoglobin subunit beta (HBβ) is a component of a larger protein called hemoglobin. The aim of this study was to evaluate blood levels of HBβ in septic patients. A prospective study of 82 patients with sepsis was conducted. Furthermore, C57BL/6 mice were subjected to cecal ligation and puncture (CLP) surgery. Alternatively, human umbilical vein endothelial cells (HUVECs) or C57BL/6 mice were exposed to lipopolysaccharide (LPS, 100 ng/ml to HUVECs or 10 mg/kg to mice). The data showed that LPS induced upregulation of the synthesis and secretion of HBβ in LPS-treated HUVECs and in LPS-injected and CLP mice. In patients admitted to the intensive care unit with sepsis, circulating levels of HBβ were significantly high (sepsis, 64.93-114.76 ng/ml, n = 30; severe sepsis, 157.37-268.69 ng/ml, n = 22; septic shock, 309.98-427.03 ng/ml, n = 30) when compared to the levels of control donors (9.76-12.28 ng/ml, n = 21). Patients with septic shock had higher HBβ levels when compared to patients with severe sepsis. Furthermore, the HBβ levels in septic patients were higher than those in healthy volunteers. These results suggest that in septic patients, HBβ blood level is related to the severity of sepsis and may represent a novel endothelial cell dysfunction marker. Moreover, HBβ can be used as a biomarker to determine the severity of sepsis.

  13. Differential expression of murine adult hemoglobins in early ontogeny

    SciTech Connect

    Wawrzyniak, C.J.; Lewis, S.E.; Popp, R.A.

    1985-01-01

    A hemoglobin mutation is described that permits study of the expression of the two adult ..beta..-globin genes throughout fetal and postnatal development. Mice with a mutation at the Hbb/sup s/, ..beta..-globin locus, were used to study the relative levels of ..beta..-s2major and ..beta..-sminor globins specified by the mutant Hbb/sup s2/ haplotype during development. At 11.5 days of gestation ..beta..-sminor comprised over 80% and ..beta..-s2major under 20% of the adult beta-globin. The relative level of ..beta..-sminor decreased through fetal development; at birth ..beta..-sminor represented 33.7% of the ..beta..-globin. The adult values of 71.0% ..beta..-s2major and 29.0% ..beta..-sminor globin are expressed in mice six days after birth. Because the two ..beta..-globin genes are expressed in mice of the Hbb/sup 2s/ haplotype, both the ..beta..-smajor and ..beta..-sminor genes must be expressed in mice of the Hbb/sup s/ haplotype. Expression of the ..beta..-sminor gene is elevated to 35.6% in Hbb/sup s2/ mice that have been bled repeatedly. Thus, the 5' ..beta..-s2major and 3' ..beta..-sminor genes of the Hbb/sup s2/ haplotype and, presumably the 5' ..beta..-smajor and 3' ..beta..-sminor genes of the Hbb/sup s/ haplotype, are regulated independently and are homologous to the 5' ..beta..-dmajor and 3' ..beta..-dminor genes of the Hbb/sup d/ haplotype. Mice of the Hbb/sup s2/ haplotype are better than mice of the Hbb/sup d/ haplotytpe for studying the mechanisms of hemoglobin switching because the Hbb/sup s2/ each of the three embryonic and two adult hemoglobins can be separated by electrophoresis. 17 refs., 3 figs.

  14. Modulating hemoglobin nitrite reductase activity through allostery: a mathematical model.

    PubMed

    Rong, Zimei; Alayash, Abdu I; Wilson, Michael T; Cooper, Chris E

    2013-11-30

    The production of nitric oxide by hemoglobin (Hb) has been proposed to play a major role in the control of blood flow. Because of the allosteric nature of hemoglobin, the nitrite reductase activity is a complex function of oxygen partial pressure PO2. We have previous developed a model to obtain the micro rate constants for nitrite reduction by R state (kR) and T state (kT) hemoglobin in terms of the experimental maximal macro rate constant kNmax and the corresponding oxygen concentration PO2max. However, because of the intrinsic difficulty in obtaining accurate macro rate constant kN, from available experiments, we have developed an alternative method to determine the micro reaction rate constants (kR and kT) by fitting the simulated macro reaction rate curve (kN versus PO2) to the experimental data. We then use our model to analyze the effect of pH (Bohr Effect) and blood ageing on the nitrite reductase activity, showing that the fall of bisphosphoglycerate (BPG) during red cell storage leads to increase NO production. Our model can have useful predictive and explanatory power. For example, the previously described enhanced nitrite reductase activity of ovine fetal Hb, in comparison to the adult protein, may be understood in terms of a weaker interaction with BPG and an increase in the value of kT from 0.0087M(-1)s(-1) to 0.083M(-1)s(-1). Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Monitoring recovery from iron deficiency using total hemoglobin mass.

    PubMed

    Wachsmuth, Nadine B; Aigner, Thomas; Völzke, Christian; Zapf, Jürgen; Schmidt, Walter F

    2015-02-01

    Using hemoglobin concentration ([Hb]) to diagnose borderline iron deficiency and monitor the progress of its treatment is difficult because of the confounding effects of plasma volume. Because hemoglobin mass (Hbmass) is not affected by plasma volume, it may be a more sensitive parameter. The aim of this study was to monitor Hbmass, iron storage, and maximal oxygen consumption (V˙O2max) during and after oral iron therapy in subjects with severe and moderate iron deficiency. Three groups of female recreational athletes were monitored for at least 22 wk, as follows: 1) severe iron deficiency group (SID) (n = 8; ferritin, ≤12 ng·mL), 2) moderate iron deficiency group (MID) (n = 14; ferritin, ≤25 ng·mL), and 3) control group (n = 8; ferritin, >25 ng·mL). Hbmass and iron status were determined before, during, and up to 12 wk after at least 10 wk of oral iron supplementation. In total, five V˙O2max tests were performed before, during, and after the supplementation period. Hbmass increased markedly in the SID group (15.6% ± 11.0%, P < 0.001) and slightly in the MID group (2.2% ± 3.7%, P < 0.05) by the end of the supplementation period and remained at this level for the following 12 wk. [Hb] and Hbmass were similarly affected, but Hbmass was more closely related to mean corpuscular volume and mean corpuscular hemoglobin than [Hb]. The SID group incorporated 534 ± 127 mg of iron into ferritin and hemoglobin, whereas the MID group incorporated 282 ± 68 mg of iron. V˙O2max increased only in the SID group by 0.20 ± 0.18 L·min (P < 0.05) and was closely related to Hbmass (P < 0.01). Hbmass is a sensitive tool for monitoring recovery from iron deficiency anemia and assessing the effectiveness of iron supplementation in individuals with severe or moderate iron deficiency.

  16. Computation of the unsteady facilitated transport of oxygen in hemoglobin

    NASA Technical Reports Server (NTRS)

    Davis, Sanford

    1990-01-01

    The transport of a reacting permeant diffusing through a thin membrane is extended to more realistic dissociation models. A new nonlinear analysis of the reaction-diffusion equations, using implicit finite-difference methods and direct block solvers, is used to study the limits of linearized and equilibrium theories. Computed curves of molecular oxygen permeating through hemoglobin solution are used to illustrate higher-order reaction models, the effect of concentration boundary layers at the membrane interfaces, and the transient buildup of oxygen flux.

  17. Purification of Bovine Hemoglobin via Fast Performance Liquid Chromatography

    PubMed Central

    Dimino, Michael L.

    2007-01-01

    Bovine hemoglobin (bHb) was purified from bovine red blood cells (bRBCs) via anion exchange chromatography preceded by dialysis. This is a fast and effective way to obtain bHb from bRBCs using Q Sepharose XL, a strong anion exchange resin. This resin had double the binding capacity for bHb compared to three other anion exchange resins that were studied in this work. Methemoglobin levels remained below 2% with bHb concentrations between 0.7 and 1.7 mM. The high purity of bHb was confirmed via SDS-PAGE and size exclusion chromatography. PMID:17581802

  18. The measurement of hemoglobin oxygen saturation using multiwavelength photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Deng, Zilin; Yang, Xiaoquan; Yu, Lejun; Gong, Hui

    2010-02-01

    Hemoglobin oxygen saturation (SO2) is one of the most critical functional parameters to the metabolism. In this paper, we mainly introduced some initial results of measuring blood oxygen using multi-wavelength photoacoustic microscopy (PAM). In phantom study, we demonstrate the photoacoustic signal amplitude increases linearly with the concentration of red or blue ink. Then the calculated concentration of red ink in double-ink mixtures with PAM has a 5% difference with the result measured with spectrophotometric analysis. In ex vivo experiment, the measured result exhibt 15% difference between the PAM and spectrophotometric analysis. Experiment results suggest that PAM could be used to determine the SO2 quantitatively.

  19. Optoacoustic monitoring of blood hemoglobin concentration: a pilot clinical study

    NASA Astrophysics Data System (ADS)

    Petrova, Irina Y.; Esenaliev, Rinat O.; Petrov, Yuriy Y.; Brecht, Hans-Peter F.; Svensen, Christer H.; Olsson, Joel; Deyo, Donald J.; Prough, Donald S.

    2005-07-01

    The optoacoustic technique is noninvasive, has high spatial resolution, and potentially can be used to measure the total hemoglobin concentration ([THb]) continuously and accurately. We performed in vitro measurements in blood and in vivo tests in healthy volunteers. Our clinical protocol included rapid infusion of intravenous saline to simulate rapid change in the [THb] during fluid therapy or surgery. Optoacoustic measurements were made from the wrist area overlying the radial artery for more than 1 h. The amplitude of the optoacoustic signal generated in the radial artery closely followed the [THb] measured directly in concurrently collected blood samples.

  20. Mössbauer studies of hemoglobin in high altitude polycythemia

    NASA Astrophysics Data System (ADS)

    Xiufang, Zhang; Linming, Shen; Songsen, Chen; Yuanyuan, Liu; Naifei, Gao; Yuanming, Zheng; Zhaohui, Ao; Liangquan, Shong

    1990-07-01

    The Mössbauer spectra have been measured in erythrocytes from normal adults and the patients with high altitude polycythemia (HAPC). The results indicated that two subspectra “a” and “b”, corresponding to oxy- and deoxyhemoglobin respectively, were present in all blood samples, and a third subspectrum “c” was found to exist in almost all samples from the patients. The parameters of the third subspectra “cl” in most samples from the patients were similar to those of carbon monoxyhemoglobin. The components were considered to be the denatured hemoglobin in RBCs (red blood cells). Together with clinical analysis, a possible mechanism of HAPC has been discussed.

  1. Interference of fetal hemoglobin with the spectrophotometric measurement of carboxyhemoglobin.

    PubMed

    Vreman, H J; Ronquillo, R B; Ariagno, R L; Schwartz, H C; Stevenson, D K

    1988-05-01

    We measured the concentration of carboxyhemoglobin (HbCO) in blood samples from 32 neonates by spectrophotometry (IL282 CO-Oximeter) and gas chromatography, finding a strong positive correlation (r = 0.89) between the concentration of fetal hemoglobin (Hb F) and HbCO as measured by spectrophotometry, but not by gas chromatography. Thus, Hb F interferes with the determination of HbCO by spectrophotometric techniques by falsely increasing apparent HbCO in direct proportion to Hb F. We conclude that, when Hb F is known or suspected to be present, blood HbCO cannot be reliably determined by methods based on spectrophotometry.

  2. The measurement of hemoglobin oxygen saturation using multiwavelength photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Deng, Zilin; Yang, Xiaoquan; Yu, Lejun; Gong, Hui

    2009-10-01

    Hemoglobin oxygen saturation (SO2) is one of the most critical functional parameters to the metabolism. In this paper, we mainly introduced some initial results of measuring blood oxygen using multi-wavelength photoacoustic microscopy (PAM). In phantom study, we demonstrate the photoacoustic signal amplitude increases linearly with the concentration of red or blue ink. Then the calculated concentration of red ink in double-ink mixtures with PAM has a 5% difference with the result measured with spectrophotometric analysis. In ex vivo experiment, the measured result exhibt 15% difference between the PAM and spectrophotometric analysis. Experiment results suggest that PAM could be used to determine the SO2 quantitatively.

  3. Extended x-ray absorption fine structure studies of hemoglobin

    SciTech Connect

    Shulman, R.G.

    1987-02-01

    Results of extended x-ray absorption fine structure (EXAFS) studies of the iron atom in deoxygenated hemoglobin are reviewed. It is shown that the iron-porphinato nitrogen distance has been determined to be 2.06 +/- 0.01 A by two independent investigations. Difficulties experienced in using this distance to calculate the iron's distance above the plane by triangulation are shown to be due to ignoring differences between ferrous and ferric hemes. It is concluded that the iron is 0.2 +/- 0.1/0.2 A above the plane of the nitrogens as originally shown.

  4. Genetic hemoglobin disorders rather than iron deficiency are a major predictor of hemoglobin concentration in women of reproductive age in rural prey Veng, Cambodia.

    PubMed

    Karakochuk, Crystal D; Whitfield, Kyly C; Barr, Susan I; Lamers, Yvonne; Devlin, Angela M; Vercauteren, Suzanne M; Kroeun, Hou; Talukder, Aminuzzaman; McLean, Judy; Green, Timothy J

    2015-01-01

    Anemia is common in Cambodian women. Potential causes include micronutrient deficiencies, genetic hemoglobin disorders, inflammation, and disease. We aimed to investigate factors associated with anemia (low hemoglobin concentration) in rural Cambodian women (18-45 y) and to investigate the relations between hemoglobin disorders and other iron biomarkers. Blood samples were obtained from 450 women. A complete blood count was conducted, and serum and plasma were analyzed for ferritin, soluble transferrin receptor (sTfR), folate, vitamin B-12, retinol binding protein (RBP), C-reactive protein (CRP), and α1 acid glycoprotein (AGP). Hemoglobin electrophoresis and multiplex polymerase chain reaction were used to determine the prevalence and type of genetic hemoglobin disorders. Overall, 54% of women had a genetic hemoglobin disorder, which included 25 different genotypes (most commonly, hemoglobin E variants and α(3.7)-thalassemia). Of the 420 nonpregnant women, 29.5% had anemia (hemoglobin <120 g/L), 2% had depleted iron stores (ferritin <15 μg/L), 19% had tissue iron deficiency (sTfR >8.3 mg/L), <3% had folate deficiency (<3 μg/L), and 1% had vitamin B-12 deficiency (<150 pmol/L). Prevalences of iron deficiency anemia (IDA) were 14.2% and 1.5% in those with and without hemoglobin disorders, respectively. There was no biochemical evidence of vitamin A deficiency (RBP <0.7 μmol/L). Acute and chronic inflammation were prevalent among 8% (CRP >5 mg/L) and 26% (AGP >1 g/L) of nonpregnant women, respectively. By using an adjusted linear regression model, the strongest predictors of hemoglobin concentration were hemoglobin E homozygous disorder and pregnancy status. Other predictors were 2 other heterozygous traits (hemoglobin E and Constant Spring), parity, RBP, log ferritin, and vitamin B-12. Multiple biomarkers for anemia and iron deficiency were significantly influenced by the presence of hemoglobin disorders, hence reducing their diagnostic sensitivity. Further

  5. Transcriptional regulation of fetal to adult hemoglobin switching: new therapeutic opportunities

    PubMed Central

    Wilber, Andrew; Nienhuis, Arthur W.

    2011-01-01

    In humans, embryonic, fetal, and adult hemoglobins are sequentially expressed in developing erythroblasts during ontogeny. For the past 40 years, this process has been the subject of intensive study because of its value to enlighten the biology of developmental gene regulation and because fetal hemoglobin can significantly ameliorate the clinical manifestations of both sickle cell disease and β-thalassemia. Understanding the normal process of loss of fetal globin expression and activation of adult globin expression could potentially lead to new therapeutic approaches for these hemoglobin disorders. Herein, we briefly review the history of the study of hemoglobin switching and then focus on recent discoveries in the field that now make new therapeutic approaches seem feasible in the future. Erythroid-specific knockdown of fetal gene repressors or enforced expression of fetal gene activators may provide clinically applicable approaches for genetic treatment of hemoglobin disorders that would benefit from increased fetal hemoglobin levels. PMID:21321359

  6. Monoclonal antibodies to human hemoglobin S and cell lines for the production thereof

    DOEpatents

    Jensen, R.H.; Vanderlaan, M.; Bigbee, W.L.; Stanker, L.H.; Branscomb, E.W.; Grabske, R.J.

    1984-11-29

    The present invention provides monoclonal antibodies specific to and distinguishing between hemoglobin S and hemoglobin A and methods for their production and use. These antibodies are capable of distinguishing between two hemoglobin types which differ from each other by only a single amino acid residue. The antibodies produced according to the present method are useful as immunofluorescent markers to enumerate circulating red blood cells which have the property of altered expression of the hemoglobin gene due to somatic mutation in stem cells. Such a measurement is contemplated as an assay for in vivo cellular somatic mutations in humans. Since the monoclonal antibodies produced in accordance with the instant invention exhibit a high degree of specificity to and greater affinity for hemoglobin S, they are suitable for labeling human red blood cells for flow cytometric detection of hemoglobin genotype. 4 figs.

  7. Monoclonal antibodies to human hemoglobin S and cell lines for the production thereof

    DOEpatents

    Jensen, Ronald H.; Vanderlaan, Martin; Bigbee, William L.; Stanker, Larry H.; Branscomb, Elbert W.; Grabske, Robert J.

    1988-01-01

    The present invention provides monoclonal antibodies specific to and distinguish between hemoglobin S and hemoglobin A and methods for their production and use. These antibodies are capable of distinguishing between two hemoglobin types which differ from each other by only a single amino acid residue. The antibodies produced according to the present method are useful as immunofluorescent markers to enumerate circulating red blood cells which have the property of altered expression of the hemoglobin gene due to somatic mutation in stem cells. Such a measurement is contemplated as an assay for in vivo cellular somatic mutations in humans. Since the monoclonal antibodies produced in accordance with the instant invention exhibit a high degree of specificity to and greater affinity for hemoglobin S, they are suitable for labeling human red blood cells for flow cytometric detection of hemoglobin genotype.

  8. Photodynamic effect occurance in photosensitizer mixtures with albumin or blood serum, or hemoglobin and blood

    NASA Astrophysics Data System (ADS)

    Torshina, Nadezgda L.; Posypanova, Anna M.; Volkova, Anna I.

    1996-05-01

    Under laser irradiation of different photosensitizers (PS) mixtures with pure albumin or without hemolysis blood serum the photodynamic effect (PE) is scarcely to be manifested. The coupling of PS with albumins prevents the interactions of dissolved oxygen molecules with PS molecules and formation of active oxygen forms. In order to promote the PE it is necessary to add the solution of hemoglobin. The PE is readily recognized in mixtures of PS with the blood. Such mixing leads to the erythrocytes' destruction and yields uncombined hemoglobin in blood plasma. The irradiation of hemoglobin mixtures with PS leads to the destruction of hemoglobin. In this case the direct combination of oxygen molecules with hemoglobin is important for PE performance (the deoxy hemoglobin can not promote PE otherwise).

  9. Modeling hemoglobin at optical frequency using the unconditionally stable fundamental ADI-FDTD method.

    PubMed

    Heh, Ding Yu; Tan, Eng Leong

    2011-04-12

    This paper presents the modeling of hemoglobin at optical frequency (250 nm - 1000 nm) using the unconditionally stable fundamental alternating-direction-implicit finite-difference time-domain (FADI-FDTD) method. An accurate model based on complex conjugate pole-residue pairs is proposed to model the complex permittivity of hemoglobin at optical frequency. Two hemoglobin concentrations at 15 g/dL and 33 g/dL are considered. The model is then incorporated into the FADI-FDTD method for solving electromagnetic problems involving interaction of light with hemoglobin. The computation of transmission and reflection coefficients of a half space hemoglobin medium using the FADI-FDTD validates the accuracy of our model and method. The specific absorption rate (SAR) distribution of human capillary at optical frequency is also shown. While maintaining accuracy, the unconditionally stable FADI-FDTD method exhibits high efficiency in modeling hemoglobin.

  10. Modeling hemoglobin at optical frequency using the unconditionally stable fundamental ADI-FDTD method

    PubMed Central

    Heh, Ding Yu; Tan, Eng Leong

    2011-01-01

    This paper presents the modeling of hemoglobin at optical frequency (250 nm – 1000 nm) using the unconditionally stable fundamental alternating-direction-implicit finite-difference time-domain (FADI-FDTD) method. An accurate model based on complex conjugate pole-residue pairs is proposed to model the complex permittivity of hemoglobin at optical frequency. Two hemoglobin concentrations at 15 g/dL and 33 g/dL are considered. The model is then incorporated into the FADI-FDTD method for solving electromagnetic problems involving interaction of light with hemoglobin. The computation of transmission and reflection coefficients of a half space hemoglobin medium using the FADI-FDTD validates the accuracy of our model and method. The specific absorption rate (SAR) distribution of human capillary at optical frequency is also shown. While maintaining accuracy, the unconditionally stable FADI-FDTD method exhibits high efficiency in modeling hemoglobin. PMID:21559129

  11. Sickle cell anemia: targeting the role of fetal hemoglobin in therapy.

    PubMed

    Coleman, Emma; Inusa, Baba

    2007-06-01

    Sickle cell anemia results from the single amino acid substitution of valine for glutamic acid in the beta-chain owing to a nucleotide defect that causes the production of abnormal beta-chains in hemoglobin S. Abnormal hemoglobin chains form polymers in the deoxygenated state, leading to the characteristic sickle cells. The polymerization of deoxygenated hemoglobin S accounts for the pathologic changes in sickle cell disease. The main-stay of therapy in sickle cell disease aims to reduce the amount of sickled hemoglobin present through the prevention of polymerization and reversal of this process. One way of discouraging polymerization is to increase the level of fetal hemoglobin, which because of its high oxygen affinity, does not participate in the polymerization process. Fetal hemoglobin production may be induced pharmacologically or by the use of gene therapy and genetic engineering techniques.

  12. Long-term variation in hemoglobin concentration in nestling great tits Parus major.

    PubMed

    Kaliński, Adam; Bańbura, Mirosława; Glądalski, Michał; Markowski, Marcin; Skwarska, Joanna; Wawrzyniak, Jarosław; Zieliński, Piotr; Cyżewska, Iwona; Bańbura, Jerzy

    2015-07-01

    Several studies have previously proposed that blood hemoglobin concentration in nestling passerines is a reliable index of individual condition and nutritional state. In this paper we present results concerning variation in hemoglobin concentration in the blood of ca. 14-day-old nestling great tits Parus major in central Poland in an 11-year-long period, 2003-2013, in two distinct habitat types: urban park and deciduous forest. The most important findings of the study were: (i) variation in hemoglobin concentration was consistent within broods, (ii) hemoglobin concentration of nestlings varied markedly across years, (iii) hemoglobin concentration was significantly higher in the forest study site which is richer in terms of food abundance during the short period of tits breeding season and (iv) high hemoglobin level was a predictor of nestling survival from hatching to fledging.

  13. O-Raffinose Crosslinking Substantially Ameliorates the Vasoconstrictive and Nitric-Oxide-Inactivating Effects of Unmodified Human Hemoglobin in the Rat

    DTIC Science & Technology

    1997-07-11

    human hemoglobin Ao. We compared the effects of unmodified hemoglobin with o-raffinose crosslinked oligomers of hemoglobin ( modified hemoglobin). The...by -20%) and mean arterial pressure (MAP) only modestly increased (by -13%). In contrast, the modified hemoglobin solution caused less increase in...molecules can be chemically modified to prevent the excretion of hemoglobin in the urine. Native hemoglobin (~64,500kD), when released from red cells

  14. Broadband diffuse optical spectroscopy assessment of hemorrhage- and hemoglobin-based blood substitute resuscitation

    NASA Astrophysics Data System (ADS)

    Lee, Jangwoen; Kim, Jae G.; Mahon, Sari; Tromberg, Bruce J.; Mukai, David; Kreuter, Kelly; Saltzman, Darin; Patino, Renee; Goldberg, Robert; Brenner, Matthew

    2009-07-01

    Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy- and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (StO2=[OHb]/[THb]×100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], StO2, and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as StO2. Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cc/kg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.

  15. RGB imaging system for mapping and monitoring of hemoglobin distribution in skin

    NASA Astrophysics Data System (ADS)

    Jakovels, Dainis; Rubins, Uldis; Spigulis, Janis

    2011-10-01

    A prototype R-G-B imaging system for mapping of skin hemoglobin distribution has been designed and tested. Device basically consists of a commercial RGB sensor (CMOS, max. frame rate 87 fps for VGA resolution), RGB LED ringlight illuminator and orthogonally orientated polarizers for reducing specular reflectance. The system was examined for monitoring of hemoglobin concentration changes during specific provocations - arterial/venous occlusions and heat test. Hemoglobin distribution maps of several skin malformations were obtained, as well.

  16. Broadband diffuse optical spectroscopy assessment of hemorrhage- and hemoglobin-based blood substitute resuscitation.

    PubMed

    Lee, Jangwoen; Kim, Jae G; Mahon, Sari; Tromberg, Bruce J; Mukai, David; Kreuter, Kelly; Saltzman, Darin; Patino, Renee; Goldberg, Robert; Brenner, Matthew

    2009-01-01

    Hemoglobin-based oxygen carriers (HBOCs) are solutions of cell-free hemoglobin (Hb) that have been developed for replacement or augmentation of blood transfusion. It is important to monitor in vivo tissue hemoglobin content, total tissue hemoglobin [THb], oxy- and deoxy-hemoglobin concentrations ([OHb], [RHb]), and tissue oxygen saturation (S(t)O(2)=[OHb][THb]x100%) to evaluate effectiveness of HBOC transfusion. We designed and constructed a broadband diffuse optical spectroscopy (DOS) prototype system to measure bulk tissue absorption and scattering spectra between 650 and 1000 nm capable of accurately determining these tissue hemoglobin component concentrations in vivo. Our purpose was to assess the feasibility of using DOS to optically monitor tissue [OHb], [RHb], S(t)O(2), and total tissue hemoglobin concentration ([THb]=[OHb]+[RHb]) during HBOC infusion using a rabbit hypovolemic shock model. The DOS prototype probe was placed on the shaved inner thigh muscle of the hind leg to assess concentrations of [OHb], [RHb], [THb], as well as S(t)O(2). Hemorrhagic shock was induced in intubated New Zealand white rabbits (N=6) by withdrawing blood via a femoral arterial line to 20% blood loss (10-15 cckg). Hemoglobin glutamer-200 (Hb-200) 1:1 volume resuscitation was administered following the hemorrhage. These values were compared against traditional invasive measurements, serum hemoglobin concentration (sHGB), systemic blood pressure, heart rate, and blood gases. DOS revealed increases of [THb], [OHb], and tissue hemoglobin oxygen saturation after Hb-200 infusion, while blood total hemoglobin values continued did not increase; we speculate, due to hyperosmolality induced hemodilution. DOS enables noninvasive in vivo monitoring of tissue hemoglobin and oxygenation parameters during shock and volume expansion with HBOC and potentially enables the assessment of efficacy of resuscitation efforts using artificial blood substitutes.

  17. Structural and redox behavior of OxyVita, a zero-linked polymeric hemoglobin: comparison with natural acellular polymeric hemoglobins.

    PubMed

    Harrington, John P; Orlik, Kseniya; Orlig, Kseniya; Zito, Samantha L; Wollocko, Jacek; Wollocko, Hanna

    2010-04-01

    A zero-linked polymeric hemoglobin (OxyVita Hb) has been developed for application as an acellular therapeutic hemoglobin-based-oxygen-carrier (HBOC). For effective and safe oxygen binding, transport and delivery, an HBOC must meet essential molecular requirements related to its structural integrity and redox stability. OxyVita is a super polymer possessing an average M.wt. of 17 x 10(6) Da. Structural integrity was determined by unfolding studies of OxyVita in the presence of increasing concentrations of urea. The unfolding midpoints (D(1/2)) of different preparations of OxyVita (solution and powder forms) were compared to Lumbricus Hb (LtHb) and Arenicola Hb (ArHb), natural acellular polymeric hemoglobins, which are serving as models for an effective and safe acellular HBOC. Reduction studies of OxyVita Hb using endogenous reducing agents were also investigated. Results from these studies indicate that: 1) OxyVita Hb exhibits greater resistance to conformational change than either LtHb or ArHb in the reduced (oxyHb) state; and 2) the reduction of met OxyVita Hb to oxyHb occurs slowly in the presence of either ascorbic acid (70% reduction in 560 min.) or beta-NADH (40% reduction in 90 min.). These studies provide consistent evidence that OxyVita Hb possesses physiochemical properties that exhibit structural integrity and redox behavior necessary for functioning as an effective and safe HBOC within clinical applications. These results are in agreement with observations made by other investigators as to the reduction in heme-loss of OxyVita Hb, essential for the reversible binding/release of molecular oxygen within the circulatory system.

  18. Modulation of hemoglobin dynamics by an allosteric effector

    PubMed Central

    Maccarini, Marco; Fouquet, Peter; Ho, Nancy T.; Ho, Chien; Makowski, Lee

    2017-01-01

    Abstract Hemoglobin (Hb) is an extensively studied paradigm of proteins that alter their function in response to allosteric effectors. Models of its action have been used as prototypes for structure‐function relationships in many proteins, and models for the molecular basis of its function have been deeply studied and extensively argued. Recent reports suggest that dynamics may play an important role in its function. Relatively little is known about the slow, correlated motions of hemoglobin subunits in various structural states because experimental and computational strategies for their characterization are challenging. Allosteric effectors such as inositol hexaphosphate (IHP) bind to both deoxy‐Hb and HbCO, albeit at different sites, leading to a lowered oxygen affinity. The manner in which these effectors impact oxygen binding is unclear and may involve changes in structure, dynamics or both. Here we use neutron spin echo measurements accompanied by wide‐angle X‐ray scattering to show that binding of IHP to HbCO results in an increase in the rate of coordinated motions of Hb subunits relative to one another with little if any change in large scale structure. This increase of large‐scale dynamics seems to be coupled with a decrease in the average magnitude of higher frequency modes of individual residues. These observations indicate that enhanced dynamic motions contribute to the functional changes induced by IHP and suggest that they may be responsible for the lowered oxygen affinity triggered by these effectors. PMID:27977887

  19. Vitreoscilla hemoglobin gene ( vgb) improves lutein production in Chlorella vulgaris

    NASA Astrophysics Data System (ADS)

    Ma, Ruijuan; Lin, Xiangzhi

    2014-03-01

    Vitreoscilla hemoglobin is an oxygen-binding protein that promotes oxygen delivery and reduces oxygen consumption under low oxygen conditions to increase the efficiency of cell respiration and metabolism. In this study, we introduced a Vitreoscilla hemoglobin gene ( vgb) into Chlorella vulgaris by Agrobacterium tumefaciens -mediated transformation (ATMT). PCR analysis confirmed that the vgb gene was successfully integrated into the Chlorella vulgaris genome. Analysis of biomass obtained in shake flasks revealed transformant biomass concentrations as high as 3.28 g/L, which was 38.81% higher than that of the wild-type strain. Lutein content of transformants also increased slightly. Further experiments recovered a maximum lutein yield of 2.91 mg/L from the transformants, which was 36.77% higher than that of the wild-type strain. The above results suggest that integrated expression of the vgb gene may improve cell growth and lutein yield in Chlorella vulgaris, with applications to lutein production from Chlorella during fermentation.

  20. Metastable Mesoscopic Clusters in Solutions of Sickle-Cell Hemoglobin

    PubMed Central

    Pan, Weichun; Galkin, Oleg; Filobelo, Luis; Nagel, Ronald L.; Vekilov, Peter G.

    2007-01-01

    Sickle cell hemoglobin (HbS) is a mutant, whose polymerization while in deoxy state in the venous circulation underlies the debilitating sickle cell anemia. It has been suggested that the nucleation of the HbS polymers occurs within clusters of dense liquid, existing in HbS solutions. We use dynamic light scattering with solutions of deoxy-HbS, and, for comparison, of oxy-HbS and oxy-normal adult hemoglobin, HbA. We show that solutions of all three Hb variants contain clusters of dense liquid, several hundred nanometers in size, which are metastable with respect to the Hb solutions. The clusters form within a few seconds after solution preparation and their sizes and numbers remain relatively steady for up to 3 h. The lower bound of the cluster lifetime is 15 ms. The clusters exist in broad temperature and Hb concentration ranges, and occupy 10−5–10−2 of the solution volume. The results on the cluster properties can serve as test data for a potential future microscopic theory of cluster stability and kinetics. More importantly, if the clusters are a part of the nucleation mechanism of HbS polymers, the rate of HbS polymerization can be controlled by varying the cluster properties. PMID:17040989

  1. Modulation of hemoglobin dynamics by an allosteric effector

    DOE PAGES

    Lal, Jyotsana; Maccarini, Marco; Fouquet, Peter; ...

    2016-12-15

    Hemoglobin (Hb) is an extensively studied paradigm of proteins that alter their function in response to allosteric effectors. Models of its action have been used as prototypes for structure-function relationships in many proteins, and models for the molecular basis of its function have been deeply studied and extensively argued. Recent reports suggest that dynamics may play an important role in its function. Relatively little is known about the slow, correlated motions of hemoglobin subunits in various structural states because experimental and computational strategies for their characterization are challenging. Allosteric effectors such as inositol hexaphosphate (IHP) bind to both deoxy-Hb andmore » HbCO, albeit at different sites, leading to a lowered oxygen affinity. The manner in which these effectors impact oxygen binding is unclear and may involve changes in structure, dynamics or both. Here we use neutron spin echo (NSE) measurements accompanied by wideangle x-ray scattering (WAXS) to show that binding of IHP to HbCO results in an increase in the rate of coordinated motions of Hb subunits relative to one another with little if any change in large scale structure. This increase of large-scale dynamics seems to be coupled with a decrease in the average magnitude of higher frequency modes of individual residues. Furthermore, these observations indicate that enhanced dynamic motions contribute to the functional changes induced by IHP and suggest that they may be responsible for the lowered oxygen affinity triggered by these effectors.« less

  2. The entropically favored osmotic "compression" of sickle cell hemoglobin gels.

    PubMed

    Chik, J K; Parsegian, V A

    2001-08-01

    Contrary to the accurate, hard-sphere depiction of monomeric hemoglobin in solution, sickle cell hemoglobin (HbS) polymerization/gelation requires attention to molecular interactions. From the temperature dependence of the osmotic compressibility of HbS gels, we were able to extract the entropy increase for concentrating HbS in this phase. Normalized per mole of water removed, the entropy increase from gel compression DeltaS(gel) is four times the previously measured DeltaS(trans), for the transition from monomeric HbS solution to HbS gel. The positive entropy change cannot emerge from the assembly of hard spheres but can indicate remodeling of HbS fibers driven by release of ordered water. The fourfold difference in DeltaS(gel) and DeltaS(trans) suggests that the act of initial fiber/gel formation from monomeric solution differs from the process of further polymerization due to tighter packing within the gel phase. Copyright 2001 John Wiley & Sons, Inc. Biopolymers 59: 120-124, 2001

  3. A Mouse Model for Human Unstable Hemoglobin Santa Ana.

    PubMed

    Miyashiro, Samantha I; Massironi, Silvia M G; Mori, Claudia M C; Cruz, Carolina C; Hagiwara, Mitika K; Maiorka, Paulo C

    2016-12-01

    In the present study, we described the phenotype, histologic morphology, and molecular etiology of a mouse model of unstable hemoglobin Santa Ana. Hematologic evaluation of anemic mice (Anem/+) discovered after N-ethyl-N-nitrosourea mutagenesis revealed moderate anemia with intense reticulocytosis and polychromasia, followed by anisocytosis, macrocytosis, hypochromia, and intraerythrocytic inclusion and Heinz bodies. The mice also demonstrated hemoglobinuria, bilirubinemia, and erythrocytic populations with differing resistance to osmotic lysis. Splenomegaly (particularly in older mutant mice) and jaundice were apparent at necropsy. Histopathologic examination revealed dramatically increased hematopoiesis and hemosiderosis in hematopoietic organs and intracellular iron deposition in tubular renal cells. These data are characteristic of a congenital hemolytic regenerative anemia, similar to human anemias due to unstable hemoglobin. Genetic mapping assigned the affected gene to mouse chromosome 7, approximately 50 cM from the Hbb locus. The sequence of the mutant Hbb gene exhibited a T→C transversion at nucleotide 179 in Hbb-b1, leading to the substitution of proline for leucine at amino acid residue 88 and thus homologous to the genetic defect underlying Santa Ana anemia in humans.

  4. Infant Responsiveness, Alertness, Hemoglobin and Growth in Rural Sidama, Ethiopia

    PubMed Central

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Thomas, David G.; Kennedy, Tay S.; Berhanu, Getenesh; Stoecker, Barbara J.; Hubbs-Tait, Laura; Hambidge, K. Michael

    2011-01-01

    Several recent studies have supported relations between infant behavior (alertness and responsiveness) and nutrition (e.g. Dempsey 2008, Wachs et al 2005) in addition to investigating infant behavior within the context of changes in iron status over time (e.g. Black et al. 2004, Murray-Kolb & Beard 2009). Existing research is typically limited to investigation of the effects of a single vitamin or mineral and no studies have been found that examined the influence that early alertness and responsiveness have on growth in early infancy, despite the fact that relations between behavior and nutritional status may be bidirectional (Hulthén 2003). The current study used a sample of Ethiopian infants and investigated anthropometrics, hemoglobin, the frequency of alertness, and the frequency of responsiveness at 6 and 9 months of age. Six-month weight-for-age predicted 9-month frequency of alertness, while 6-month hemoglobin predicted 9-month frequency of responsiveness. Compared to responsive infants, non-responsive infants at 6 months remained more non-responsive at 9 months, though weight-for-age for both groups converged at 9 months. Results support relations between nutrition and behavior (alertness and responsiveness) and provide evidence of a potentially useful tool (the Laboratory Temperament Assessment Battery [Lab-TAB]) that was adapted to evaluate these relations in Ethiopia. PMID:22233352

  5. Kinetic studies on the cupric ion oxidation of sheep hemoglobin.

    PubMed

    Brittain, T; Ivanetich, K M

    1980-11-01

    The oxidation of sheep hemoglobin, in both the oxygenated and deoxygenated forms, by cuprous ions have been studied by spectrophotometric and stopped-flow techniques. Mixing of both the oxy and deoxy forms with excess Cu2+ leads to the rapid oxidation of the iron atoms of all four of the hem groups of the tetrameric protein, followed by the slow formation of hemichromes (low spin FeIII forms of hemoglobin). Stopped-flow studies show that the oxidations follow simple monophasic kinetics with second-order rate constants of 65 and 310 M-1 sec-1 for the oxy and deoxy forms, respectively. Variable temperature studies yield Arrhenius activation energies of 43 for the oxy form and 113 kJ mole-1 for the deoxy form. For each form of the protein the activation energy is very similar to the activation enthalpy. While the deoxy form is characterized by an activation energy and enthalpy that is more than twice the corresponding value in the oxy form. The activation entropies show highly significant differences being -128 e.u. and 136 e.u. at 25 degrees C for the oxy and deoxy forms, respectively.

  6. Hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery.

    PubMed

    Najafi, Mahdi; Faraoni, David

    2015-07-26

    Although red blood cells (RBCs) transfusion is sometimes associated with adverse reactions, anemia could also lead to increased morbidity and mortality in high-risk patients. For these reasons, the definition of perioperative strategies that aims to detect and treat preoperative anemia, prevent excessive blood loss, and define "optimal" transfusion algorithms is crucial. Although the treatment with preoperative iron and erythropoietin has been recommended in some specific conditions, several controversies exist regarding the benefit-to-risk balance associated with these treatments. Further studies are needed to better define the indications, dosage, and route of administration for preoperative iron with or without erythropoietin supplementation. Although restrictive transfusion strategies in patients undergoing cardiac surgery have been shown to effectively reduce the incidence and the amount of RBCs transfusion without increase in side effects, some high-risk patients (e.g., symptomatic acute coronary syndrome) could benefit from higher hemoglobin concentrations. Despite all efforts made last decade, a significant amount of work remains to be done to improve hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery.

  7. Stability of blood carbon monoxide and hemoglobins during heating.

    PubMed

    Seto, Y; Kataoka, M; Tsuge, K

    2001-09-15

    The effects of heating on hemoglobin (Hb) and carbon monoxide (CO) levels in human blood were investigated by in vitro experiments. Head-space gas chromatography (HS-GC) using a molecular sieve 5A stationary phase and thermal conductivity detection was adopted for the measurement of CO gas, and spectrophotometric methods were used for the measurement of various Hb forms, protein and heme contents. Deteriorated absorbance spectra were observed for heat-treated blood samples, and double wavelength spectrophotometry was proven to give wrong percent saturation of carboxyhemoglobin content (% CO-Hb). The blood sample taken from one fatal fire casualty gave significantly higher % CO-Hb measured spectrophotometrically, compared to that by HS-GC. Control blood or purified Hb solution, which was saturated with CO in designated extent, was heated in a sealed vial. Under the incubation below 54 degrees C, all Hb forms were stable, except for oxyhemoglobin (Hb-O(2)), which was partially oxidized to met-hemoglobin (Met-Hb). In contrast, under the incubation at 65 degrees C, Met-Hb was denatured completely to be insoluble, and Hb-O(2) was partially denatured via Met-Hb formation. CO-Hb was resistant against heating. The difference of heat susceptibility and precipitability among Hb forms resulted in artificial increase of % CO-Hb. During heating, spontaneous CO was produced from blood.

  8. [Minor beta thalassemia masked by a hemoglobin A2 mutant].

    PubMed

    Omar, Souheil; Hammami, Mohamed Bassem; Taeib, Sameh Haj; Feki, Moncef; Abbes, Salem; Kaabachi, Naziha

    2010-09-01

    The elevation of hemoglobin A2 (HbA2) is an essential criterion in the diagnosis of minor ss thalassemia. To report a case of minor ss thalassemia HbA2 with normal HbA2 rate. We report the case of ten years old boy, with hypochromic microcytic anemia, refractory to iron treatment. The study of hemoglobin (Hb) has revealed the presence of a minor abnormal fraction of Hb, amounted to 2.8%, associated with the presence of HbF and normal levels of HbA2. Family study revealed the presence of two Hb abnormalities (ss thalassemia trait and HbA2 mutant) transmitted to offspring in isolation or associated. The genotypic study confirmed the presence of minor, 0 thalassemia and a ⁰/₀₀ gene mutation, causing a new mutant HbA2 named HbA2 Pasteur-Tunis [⁰/₀₀ 59(E3)LysgAsn(AAGgAAC)]. The presence of ⁰/₀₀ mutant reduces HbA2 level and could hide ss thalassemia trait. Rigorous and methodical interpretation of phenotypic data is crucial to not overlook the presence of ss thalassemia trait, whose diagnosis is crucial for genetic counseling and prenatal diagnosis.

  9. Carnivora: primary structure of the hemoglobins from ratel (Mellivora capensis).

    PubMed

    Rodewald, K; Braunitzer, G; Göltenboth, R

    1988-10-01

    The erythrocytes of adult ratel contain two hemoglobin components, with two alpha- and one beta-chains. In this paper, their complete amino acid sequences are presented. The two alpha-chains differ in one residue at position 34 (Ala----Val) only. The primary structure of the chains was determined by sequencing the N-terminal regions (45 steps) and the tryptic peptides after their isolation from the digests by reversed-phase high-performance liquid chromatography. The alignment of these peptides was deduced from homology with other carnivora globins. The alpha-chains show 21 and the beta-chains 11 exchanges compared with human globin chains. In the alpha-chains, one heme- and two alpha 1/beta 1 contacts are exchanged. In the beta-chains there are three exchanges which involve one alpha 1/beta 1-, one alpha 1/beta 2- and one heme-contact. Between the ratel hemoglobin and those of carnivora a high degree of homology was found.

  10. Biphasic Oxidation of Oxy-Hemoglobin in Bloodstains

    PubMed Central

    Bremmer, Rolf H.; de Bruin, Daniel M.; de Joode, Maarten; Buma, Wybren Jan; van Leeuwen, Ton G.; Aalders, Maurice C. G.

    2011-01-01

    Background In forensic science, age determination of bloodstains can be crucial in reconstructing crimes. Upon exiting the body, bloodstains transit from bright red to dark brown, which is attributed to oxidation of oxy-hemoglobin (HbO2) to met-hemoglobin (met-Hb) and hemichrome (HC). The fractions of HbO2, met-Hb and HC in a bloodstain can be used for age determination of bloodstains. In this study, we further analyze the conversion of HbO2 to met-Hb and HC, and determine the effect of temperature and humidity on the conversion rates. Methodology The fractions of HbO2, met-Hb and HC in a bloodstain, as determined by quantitative analysis of optical reflectance spectra (450–800 nm), were measured as function of age, temperature and humidity. Additionally, Optical Coherence Tomography around 1300 nm was used to confirm quantitative spectral analysis approach. Conclusions The oxidation rate of HbO2 in bloodstains is biphasic. At first, the oxidation of HbO2 is rapid, but slows down after a few hours. These oxidation rates are strongly temperature dependent. However, the oxidation of HbO2 seems to be independent of humidity, whereas the transition of met-Hb into HC strongly depends on humidity. Knowledge of these decay rates is indispensable for translating laboratory results into forensic practice, and to enable bloodstain age determination on the crime scene. PMID:21789186

  11. Multiwavelength pulse oximetry in the measurement of hemoglobin fractions

    NASA Astrophysics Data System (ADS)

    Manzke, Bernd; Schwider, Johannes; Lutter, Norbert O.; Engelhardt, Kai; Stork, Wilhelm

    1996-04-01

    The two wavelength design of the majority of pulse oximeters assumes only two absorbing hemoglobin fractions, oxyhemoglobin (O2Hb), and reduced hemoglobin (HHb) irrespective of the presence of methemoglobin (MetHb) and carboxyhemoglobin (COHb). If MetHb or COHb is present, it contributes to the pulse-added absorbance signal and will be interpreted as either HHb or O2Hb or some combination of the two. In this paper we describe a noninvasive multi-wavelength pulse oximeter measuring O2Hb, HHb, MetHb, and COHb at a specified accuracy of 1.0%. The system was designed with respect to the results of numerical simulations. It consists of 9 laserdiodes (LDs) and 7 light emitting diodes (LEDs), a 16-bit analog-digital converter (ADC) and has a sampling rate of 16 kHz. The laser didoes and LEDs were coupled into multi-mode fibers and led with a liquid lightguide to the finger clip and then the photodiode. It also presents the results of a clinical study, including a setup with a quartz tungsten halogen lamp (with fiber output) and a diode array spectrometer, a standard pulse oximeter and two in-vitro oximeters (radiometer OSM3 and radiometer ABL 520) as references.

  12. Autofluorescence characterization of advanced glycation end products of hemoglobin

    NASA Astrophysics Data System (ADS)

    Vigneshwaran, Nadanathangam; Bijukumar, Gopalakrishnapillai; Karmakar, Nivedita; Anand, Sneh; Misra, Anoop

    2005-01-01

    This article describes the analysis of autofluorescence of advanced glycation end products of hemoglobin (Hb-AGE). Formed as a result of slow, spontaneous and non-enzymatic glycation reactions, Hb-AGE possesses a characteristic autofluorescence at 308/345 nm ( λex/ λem). Even in the presence of heme as a quenching molecule, the surface presence of the glycated adduct gave rise to autofluorescence with the quantum yield of 0.19. The specificity of monoclonal antibody developed against common AGE structure with Hb-AGE was demonstrated using reduction in fluorescence polarization value due to increased molecular volume while binding. The formation of fluorescent adduct in hemoglobin in the advanced stage of glycation and the non-fluorescent HbA 1c will be of major use in distinguishing and to know the past status of diabetes mellitus. While autofluorescence correlated highly with HbA 1c value under in vivo condition ( r=0.85), it was moderate in the clinical samples ( r=0.55). The results suggest a non-linear relation between glycemia and glycation, indicating the application of Hb-AGE as a measure of susceptibility to glycation rather than glycation itself.

  13. Carbon monoxide binding by hemoglobin and myoglobin under photodissociating conditions.

    PubMed

    Brunori, M; Bonaventura, J; Bonaventura, C; Antonini, E; Wyman, J

    1972-04-01

    Carbon monoxide binding by myoglobin and hemoglobin has been studied under conditions of constant illumination. For hemoglobin, the homotropic heme-heme interaction (cooperativity) and the heterotropic Bohr effect are invariant with light intensity over a 1000-fold change of c((1/2)). The dissociation constant, measured as c((1/2)), increases linearly with light intensity, indicating that photodissociation is a one-quantum process. At sufficiently high illumination the apparent enthalpy of ligand binding becomes positive, although in the absence of light it is known to be negative. This finding indicates that light acts primarily by increasing the "off" constants by an additive factor. The invariance of both cooperativity and Bohr effect raises a perplexing issue. It would appear to demand either that the "off" constants for the various elementary steps are all alike (which is contrary to current ideas) or that the additive factor is in each case proportional to the particular "off" constant to which it is added (a seemingly improbable alternative).

  14. Interaction of recombinant octameric hemoglobin with endothelial cells.

    PubMed

    Gaucher, Caroline; Domingues-Hamdi, Élisa; Prin-Mathieu, Christine; Menu, Patrick; Baudin-Creuza, Véronique

    2015-02-01

    Hemoglobin-based oxygen carriers (HBOCs) may generate oxidative stress, vasoconstriction and inflammation. To reduce these undesirable vasoactive properties, we increased hemoglobin (Hb) molecular size by genetic engineering with octameric Hb, recombinant (r) HbβG83C. We investigate the potential side effects of rHbβG83C on endothelial cells. The rHbβG83C has no impact on cell viability, and induces a huge repression of endothelial nitric oxide synthase gene transcription, a marker of vasomotion. No induction of Intermolecular-Adhesion Molecule 1 and E-selectin (inflammatory markers) transcription was seen. In the presence of rHbβG83C, the transcription of heme oxygenase-1 (oxidative stress marker) is weakly increased compared to the two other HBOCs (references) or Voluven (control). This genetically engineered octameric Hb, based on a human Hb βG83C mutant, leads to little impact at the level of endothelial cell inflammatory response and thus appears as an interesting molecule for HBOC development.

  15. Optical mammography: bilateral breast symmetry in hemoglobin saturation maps

    NASA Astrophysics Data System (ADS)

    Anderson, Pamela G.; Sassaroli, Angelo; Kainerstorfer, Jana M.; Krishnamurthy, Nishanth; Kalli, Sirishma; Makim, Shital S.; Graham, Roger A.; Fantini, Sergio

    2016-10-01

    We present a study of the bilateral symmetry of human breast hemoglobin saturation maps measured with a broadband optical mammography instrument. We have imaged 21 patients with unilateral breast cancer, 32 patients with unilateral benign lesions, and 27 healthy patients. An image registration process was applied to the bilateral hemoglobin saturation (SO2) images by assigning each pixel to the low, middle, or high range of SO2 values, where the thresholds for the categories were the 15th and 85th percentiles of the individual saturation range. The Dice coefficient, which is a measure of similarity, was calculated for each patient's pair of right and left breast SO2 images. The invasive cancer patients were found to have an average Dice coefficient value of 0.55±0.07, which was significantly lower than the benign and healthy groups (0.61±0.11 and 0.62±0.12, respectively). Although differences were seen in a group analysis, the healthy patient Dice coefficients spanned a wide range, limiting the diagnostic capabilities of this SO2 symmetry analysis on an individual basis. Our results suggest that for assessing the SO2 contrast of breast lesions, it may be better to select a reference tissue in the ipsilateral rather than the contralateral breast.

  16. Oxygen-induced changes in hemoglobin expression in Drosophila.

    PubMed

    Gleixner, Eva; Abriss, Daniela; Adryan, Boris; Kraemer, Melanie; Gerlach, Frank; Schuh, Reinhard; Burmester, Thorsten; Hankeln, Thomas

    2008-10-01

    The hemoglobin gene 1 (dmeglob1) of the fruit fly Drosophila melanogaster is expressed in the tracheal system and fat body, and has been implicated in hypoxia resistance. Here we investigate the expression levels of dmeglob1 and lactate dehydrogenase (a positive control) in embryos, third instar larvae and adult flies under various regimes of hypoxia and hyperoxia. As expected, mRNA levels of lactate dehydrogenase increased under hypoxia. We show that expression levels of dmeglob1 are decreased under both short- and long-term hypoxia, compared with the normoxic (21% O2) control. By contrast, a hypoxia/reoxygenation regime applied to third instar larvae elevated the level of dmeglob1 mRNA. An excess of O2 (hyperoxia) also triggered an increase in dmeglob1 mRNA. The data suggest that Drosophila hemoglobin may be unlikely to function merely as a myoglobin-like O2 storage protein. Rather, dmeglob1 may protect the fly from an excess of O2, either by buffering the flux of O2 from the tracheoles to the cells or by degrading noxious reactive oxygen species.

  17. Transient Ligand Docking Sites in Cerebratulus lacteus Mini-Hemoglobin

    PubMed Central

    Deng, Pengchi; Nienhaus, Karin; Palladino, Pasquale; Olson, John S.; Blouin, George; Moens, Luc; Dewilde, Sylvia; Geuens, Eva; Nienhaus, G. Ulrich

    2007-01-01

    The monomeric hemoglobin of the nemertean worm Cerebratulus lacteus functions as an oxygen storage protein to maintain neural activity under hypoxic conditions. It shares a large, apolar matrix tunnel with other small hemoglobins, which has been implicated as a potential ligand migration pathway. Here we explore ligand migration and binding within the distal heme pocket, to which the tunnel provides access to ligands from the outside. FTIR/TDS experiments performed at cryogenic temperatures reveal the presence of three transient ligand docking sites within the distal pocket, the primary docking site B on top of pyrrole C and secondary sites C and D. Site C is assigned to a cavity adjacent to the distal portion of the heme pocket, surrounded by the B and E helices. It has an opening to the apolar tunnel and is expected to be on the pathway for ligand entry and exit, whereas site D, circumscribed by TyrB10, GlnE7, and the CD corner, most likely is located on a side pathway of ligand migration. Flash photolysis experiments at ambient temperatures indicate that the rate-limiting step for ligand binding to CerHb is migration through the apolar channel to site C. Movement from C to B and iron-ligand bond formation involve low energy barriers and thus are very rapid processes in the wt protein. PMID:17531406

  18. Carbon dioxide and oxygen linkage in human hemoglobin tetramers.

    PubMed

    Doyle, M L; Di Cera, E; Robert, C H; Gill, S J

    1987-08-20

    Differential binding curve measurements for oxygen in the presence of fixed carbon dioxide activities have allowed a detailed determination of the linkage between carbon dioxide and the oxygenated intermediates of human hemoglobin. Model-independent analysis of the data shows that at pH 7.4: (1) the oxygen binding curves are asymmetrical, the population of the triply oxygenated species being negligible; (2) the shape of the oxygen binding curve is invariant with carbon dioxide activity; (3) the maximum linkage is -0.32 moles carbon dioxide per mole oxygen; and (4) the overall carbon dioxide-dependent shift in the oxygen binding curve cannot be explained in terms of carbamino formation alone, the additional influence of bicarbonate being required. An allosteric model that accounts for the low population of triply oxygenated hemoglobin species is employed here as a framework from which to explore the carbon dioxide linkage mechanism at the intermediate stages of oxygenation. Carbon dioxide binding constants are found to be 780 M-1 and 580 M-1 for carbon dioxide binding to the deoxygenated alpha and beta chains, respectively, and 150 M-1 for carbon dioxide binding to the oxygenated form of both chains, as determined by simultaneous fitting of the oxygen binding curves with the model. Finally, by use of the determined binding polynomial for the carbon dioxide-oxygen linkage scheme, we have constructed a series of linkage graphs.

  19. Molecular dynamics simulation of photodissociation of carbon monoxide from hemoglobin

    SciTech Connect

    Henry, E.R.; Levitt, M.; Eaton, W.A.

    1985-04-01

    A molecular dynamics simulation of the photodissociation of carbon monoxide from the alpha subunit of hemoglobin is described. To initiate photodissociation, trajectories of the liganded molecule were interrupted, the iron-carbon monoxide bond was broken, and the parameters of the iron-nitrogen bonds were simultaneously altered to produce a deoxyheme conformation. Heme potential functions were used that reproduce the energies and forces for the iron out-of-plane motion obtained from quantum mechanical calculations. The effect of the protein on the rate and extent of the displacement of the iron from the porphyrin plane was assessed by comparing the results with those obtained for an isolated complex of heme with imidazole and carbon monoxide. The half-time for the displacement of the iron from the porphyrin plane was found to be 50-150 fs for both the protein and the isolated complex. These results support the interpretation of optical absorption studies using 250-fs laser pulses that the iron is displaced from the porphyrin plane within 350 fs in both hemoglobin and a free heme complex in solution.

  20. Iron absorption from concentrated hemoglobin hydrolysate by rat.

    PubMed

    Vaghefi, Nikta; Nedjaoum, Fuzia; Guillochon, Didier; Bureau, François; Arhan, Pierre; Bouglé, Dominique

    2005-06-01

    Although heme iron is highly bioavailable, the low iron content of hemoglobin prevents its use for dietary fortification; on the other hand, purified heme has low solubility and absorption rate. The present study was designed to assess the interactions between concentrated heme iron and peptides released during globin hydrolysis and cysteine and their relation with iron absorption. Hemoglobin was hydrolyzed by pepsin or subtilisin, and then, heme iron was concentrated by ultrafiltration. Iron absorption was studied in a Ussing chamber; gluconate was used as control. Iron uptake from nonconcentrated pepsin hydrolysate and gluconate was lower than from other groups. Cysteine significantly enhanced iron uptake except from the concentrated subtilisin hydrolysate. There was no significant difference between cysteine-supplemented groups. According to the different hydrolysis pathways of enzymes, it is assumed that the presence of hydrophobic peptides and the strength of heme-peptide interactions are both determining factors of heme iron absorption. These interactions occur mainly before iron uptake, as emphasized by the effect of cysteine.

  1. Structure of Greyhound hemoglobin: origin of high oxygen affinity.

    PubMed

    Bhatt, Veer S; Zaldívar-López, Sara; Harris, David R; Couto, C Guillermo; Wang, Peng G; Palmer, Andre F

    2011-05-01

    This study presents the crystal structure of Greyhound hemoglobin (GrHb) determined to 1.9 Å resolution. GrHb was found to crystallize with an α₁β₁ dimer in the asymmetric unit and belongs to the R2 state. Oxygen-affinity measurements combined with the fact that GrHb crystallizes in the R2 state despite the high-salt conditions used for crystallization strongly indicate that GrHb can serve as a model high-oxygen-affinity hemoglobin (Hb) for higher mammals, especially humans. Structural analysis of GrHb and its comparison with the R2-state of human Hb revealed several regions that can potentially contribute to the high oxygen affinity of GrHb and serve to rationalize the additional stability of the R2-state of GrHb. A previously well studied hydrophobic cluster of bar-headed goose Hb near α119 was also incorporated in the comparison between GrHb and human Hb. Finally, a structural comparison with generic dog Hb and maned wolf Hb was conducted, revealing that in contrast to GrHb these structures belong to the R state of Hb and raising the intriguing possibility of an additional allosteric factor co-purifying with GrHb that can modulate its quaternary structure.

  2. Red blood cell lifespan, erythropoiesis and hemoglobin control.

    PubMed

    Kruse, Anja; Uehlinger, Dominik E; Gotch, Frank; Kotanko, Peter; Levin, Nathan W

    2008-01-01

    Erythropoietin (EPO) and iron deficiency as causes of anemia in patients with limited renal function or end-stage renal disease are well addressed. The concomitant impairment of red blood cell (RBC) survival has been largely neglected. Properties of the uremic environment like inflammation, increased oxidative stress and uremic toxins seem to be responsible for the premature changes in RBC membrane and cytoskeleton. The exposure of antigenic sites and breakdown of the phosphatidylserine asymmetry promote RBC phagocytosis. While the individual response to treatment with EPO-stimulating agents (ESA) depends on both the RBC's lifespan and the production rate, uniform dosing algorithms do not meet that demand. The clinical use of mathematical models predicting ESA-induced changes in hematocrit might be greatly improved once independent estimates of RBC production rate and/or lifespan become available, thus making the concomitant estimation of both parameters unnecessary. Since heme breakdown by the hemoxygenase pathway results in carbon monoxide (CO) which is exhaled, a simple CO breath test has been used to calculate hemoglobin turnover and therefore RBC survival and lifespan. Future research will have to be done to validate and implement this method in patients with kidney failure. This will result in new insights into RBC kinetics in renal patients. Eventually, these findings are expected to improve our understanding of the hemoglobin variability in response to ESA.

  3. [Hemoglobin and testosterone: importance on high altitude acclimatization and adaptation].

    PubMed

    Gonzales, Gustavo F

    2011-03-01

    The different types of response mechanisms that the organism uses when exposed to hypoxia include accommodation, acclimatization and adaptation. Accommodation is the initial response to acute exposure to high altitude hypoxia and is characterized by an increase in ventilation and heart rate. Acclimatization is observed in individuals temporarily exposed to high altitude, and to some extent, it enables them to tolerate the high altitudes. In this phase, erythropoiesis is increased, resulting in higher hemoglobin and hematocrit levels to improve oxygen delivery capacity. Adaptation is the process of natural acclimatization where genetical variations and acclimatization play a role in allowing subjects to live without any difficulties at high altitudes. Testosterone is a hormone that regulates erythropoiesis and ventilation and could be associated to the processes of acclimatization and adaptation to high altitude. Excessive erythrocytosis, which leads to chronic mountain sickness, is caused by low arterial oxygen saturation, ventilatory inefficiency and reduced ventilatory response to hypoxia. Testosterone increases during acute exposure to high altitude and also in natives at high altitude with excessive erythrocytosis. Results of current research allow us to conclude that increase in serum testosterone and hemoglobin is adequate for acclimatization, as they improve oxygen transport, but not for high altitude adaptation, since high serum testosterone levels are associated to excessive erythrocytosis.

  4. 17α-Ethinylestradiol can disrupt hemoglobin catabolism in amphibians.

    PubMed

    Garmshausen, Josefin; Kloas, Werner; Hoffmann, Frauke

    2015-05-01

    Different chemical substances, which enter the environment due to anthropogenic influences, can affect the endocrine system and influence development and physiology of aquatic animals. One of these endocrine disrupting chemicals is the synthetic estrogen, 17α-ethinylestradiol (EE2), which is a main component of various oral contraceptives and demonstrably affects many different aquatic vertebrates at extremely low concentrations by feminization phenomena. The aim of the present study was to investigate whether a four week exposure to three different concentrations of EE2 (0.3 ng/L, 29.6 ng/L and 2960 ng/L) affects the catabolism of hemoglobin of the amphibian Xenopus laevis. The results of this study demonstrate for the first time that beside an increase of the hepatic vitellogenin gene expression, exposure to EE2 also decreases the gene expression of the hepatic heme oxygenase 1 and 2 (HO1, HO2), degrading heme of different heme proteins to biliverdin, as well as of the biliverdin reductase A (BLVRA), which converts biliverdin to bilirubin. The results further suggest that EE2 already at the environmentally relevant concentration of (29.6 ng/L) can disrupt hemoglobin catabolism, indicated by decreased gene expression of HO2, which becomes evident at the highest EE2 concentration that led to a severe increase of biliverdin in plasma.

  5. [Hemoglobin beta S haplotype in the Kebili region (southern Tunisia)].

    PubMed

    Frikha, M; Fakhfakh, F; Mseddi, S; Gargouri, J; Ghali, L; Labiadh, Z; Harrabi, M; Souissi, T; Ayadi, H

    1998-04-01

    Sickle cell anemia is a monogenic hereditary disease characterized by a mutation in the beta globin gene. Five major haplotypes associated with the beta S mutation have been defined: Benin, Bantu, Senegalian, Camerounian, and Arabo-Indian. Previous studies in northern Tunisia showed that sickle cell anemia was of Benin origin in this region. Patients from the south of Tunisia, mainly from the Kebili region, were not previously concerned. In this study, we have determined the beta S haplotype and evaluated phenotypical expression of the disease in 14 patients from this latter region. The use of four restriction endonucleases having polymorphic sites in the beta globin gene showed that all patients had the Benin haplotype, confirming the Benin origin of sickle cell anemia in Tunisia. This haplotype is associated with an heterogeneous expression of fetal hemoglobin (HbF) with extremes varying from 2.4 to 16.3% and a mean expression rate of 8.16%, which is in accordance with literature data. In spite of the haplotype homogeneity in our patients, clinical heterogeneity was noted. A unique case of alpha-thalassemia could not explain this heterogeneity. In contrast, we found a certain correlation between fetal hemoglobin expression and clinical severity.

  6. Screening for Structural Hemoglobin Variants in Bahia, Brazil

    PubMed Central

    Silva, Wellington Santos; de Oliveira, Roberto Ferreira; Ribeiro, Sanzia Bezerra; da Silva, Isabel Batista; de Araújo, Edna Maria; Baptista, Abrahão Fontes

    2016-01-01

    Brazil was the country that received the largest number of Africans during the time of colonization, and Bahia was the Brazilian state that received the largest number of slaves from Africa. The purpose of this study was to evaluate the coverage of the newborn screening program for sickle cell disease in the Recôncavo Baiano region of the state of Bahia, and to show the frequency of the subjects with hemoglobin variants in the 2006–2009 period. Blood samples from neonates in twelve cities in the Recôncavo Baiano region were analyzed by High Performance Liquid Chromatography. A total of 16,402 children were born in this period, 14,773 of which underwent newborn screening. In this period 1416 children were born carrying hemoglobin variants HbS and HbC. Forty-seven patients—20 HbSS genotype and 27 HbSC genotype—were diagnosed in eleven of the twelve cities surveyed. The proportion of children born with sickle cell disease in the Recôncavo Baiano region was 1/314, which was higher than the 1/650 rate for the state of Bahia. The data presented in this study confirm the high frequency of sickle cell disease in Recôncavo Baiano, demonstrating the need to create a referral center for the care of patients with sickle cell diseases in the region. PMID:26901212

  7. Fetal hemoglobin in sickle cell anemia: a glass half full?

    PubMed

    Steinberg, Martin H; Chui, David H K; Dover, George J; Sebastiani, Paola; Alsultan, Abdulrahman

    2014-01-23

    Fetal hemoglobin (HbF) modulates the phenotype of sickle cell anemia by inhibiting deoxy sickle hemoglobin (HbS) polymerization. The blood concentration of HbF, or the number of cells with detectable HbF (F-cells), does not measure the amount of HbF/F-cell. Even patients with high HbF can have severe disease because HbF is unevenly distributed among F-cells, and some cells might have insufficient concentrations to inhibit HbS polymerization. With mean HbF levels of 5%, 10%, 20%, and 30%, the distribution of HbF/F-cell can greatly vary, even if the mean is constant. For example, with 20% HbF, as few as 1% and as many as 24% of cells can have polymer-inhibiting, or protective, levels of HbF of ∼10 pg; with lower HbF, few or no protected cells can be present. Only when the total HbF concentration is near 30% is it possible for the number of protected cells to approach 70%. Rather than the total number of F-cells or the concentration of HbF in the hemolysate, HbF/F-cell and the proportion of F-cells that have enough HbF to thwart HbS polymerization is the most critical predictor of the likelihood of severe sickle cell disease.

  8. Light scattering from Sickle Cell Hemoglobin: Polarized and Unpolarized

    NASA Astrophysics Data System (ADS)

    Chen, Kejing; Hantgan, Roy R.; Kim-Shapiro, Daniel B.

    1999-11-01

    Sickle cell polymers form due to aggregation of a mutant form of hemoglobin (HbS). The polymerization of HbS leads to microvascular occlusion characteristic of Sickle Cell Disease. A good understanding of HbS polymerization requires a way to quantify the degree of polymerization. As our calculations show, total intensity light scattering is not always linearly dependent on the amount of polymer. Polarized light scattering has been proposed as a more accurate way to measure polymer content. We use a new modulation method to measure all 16 Mueller Matrix elements, which completely describe how the Polarization State of light is altered upon scattering. Preliminary results of light scattering measurements from spheres and hemoglobin show that the instrument works properly. In future experiments, we will attempt to use polarized light scattering as an accurate measure of polymerization. In addition, Polarized light scattering may provide information on the higher order structure of sickle polymer bundles that has not been obtainable by other means.

  9. Hemoglobin variability and hyporesponsiveness: much ado about something or nothing?

    PubMed

    Yee, Jerry; Zasuwa, Gerard; Frinak, Stanley; Besarab, Anatole

    2009-03-01

    Hemoglobin (Hb) variability is considered a discrete clinical entity that when present may presage poor clinical outcomes. However, Hb variability is an intrinsic property of biological systems and is present in all patients, those with and without the anemia of chronic kidney disease. Taken together, variability actually represents the integration of multiple influences at multiple levels in the life of a red cell, namely the summation of positive and negative influences on erythropoiesis. Thus, Hb variability may be interpreted as a mathematic function of time and is the result of a host of influences including definition of the normal Hb range, native erythron responsiveness/hyporesponsiveness, temporal changes in endogenous and exogenous erythropoiesis-stimulating agent (ESA) levels, the algorithms used to dose ESAs and their duration of action, the presence of biologically available iron, red cell turnover, and recyclable and non-recyclable blood loss and gain. When viewed within this construct of matrixed determinants, the source of hemoglobin variability is more readily identified. When variability is present but the etiology is not easily discerned, erythropoietic hyporesponsiveness must be considered and evaluated. Finally, integration of all of these concepts is possible within the context of an anemia management protocol.

  10. Optical mammography: bilateral breast symmetry in hemoglobin saturation maps

    PubMed Central

    Anderson, Pamela G.; Sassaroli, Angelo; Kainerstorfer, Jana M.; Krishnamurthy, Nishanth; Kalli, Sirishma; Makim, Shital S.; Graham, Roger A.; Fantini, Sergio

    2016-01-01

    Abstract. We present a study of the bilateral symmetry of human breast hemoglobin saturation maps measured with a broadband optical mammography instrument. We have imaged 21 patients with unilateral breast cancer, 32 patients with unilateral benign lesions, and 27 healthy patients. An image registration process was applied to the bilateral hemoglobin saturation (SO2) images by assigning each pixel to the low, middle, or high range of SO2 values, where the thresholds for the categories were the 15th and 85th percentiles of the individual saturation range. The Dice coefficient, which is a measure of similarity, was calculated for each patient’s pair of right and left breast SO2 images. The invasive cancer patients were found to have an average Dice coefficient value of 0.55±0.07, which was significantly lower than the benign and healthy groups (0.61±0.11 and 0.62±0.12, respectively). Although differences were seen in a group analysis, the healthy patient Dice coefficients spanned a wide range, limiting the diagnostic capabilities of this SO2 symmetry analysis on an individual basis. Our results suggest that for assessing the SO2 contrast of breast lesions, it may be better to select a reference tissue in the ipsilateral rather than the contralateral breast. PMID:26849841

  11. Serum iron, total iron binding capacity, plasma copper and hemoglobin types in anemic and poikilocytic calves.

    PubMed Central

    McGillivray, S R; Searcy, G P; Hirsch, V M

    1985-01-01

    Ninety-eight calves were studied to determine if anemia and poikilocytosis were related to iron or copper status or hemoglobin type. No significant differences were found in serum iron, total iron binding capacity, marrow iron, plasma copper or hemoglobin type between affected and normal calves. Poikilocytes were strongly inversely correlated (-0.9177) with age. Calves less than six weeks of age had more poikilocytes, lower serum iron, higher total iron binding capacity, less adult hemoglobin and more neonatal and fetal hemoglobin than calves greater than six weeks of age. Images Fig. 1. PMID:2412677

  12. Energetic Differences at The Subunit Interfaces of Normal Human Hemoglobins Correlate with Their Developmental Profile†

    PubMed Central

    Manning, Lois R.; Russell, J. Eric; Popowicz, Anthony M.; Manning, Robert S.; Padovan, Julio C.; Manning, James M.

    2013-01-01

    A previously unrecognized function of normal human hemoglobins occurring during protein assembly is described - - self-regulation of subunit pairings and their durations arising from the variable strengths of their subunit interactions. Although it is known that many mutant human hemoglobins have altered subunit interface strengths, those of the normal embryonic, fetal, and adult human hemoglobins have not been considered to differ significantly. However, in a comprehensive study of both types of subunit interfaces of seven of the eight normal oxy human hemoglobins, we found that the strength, i.e. the free energies of the tetramer-dimer interfaces, contrary to previous reports, differ by 3-orders of magnitude and display an undulating profile similar to the transitions (“switches”) of various globin subunit types over time. The dimer interface strengths are also variable and correlate linearly with their developmental profile; embryonic hemoglobins are the weakest, fetal hemoglobin is of intermediate strength, and adult hemoglobins are the strongest. The pattern also correlates generally with their different O2 affinities and responses to allosteric regulatory molecules. Acetylation of fetal hemoglobin weakens its unusually strong subunit interactions and occurs progressively as its expression diminishes and adult hemoglobin A formations begins; a causal relationship is suggested. The relative contributions of globin gene order and competition among subunits due to differences in their interface strengths were found to be complementary and establish a connection between genetics, thermodynamics, and development. PMID:19583196

  13. Relationship of hemoglobin A1c to mortality in nonsmoking insurance applicants.

    PubMed

    Stout, Robert L; Fulks, Michael; Dolan, Vera F; Magee, Mark E; Suarez, Luis

    2007-01-01

    Determine the relationship between hemoglobin A1c value and 5-year, all-cause mortality in nonsmoking life insurance applicants. By use of the Social Security Master Death Index, mortality was examined in 286,443 non-smoking insurance applicants aged 40 and up for whom blood samples for hemoglobin A1c were submitted to the Clinical Reference Laboratory. Results were stratified by hemoglobin A1c value, gender and age bands 40 to 59, 60 to 69 and 70 and up. Increased mortality is apparent at hemoglobin A1c values of 6% and above, is linear, and on a percentage basis decreases with age. Hemoglobin A1c values less than 5% also are associated with increased mortality. Absolute mortality rates for females with elevated hemoglobin A1c are generally lower than rates for males, although mortality relative to the gender-specific reference group with hemoglobin A1c of 5% to 5.9% is generally the same for both. The importance of even small elevations of hemoglobin A1c above 5.9% is apparent. For screening, it is the degree of blood sugar elevation as measured by hemoglobin A1c rather than any diagnostic label that is critical in risk assessment.

  14. Aggregation of normal and sickle hemoglobin in high concentration phosphate buffer.

    PubMed

    Chen, Kejing; Ballas, Samir K; Hantgan, Roy R; Kim-Shapiro, Daniel B

    2004-12-01

    Sickle cell disease is caused by a mutant form of hemoglobin, hemoglobin S, that polymerizes under hypoxic conditions. The extent and mechanism of polymerization are thus the subject of many studies of the pathophysiology of the disease and potential treatment strategies. To facilitate such studies, a model system using high concentration phosphate buffer (1.5 M-1.8 M) has been developed. To properly interpret results from studies using this model it is important to understand the similarities and differences in hemoglobin S polymerization in the model compared to polymerization under physiological conditions. In this article, we show that hemoglobin S and normal adult hemoglobin, hemoglobin A, aggregate in high concentration phosphate buffer even when the concentration of hemoglobin is below the solubility defined for polymerization. This phenomenon was not observed using 0.05 M phosphate buffer or in another model system we studied that uses dextran to enhance polymerization. We have used static light scattering, dynamic light scattering, and differential interference contrast microscopy to confirm aggregation of deoxygenated and oxygenated hemoglobins below their solubility and have shown that this aggregation is not observable using turbidity measurements, a common technique for assessing polymerization. We have also shown that the aggregation increases with increasing temperature in the range of 15 degrees -37 degrees C and that it increases as the concentration of phosphate increases. These studies contribute to the working knowledge of how to properly apply studies of hemoglobin S polymerization that are conducted using the high phosphate model.

  15. Oxidative stress in preeclampsia and the role of free fetal hemoglobin

    PubMed Central

    Hansson, Stefan R.; Nääv, Åsa; Erlandsson, Lena

    2015-01-01

    Preeclampsia is a leading cause of pregnancy complications and affects 3–7% of pregnant women. This review summarizes the current knowledge of a new potential etiology of the disease, with a special focus on hemoglobin-induced oxidative stress. Furthermore, we also suggest hemoglobin as a potential target for therapy. Gene and protein profiling studies have shown increased expression and accumulation of free fetal hemoglobin in the preeclamptic placenta. Predominantly due to oxidative damage to the placental barrier, fetal hemoglobin leaks over to the maternal circulation. Free hemoglobin and its metabolites are toxic in several ways; (a) ferrous hemoglobin (Fe2+) binds strongly to the vasodilator nitric oxide (NO) and reduces the availability of free NO, which results in vasoconstriction, (b) hemoglobin (Fe2+) with bound oxygen spontaneously generates free oxygen radicals, and (c) the heme groups create an inflammatory response by inducing activation of neutrophils and cytokine production. The endogenous protein α1-microglobulin, with radical and heme binding properties, has shown both ex vivo and in vivo to have the ability to counteract free hemoglobin-induced placental and kidney damage. Oxidative stress in general, and more specifically fetal hemoglobin-induced oxidative stress, could play a key role in the pathology of preeclampsia seen both in the placenta and ultimately in the maternal endothelium. PMID:25628568

  16. Methyglyoxal administration induces modification of hemoglobin in experimental rats: An in vivo study.

    PubMed

    Banerjee, Sauradipta

    2017-02-01

    Methylglyoxal, a highly reactive α-oxoaldehyde, increases in diabetic condition and reacts with proteins to form advanced glycation end products (AGEs) following Maillard-like reaction. In the present study, the effect of methylglyoxal on experimental rat hemoglobin in vivo has been investigated with respect to structural alterations and amino acid modifications, after external administration of the α-dicarbonyl compound in animals. Different techniques, mostly biophysical, were used to characterize and compare methylglyoxal-treated rat hemoglobin with that of control, untreated rat hemoglobin. In comparison with methylglyoxal-untreated, control rat hemoglobin, hemoglobin of methylglyoxal-treated rats (32mg/kgbodywt.dose) exhibited slightly decreased absorbance around 280nm, reduced intrinsic fluorescence and lower surface hydrophobicity. The secondary structures of hemoglobin of control and methylglyoxal-treated rats were more or less identical with the latter exhibiting slightly increased α-helicity compared to the former. Compared to control rat hemoglobin, methylglyoxal-treated rat hemoglobin showed higher stability. Peptide mass fingerprinting analysis revealed modifications of Arg-31α, Arg-92α and Arg-104β of methylglyoxal-treated rat hemoglobin to hydroimidazolone adducts. The modifications thus appear to be associated with the observed structural alterations of the heme protein. Considering the increased level of methylglyoxal in diabetes mellitus as well as its high reactivity, AGE-induced modifications may have physiological significance.

  17. A proposal to standardize reporting units for fecal immunochemical tests for hemoglobin.

    PubMed

    Fraser, Callum G; Allison, James E; Halloran, Stephen P; Young, Graeme P

    2012-06-06

    Fecal immunochemical tests for hemoglobin are replacing traditional guaiac fecal occult blood tests in population screening programs for many reasons. However, the many available fecal immunochemical test devices use a range of sampling methods, differ with regard to hemoglobin stability, and report hemoglobin concentrations in different ways. The methods for sampling, the mass of feces collected, and the volume and characteristics of the buffer used in the sampling device also vary among fecal immunochemical tests, making comparisons of test performance characteristics difficult. Fecal immunochemical test results may be expressed as the hemoglobin concentration in the sampling device buffer and, sometimes, albeit rarely, as the hemoglobin concentration per mass of feces. The current lack of consistency in units for reporting hemoglobin concentration is particularly problematic because apparently similar hemoglobin concentrations obtained with different devices can lead to very different clinical interpretations. Consistent adoption of an internationally accepted method for reporting results would facilitate comparisons of outcomes from these tests. We propose a simple strategy for reporting fecal hemoglobin concentration that will facilitate the comparison of results between fecal immunochemical test devices and across clinical studies. Such reporting is readily achieved by defining the mass of feces sampled and the volume of sample buffer (with confidence intervals) and expressing results as micrograms of hemoglobin per gram of feces. We propose that manufacturers of fecal immunochemical tests provide this information and that the authors of research articles, guidelines, and policy articles, as well as pathology services and regulatory bodies, adopt this metric when reporting fecal immunochemical test results.

  18. The temperature dependence of refractive index of hemoglobin at the wavelengths 930 and 1100 nm

    NASA Astrophysics Data System (ADS)

    Lazareva, Ekaterina N.; Tuchin, Valery V.

    2016-04-01

    In this study, the refractive index of hemoglobin was measured at different temperatures within a physiological range and above that is characteristic to light-blood interaction at laser therapy. Measurements were carried out using the multi-wavelength Abbe refractometer (Atago, Japan). The refractive index was measured at two NIR wavelengths of 930 nm and 1100 nm. Samples of hemoglobin solutions with concentration of 80, 120 and 160 g/l were investigated. The temperature was varied between 25 and 55 °C. It was shown that the dependence of the refractive index of hemoglobin is nonlinear with temperature, which may be associated with changes in molecular structure of hemoglobin.

  19. The acetylation of hemoglobin by aspirin. In vitro and in vivo.

    PubMed Central

    Bridges, K R; Schmidt, G J; Jensen, M; Cerami, A; Bunn, H F

    1975-01-01

    The chemical modification of hemoglobin by aspirin (ASA) has been studied, both in intact human red cells and in purified hemoglobin solutions. After incubation of red cells with 20 mM [acetyl-1minus14C]ASA, incorporation of radioactivity into hemoglobin was observed in agreement with the results of Klotz and Tam (1973. Proc. Natl. Acad. Sci. U. S. A. 70: 1313-1315). In contrast, no labeling of hemoglobin was seen when [carbosyl-14-C]ASA was used. These results indicate that ASA acetylates hemoglobin. The acetylated hemoglobin was readily separated from unmodified hemoglobin by both gel electrofocusing and by column chromatography. Quantitation of the extent of acetylation by densitometric scanning of gels agreed very well with estimates obtained from radioactivity measurements. Hemolysates prepared from red cells incubated with ASA showed normal oxygen affinity and heme-heme interaction. Purified acetylated hemoglobin had a slightly increased oxygen affinity and decreased heme-heme interaction. There was no difference in the rate of acetylation of oxy- and deoxyhemoglobin. ASA acetylated column-purified hemoglobin A more readily than hemoglobin in crude hemolysate, but less rapidly than purified human serum albumin. The rate of acetylation of hemoglobulin increased with pH up to approximately pH 8,5. Structural studies were done on hemoglobin incubated with 2.0 mM and 20 mM [acetyl-1-14-C]ASA. Alpha- and beta-chains were acetylated almost equally. Tryptic digests of purified acetylated subunits were fingerprinted on cellulose thin layer plates and autoradiographed. Both alpha- and beta-chains showed a number of radioactive spots that were either ninhydrin negative or weakly ninhydrin positive. These results indicate that hemoglobin is acetylated at a number of sites, probably at the epislon-amino group of lysine residues. To determine whether ASA acetylates hemoglobin in vivo, hemolysates of 14 patients on long-term high-dose ASA therapy were analyzed by gel

  20. High altitude genetic adaptation in Tibetans: no role of increased hemoglobin-oxygen affinity

    PubMed Central

    Tashi, Tsewang; Feng, Tang; Koul, Parvaiz; Amaru, Ricardo; Hussey, Dottie; Lorenzo, Felipe R.; RiLi, Ge; Prchal, Josef T.

    2014-01-01

    High altitude exerts selective evolutionary pressure primarily due to its hypoxic environment, resulting in multiple adaptive responses. High hemoglobin-oxygen affinity is postulated to be one such adaptive change, which has been reported in Sherpas of the Himalayas. Tibetans have lived on the Qinghai-Tibetan plateau for thousands of years and have developed unique phenotypes, such as protection from polycythemia which has been linked to PDH2 mutation, resulting in downregulation of HIF pathway. In order to see if Tibetans also developed high hemoglobin-oxygen affinity as a part of their genetic adaptation, we conducted this study assessing hemoglobin-oxygen affinity and their fetal hemoglobin levels in Tibetan subjects from 3 different altitudes. We found normal hemoglobin-oxygen affinity in all subjects, fetal hemoglobin levels were normal in all except one and no hemoglobin variants in any of the subjects. We conclude that increased hemoglobin-oxygen affinity or increased fetal hemoglobin are not adaptive phenotypes of the Tibetan highlanders. PMID:24618341

  1. Concentration Dependence of the Self-Diffusion of Human and Lumbricus terrestris Hemoglobin

    PubMed Central

    Gros, Gerolf

    1978-01-01

    The self-diffusion coefficient of the extracellular hemoglobin of Lumbricus terrestris (mol wt 3.7 × 106 daltons) has been measured at protein concentrations ranging from 2 to 25 g/100 ml. The self-diffusion coefficient of human hemoglobin has been measured at concentrations between 10 and 43 g/100 ml. For these measurements, 14C-labeled hemoglobin was made to diffuse from one Millipore filter into three consecutively arranged Millipore filters containing unlabeled hemoglobin. After a suitable time the filters were separated, and the protein diffusion coefficient was determined from the distribution of radioactivity in the four filters with a table given by Kawalki (1894, Ann. Phys. Chem. 52:166-190.). The following results were obtained. The diffusion coefficient of Lumbricus hemoglobin is 1.2 × 10-7 cm2s-1 at a protein concentration of 2.1 g/100 ml, and is reduced to about 1/10 of this value when the concentration is 25 g/100 ml (T = 21°C). Between 0 and 16 g/100 ml the logarithm of the diffusion coefficient of Lumbricus hemoglobin falls linearly with concentration. Above 16 g/100 ml a marked increase in the concentration dependence of the diffusion coefficient is observed. Extrapolation of the data to zero hemoglobin concentration yields a limiting value of the diffusion coefficient of Lumbricus hemoglobin of 1.3 × 10-7 cm2s-1. The diffusion coefficient of human hemoglobin is 4.5 × 10-7 cm2s-1 at a hemoglobin concentration of 9.7 g/100 ml, and falls to 0.14 × 10-7 cm2s-1 at a hemoglobin concentration of 43.0 g/100 ml. In addition to diffusivities, the viscosities of human and Lumbricus hemoglobin solutions were measured in a wide range of protein concentrations. The concentration dependence of the diffusivity of Lumbricus hemoglobin is compared to that of myoglobin, ovalbumin, and tetrameric hemoglobin. Proportionality between the diffusion coefficient and the reciprocal of the viscosity of the protein solution is found for all these proteins. It is also

  2. Aggregation of Normal and Sickle Hemoglobin in High Concentration Phosphate Buffer

    PubMed Central

    Chen, Kejing; Ballas, Samir K.; Hantgan, Roy R.; Kim-Shapiro, Daniel B.

    2004-01-01

    Sickle cell disease is caused by a mutant form of hemoglobin, hemoglobin S, that polymerizes under hypoxic conditions. The extent and mechanism of polymerization are thus the subject of many studies of the pathophysiology of the disease and potential treatment strategies. To facilitate such studies, a model system using high concentration phosphate buffer (1.5 M–1.8 M) has been developed. To properly interpret results from studies using this model it is important to understand the similarities and differences in hemoglobin S polymerization in the model compared to polymerization under physiological conditions. In this article, we show that hemoglobin S and normal adult hemoglobin, hemoglobin A, aggregate in high concentration phosphate buffer even when the concentration of hemoglobin is below the solubility defined for polymerization. This phenomenon was not observed using 0.05 M phosphate buffer or in another model system we studied that uses dextran to enhance polymerization. We have used static light scattering, dynamic light scattering, and differential interference contrast microscopy to confirm aggregation of deoxygenated and oxygenated hemoglobins below their solubility and have shown that this aggregation is not observable using turbidity measurements, a common technique for assessing polymerization. We have also shown that the aggregation increases with increasing temperature in the range of 15°–37°C and that it increases as the concentration of phosphate increases. These studies contribute to the working knowledge of how to properly apply studies of hemoglobin S polymerization that are conducted using the high phosphate model. PMID:15465861

  3. Light Scattering and Absorption Studies of Sickle Cell Hemoglobin

    NASA Astrophysics Data System (ADS)

    Kim-Shapiro, Daniel

    1997-11-01

    The use of physical techniques has been very important in understanding the pathophysiology of sickle cell disease. In particular, light scattering and absorption studies have been used to measure the kinetics of sickle cell hemoglobin polymerization and depolymerization (melting). The theory of sickle cell polymerization that has been derived and tested by these methods has not only led to an increased understanding of the pathophysiology of the disease but has also led to improved treatment strategies. Sickle cell disease effects about 1 out of 600 people of African descent born in the United States. The disease is caused by a mutant form of hemoglobin (the oxygen transporting molecule in the blood), hemoglobin S (HbS), which differs from normal adult hemoglobin by the substitution of a single amino acid for another. The polymerization of HbS, which occurs under conditions of low oxygen pressure, causes distortion and increased rigidity of the sickle red blood cell that leads to blockage of the capillaries and a host of resulting complications. The disease is associated with tissue damage, severe painful crises and a high degree of mortality. Light scattering studies of purified HbS and whole cells (conducted by F.A. Ferrone, J. Hofrichter, W.A. Eaton, and their associates) have been used to determine the mechanism of HbS polymerization. Polymerization will generally not occur when the hemoglobin is in an oxygen-rich environment. The question is, when HbS is rapidly deoxygenated (as it is when going from the lungs to the tissues) what is the kinetics of polymerization? Photolysis methods were used to rapidly deoxygenate HbS and light scattering was used as a function of time to measure the kinetics of polymerization. Polarized light scattering may be a more effective way to measure polymer content than total intensity light scattering. It was found that no polymerization occurs during a period of time called the delay time and subsequent polymerization occurs

  4. Effects of Hemoglobin Variants on Hemoglobin A1c Values Measured Using a High-Performance Liquid Chromatography Method

    PubMed Central

    De-La-Iglesia, Silvia; Ropero, Paloma; Nogueira-Salgueiro, Patricia; Santana-Benitez, Jesus

    2014-01-01

    Hemoglobin A1c (HbA1c) is routinely used to monitor long-term glycemic control and for diagnosing diabetes mellitus. However, hemoglobin (Hb) gene variants/modifications can affect the accuracy of some methods. The potential effect of Hb variants on HbA1c measurements was investigated using a high-performance liquid chromatography (HPLC) method compared with an immunoturbimetric assay. Fasting plasma glucose (FPG) and HbA1c levels were measured in 42 371 blood samples. Samples producing abnormal chromatograms were further analyzed to characterize any Hb variants. Fructosamine levels were determined in place of HbA1c levels when unstable Hb variants were identified. Abnormal HPLC chromatograms were obtained for 160 of 42 371 samples. In 26 samples HbS was identified and HbA1c results correlated with FPG. In the remaining 134 samples HbD, Hb Louisville, Hb Las Palmas, Hb N-Baltimore, or Hb Porto Alegre were identified and HbA1c did not correlate with FPG. These samples were retested using an immunoturbidimetric assay and the majority of results were accurate; only 3 (with the unstable Hb Louisville trait) gave aberrant HbA1c results. Hb variants can affect determination of HbA1c levels with some methods. Laboratories should be aware of Hb variants occurring locally and choose an appropriate HbA1c testing method. PMID:25355712

  5. [Role of alpha-hemoglobin molecular chaperone in the hemoglobin formation and clinical expression of some hemoglobinopathies].

    PubMed

    Vasseur, C; Baudin-Creuza, V

    2015-03-01

    Alpha-hemoglobin stabilizing protein (AHSP), described as a chaperone of alpha-hemoglobin (α-Hb), is synthesized at a high concentration in the erythroid precursors. AHSP specifically recognizes the G and H helices of α-Hb and forms a stable complex with free α-Hb until its association with the partner β-subunits. Unlike the free β-Hb which are soluble and form homologous tetramers, freshly synthesized α-Hb chains are highly unstable molecular species which precipitate and generate reactive oxygen species within the erythrocyte precursors of the bone marrow leading to apoptosis and ineffective erythropoiesis. AHSP protects the free α-Hb chains in maintaining it in the soluble state. In this review, we report data from the literature and our laboratory concerning the key role of AHSP in the biosynthesis of Hb and its possible involvement in some disorders of the red blood cell as well as the hemoglobinopathies and we discuss its use as a prognostic tool in thalassemia syndromes.

  6. In Vivo Wound Healing Activity of Crocodile (Crocodylus siamensis) Hemoglobin and Evaluation of Antibacterial and Antioxidant Properties of Hemoglobin and Hemoglobin Hydrolysate.

    PubMed

    Pakdeesuwan, Anawat; Araki, Tomohiro; Daduang, Sakda; Payoungkiattikun, Wisarut; Jangpromma, Nisachon; Klaynongsruang, Sompong

    2016-10-06

    The hydrolysis of proteins constitutes an invaluable tool granting access to a variety of peptide fragments with potentially interesting biological properties. Therefore, hemoglobin (Hb) hydrolysate of Crocodylus siamensis was generated by digestion under acidic conditions. The antibacterial and antioxidant activity of Hb hydrolysate were assessed in comparison with intact Hb. A disc diffusion assay revealed that the Hb hydrolysate exhibited antibacterial activity against eight strains of Gram-positive bacteria and showed a higher efficacy than intact Hb. Moreover, the antioxidant activity of intact Hb and its hydrolysate was evaluated using ABTS and DPPH radical scavenging assays. The Hb hydrolysate exhibited free radical scavenging rates of 6-32%, whereas intact Hb showed a slightly higher activity. In addition, non-toxicity to human erythrocytes was observed after treatment with the quantities of Hb hydrolysate up to 10 µg. Moreover, active fragmented Hb (P3) was obtained after purifying the Hb hydrolysate by reversed-phase HPLC. Scanning electron microscopy demonstrated the induction of bacterial cell membrane abnormalities after exposure to P3. Antibacterial and antioxidant activity plays a crucial role for supporting the wound healing activity. Consequently, an in vivo mice excisional skin wound healing assay was carried out to investigate the effects of intact Hb treatment on wound healing in more detail. The results clearly demonstrate that intact Hb is capable of promoting 75% wound closure within 6 days. These findings imply that intact Hb of C. siamensis and its acid hydrolysate may serve as valuable precursors for food supplementary products benefitting human health.

  7. Nitric oxide from nitrite reduction by hemoglobin in the plasma and erythrocytes

    PubMed Central

    Chen, Kejing; Piknova, Barbora; Pittman, Roland N.; Schechter, Alan N.; Popel, Aleksander S.

    2008-01-01

    Experimental evidence has shown that nitrite anion plays a key role in one of the proposed mechanisms for hypoxic vasodilation, in which the erythrocyte acts as a NO generator and deoxygenated hemoglobin in pre-capillary arterioles reduces nitrite to NO, which contributes to vascular smooth muscle relaxation. However, because of the complex reactions among nitrite, hemoglobin, and the NO that is formed, the amount of NO delivered by this mechanism under various conditions has not been quantified experimentally. Furthermore, paracrine NO is scavenged by cell-free hemoglobin, as shown by studies of diseases characterized by extensive hemolysis (e.g., sickle cell disease) and the administration of hemoglobin-based oxygen carriers. Taking into consideration the free access of cell-free hemoglobin to the vascular wall and its ability to act as a nitrite reductase, we have now examined the hypothesis that in hypoxia this cell-free hemoglobin could serve as an additional endocrine source of NO. In this study, we constructed a multicellular model to characterize the amount of NO delivered by the reaction of nitrite with both intraerythrocytic and cell-free hemoglobin, while intentionally neglecting all other possible sources of NO in the vasculature. We also examined the roles of hemoglobin molecules in each compartment as nitrite reductases and NO scavengers using the model. Our calculations show that: (1) ~0.04 pM NO from erythrocytes could reach the smooth muscle if free diffusion were the sole export mechanism; however, this value could rise to ~43 pM with a membrane-associated mechanism that facilitated NO release from erythrocytes; the results also strongly depend on the erythrocyte membrane permeability to NO; (2) despite the closer proximity of cell-free hemoglobin to the smooth muscle, cell-free hemoglobin reaction with nitrite generates approximately 0.02 pM of free NO that can reach the vascular wall, because of a strong self-capture effect. However, it is worth

  8. Low Diagnostic Utility of Rechecking Hemoglobins Within 24 Hours in Hospitalized Patients.

    PubMed

    Rajkomar, Alvin; McCulloch, Charles E; Fang, Margaret C

    2016-11-01

    Clinicians often repeat hemoglobin tests within a 24 hour period to detect or monitor anemia. We sought to determine the percentage of hemoglobin tests repeated within a single hospital day that were at least 1.0 g/dL lower than the first test. We performed a retrospective cross-sectional analysis of hospitalized adults on medical or surgical services over 1 year at a single academic hospital. Using patient and laboratory data in the electronic health record, we analyzed the proportion of repeated hemoglobin test results that were at least 1 g/dL less than the initial hemoglobin value of that day, excluding days when transfusions were administered. A total of 88,722 hemoglobin tests were obtained from 12,877 unique patients, who contributed a total of 86,859 hospitalization days. In 12,230 (14.1%) of those days, 2 or more hemoglobin tests were obtained within a single day. In the 6969 days with 2 hemoglobin tests obtained and no transfusions given, 949 (13.5%) were ≥1 g/dL lower than the initial hemoglobin value of that day, and 260 (3.7%) were ≥2 g/dL lower. Repeated tests did not often reach transfusion thresholds: 482 (6.9%) of repeat hemoglobin values were <8 g/dL, and 64 (0.9%) were <7 g/dL. Hemoglobin tests were repeated in 14% of hospital days. For patients who had 2 hemoglobin tests obtained on the same day, 13.5% demonstrated a clinically significant drop. This information may be helpful to clinicians when considering whether repeat testing is appropriate. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Association between hemoglobin and prognosis in patients admitted to hospital for COPD

    PubMed Central

    Toft-Petersen, Anne Pernille; Torp-Pedersen, Christian; Weinreich, Ulla Møller; Rasmussen, Bodil Steen

    2016-01-01

    Low concentrations of hemoglobin have previously been demonstrated in many patients with COPD. There is evidence of anemia as a prognostic factor in acute exacerbations, but the detailed relationship between concentrations of hemoglobin and mortality is not known. A register-based cohort of patients admitted for the first time to Danish hospitals for acute exacerbations of COPD from 2007 through 2012 was established. Age, sex, comorbidities, medication, renal function, and concentrations of hemoglobin were retrieved. Sex-specific survival analyses were fitted for different rounded concentrations of hemoglobin. The cohort encompassed 6,969 patients. Hemoglobin below 130 g/L was present in 39% of males and below 120 g/L in 24% of females. The in-hospital mortality rates for patients with hemoglobin below or above these limits were 11.6% and 5.4%, respectively. After discharge, compared to hemoglobin 130 g/L, the hazard ratio (HR) for males with hemoglobin 120 g/L was 1.45 (95% confidence interval [CI] 1.22–1.73), adjusted HR 1.37 (95% CI 1.15–1.64). Compared to hemoglobin 120 g/L, the HR for females with hemoglobin 110 g/L was 1.4 (95% CI 1.17–1.68), adjusted HR 1.28 (95% CI 1.06–1.53). In conclusion, low concentrations of hemoglobin are frequent in COPD patients with acute exacerbations, and predict long-term mortality. PMID:27877035

  10. Human adipose tissue contains erythroid progenitors expressing fetal hemoglobin

    PubMed Central

    Navarro, Amparo; Carbonell-Uberos, Francisco; Marín, Severiano; Miñana, María Dolores

    2013-01-01

    AIM: To investigate the origin of hematopoietic progenitors contained in the stromal vascular fraction (SVF) of human adipose tissue. METHODS: Tissue samples obtained from lipectomies were subjected to enzymatic digestion with collagenase to obtain a single-cell suspension. The centrifuged cell pellet, termed SVF, was separated immunomagnetically into CD45+ and CD45- cells and cultured in serum-free medium containing hematopoietic cytokines. The freshly isolated and cultured cells were evaluated to determine their ability to form hematopoietic colony-forming units in clonogenic assays and for the expression of certain hematopoietic transcription factors by reverse transcription-polymerase chain reaction; the gene expression level was compared to that in CD34+ hematopoietic progenitor cells from cord blood (CB) and adult peripheral blood (PB). To characterize erythroid progenitors, burst-forming units-erythroid (BFU-E) were developed in a semisolid medium under different culture conditions, and the hemoglobin composition and globin gene expression in the erythroid colonies were determined. RESULTS: The transcription factors SCL/TAL1, RUNX1, RUNX2 and GATA2 were expressed in both the CD45+ and CD45- SVF populations; however, in contrast to our observations in the CD34+ cells from CB and adult PB, GATA1 was not detected. Nevertheless, GATA1 could be detected in the SVF cells after seven days in culture, whereas its expression was upregulated in the CB CD34+ cells. The analysis of BFU-E-derived colonies revealed that virtually all erythroid cells produced by SVF cells expressed fetal hemoglobin, and the γ-globin mRNA levels ranged between those obtained in the adult- and neonatal-derived erythroid cells. Moreover, the SVF-derived erythroid cells synthesized similar levels of α- and β-globin mRNA, whereas the α-globin transcript levels were consistently higher those of β-globin in the cells derived from CB or PB CD34+ cells. Furthermore, although the cellular

  11. α-Hemoglobin stabilizing protein: a modulating factor in thalassemias?

    PubMed

    Wajcman, Henri; Vasseur, Corinne; Pissard, Serge; Baudin-Creuza, Veronique

    2011-01-01

    α-Hemoglobin stabilizing protein (AHSP) is a small protein of 102 residues induced by GATA-1, Oct-1- and EKLF. It is synthesized at a high level in the red blood cell precursors and acts as a chaperone protecting the α-hemoglobin (α-Hb) chains against precipitation. α-Hemoglobin stabilizing protein forms a heterodimer complex with α-Hb, then displaying modified oxygen binding kinetics. In the absence of AHSP, α-Hb oxidizes and precipitates within the erythrocyte precursors of bone marrow leading to apoptosis and defective erythropoiesis. Several α-Hb variants with a structural abnormality, frequently located in the contact area between α-Hb and AHSP, exhibit instability and a thalassemia-like syndrome when they are associated with another α-thalassemia (α-thal) determinant. We suggest that this disorder could result from a disturbed interaction between the abnormal α-Hb chains and AHSP. Hb Groene Hart (Pro119>Ser) was one of the first examples in which we observed this abnormality. We later verified this mechanism in a list of several variants, now considered as being nondeletional α-thalassemias. Conversely, it was hypothesized from studies on knock-out mice, that a defect affecting AHSP could cause a thalassemia-like syndrome. This was supported in man by studies showing that a decreased expression of AHSP linked to specific genetic clades could act as a modulating factor in some thalassemia phenotypes. It was also supported by our observation of a family from Southeast Asia, in which a child homozygous for an AHSP mutant (Val56>Gly) displayed, in his first year of life, a moderate thalassemia syndrome. This mutant AHSP was expressed in vitro and demonstrated by biochemical and biophysical studies to display a clear defective interaction with α-Hb, which could support the hypothesis that the reb blood cell (RBC) disorders of the child resulted from this abnormality. It therefore appears that AHSP is a factor with a key role in the formation of Hb

  12. Hair cortisol concentration and glycated hemoglobin in African American adults.

    PubMed

    Lehrer, H Matthew; Dubois, Susan K; Maslowsky, Julie; Laudenslager, Mark L; Steinhardt, Mary A

    2016-10-01

    African Americans have higher diabetes prevalence compared to Whites. They also have elevated cortisol levels - indicating possible HPA axis dysregulation - which may raise blood glucose as part of the biological response to physiological and psychosocial stress. Little is known about chronic cortisol levels in African Americans, and even less about the role of chronically elevated cortisol in type 2 diabetes development in this racial group. We used analysis of cortisol in hair to examine associations of long-term (∼3months) cortisol levels with glycated hemoglobin (HbA1c) in a group of African American adults. In exploratory analyses, we also studied the relationship of hair dehydroepiandrosterone (DHEA) with HbA1c. Participants were 61 community-dwelling African American adults (85% female; mean age 54.30 years). The first 3cm of scalp-near hair were analyzed for cortisol and DHEA concentration using enzyme-linked immunoassay analysis. Glycated hemoglobin was assessed, and regression analyses predicting HbA1c from hair cortisol and DHEA were performed in the full sample and in a subsample of participants (n=20) meeting the National Institute of Diabetes and Digestive Kidney Disease (NIDDK) criteria for type 2 diabetes (HbA1c≥6.5%). In the full sample, HbA1c increased with hair cortisol level (β=0.22, p=0.04, f(2)=0.10), independent of age, sex, chronic health conditions, diabetes medication use, exercise, and depressive symptoms. In the subsample of participants with an HbA1c≥6.5%, hair cortisol was also positively related to HbA1c (β=0.45, p=0.04, f(2)=0.32), independent of diabetes medication use. Glycated hemoglobin was unrelated to hair DHEA in both the full sample and HbA1c≥6.5% subsample. Long-term HPA axis dysregulation in the form of elevated hair cortisol is associated with elevated HbA1c in African American adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. A Hemoglobin Based Oxygen Carrier, Bovine Polymerized Hemoglobin (HBOC-201) versus Hetastarch (HEX) in an Uncontrolled Liver Injury Hemorrhagic Shock Swine Model with Delayed Evacuation

    DTIC Science & Technology

    2004-10-01

    A Hemoglobin Based Oxygen Carrier, Bovine Polymerized Hemoglobin (HBOC-201) versus Hetastarch (HEX) in an Uncontrolled Liver Injury Hemorrhagic Shock...Transcutaneous tis- sue oxygenation was restored more rap- idly in HBOC-201 pigs, there was a trend to lower lactic acid, and base deficit was less...lactic acidosis and base deficit (BD) abnormalities, indicating on-going hypoperfusion.2–4 As these abnormalities measured upon hospital arrival

  14. Aza-heterocyclic Receptors for Direct Electron Transfer Hemoglobin Biosensor

    PubMed Central

    Kumar, Vinay; Kashyap, D. M. Nikhila; Hebbar, Suraj; Swetha, R.; Prasad, Sujay; Kamala, T.; Srikanta, S. S.; Krishnaswamy, P. R.; Bhat, Navakanta

    2017-01-01

    Direct Electron Transfer biosensors, facilitating direct communication between the biomolecule of interest and electrode surface, are preferable compared to enzymatic and mediator based sensors. Although hemoglobin (Hb) contains four redox active iron centres, direct detection is not possible due to inaccessibility of iron centres and formation of dimers, blocking electron transfer. Through the coordination of iron with aza-heterocyclic receptors - pyridine and imidazole - we report a cost effective, highly sensitive and simple electrochemical Hb sensor using cyclic voltammetry and chronoamperometry. The receptor can be either in the form of liquid micro-droplet mixed with blood or dry chemistry embedded in paper membrane on top of screen printed carbon electrodes. We demonstrate excellent linearity and robustness against interference using clinical samples. A truly point of care technology is demonstrated by integrating disposable test strips with handheld reader, enabling finger prick to result in less than a minute. PMID:28169325

  15. SANS studies of interacting hemoglobin in intact erythrocytes.

    PubMed Central

    Krueger, S; Nossal, R

    1988-01-01

    Small angle neutron scattering (SANS) was used to investigate interaction forces between hemoglobin (Hb) molecules contained within human red cells. The scattering separately attributable to cell membranes and intracellular Hb was identified. A series of D2O-H2O contrast variation measurements were made in order to establish conditions for which scattering from the cell membrane is minimized (approximately 15% D2O). Measurements then were performed to examine changes in intermolecular Hb interactions occurring when the cells are contracted or swollen by varying the ionic strength of the suspension buffer. The scattering cross-sections were fitted to structure factors computed by a mean spherical approximation, and molecular parameters thereby extracted. Oxygenation studies on normal cells were performed, and results contrasted with those of similar studies of erythrocytes obtained from sickle cell disease patients. PMID:2829985

  16. Hemoglobin-based oxygen carriers for hemorrhagic shock.

    PubMed

    Elmer, Jonathan; Alam, Hasan B; Wilcox, Susan R

    2012-03-01

    Hemorrhagic shock is a pathologic state in which intravascular volume and tissue oxygen delivery are impaired, leading to circulatory collapse and cellular ischemia. Resuscitation with hemoglobin-based oxygen carriers (HBOCs) is appealing in that their use can both restore intravascular volume and tissue oxygenation, without the limitations in supply and immunomodulatory effects of packed red blood cells. However, the development of safe and effective agents has been elusive. In this article, we briefly discuss the major limitations of traditional resuscitative fluids which have driven the continued interest in HBOCs. We then review the history of early HBOC development and the modern understanding of their mechanisms of toxicity, which has informed the rational design of second-generation agents. Finally, we provide an overview of these second-generation HBOCs that are under active investigation or have recently completed phase 3 clinical trials.

  17. Aza-heterocyclic Receptors for Direct Electron Transfer Hemoglobin Biosensor.

    PubMed

    Kumar, Vinay; Kashyap, D M Nikhila; Hebbar, Suraj; Swetha, R; Prasad, Sujay; Kamala, T; Srikanta, S S; Krishnaswamy, P R; Bhat, Navakanta

    2017-02-07

    Direct Electron Transfer biosensors, facilitating direct communication between the biomolecule of interest and electrode surface, are preferable compared to enzymatic and mediator based sensors. Although hemoglobin (Hb) contains four redox active iron centres, direct detection is not possible due to inaccessibility of iron centres and formation of dimers, blocking electron transfer. Through the coordination of iron with aza-heterocyclic receptors - pyridine and imidazole - we report a cost effective, highly sensitive and simple electrochemical Hb sensor using cyclic voltammetry and chronoamperometry. The receptor can be either in the form of liquid micro-droplet mixed with blood or dry chemistry embedded in paper membrane on top of screen printed carbon electrodes. We demonstrate excellent linearity and robustness against interference using clinical samples. A truly point of care technology is demonstrated by integrating disposable test strips with handheld reader, enabling finger prick to result in less than a minute.

  18. Aza-heterocyclic Receptors for Direct Electron Transfer Hemoglobin Biosensor

    NASA Astrophysics Data System (ADS)

    Kumar, Vinay; Kashyap, D. M. Nikhila; Hebbar, Suraj; Swetha, R.; Prasad, Sujay; Kamala, T.; Srikanta, S. S.; Krishnaswamy, P. R.; Bhat, Navakanta

    2017-02-01

    Direct Electron Transfer biosensors, facilitating direct communication between the biomolecule of interest and electrode surface, are preferable compared to enzymatic and mediator based sensors. Although hemoglobin (Hb) contains four redox active iron centres, direct detection is not possible due to inaccessibility of iron centres and formation of dimers, blocking electron transfer. Through the coordination of iron with aza-heterocyclic receptors - pyridine and imidazole - we report a cost effective, highly sensitive and simple electrochemical Hb sensor using cyclic voltammetry and chronoamperometry. The receptor can be either in the form of liquid micro-droplet mixed with blood or dry chemistry embedded in paper membrane on top of screen printed carbon electrodes. We demonstrate excellent linearity and robustness against interference using clinical samples. A truly point of care technology is demonstrated by integrating disposable test strips with handheld reader, enabling finger prick to result in less than a minute.

  19. Molecular and functional adaptations in deep-sea hemoglobins.

    PubMed

    Hourdez, Stéphane; Weber, Roy E

    2005-01-01

    The past 20 years have witnessed the publication of numerous studies on hemoglobins (Hbs) from deep-sea animals. Most of the animals studied were collected at deep-sea hydrothermal vents and cold seeps, both being environments where the physical-chemical conditions may be severely challenging for metazoans. These environments may be characterized by deep, chronic hypoxia and high concentrations of toxic compounds such as sulfide and heavy metals. Many species from these environments express Hbs, even though they belong to taxa that otherwise were characterised by the absence of respiratory pigments. Hbs from vent and seep invertebrates commonly exhibit high affinities for oxygen when compared to related species from normoxic, shallow-water environments, and marked pH-dependence. These high affinities permit uptake of oxygen from hypoxic waters and the strong Bohr effects favor its release in the metabolizing acidic organs.

  20. Effects of Hemoglobin-Based Oxygen Carriers on Blood Coagulation

    PubMed Central

    Roghani, Kimia; Holtby, Randall J.; Jahr, Jonathan S.

    2014-01-01

    For many decades, Hemoglobin-based oxygen carriers (HBOCs) have been central in the development of resuscitation agents that might provide oxygen delivery in addition to simple volume expansion. Since 80% of the world population lives in areas where fresh blood products are not available, the application of these new solutions may prove to be highly beneficial (Kim and Greenburg 2006). Many improvements have been made to earlier generation HBOCs, but various concerns still remain, including coagulopathy, nitric oxide scavenging, platelet interference and decreased calcium concentration secondary to volume expansion (Jahr et al. 2013). This review will summarize the current challenges faced in developing HBOCs that may be used clinically, in order to guide future research efforts in the field. PMID:25514567

  1. A Journey in Science: Early Lessons from the Hemoglobin Field

    PubMed Central

    Weatherall, David J

    2014-01-01

    Real innovations in medicine and science are historic and singular; the stories behind each occurrence are precious. At Molecular Medicine we have established the Anthony Cerami Award in Translational Medicine to document and preserve these histories. The monographs recount the seminal events as told in the voice of the original investigators who provided the crucial early insight. These essays capture the essence of discovery, chronicling the birth of ideas that created new fields of research; and launched trajectories that persisted and ultimately influenced how disease is prevented, diagnosed, and treated. In this volume, the Cerami Award Monograph is by David J Weatherall, Founder, Weatherall Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital. A visionary in the field of hemoglobin, this is the story of Professor Weatherall’s scientific journey. PMID:25548947

  2. Picosecond transient absorption study of photodissociated carboxy hemoglobin and myoglobin

    SciTech Connect

    Janes, S.M.; Dalickas, G.A.; Eaton, W.A.; Hochstrasser, R.M.

    1988-09-01

    The optical transient absorption spectra at 30 ps and 6.5 ns after photolysis are compared for both carboxy hemoglobin (HbCO) and carboxy myoglobin (MbCO). Both 355- and 532-nm excitation pulses were used. In all cases the shapes of the optical difference spectra thus generated are stationary over the complete time-scale studied. The photolysis spectra for MbCO are not significantly different from the equilibrium difference spectra generated on the same picosecond spectrometer when measured to an accuracy of +/- 0.5 nm. In addition, spectral parameters for delegated HbCO generated on the same spectrometer but detected by two different techniques, either by a Vidicon detector or point by point with photomultiplier tubes, are reported; the results are different from some of the previously reported picosecond experiments.

  3. Probing confined and unconfined hemoglobin molecules with photoacoustics

    NASA Astrophysics Data System (ADS)

    Saha, Ratan K.; Karmakar, Subhajit; Roy, Madhusudan

    2014-03-01

    Photoacoustic (PA) measurements on confined and unconfined hemoglobin molecules are presented. In vitro experiments were performed with porcine red blood cells (RBCs) at 532 and 1064 nm at various laser fluences. Fluence was gradually changed from 8 to 21 mJ/cm2/pulse for 532 nm and 353 to 643 mJ/cm2/pulse for 1064 nm. PA signals from suspended RBCs (SRBCs) and hemolyzed RBCs (HRBCs) were measured using a needle hydrophone at hematocrits ranging from 10 to 60%. PA amplitude was found to be varied linearly with the laser fluence for each type of samples at the above two optical radiations. At 532 nm, PA signals from SRBCs and HRBCs were measured to be nearly equal, whereas, at 1064 nm, signal amplitude for SRBCs was approximately 2 times higher than that of HRBCs. The results suggest that it may be feasible to detect hemolysis with PAs.

  4. SANS studies of interacting hemoglobin in intact erythrocytes

    SciTech Connect

    Krueger, S.; Nossal, R.

    1988-01-01

    Small angle neutron scattering (SANS) was used to investigate interaction forces between hemoglobin (Hb) molecules contained within human red cells. The scattering separately attributable to cell membranes and intracellular Hb was identified. A series of D/sub 2/O-H/sub 2/O contrast variation measurements were made in order to establish conditions for which scattering from the cell membrane is minimized (approximately 15% D/sub 2/O). Measurements then were performed to examine changes in intermolecular Hb interactions occurring when the cells are contracted or swollen by varying the ionic strength of the suspension buffer. The scattering cross-sections were fitted to structure factors computed by a mean spherical approximation, and molecular parameters thereby extracted. Oxygenation studies on normal cells were performed, and results contrasted with those of similar studies of erythrocytes obtained from sickle cell disease patients.

  5. Brownian dynamics simulation of sickle hemoglobin bundle formation

    NASA Astrophysics Data System (ADS)

    Liu, Ya; Gunton, James; Chakrabarti, Amit

    2010-03-01

    The physical properties of biopolymer fibers, such as their stability and degree of aggregation, are implicated in many diseases, including sickle cell anemia. The natural chirality of protofilaments plays a crucial role in the formation of sickle hemoglobin fiber which leads to the permanent blockage of microvessels. We use Brownian dynamics to investigate the kinetics of fiber aggregation. The geometrical helical structure and chirality of the filaments are modeled by anisotropic patch-like interactions. We present the kinetics of fiber formation and study the possibility of a finite critical fiber bundle size. We compare our results with various experimental and theoretical results. This work is supported by grants from the NSF and the G. Harold and Leila Y. Mathers Foundation.

  6. High hemoglobin mixed disulfide content in hemolysates from stressed shark.

    PubMed

    Dafré, A L; Reischl, E

    1990-01-01

    1. Hemolysate from heavily stressed smooth hammerhead shark, Sphyrna zygaena, shows three electrophoretic components, SZ I, SZ II and SZ III, whose relative concentrations are 36.4 +/- 6.8, 36.4 +/- 5.0 and 20.8 +/- 5.7%, respectively. After reduction with DTE only SZ I remained. 2. SZ I reacted with glutathione disulfide reconstitute SZ II and SZ III. 3. Non-reduced, DTE-reduced, and denatured hemoglobin were found to have 2.0 +/- 0.4, 3.7 +/- 0.6, and 9.4 +/- 0.7-SH groups, respectively. 4. Erythrocyte non-protein--SH (NPSH), including glutathione present as mixed disulfide with SZ II and SZ III, is 1.7 NPSH/Hb.

  7. Mechanisms of the adjuvant effect of hemoglobin in experimental peritonitis. VII. Hemoglobin does not inhibit clearance of Escherichia coli from the peritoneal cavity

    SciTech Connect

    Dunn, D.L.; Barke, R.A.; Lee, J.T. Jr.; Condie, R.M.; Humphrey, E.W.; Simmons, R.L.

    1983-09-01

    Hemoglobin has been shown to be a potent adjuvant in experimental Escherichia coli peritonitis, although a satisfactory mechanistic rationale is still obscure. Hemoglobin has been thought to impair intraperitoneal neutrophil function, delay clearance of bacteria from the peritoneal cavity by the normal absorptive mechanisms, or directly enhance bacterial growth. Using highly purified stroma-free hemoglobin (SFHgb), we have largely discounted any direct effect of hemoglobin on peritoneal white blood cell function. In the present study, we confirmed that uncontrolled proliferation of bacteria takes place in the presence of hemoglobin in the peritoneal cavity. Nonviable 5-iododeoxyuridine /sup 125/I-labelled bacteria were then used to directly study peritoneal clearance kinetics, eliminating the problem of bacterial growth. SFHgb had no influence on the removal of intraperitoneal bacteria. The rate of bloodstream appearance of radiolabel was similar with or without intraperitoneal SFHgb. Thus, SFHgb does not prevent clearance of bacteria from the peritoneal cavity by interfering with normal host clearance mechanisms. SFHgb may act as a bacterial growth adjuvant, either by serving as a bacterial nutrient or by suitably modifying the environment so that extensive bacterial proliferation can occur. The latter hypothesis appears to be an area in which investigation concerning the adjuvant effect of hemoglobin may prove most fruitful.

  8. Modification of hemoglobin H disease by sickle trait.

    PubMed

    Matthay, K K; Mentzer, W C; Dozy, A M; Kan, Y W; Bainton, D F

    1979-10-01

    The rarity of hemoglobin (Hb) H disease in combination with sickle trait may be due in part to the absence of actual Hb H in individuals who, nonetheless, have inherited the deletion of three alpha-globin genes. We describe here a boy with persistent microcytic, hypochromic anemia despite adequate iron stores, who exhibited splenomegaly with a normal reticulocyte count and only rare inclusions in circulating erythrocytes. Starch gel electrophoresis and isoelectric focusing at age 5 yr showed 21% Hb S, persistent Hb Bart's, but no Hb H. Recticulocyte alpha/non-alpha globin chain synthesis ratio was 0.58 at age 5. The mother (Asian) had laboratory evidence of alpha-thalassemia trait and the father (Black) had sickle trait. The nature of alpha-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the alpha-globin structural gene identified by hybridization with complementary DNA. The patient had only one alpha-globin structural gene, located in a DNA fragment shorter than that found in normal or alpha-thalassemia trait individuals, but similar to that present in other patients with Hb H disease. Morphologic studies of bone marrow by light and electron microscopy revealed erythroid hyperplasia with inclusions in polychromatic and orthochromatic erythroblasts, suggesting early precipitation of an unstable hemoglobin. The lack of demonstrable Hb H may be the result of both diminished amounts of beta(A) available for Hb H formation (since one beta-globin gene is beta(S)) and the greater affinity of alpha-chains for beta(A) than beta(S)-globin chains leading to the formation of relatively more Hb A than Hb S. The presence of a beta(S) gene may thus modify the usual clinical expression of Hb H disease.

  9. Modification of Hemoglobin H Disease by Sickle Trait

    PubMed Central

    Matthay, Katherine K.; Mentzer, William C.; Dozy, Andree M.; Wai Kan, Yuet; Bainton, Dorothy F.

    1979-01-01

    The rarity of hemoglobin (Hb) H disease in combination with sickle trait may be due in part to the absence of actual Hb H in individuals who, nonetheless, have inherited the deletion of three α-globin genes. We describe here a boy with persistent microcytic, hypochromic anemia despite adequate iron stores, who exhibited splenomegaly with a normal reticulocyte count and only rare inclusions in circulating erythrocytes. Starch gel electrophoresis and isoelectric focusing at age 5 yr showed 21% Hb S, persistent Hb Bart's, but no Hb H. Recticulocyte α/non-α globin chain synthesis ratio was 0.58 at age 5. The mother (Asian) had laboratory evidence of α-thalassemia trait and the father (Black) had sickle trait. The nature of α-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the α-globin structural gene identified by hybridization with complementary DNA. The patient had only one α-globin structural gene, located in a DNA fragment shorter than that found in normal or α-thalassemia trait individuals, but similar to that present in other patients with Hb H disease. Morphologic studies of bone marrow by light and electron microscopy revealed erythroid hyperplasia with inclusions in polychromatic and orthochromatic erythroblasts, suggesting early precipitation of an unstable hemoglobin. The lack of demonstrable Hb H may be the result of both diminished amounts of βA available for Hb H formation (since one β-globin gene is βS) and the greater affinity of α-chains for βA than βS-globin chains leading to the formation of relatively more Hb A than Hb S. The presence of a βS gene may thus modify the usual clinical expression of Hb H disease. Images PMID:479366

  10. Low Modulus Biomimetic Microgel Particles with High Loading of Hemoglobin

    PubMed Central

    Chen, Kai; Merkel, Timothy J.; Pandya, Ashish; Napier, Mary E.; Luft, J. Christopher; Daniel, Will; Sheiko, Sergei

    2012-01-01

    We synthesized extremely deformable red blood cell-like microgel particles and loaded them with bovine hemoglobin (Hb) to potentiate oxygen transport. With similar shape and size as red blood cells (RBCs), the particles were fabricated using the PRINT® (Particle Replication In Non-wetting Templates) technique. Low crosslinking of the hydrogel resulted in very low mesh density for these particles, allowing passive diffusion of hemoglobin throughout the particles. Hb was secured in the particles through covalent conjugation of the lysine groups of Hb to carboxyl groups in the particles via EDC/NHS coupling. Confocal microscopy of particles bound to fluorescent dye-labeled Hb confirmed the uniform distribution of Hb throughout the particle interior, as opposed to the surface conjugation only. High loading ratios, up to 5 times the amount of Hb to polymer by weight, were obtained, without a significant effect on particle stability, shape, though particle diameter decreased slightly with Hb conjugation. Analysis of the protein by circular dichroism (CD) spectroscopy showed that the secondary structure of Hb was unperturbed by conjugation to the particles. Methemoglobin in the particles could be maintained at a low level and the loaded Hb could still bind oxygen as studied by UV-vis spectroscopy. Hb-loaded particles with moderate loading ratios demonstrated excellent deformability in microfluidic devices, easily deforming to pass through restricted pores half as wide as the diameter of the particles. The suspension of concentrated particles with Hb concentration of 5.2 g/dL showed comparable viscosity to that of mouse blood, and the particles remained intact even after being sheared at a constant high rate (1,000 1/s) for 10 min. Armed with the ability to control size, shape, deformability, and loading of Hb into RBC mimics, we will discuss the implications for artificial blood. PMID:22852860

  11. Sickle hemoglobin gelation. Reaction order and critical nucleus size.

    PubMed Central

    Behe, M J; Englander, S W

    1978-01-01

    Sickle hemoglobin (Hb S) gelation displays kinetics consistent with a rate-limiting nucleation step. The approximate size of the critical nucleus can be inferred from the order of the reaction with respect to Hb S activity, but determination of the reaction order is complicated by the fact that Hb S activity is substantially different from Hb S concentration at the high protein concentrations required for gelation. Equilibrium and kinetic experiments on Hb S gelation were designed to evaluate the relative activity coefficient of Hb S as a function of concentration. These experiments used non-Hb S proteins to mimic, and thus evaluate, the effect on activity coefficients of increasing Hb S concentration. At Hb S concentrations near 20% the change in Hb S activity coefficient generates two-thirds of the apparent dependence of nucleation rate on Hb S concentration. When this effect is explicitly accounted for, the nucleation reaction is seen to be approximately 10th-order with respect to effective number concentration of Hb S. The closeness of the reaction order to the number of strands in models of Hb S fibers suggests a nucleus close to the size of one turn of the Hb S fiber. These experiments introduce a new approach to the study of Hb S gelation, the equal activity isotherm, used here also to show that Hb S.Hb A (normal adult hemoglobin) hybrids do incorporate into growing nuclei and stable microtubules but that A.S hybridization is neutral with respect to promotion of Hb S nucleation and the sol-gel equilibrium. PMID:667302

  12. Facile heme vinyl posttranslational modification in a hemoglobin.

    PubMed

    Preimesberger, Matthew R; Wenke, Belinda B; Gilevicius, Lukas; Pond, Matthew P; Lecomte, Juliette T J

    2013-05-21

    Iron-protoporphyrin IX, or b heme, is utilized as such by a large number of proteins and enzymes. In some cases, notably the c-type cytochromes, this group undergoes a posttranslational covalent attachment to the polypeptide chain, which adjusts the physicochemical properties of the holoprotein. The hemoglobin from the cyanobacterium Synechocystis sp. PCC 6803 (GlbN), contrary to the archetypical hemoglobin, modifies its b heme covalently. The posttranslational modification links His117, a residue that does not coordinate the iron, to the porphyrin 2-vinyl substituent and forms a hybrid b/c heme. The reaction is an electrophilic addition that occurs spontaneously in the ferrous state of the protein. This apparently facile type of heme modification has been observed in only two cyanobacterial GlbNs. To explore the determinants of the reaction, we examined the behavior of Synechocystis GlbN variants containing a histidine at position 79, which is buried against the porphyrin 4-vinyl substituent. We found that L79H/H117A GlbN bound the heme weakly but nevertheless formed a cross-link between His79 Nε2 and the heme 4-Cα. In addition to this linkage, the single variant L79H GlbN also formed the native His117-2-Cα bond yielding an unprecedented bis-alkylated protein adduct. The ability to engineer the doubly modified protein indicates that the histidine-heme modification in GlbN is robust and could be engineered in different local environments. The rarity of the histidine linkage in natural proteins, despite the ease of reaction, is proposed to stem from multiple sources of negative selection.

  13. Prospective, randomized trial of higher goal hemoglobin after subarachnoid hemorrhage.

    PubMed

    Naidech, Andrew M; Shaibani, Ali; Garg, Rajeev K; Duran, Isis M; Liebling, Storm M; Bassin, Sarice L; Bendok, Bernard R; Bernstein, Richard A; Batjer, H Hunt; Alberts, Mark J

    2010-12-01

    In patients with subarachnoid hemorrhage (SAH), higher hemoglobin (HGB) has been associated with better outcomes, but packed red blood cell (PRBC) transfusions with worse outcomes. We performed a prospective pilot trial of goal HGB after SAH. Forty-four patients with SAH and high risk for vasospasm were randomized to goal HGB concentration of at least 10 or 11.5 g/dl. We obtained blinded clinical outcomes at 14 days (NIH Stroke Scale and modified Rankin Scale, mRS), 28 days (mRS), and 3 months (mRS), and blinded interpretation of brain MRI for cerebral infarction at 14 days. This trial is registered at www.stroketrials.org. Forty-four patients were randomized. Patients with goal HGB 11.5 g/dl received more PRBC units per transfusion [1 (1-2) vs. 1 (1-1), P < 0.001] and more total PRBC units [3 (2-4) vs. 2 (1-3), P = 0.045]. Prospectively defined safety endpoints were not different between groups. HGB concentration was different between study groups from day 4 onwards. The number of cerebral infarctions on MRI (6 of 20 vs. 9 of 22), NIH Stroke Scale scores at 14 days [1 (0-9.75) vs. 2 (0-16)], and rates of independence on the mRS at 14 days (65% vs. 44%) and 28 days (80% vs. 67%) were similar, but favored higher goal HGB (P > 0.1 for all). Higher goal hemoglobin in patients with SAH seems to be safe and feasible. A phase III trial of goal HGB after SAH is warranted.

  14. The correlation of hemoglobin A1c to blood glucose.

    PubMed

    Sikaris, Ken

    2009-05-01

    The understanding that hemoglobin A1c (HbA1c) represents the average blood glucose level of patients over the previous 120 days underlies the current management of diabetes. Even in making such a statement, we speak of "average blood glucose" as though "blood glucose" were itself a simple idea. When we consider all the blood glucose forms-arterial versus venous versus capillary, whole blood versus serum versus fluoride-preserved plasma, fasting versus nonfasting-we can start to see that this is not a simple issue. Nevertheless, it seems as though HbA1c correlates to any single glucose measurement. Having more than one measurement and taking those measurements in the preceding month improves the correlation further. In particular, by having glucose measurements that reflect both the relatively lower overnight glucose levels and measurements that reflect the postprandial peaks improves not only our ability to manage diabetes patients, but also our understanding of how HbA1c levels are determined. Modern continuous glucose monitoring (CGM) devices may take thousands of glucose results over a week. Several studies have shown that CGM glucose averages account for the vast proportion of the variation of HbA1c. The ability to relate HbA1c to average glucose may become a popular method for reporting HbA1c, eliminating current concerns regarding differences in HbA1c standardization. Hemoglobin A1c expressed as an average glucose may be more understandable to patients and improve not only their understanding, but also their ability to improve their diabetes management. 2009 Diabetes Technology Society.

  15. The Correlation of Hemoglobin A1c to Blood Glucose

    PubMed Central

    Sikaris, Ken

    2009-01-01

    The understanding that hemoglobin A1c (HbA1c) represents the average blood glucose level of patients over the previous 120 days underlies the current management of diabetes. Even in making such a statement, we speak of “average blood glucose” as though “blood glucose” were itself a simple idea. When we consider all the blood glucose forms—arterial versus venous versus capillary, whole blood versus serum versus fluoride-preserved plasma, fasting versus nonfasting—we can start to see that this is not a simple issue. Nevertheless, it seems as though HbA1c correlates to any single glucose measurement. Having more than one measurement and taking those measurements in the preceding month improves the correlation further. In particular, by having glucose measurements that reflect both the relatively lower overnight glucose levels and measurements that reflect the postprandial peaks improves not only our ability to manage diabetes patients, but also our understanding of how HbA1c levels are determined. Modern continuous glucose monitoring (CGM) devices may take thousands of glucose results over a week. Several studies have shown that CGM glucose averages account for the vast proportion of the variation of HbA1c. The ability to relate HbA1c to average glucose may become a popular method for reporting HbA1c, eliminating current concerns regarding differences in HbA1c standardization. Hemoglobin A1c expressed as an average glucose may be more understandable to patients and improve not only their understanding, but also their ability to improve their diabetes management. PMID:20144279

  16. Glycated Hemoglobin Levels in Patients with Decompensated Cirrhosis

    PubMed Central

    Satapathy, Sanjaya K.

    2016-01-01

    Introduction. Aim of this study is to determine if HbA1c levels are a reliable predictor of glycemic control in patients with decompensated cirrhosis. Methods. 200 unique patients referred for liver transplantation at University of Tennessee/Methodist University Transplant Institute with a HbA1c result were included. Three glucose levels prior to the “measured” A1c (MA1c) were input into an HbA1c calculator from the American Diabetes Association website to determine the “calculated” A1c (CA1c). The differences between MA1c and CA1c levels were computed. Patients were divided into three groups: group A, difference of <0.5; group B, 0.51–1.5; and group C, >1.5. Results. 97 (49%) patients had hemoglobin A1c of less than 5%. Discordance between calculated and measured HbA1c of >0.5% was seen in 47% (n = 94). Higher level of discordance of greater than >1.5 was in 12% of patients (n = 24). Hemoglobin was an independent predictor for higher discordance (odds ratio 0.77 95%, CI 0.60–0.99, and p value 0.04). HbA1c was an independent predictor of occurrence of HCC (OR 2.69 955, CI 1.38–5.43, and p value 0.008). Conclusion. HbA1c is not a reliable predictor of glycemic control in patients with decompensated cirrhosis, especially in those with severe anemia. PMID:27882051

  17. Hemoglobin e syndromes: emerging diagnostic challenge in north India.

    PubMed

    Sharma, Anjali; Marwah, Sadhna; Buxi, Gurdeep; Yadav, Rajbala

    2013-03-01

    Hemoglobin E (HbE) is one of the world's most common and important mutations. HbE disorders may be found in heterozygous (AE), homozygous (EE) and compound heterozygous state. It is important to distinguish HbE disorders diagnostically because of marked differences in clinical course among different genotypes. To find out whether RBC indices as obtained from automated cell counter can provide a clue to the diagnosis of HbE disease. This study was carried out in the Department of Clinical Pathology, PGIMER, Dr. Ram Manohar Lohia Hospital, New Delhi. It included antenatal pregnant females brought for routine check-up as well as referred patients suspected of having hemoglobinopathies. High Performance liquid chromatography was used as a confirmatory test for identification of hemoglobinopathy. Total 20 cases of subtype homozygous HbE (3), HbE trait (12) and Eβ-thalassemia (5) were identified. Statistical analysis was done to find out correlation between levels of HBA2, HBF with RBC indices. (a) There was negative correlation between HbA2/E peak values and RBC indices (Mean corpuscular volume (MCV) and Mean corpuscular hemoglobin) among all the three groups taken together. (b) There was positive correlation between HbA2/E and Red cell distribution width (RDW). (c) There was positive correlation between HbF values with MCV. The finding of positive correlation between HbA2/E and RDW may help in differentiating βthal (RDW normal) from HbE/βthal. In a patient with microcytic hypochromic blood picture and increased RDW, diagnosis of HbE/βthal should also be considered along with the more common Iron deficiency anemia. Thus, new insights into the knowledge of these diseases are important because they impart diagnostic challenges to all the experts involved in the treatment of anemic patients.

  18. Hemoglobin genetics: recent contributions of GWAS and gene editing.

    PubMed

    Smith, Elenoe C; Orkin, Stuart H

    2016-10-01

    The β-hemoglobinopathies are inherited disorders resulting from altered coding potential or expression of the adult β-globin gene. Impaired expression of β-globin reduces adult hemoglobin (α2β2) production, the hallmark of β-thalassemia. A single-base mutation at codon 6 leads to formation of HbS (α2β(S)2) and sickle cell disease. While the basis of these diseases is known, therapy remains largely supportive. Bone marrow transplantation is the only curative therapy. Patients with elevated levels of fetal hemoglobin (HbF, α2γ2) as adults exhibit reduced symptoms and enhanced survival. The β-globin gene locus is a paradigm of cell- and developmental stage-specific regulation. Although the principal erythroid cell transcription factors are known, mechanisms responsible for silencing of the γ-globin gene were obscure until application of genome-wide association studies (GWAS). Here, we review findings in the field. GWAS identified BCL11A as a candidate negative regulator of γ-globin expression. Subsequent studies have established BCL11A as a quantitative repressor. GWAS-related single-nucleotide polymorphisms lie within an essential erythroid enhancer of the BCL11A gene. Disruption of a discrete region within the enhancer reduces BCL11A expression and induces HbF expression, providing the basis for gene therapy using gene editing tools. A recently identified, second silencing factor, leukemia/lymphoma-related factor/Pokemon, shares features with BCL11A, including interaction with the nucleosome remodeling deacetylase repressive complex. These findings suggest involvement of a common pathway for HbF silencing. In addition, we discuss other factors that may be involved in γ-globin gene silencing and their potential manipulation for therapeutic benefit in treating the β-hemoglobinopathies.

  19. Structure and ligand selection of hemoglobin II from Lucina pectinata.

    PubMed

    Gavira, José A; Camara-Artigas, Ana; De Jesús-Bonilla, Walleska; López-Garriga, Juan; Lewis, Ariel; Pietri, Ruth; Yeh, Syun-Ru; Cadilla, Carmen L; García-Ruiz, Juan Manuel

    2008-04-04

    Lucina pectinata ctenidia harbor three heme proteins: sulfide-reactive hemoglobin I (HbI(Lp)) and the oxygen transporting hemoglobins II and III (HbII(Lp) and HbIII(Lp)) that remain unaffected by the presence of H(2)S. The mechanisms used by these three proteins for their function, including ligand control, remain unknown. The crystal structure of oxygen-bound HbII(Lp) shows a dimeric oxyHbII(Lp) where oxygen is tightly anchored to the heme through hydrogen bonds with Tyr(30)(B10) and Gln(65)(E7). The heme group is buried farther within HbII(Lp) than in HbI(Lp). The proximal His(97)(F8) is hydrogen bonded to a water molecule, which interacts electrostatically with a propionate group, resulting in a Fe-His vibration at 211 cm(-1). The combined effects of the HbII(Lp) small heme pocket, the hydrogen bonding network, the His(97) trans-effect, and the orientation of the oxygen molecule confer stability to the oxy-HbII(Lp) complex. Oxidation of HbI(Lp) Phe(B10) --> Tyr and HbII(Lp) only occurs when the pH is decreased from pH 7.5 to 5.0. Structural and resonance Raman spectroscopy studies suggest that HbII(Lp) oxygen binding and transport to the host bacteria may be regulated by the dynamic displacements of the Gln(65)(E7) and Tyr(30)(B10) pair toward the heme to protect it from changes in the heme oxidation state from Fe(II) to Fe(III).

  20. Hemoglobin is associated with retinal vascular fractals in type 1 diabetes patients.

    PubMed

    Nybo, Mads; Hodgson, Lauren A B; Kawasaki, Ryo; Wong, Tien Yin; Grauslund, Jakob

    2014-10-01

    Retinal vascular fractal dimension, a measure of the density of the retinal vasculature, has been suggested as a marker of systemic microvascular disorders in diabetes. As hemoglobin concentration is tightly related to vascular physiology and hypoxia, the hypothesis was that hemoglobin concentration would be associated with retinal vascular fractals in a relevant population. In a cross-sectional study of 204 long-term type 1 diabetes patients from a population-based cohort, retinal digital photos were captured and graded for fractal dimension (Df) by International Retinal Imaging Software - Fractal (IRIS-Fractal). Df was calculated from a disc-centered retinal photo from the right eye. Hemoglobin concentrations were measured using routine equipment. Of 175 patients with gradable images, median age was 57.7 years and median duration of diabetes was 42 years. Median retinal Df was 1.4606 (inter-quartile range 0.0264). A positive correlation was found between hemoglobin concentration and retinal vascular Df (r = 0.23, p = 0.0018). In a multiple linear regression model, Df was associated with hemoglobin (coefficient 0.0054 per 1.0 mmol/L increase in hemoglobin, p = 0.01) and age (coefficient -0.0046 for each 10-year increase in age, p = 0.04). Hemoglobin correlated independently with retinal vascular fractals indicating a relationship between hemoglobin availability and retinal vascular structure.

  1. Iron bioavailability of maize hemoglobin in a Caco-2 cell culture model

    USDA-ARS?s Scientific Manuscript database

    Maize is an important staple crop in many parts of the world but has low iron bioavailability, in part due to its high phytate content. Hemoglobin is a form of iron that is highly bioavailable and its bioavailability is not inhibited by phytate. We hypothesize that maize hemoglobin is a highly bioav...

  2. Using the Cascade Model to Improve Antenatal Screening for the Hemoglobin Disorders

    ERIC Educational Resources Information Center

    Gould, Dinah; Papadopoulos, Irena; Kelly, Daniel

    2012-01-01

    Introduction: The inherited hemoglobin disorders constitute a major public health problem. Facilitators (experienced hemoglobin counselors) were trained to deliver knowledge and skills to "frontline" practitioners to enable them to support parents during antenatal screening via a cascade (train-the-trainer) model. Objectives of…

  3. Comparison of techniques for stabilizing hemoglobins of rainbow trout (Salmo gairdneri) during frozen storage

    USGS Publications Warehouse

    Reinitz, G.L.

    1976-01-01

    1. The stability of hemoglobin of rainbow trout under frozen conditions in oxyform, carboxyform, and cyanometform was examined.2. Carboxyhemoglobin retained its original electrophoretic banding pattern after 14 days of frozen storage, whereas oxyform and cyanometform hemoglobins did not.3. Banding patterns changed in some samples in all treatment groups after 21 days of storage.

  4. A Simple Question to Think about When Considering the Hemoglobin Function

    ERIC Educational Resources Information Center

    Ruiz-Larrea, M. Begona

    2002-01-01

    Hemoglobin is a complex protein formed by various subunits interacting with each other. These noncovalent interactions, quaternary structure, are responsible for hemoglobin functioning as an excellent oxygen transporter, loading up with oxygen in the lungs and delivering it to tissues, where the oxygen pressure is lower. The communications between…

  5. Immunolocalization of Non-Symbiotic Hemoglobins During Somatic Embryogenesis in Chicory

    PubMed Central

    Smagghe, Benoît J; Blervacq, Anne-Sophie; Blassiau, Christelle; Decottignies, Jean-Pierre; Jacquot, Jean-Pierre; Hargrove, Mark S

    2007-01-01

    Hemoglobins are ancient O2-binding proteins, ubiquitously found in eukaryotes. They have been categorized as symbiotic, nonsymbiotic and truncated hemoglobins. We have investigated the cellular localization of nonsymbiotic hemoglobin proteins during somatic embryogenesis in Cichorium hybrid leaves (Cichorium intybus L. var. sativum × C. endivia var. latifolia) using immunolocalization technique. These proteins were detected during the two steps of culture: induction and expression. In leaves, hemoglobins colocalised with plastids, which were dispersed in the parietal cytoplasm as well as in the two guard cells of a stomata, but not in epidermis cells. Upon induction of embryogenesis, in the dark, this pattern disappeared. During the induction phase, where competent cells reinitiate the cell cycle and prepare for mitosis, hemoglobins appeared initially near chloroplasts, and then in the vicinity of vascular vessels especially in the phloem and in cells surrounding the xylem vessels. When leaf fragments were transferred to another medium for the expression phase, hemoglobins were observed in the majority of the leaf blade cells and in small young embryos but not in the older ones. Hemoglobins were also detected in other leaves cells or tissues all along the process. The role of these nonsymbiotic hemoglobins during somatic embryogenesis is discussed. PMID:19516967

  6. Molecular Cloning and Sequencing of Hemoglobin-Beta Gene of Channel Catfish, Ictalurus Punctatus Rafinesque

    USDA-ARS?s Scientific Manuscript database

    : Hemoglobin-y gene of channel catfish , lctalurus punctatus, was cloned and sequenced . Total RNA from head kidneys was isolated, reverse transcribed and amplified . The sequence of the channel catfish hemoglobin-y gene consists of 600 nucleotides . Analysis of the nucleotide sequence reveals one o...

  7. [Change in the total potassium content, hemoglobin volume and bromine space in Soiuz-14 crewmembers].

    PubMed

    Balakhovskiĭ, I S; Kiselev, R K; Kaplan, M A; Sereda, M G

    1978-01-01

    The specific factors of the 15-day space flight caused the predominance of catabolic over anabolic processes. This was equally true of tissue proteins and hemoglobin. Red blood cell and hemoglobin losses developed in parallel. They were more pronounced in the flight engineer than in the commander. No significant signs of body dehydration were noted.

  8. Hemoglobin Aggregation in Single Red Blood Cells of Sickle Cell Anemia

    NASA Astrophysics Data System (ADS)

    Nishio, Izumi; Tanaka, Toyoichi; Sun, Shao-Tang; Imanishi, Yuri; Tsuyoshi Ohnishi, S.

    1983-06-01

    A laser light scattering technique was used to observe the extent of hemoglobin aggregation in solitary red blood cells of sickle cell anemia. Hemoglobin aggregation was confirmed in deoxygenated cells. The light scattering technique can also be applied to cytoplasmic studies of any biological cell.

  9. Inhibition of pseudoperoxiadse activity of human red blood cell hemoglobin by methocarbamol.

    PubMed

    Minai-Tehrani, Dariush; Toofani, Sara; Yazdi, Fatemeh; Minai-Tehrani, Arash; Mollasalehi, Hamidreza; Bakhtiari Ziabari, Kourosh

    2017-01-01

    After red blood cells lysis, hemoglobin is released to blood circulation. Hemoglobin is carried in blood by binding to haptoglobin. In normal individuals, no free hemoglobin is observed in the blood, because most of the hemoglobin is in the form of haptoglobin complex. In some diseases that are accompanied by hemolysis, the amount of released hemoglobin is higher than its complementary haptoglobin. As a result, free hemoglobin appears in the blood, which is a toxic compound for these patients and may cause renal failure, hypertensive response and risk of atherogenesis. Free hemoglobin has been determined to have peroxidase activity and considered a pseudoenzyme. In this study, the effect of methocarbamol on the peroxidase activity of human hemoglobin was investigated. Our results showed that the drug inhibited the pseudoenzyme by un-competitive inhibition. Both Km and Vmax decreased by increasing the drug concentration. Ki and IC50 values were determined as 6 and 10mM, respectively. Docking results demonstrated that methocarbamol did not attach to heme group directly. A hydrogen bond linked NH2 of carbamate group of methocarbamol to the carboxyl group of Asp126 side chain. Two other hydrogen bonds could be also observed between hydroxyl group of the drug and Ser102 and Ser133 residues of the pseudoenzyme.

  10. Hemoglobin levels in persons with depressive and/or anxiety disorders.

    PubMed

    Lever-van Milligen, Bianca A; Vogelzangs, Nicole; Smit, Johannes H; Penninx, Brenda W J H

    2014-04-01

    Both low and high hemoglobin levels lead to more physical diseases, and both are linked to mortality. Low hemoglobin, often classified as anemia, has also been linked to more depressive symptoms, but whether both hemoglobin extremes are associated with depressive disorder and potentially also with anxiety disorder has not been examined before. This study examines to which extent hemoglobin levels are associated with depression and anxiety disorders in a large cohort. The study sample consisted of 2920 persons from the Netherlands Study of Depression and Anxiety. Hemoglobin levels were determined after venipuncture. Depressive and anxiety disorders were determined according to a DSM-IV-based psychiatric interview. Clinical psychiatric characteristics included the severity of depression and anxiety, the duration of symptoms, the age of onset and the antidepressant use. Higher hemoglobin levels were found in those with current depressive and/or anxiety disorders after sociodemographic adjustment and both higher, and lower hemoglobin levels were found in persons with higher depression and anxiety severity. However, after full adjustment for sociodemographics, disease indicators and lifestyle, associations were no longer significant. This cohort study showed that there is no independent association between depressive and/or anxiety disorders and hemoglobin levels or anemia status. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Mapping of hemoglobin in erythrocytes and erythrocyte ghosts using two photon excitation fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Bukara, Katarina; Jovanić, Svetlana; Drvenica, Ivana T.; Stančić, Ana; Ilić, Vesna; Rabasović, Mihailo D.; Pantelić, Dejan; Jelenković, Branislav; Bugarski, Branko; Krmpot, Aleksandar J.

    2017-02-01

    The present study describes utilization of two photon excitation fluorescence (2PE) microscopy for visualization of the hemoglobin in human and porcine erythrocytes and their empty membranes (i.e., ghosts). High-quality, label- and fixation-free visualization of hemoglobin was achieved at excitation wavelength 730 nm by detecting visible autofluorescence. Localization in the suspension and spatial distribution (i.e., mapping) of residual hemoglobin in erythrocyte ghosts has been resolved by 2PE. Prior to the 2PE mapping, the presence of residual hemoglobin in the bulk suspension of erythrocyte ghosts was confirmed by cyanmethemoglobin assay. 2PE analysis revealed that the distribution of hemoglobin in intact erythrocytes follows the cells' shape. Two types of erythrocytes, human and porcine, characterized with discocyte and echinocyte morphology, respectively, showed significant differences in hemoglobin distribution. The 2PE images have revealed that despite an extensive washing out procedure after gradual hypotonic hemolysis, a certain amount of hemoglobin localized on the intracellular side always remains bound to the membrane and cannot be eliminated. The obtained results open the possibility to use 2PE microscopy to examine hemoglobin distribution in erythrocytes and estimate the purity level of erythrocyte ghosts in biotechnological processes.

  12. Role of Hemoglobin and Iron in Hydrocephalus After Neonatal Intraventricular Hemorrhage

    PubMed Central

    Strahle, Jennifer M.; Garton, Thomas; Bazzi, Ahmad A.; Kilaru, Harish; Garton, Hugh J.L.; Maher, Cormac O.; Muraszko, Karin M.; Keep, Richard; Xi, Guohua

    2014-01-01

    Background Neonatal germinal matrix hemorrhage/intraventricular hemorrhage (GMH/IVH) is common and often results in hydrocephalus. The pathogenesis of post-hemorrhagic hydrocephalus is not fully understood. Objective To explore the potential role of hemoglobin and iron released after hemorrhage. Methods Artificial cerebrospinal fluid (aCSF), hemoglobin, or iron was injected into the right lateral ventricle of postnatal day-7 Sprague Dawley rats. Ventricle size, heme oxygenase-1 (HO-1) expression, and presence of iron were evaluated 24 and 72 hours after injection. A subset of animals was treated with an iron chelator (deferoxamine) or vehicle for 24 hours after hemoglobin injection, and ventricle size and cell death were evaluated. Results Intraventricular injection of hemoglobin and iron resulted in ventricular enlargement at 24 hours compared to injection of aCSF. Protoporphyrin IX, the iron-deficient immediate heme precursor, did not result in ventricular enlargement after injection into the ventricle. HO-1, the enzyme that releases iron from heme, was increased in the hippocampus and cortex of hemoglobin-injected animals at 24 hours compared to aCSF-injected controls. Treatment with an iron chelator, deferoxamine, decreased hemoglobin-induced ventricular enlargement and cell death. Conclusion Intraventricular injection of hemoglobin and iron can induce hydrocephalus. Treatment with an iron chelator reduced hemoglobin-induced ventricular enlargement. This has implications for pathogenesis and treatment of post-hemorrhagic hydrocephalus. PMID:25121790

  13. The relationship of regional hemoglobin A1c testing and amputation rate among patients with diabetes.

    PubMed

    Newhall, Karina A; Bekelis, Kimon; Suckow, Bjoern D; Gottlieb, Daniel J; Farber, Adrienne E; Goodney, Philip P; Skinner, Jonathan S

    2017-04-01

    Objective The risk of leg amputation among patients with diabetes has declined over the past decade, while use of preventative measures-such as hemoglobin A1c monitoring-has increased. However, the relationship between hemoglobin A1c testing and amputation risk remains unclear. Methods We examined annual rates of hemoglobin A1c testing and major leg amputation among Medicare patients with diabetes from 2003 to 2012 across 306 hospital referral regions. We created linear regression models to study associations between hemoglobin A1c testing and lower extremity amputation. Results From 2003 to 2012, the proportion of patients who received hemoglobin A1c testing increased 10% (74% to 84%), while their rate of lower extremity amputation decreased 50% (430 to 232/100,000 beneficiaries). Regional hemoglobin A1c testing weakly correlated with crude amputation rate in both years (2003 R = -0.20, 2012 R = -0.21), and further weakened with adjustment for age, sex, and disability status (2003 R = -0.11, 2012 R = -0.17). In a multivariable model of 2012 amputation rates, hemoglobin A1c testing was not a significant predictor. Conclusion Lower extremity amputation among patients with diabetes nearly halved over the past decade but only weakly correlated with hemoglobin A1c testing throughout the study period. Better metrics are needed to understand the relationship between preventative care and amputation.

  14. Enhancement of Salinity Tolerance during Rice Seed Germination by Presoaking with Hemoglobin

    PubMed Central

    Xu, Sheng; Hu, Bing; He, Ziyi; Ma, Fei; Feng, Jianfei; Shen, Wenbiao; Yang, Jie

    2011-01-01

    Salinity stress is an important environmental constraint limiting the productivity of many crops worldwide. In this report, experiments were conducted to investigate the effects of seed presoaking by bovine hemoglobin, an inducer of heme oxygenase-1 (HO-1), on salinity tolerance in rice (Oryza sativa) plants. The results showed that different concentrations of the hemoglobin (0.01, 0.05, 0.2, 1.0, and 5.0 g/L) differentially alleviated the inhibition of rice seed germination and thereafter seedling shoot growth caused by 100 mM NaCl stress, and the responses of 1.0 g/L hemoglobin was the most obvious. Further analyses showed that application of hemoglobin not only increased the HO-1 gene expression, but also differentially induced catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities or transcripts, thus decreasing the lipid peroxidation in germinating rice seeds subjected to salt stress. Compared with non-hemoglobin treatment, hemoglobin presoaking also increased the potassium (K) to sodium (Na) ratio both in the root and shoot parts after salinity stress. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) blocked the positive actions of hemoglobin on seed germination and seedling shoot growth. Overall, these results suggested that hemoglobin performs an advantageous role in enhancement of salinity tolerance during rice seed germination. PMID:21731454

  15. Purification of Hemoglobin from the Actinorhizal Root Nodules of Myrica gale L.

    PubMed Central

    Pathirana, S. M.; Tjepkema, J. D.

    1995-01-01

    Hemoglobins are generally absent or present in low concentrations in the nodules of actinorhizal plants. An exception is Casuarina, where a hemoglobin occurs at relatively high concentration. However, this plant is unique in that Frankia, the microsymbiont, lacks the vesicles that are normally the site of nitrogen fixation. The present paper shows that a hemoglobin also occurs at high concentrations in Myrica gale L., an actinorhizal plant in which Frankia does form vesicles. Hemoglobin was extracted from root nodules under anaerobic conditions using a buffer containing CO, detergent, and a reducing agent. Carboxyhemoglobin was purified using gel filtration followed by aerobic ion-exchange chromatography. The optical absorption spectra of the oxy-, deoxy-, and carboxyhemoglobins were similar to those of other hemoglobins. The molecular mass of the native hemoglobin estimated by gel filtration was 38,500 D. The molecular mass of the subunits estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 16,200 D, consistent with the mass of other hemoglobin subunits. Thus, the native hemoglobin is probably a dimer. PMID:12228407

  16. A Simple Question to Think about When Considering the Hemoglobin Function

    ERIC Educational Resources Information Center

    Ruiz-Larrea, M. Begona

    2002-01-01

    Hemoglobin is a complex protein formed by various subunits interacting with each other. These noncovalent interactions, quaternary structure, are responsible for hemoglobin functioning as an excellent oxygen transporter, loading up with oxygen in the lungs and delivering it to tissues, where the oxygen pressure is lower. The communications between…

  17. Using the Cascade Model to Improve Antenatal Screening for the Hemoglobin Disorders

    ERIC Educational Resources Information Center

    Gould, Dinah; Papadopoulos, Irena; Kelly, Daniel

    2012-01-01

    Introduction: The inherited hemoglobin disorders constitute a major public health problem. Facilitators (experienced hemoglobin counselors) were trained to deliver knowledge and skills to "frontline" practitioners to enable them to support parents during antenatal screening via a cascade (train-the-trainer) model. Objectives of…

  18. Enhancement of salinity tolerance during rice seed germination by presoaking with hemoglobin.

    PubMed

    Xu, Sheng; Hu, Bing; He, Ziyi; Ma, Fei; Feng, Jianfei; Shen, Wenbiao; Yang, Jie

    2011-01-01

    Salinity stress is an important environmental constraint limiting the productivity of many crops worldwide. In this report, experiments were conducted to investigate the effects of seed presoaking by bovine hemoglobin, an inducer of heme oxygenase-1 (HO-1), on salinity tolerance in rice (Oryza sativa) plants. The results showed that different concentrations of the hemoglobin (0.01, 0.05, 0.2, 1.0, and 5.0 g/L) differentially alleviated the inhibition of rice seed germination and thereafter seedling shoot growth caused by 100 mM NaCl stress, and the responses of 1.0 g/L hemoglobin was the most obvious. Further analyses showed that application of hemoglobin not only increased the HO-1 gene expression, but also differentially induced catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities or transcripts, thus decreasing the lipid peroxidation in germinating rice seeds subjected to salt stress. Compared with non-hemoglobin treatment, hemoglobin presoaking also increased the potassium (K) to sodium (Na) ratio both in the root and shoot parts after salinity stress. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) blocked the positive actions of hemoglobin on seed germination and seedling shoot growth. Overall, these results suggested that hemoglobin performs an advantageous role in enhancement of salinity tolerance during rice seed germination.

  19. Correlation of Oxygenated Hemoglobin Concentration and Psychophysical Amount on Speech Recognition

    NASA Astrophysics Data System (ADS)

    Nozawa, Akio; Ide, Hideto

    The subjective understanding on oral language understanding task is quantitatively evaluated by the fluctuation of oxygenated hemoglobin concentration measured by the near-infrared spectroscopy. The English listening comprehension test wihch consists of two difficulty level was executed by 4 subjects during the measurement. A significant correlation was found between the subjective understanding and the fluctuation of oxygenated hemoglobin concentration.

  20. Deer mouse hemoglobin exhibits a lowered oxygen affinity owing to mobility of the E helix

    PubMed Central

    Inoguchi, Noriko; Oshlo, Jake R.; Natarajan, Chandrasekhar; Weber, Roy E.; Fago, Angela; Storz, Jay F.; Moriyama, Hideaki

    2013-01-01

    The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hanging-drop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the hydrogen bond between α1Trp14 in the A helix and α1Thr67 in the E helix owing to the Thr67Ala substitution. In addition, deer mouse hemoglobin has a unique hydrogen bond at the α1β1 interface between residues α1Cys34 and β1Ser128. PMID:23545644

  1. The potential of Angeli’s salt to decrease nitric oxide scavenging by plasma hemoglobin

    PubMed Central

    He, Xiaojun; Azarov, Ivan; Jeffers, Anne; Presley, Tennille; Richardson, Jodi; King, S. Bruce; Gladwin, Mark T.; Kim-Shapiro, Daniel B.

    2008-01-01

    Release of hemoglobin from the erythrocyte during intravascular hemolysis contributes to the pathology of a variety of diseased states. This effect is partially due to the enhanced ability of cell-free plasma hemoglobin, which is primarily found in the ferrous, oxygenated state, to scavenge nitric oxide. Oxidation of the cell-free hemoglobin to methemoglobin, which does not effectively scavenge nitric oxide, using inhaled nitric oxide has been shown to be effective in limiting pulmonary and systemic vasoconstriction. However, the ferric heme species may be reduced back to ferrous hemoglobin in plasma and has the potential to drive injurious redox chemistry. We propose that compounds that selectively convert cell-free hemoglobin to ferric, and ideally iron-nitrosylated heme species that do not actively scavenge nitric oxide would effectively treat intravascular hemolysis. We show here that nitroxyl, generated by Angeli’s salt (Sodium α-oxyhyponitrite, Na2N2O3), preferentially reacts with cell-free hemoglobin compared to that encapsulated in the red blood cell under physiologically relevant conditions. Nitroxyl oxidizes oxygenated ferrous hemoglobin to methemoglobin and can convert the methemoglobin to a more stable, less toxic species, iron-nitrosyl hemoglobin. These results support the notion that Angeli’s salt or a similar compound could be used to effectively treat conditions associated with intravascular hemolysis. PMID:18243145

  2. Biocatalytic oxidation of polycyclic aromatic hydrocarbons by hemoglobin and hydrogen peroxide.

    PubMed

    Ortiz-Leon, M; Velasco, L; Vazquez-Duhalt, R

    1995-10-24

    Hemoglobin is able to oxidize polycyclic aromatic hydrocarbons, PAH's, in presence of hydrogen peroxide. Among 12 aromatic compounds tested, six were oxidized; anthracene, carbazole, dibenzothiophene, fluorene, 9-hexylanthracene and pyrene. The products were identified as aromatic ketones and sulfoxides. Effect of organic solvent concentration and hemoglobin stability were determined.

  3. Prevalence of common hemoglobin variants in an afro-descendent Ecuadorian population

    PubMed Central

    2013-01-01

    Background Hemoglobinopathies are among the most studied and frequent pathologies. These genetic disorders are considered a very important health care threat in many tropical countries. Ecuador is a tropical Latin-American country with an important presence of afro-descendants (7.2%). Afro-descendants are among the ethnic groups with higher frequency of hemoglobinopathies reported. Ambuqui is a region within the Imbabura province with an important presence of afro-descendants (>50%). The present study analyzed the frequency of the most common hemoglobin variants in an asymptomatic afro-descendent population using capillary electrophoresis. Findings From 114 individuals, 25 (22%) reported a hemoglobin variant. All individuals that presented hemoglobin variants were heterozygotes (asymptomatic). Hemoglobin S (sickle cell trait) was the most frequent variant found (14%), followed by hemoglobin E (4.4%), Fetal (2.6%) and C (1%). Conclusion Prevalence of hemoglobin S was consistent with populations from other countries, but it was lower than other Ecuadorian afro-descendent populations. Frequency of hemoglobin C was lower than other afro-descendent populations. This data suggests the possibility of gene flow from Native American individuals to the Ambuqui population there by lowering the frequency of their hemoglobin variants compared with other afro-descendant populations. Evaluating the frequency of hemoglobinopathies in Ecuadorian populations is essential. Despite the high frequency of these disorders, very few health care facilities implement hemoglobinopathies tests as a routine practice. PMID:23557107

  4. Prevalence of common hemoglobin variants in an afro-descendent Ecuadorian population.

    PubMed

    Domínguez, Yamila; Zurita, Camilo; Calvopiña, Diego; Villacís, Jacqueline; Mora, Marcelo

    2013-04-04

    Hemoglobinopathies are among the most studied and frequent pathologies. These genetic disorders are considered a very important health care threat in many tropical countries. Ecuador is a tropical Latin-American country with an important presence of afro-descendants (7.2%). Afro-descendants are among the ethnic groups with higher frequency of hemoglobinopathies reported. Ambuqui is a region within the Imbabura province with an important presence of afro-descendants (>50%). The present study analyzed the frequency of the most common hemoglobin variants in an asymptomatic afro-descendent population using capillary electrophoresis. From 114 individuals, 25 (22%) reported a hemoglobin variant. All individuals that presented hemoglobin variants were heterozygotes (asymptomatic). Hemoglobin S (sickle cell trait) was the most frequent variant found (14%), followed by hemoglobin E (4.4%), Fetal (2.6%) and C (1%). Prevalence of hemoglobin S was consistent with populations from other countries, but it was lower than other Ecuadorian afro-descendent populations. Frequency of hemoglobin C was lower than other afro-descendent populations. This data suggests the possibility of gene flow from Native American individuals to the Ambuqui population there by lowering the frequency of their hemoglobin variants compared with other afro-descendant populations. Evaluating the frequency of hemoglobinopathies in Ecuadorian populations is essential. Despite the high frequency of these disorders, very few health care facilities implement hemoglobinopathies tests as a routine practice.

  5. Monitoring the concentration and oxygen saturation of hemoglobin using photoacoustic technique

    NASA Astrophysics Data System (ADS)

    Su, Yi-Xiong; Wang, Ruikang K.; Lu, Tao; Song, Zhi-Yuan

    2007-02-01

    Time-resolved photoacoustic spectroscopy is a novel and potential tool for the noninvasive measurements of chromophore concentrations in vivo. In this study, noninvasive measurement of concentration and oxygen saturation of hemoglobin has been investigated by using photoacoustic method. We detailedly report a home-made photoacoustic experiment system for this study. In our system, a Q-switched ND: YAG pulse laser operating at 1064nm with a 10ns pulse width has been employed to generate photoacoustic signals. The photoacoustic signals, generated by varying the hemoglobin concentration or oxygenation saturation in blood experimentally, were picked up and analyzed. The results show that the photoacoustic technique is a useful and helpful tool for noninvasive monitoring of the total hemoglobin concentration and the oxygen saturation, for it can accurately detect the variation of the total hemoglobin concentration and oxygen saturation of hemoglobin, even when the blood vessel is deep in high scattering medium for 1cm.

  6. Radiation-induced changes in the optical properties of hemoglobin molecule.

    PubMed

    Selim, Nabila S; El-Marakby, Seham M

    2010-06-01

    Adult male Albino rats were exposed to different doses of gamma radiation from Cs-137 source. Hemoglobin samples were analyzed 24 h after irradiation. The UV-visible spectrum of hemoglobin molecule was measured in the range 200-700 nm. The overall spectrum of the hemoglobin molecule showed hypochromicity that increased with dose increase. To investigate the effect of radiation on the hemoglobin molecule, different parameters of the spectrum were calculated: molar absorption coefficient, absorption cross-section, transition dipole moment, dipole length, the optical energy gap and activation energy for each characteristic peak. The obtained results revealed that the radiation effect can induce rearrangement of the transition dipole moments and change molecular energy levels of the hemoglobin molecule.

  7. Radiation-induced changes in the optical properties of hemoglobin molecule

    NASA Astrophysics Data System (ADS)

    Selim, Nabila S.; El-Marakby, Seham M.

    2010-06-01

    Adult male Albino rats were exposed to different doses of gamma radiation from Cs-137 source. Hemoglobin samples were analyzed 24 h after irradiation. The UV-visible spectrum of hemoglobin molecule was measured in the range 200-700 nm. The overall spectrum of the hemoglobin molecule showed hypochromicity that increased with dose increase. To investigate the effect of radiation on the hemoglobin molecule, different parameters of the spectrum were calculated: molar absorption coefficient, absorption cross-section, transition dipole moment, dipole length, the optical energy gap and activation energy for each characteristic peak. The obtained results revealed that the radiation effect can induce rearrangement of the transition dipole moments and change molecular energy levels of the hemoglobin molecule.

  8. Identification of hemoglobin variants by top-down mass spectrometry using selected diagnostic product ions.

    PubMed

    Coelho Graça, Didia; Hartmer, Ralf; Jabs, Wolfgang; Beris, Photis; Clerici, Lorella; Stoermer, Carsten; Samii, Kaveh; Hochstrasser, Denis; Tsybin, Yury O; Scherl, Alexander; Lescuyer, Pierre

    2015-04-01

    Hemoglobin disorder diagnosis is a complex procedure combining several analytical steps. Due to the lack of specificity of the currently used protein analysis methods, the identification of uncommon hemoglobin variants (proteoforms) can become a hard task to accomplish. The aim of this work was to develop a mass spectrometry-based approach to quickly identify mutated protein sequences within globin chain variants. To reach this goal, a top-down electron transfer dissociation mass spectrometry method was developed for hemoglobin β chain analysis. A diagnostic product ion list was established with a color code strategy allowing to quickly and specifically localize a mutation in the hemoglobin β chain sequence. The method was applied to the analysis of rare hemoglobin β chain variants and an (A)γ-β fusion protein. The results showed that the developed data analysis process allows fast and reliable interpretation of top-down electron transfer dissociation mass spectra by nonexpert users in the clinical area.

  9. The hemoglobins of the cold-adapted Antarctic teleost Cygnodraco mawsoni.

    PubMed

    Caruso, C; Rutigliano, B; Romano, M; di Prisco, G

    1991-06-24

    The blood of the teleost Cygnodraco mawsoni, of the endemic Antarctic family Bathydraconidae, contains a major hemoglobin (Hb 1), accompanied by a minor component (Hb 2, about 5% of total). The two hemoglobins have identical alpha chains and differ by the beta chain. The complete amino acid sequence of the three chains has been elucidated, thus establishing the primary structure of both hemoglobins. The sequences show a 53-65% identity with non-Antarctic poikilotherm fish species; on the other hand, a very high degree of similarity (83-88%) has been found between Hb 1 and the major component of another Antarctic species of a different family. The hemoglobin functional properties relative to oxygen binding have been investigated in intact erythrocytes, 'stripped' hemolysate and purified components of C. mawsoni. The hemoglobins display the Bohr and Root effects, indicating fine regulation of oxygen binding by pH and by the physiological effectors organic phosphates.

  10. Investigations on the binding of human hemoglobin with orange I and orange II.

    PubMed

    Wang, Yan-Qing; Zhang, Hong-Mei

    2012-08-01

    The interactions between human hemoglobin and orange I (or orange II) were investigated by UV/vis absorption, circular dichroism, fluorescence spectra techniques, and molecular modeling method. Orange I and orange II effectively quenched the intrinsic fluorescence of human hemoglobin by static quenching. The processes of the binding orange I and orange II on human hemoglobin were spontaneous molecular interaction procedure with hydrogen bonds, van der Waals force, hydrophobic and electrostatic interactions according to van't Hoff equation and molecular modeling. There is a single class of binding site of orange I (orange II) in human hemoglobin and the molecular modeling study shows that orange I and orange II are dipped into α(2) chain. The results of CD, synchronous fluorescence and three-dimensional fluorescence spectra indicated a small loss of α-helical secondary structure of human hemoglobin induced by orange I and orange II.

  11. Blood Transcriptomic Meta-analysis Identifies Dysregulation of Hemoglobin and Iron Metabolism in Parkinson' Disease.

    PubMed

    Santiago, Jose A; Potashkin, Judith A

    2017-01-01

    Disrupted iron metabolism has been implicated in the pathogenesis of Parkinson's disease (PD), a progressive neurodegenerative disorder that severely affects movement and coordination, yet the molecular mechanisms underlying this association remain unknown. To this end, we performed a transcriptomic meta-analysis of four blood microarrays in PD. We observed a significant downregulation of genes related to hemoglobin including, hemoglobin delta (HBD), alpha hemoglobin stabilizing protein (ASHP), genes implicated in iron metabolism including, solute carrier family 11 member 2 (SLC11A2), ferrochelatase (FECH), and erythrocyte-specific genes including erythrocyte membrane protein (EPB42), and 5'-aminolevulinate synthase 2 (ALAS2). Pathway and network analysis identified enrichment in processes related to mitochondrial membrane, oxygen transport, oxygen and heme binding, hemoglobin complex, erythrocyte development, tetrapyrrole metabolism and the spliceosome. Collectively, we identified a subnetwork of genes in blood that may provide a molecular explanation for the disrupted hemoglobin and iron metabolism in the pathogenesis of PD.

  12. Hemoglobin measurement prior to initiating copper intrauterine devices: a systematic review.

    PubMed

    Tepper, Naomi K; Steenland, Maria W; Marchbanks, Polly A; Curtis, Kathryn M

    2013-05-01

    Women using copper intrauterine devices (IUDs) frequently experience bleeding abnormalities. This review was conducted to evaluate the evidence regarding whether hemoglobin levels should be measured prior to copper IUD insertion. The PubMed database was searched from database inception through March 2012 for all peer-reviewed articles in any language concerning hemoglobin changes among women with anemia who have copper IUDs inserted. Articles were included if they reported changes in hemoglobin among anemic women over a specified period of time following copper IUD insertion. Articles were excluded in which there were no women with anemia at baseline or outcomes among women with anemia were not reported separately. For indirect evidence, articles were included which addressed hemoglobin changes among women without anemia who had copper IUDs inserted. The quality of each direct study was assessed using the US Preventive Services Task Force grading system. Four level I to II-2 studies of fair quality met inclusion criteria as direct evidence. Evidence from one randomized trial and one prospective cohort study showed no statistically significant changes in hemoglobin among copper IUD users with anemia, while two prospective cohort studies showed a statistically significant, but clinically small, mean decrease in hemoglobin levels over 12 months of follow-up. We also identified 21 studies examining changes in hemoglobin among healthy women using copper IUDs as indirect evidence; this body of evidence was not graded. These studies generally showed no clinically significant changes in hemoglobin levels with up to 5 years of follow-up. Limited fair-quality evidence was mixed but generally showed no clinically significant changes in hemoglobin among women with anemia who used copper IUDs for up to 12 months. Indirect evidence among healthy women using copper IUDs did not show clinically significant changes in hemoglobin levels when followed for up to 5 years of use

  13. Impact of higher hemoglobin targets on blood pressure and clinical outcomes: a secondary analysis of CHOIR

    PubMed Central

    Inrig, Jula K.; Sapp, Shelly; Barnhart, Huiman; Patel, Uptal D.; Reddan, Donal; Singh, Ajay; Califf, Robert M.; Szczech, Lynda

    2012-01-01

    Background Targeting a higher hemoglobin in patients with chronic kidney disease leads to adverse cardiovascular outcomes, yet the reasons remain unclear. Herein, we sought to determine whether changes in erythropoiesis-stimulating agent (ESA) dose and in hemoglobin were predictive of changes in blood pressure (BP) and whether these changes were associated with cardiovascular outcomes. Methods In this secondary analysis of 1421 Correction of Hemoglobin and Outcomes in Renal Disease (CHOIR) participants, mixed model analyses were used to describe monthly changes in ESA dose and hemoglobin with changes in diastolic BP (DBP) and systolic BP (SBP). Poisson modeling was performed to determine whether changes in hemoglobin and BP were associated with the composite end point of death or cardiovascular outcomes. Results Monthly average DBP, but not SBP, was higher in participants in the higher hemoglobin arm. Increases in ESA doses and in hemoglobin were significantly associated with linear increases in DBP, but not consistently with increases in SBP. In models adjusted for demographics and comorbid conditions, increases in ESA dose (>0 U) and larger increases in hemoglobin (>1.0 g/dL/month) were associated with poorer outcomes [event rate ratio per 1000 U weekly dose per month increase 1.05, (1.02–1.08), P = 0.002 and event rate ratio 1.70 (1.02–2.85), P = 0.05, respectively]. However, increasing DBP was not associated with adverse outcomes [event rate ratio 1.01 (0.98–1.03), P = 0.7]. Conclusion Among CHOIR participants, higher hemoglobin targets, increases in ESA dose and in hemoglobin were associated both with increases in DBP and with higher event rates; however, increasing DBP was not associated with adverse outcomes. PMID:22573238

  14. A disposable amperometric dual-sensor for the detection of hemoglobin and glycated hemoglobin in a finger prick blood sample.

    PubMed

    Moon, Jong-Min; Kim, Dong-Min; Kim, Moo Hyun; Han, Jin-Yeong; Jung, Dong-Keun; Shim, Yoon-Bo

    2017-05-15

    A disposable microfluidic amperometric dual-sensor was developed for the detection of glycated hemoglobin (HbA1C) and total hemoglobin (Hb), separately, in a finger prick blood sample. The accurate level of total Hb was determined through the measurements of the cathodic currents of total Hb catalyzed by a toluidine blue O (TBO)-modified working electrode. Subsequently, after washing unbound Hb in the fluidic channel of dual sensor with PBS, the cathodic current by only HbA1C captured on aptamer was monitored using another aptamer/TBO-modified working electrode in the channel. To modify the sensor probe, poly(2,2´:5´,5″-terthiophene-3´-p-benzoic acid) and a multi-wall carbon nanotube (MWCNT) composite layer (pTBA@MWCNT) was electropolymerized on a screen printed carbon electrode (SPCE), followed by immobilization of TBO for the total Hb probe and aptamer/TBO for the HbA1C probe, respectively. The characterization of each sensor surface was performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The experimental conditions affecting the analytical signal were optimized in terms of the amount of TBO, pH, temperature, binding time, applied potential, and the content ratio of monomer and MWCNT. The dynamic ranges of Hb and HbA1C were from 0.1 to 10µM and from 0.006 to 0.74µM, with detection limits of 82(±4.2)nM and 3.7(±0.8)nM, respectively. The reliability of the proposed microfluidic dual-sensor for a finger prick blood sample (1µL) was evaluated in parallel with a conventional method (HPLC) for point-of-care analysis.

  15. Development of a Method To Produce Hemoglobin in a Bioreactor Culture of Escherichia coli BL21(DE3) Transformed with a Plasmid Containing Plesiomonas shigelloides Heme Transport Genes and Modified Human Hemoglobin Genes ▿

    PubMed Central

    Smith, B. J. Z.; Gutierrez, P.; Guerrero, E.; Brewer, C. J.; Henderson, D. P.

    2011-01-01

    We describe a method for production of recombinant human hemoglobin by Escherichia coli grown in a bioreactor. E. coli BL21(DE3) transformed with a plasmid containing hemoglobin genes and Plesiomonas shigelloides heme transport genes reached a cell dry weight of 83.64 g/liter and produced 11.92 g/liter of hemoglobin in clarified lysates. PMID:21803893

  16. Hemoglobin polymerized with a naturally occurring crosslinking agent as a blood substitute: in vitro and in vivo studies.

    PubMed

    Chang, Wen-Hsiang; Chang, Yen; Chen, Yi-Chien; Sung, Hsing-Wen

    2004-05-01

    A naturally occurring crosslinking agent, genipin, extracted from the fruits of Gardenia jasminoides ELLIS was used by our group to chemically modified biomolecules. Genipin and its related iridoid glucosides have been widely used as an antiphlogistic and cholagogue in herbal medicine. Our previous study showed that the cytotoxicity of genipin is significantly lower than glutaraldehyde. The study was to investigate the feasibility of using genipin to polymerize hemoglobin as a blood substitute. The results indicated that the rate of hemoglobin polymerization by glutaraldehyde was significantly faster than that by genipin and it readily produced polymers with molecular masses greater than 500,000 Da. It was found that the maximum degree of hemoglobin polymerization by genipin was approximately 40% if over-polymerization is to be prevented. With increasing the reaction temperature, hemoglobin concentration, and genipin-to-hemoglobin molar ratio, the duration taken to achieve the maximum degree of hemoglobin polymerization by genipin became significantly shorter. The P50 value of the unmodified hemoglobin was 9 mmHg, while that of the genipin-polymerized PLP-hemoglobin increased to 21 mmHg. It was found in a rat model that the genipin-polymerized PLP-hemoglobin resulted in a longer circulation time than the unmodified hemoglobin. In conclusion, the results of the study indicated that the genipin-polymerized hemoglobin solution has a lower oxygen affinity and a longer vascular retention time than the unmodified hemoglobin solution.

  17. Maternal HIV status affects the infant hemoglobin level

    PubMed Central

    Feleke, Berhanu Elfu

    2016-01-01

    Abstract Children, especially infants, are highly vulnerable to iron-deficiency anemia because of their rapid growth of the brain and the rest of the body. The objectives of this study were to compare the prevalence of iron-deficiency anemia in infants born from HIV-positive mothers and HIV-negative mothers and to identify the determinants of iron-deficiency anemia in infants. A comparative cross-sectional study was conducted in Bahir Dar city. Simple random sampling technique was used to select the study participants. Mothers were interviewed; blood samples were collected from mothers and infants to measure the hemoglobin level and anthropometric indicators were obtained from the infants using world health organization standards. Descriptive statistics were used to estimate the prevalence of infantile anemia. Binary logistic regression and multiple linear regressions were used to identify the determinants of infant anemia. A total of 1459 infants born from HIV-positive and HIV-negative mothers were included. The prevalence of iron-deficiency anemia in infants born from HIV-positive and HIV-negative mothers was 41.9% (95% CI: 39–44). Infantile iron-deficiency anemia was associated with maternal HIV infection (adjusted odds ratio [AOR] 2.54 [95% CI: 1.65–3.9]), stunting (AOR 3.46 [95% CI: 2.41–4.97]), low income (AOR 2.72 [95% CI: 2–3.73]), maternal malaria during pregnancy (AOR 1.81 [95% CI: 1.33–2.47]), use of cow milk before 6 month (AOR 1.82 [95% CI: 1.35–2.45]), residence (AOR 0.09 [95% CI: 0.06–0.13]), history of cough or fever 7 days preceding the survey (AOR 2.71 [95% CI: 1.99–3.69]), maternal hemoglobin (B 0.65 [95% CI: 0.61–0.68]), educational status of mother (B 0.22 [95% CI: 0.2–0.23]), age of the mother (B –0.03 [95% CI: –0.03, –0.02]), and family size (B –0.14 [95% CI: –0.18,–0.11]). PMID:27495044

  18. Trichomonas vaginalis: the adhesins AP51 and AP65 bind heme and hemoglobin.

    PubMed

    Ardalan, Shahed; Lee, B Craig; Garber, Gary E

    2009-04-01

    Trichomonas vaginalis is the cause of human trichomoniasis, the most common non-viral sexually transmitted disease worldwide. Although acquisition of iron by binding to host hemoglobin through distinct receptor(s) has been described, no specific heme- or hemoglobin-binding site has been reported in this parasite. To determine the presence of hemoglobin-binding protein(s), membrane proteins were subjected to hemoglobin-affinity chromatography. Eluted proteins were analysed by SDS-PAGE. Two protein bands of 48 and 63 kDa were detected. Competition assay with an excess amount of hemoglobin or hemin in hemoglobin-affinity chromatography could block the 63- and 48-kDa bands, respectively. Further analysis by mass spectrometry indicated that the 48- and 63-kDa proteins had identity with two T. vaginalis adhesins: AP51 and AP65, respectively. This study confirms the existence of multifunctional proteins in T. vaginalis, and suggested that AP51 and AP65, besides serving as adhesion molecules, could also act as heme- and hemoglobin-binding proteins.

  19. Role of Reversible Histidine Coordination in Hydroxylamine Reduction by Plant Hemoglobins (Phytoglobins).

    PubMed

    Athwal, Navjot Singh; Alagurajan, Jagannathan; Andreotti, Amy H; Hargrove, Mark S

    2016-10-18

    Reduction of hydroxylamine to ammonium by phytoglobin, a plant hexacoordinate hemoglobin, is much faster than that of other hexacoordinate hemoglobins or pentacoordinate hemoglobins such as myoglobin, leghemoglobin, and red blood cell hemoglobin. The reason for differences in reactivity is not known but could be intermolecular electron transfer between protein molecules in support of the required two-electron reduction, hydroxylamine binding, or active site architecture favoring the reaction. Experiments were conducted with phytoglobins from rice, tomato, and soybean along with human neuroglobin and soybean leghemoglobin that reveal hydroxylamine binding as the rate-limiting step. For hexacoordinate hemoglobins, binding is limited by the dissociation rate constant for the distal histidine, while leghemoglobin is limited by an intrinsically low affinity for hydroxylamine. When the distal histidine is removed from rice phytoglobin, a hydroxylamine-bound intermediate is formed and the reaction rate is diminished, indicating that the distal histidine imidazole side chain is critical for the reaction, albeit not for electron transfer but rather for direct interaction with the substrate. Together, these results demonstrate that phytoglobins are superior at hydroxylamine reduction because they have distal histidine coordination affinity constants near 1, and facile rate constants for binding and dissociation of the histidine side chain. Hexacoordinate hemoglobins such as neuroglobin are limited by tighter histidine coordination that blocks hydroxylamine binding, and pentacoordinate hemoglobins have intrinsically lower hydroxylamine affinities.

  20. NO Dioxygenase Activity in Hemoglobins Is Ubiquitous In Vitro, but Limited by Reduction In Vivo

    PubMed Central

    Smagghe, Benoit J.; Trent, James T.; Hargrove, Mark S.

    2008-01-01

    Genomics has produced hundreds of new hemoglobin sequences with examples in nearly every living organism. Structural and biochemical characterizations of many recombinant proteins reveal reactions, like oxygen binding and NO dioxygenation, that appear general to the hemoglobin superfamily regardless of whether they are related to physiological function. Despite considerable attention to “hexacoordinate” hemoglobins, which are found in nearly every plant and animal, no clear physiological role(s) has been assigned to them in any species. One popular and relevant hypothesis for their function is protection against NO. Here we have tested a comprehensive representation of hexacoordinate hemoglobins from plants (rice hemoglobin), animals (neuroglobin and cytoglobin), and bacteria (Synechocystis hemoglobin) for their abilities to scavenge NO compared to myoglobin. Our experiments include in vitro comparisons of NO dioxygenation, ferric NO binding, NO-induced reduction, NO scavenging with an artificial reduction system, and the ability to substitute for a known NO scavenger (flavohemoglobin) in E. coli. We conclude that none of these tests reveal any distinguishing predisposition toward a role in NO scavenging for the hxHbs, but that any hemoglobin could likely serve this role in the presence of a mechanism for heme iron re-reduction. Hence, future research to test the role of Hbs in NO scavenging would benefit more from the identification of cognate reductases than from in vitro analysis of NO and O2 binding. PMID:18446211