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Sample records for hemoglobin a

  1. Hemoglobin

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hemoglobin Share this page: Was this page helpful? Also known as: Hgb; Hb; H and H (Hemoglobin and Hematocrit) Formal name: Hemoglobin Related tests: Complete ...

  2. 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.

  3. 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- ...

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Hemoglobin (image)

    MedlinePlus

    Hemoglobin is the most important component of red blood cells. It is composed of a protein called ... exchanged for carbon dioxide. Abnormalities of an individual's hemoglobin value can indicate defects in the normal balance ...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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 ...

  2. 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.

  3. 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).

  4. 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.

  5. 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.

  6. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... polypeptide chains). (b) Classification. Class II (performance standards)....

  7. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... polypeptide chains). (b) Classification. Class II (performance standards)....

  8. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... polypeptide chains). (b) Classification. Class II (performance standards)....

  9. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... polypeptide chains). (b) Classification. Class II (performance standards)....

  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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... polypeptide chains). (b) Classification. Class II (performance standards)....

  11. 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…

  12. 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.

  13. 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.

  14. 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 ...

  15. 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.

  16. 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.

  17. Blood Test: Hemoglobin A1C

    MedlinePlus

    ... few minutes. previous continue What to Expect Either method (finger or heel sticking or vein withdrawal) of ... that since labs and offices may use different methods to measure HbA1c, the range of normal values ...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Iron bioavailability of maize hemoglobin in a Caco-2 cell culture model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. 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

  9. 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…

  10. 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

  11. A Review on Glycosylated Hemoglobin in Polycystic Ovary Syndrome.

    PubMed

    Rezaee, Mohsen; Asadi, Nasrin; Pouralborz, Yasna; Ghodrat, Mahshid; Habibi, Shaghayegh

    2016-12-01

    Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine disorders among women of reproductive age, with a variety of complications and consequences mostly due to hyperandrogenism and insulin resistance (IR). PCOS patients with IR are at risk for metabolic syndrome and diabetes mellitus (DM) along with its complications such as cardiovascular events. There are several methods for screening IR in patients with PCOS to predict DM and other complications. Fasting plasma glucose test, oral glucose tolerance test, and insulin and glycosylated hemoglobin (HbA1c) levels are some available screening tools for IR. The American Diabetes Association recommended HbA1c to screen for DM because HbA1c is not affected by day-to-day plasma glucose levels and reflects the plasma glucose status during 2-3 months before measurement. Some studies have evaluated the role of HbA1c as a screening method to predict DM in PCOS patients, however, there are still controversies in this matter. Also some studies reported that HbA1c has a correlation with complications of PCOS such as metabolic syndrome and cardiovascular events. We found that HbA1c could be a suitable screening test for IR in PCOS patients but more studies are recommended, omitting confounding factors that could affect IR in patients with PCOS, such as antihyperglycemic agents like metformin, or lifestyle modification, which can be effective in reducing IR in patients with PCOS.

  12. Extracellular hemoglobin: the case of a friend turned foe

    PubMed Central

    Quaye, Isaac K.

    2015-01-01

    Hemoglobin (Hb) is a highly conserved molecule present in all life forms and functionally tied to the complexity of aerobic organisms on earth in utilizing oxygen from the atmosphere and delivering to cells and tissues. This primary function sustains the energy requirements of cells and maintains cellular homeostasis. Decades of intensive research has presented a paradigm shift that shows how the molecule also functions to facilitate smooth oxygen delivery through the cardiovascular system for cellular bioenergetic homeostasis and signaling for cell function and defense. These roles are particularly highlighted in the binding of Hb to gaseous molecules carbon dioxide (CO2), nitric oxide (NO) and carbon monoxide (CO), while also serving indirectly or directly as sources of these signaling molecules. The functional activities impacted by Hb outside of bioenergetics homeostasis, include fertilization, signaling functions, modulation of inflammatory responses for defense and cell viability. These activities are efficiently executed while Hb is sequestered safely within the confines of the red blood cell (rbc). Outside of rbc confines, Hb disaggregates and becomes a danger molecule to cell survival. In these perpectives, Hb function is broadly dichotomous, either a friend in its natural environment providing and facilitating the means for cell function or foe when dislocated from its habitat under stress or pathological condition disrupting cell function. The review presents insights into how this dichotomy in function manifests. PMID:25941490

  13. A transgenic mouse model of hemoglobin S Antilles disease.

    PubMed

    Popp, R A; Popp, D M; Shinpock, S G; Yang, M Y; Mural, J G; Aguinaga, M P; Kopsombut, P; Roa, P D; Turner, E A; Rubin, E M

    1997-06-01

    Hemoglobin (Hb) S Antilles is a naturally occurring form of sickling human Hb but causes a more severe phenotype than Hb S. Two homozygous viable Hb S Antilles transgene insertions from Tg58Ru and Tg98Ru mice were bred into MHOAH mice that express high oxygen affinity (P50 approximately 24.5 mm Hg) rather than normal (P50 approximately 40 mm Hg) mouse Hbs. The rationale was that the high oxygen affinity MHOAH Hb, the lower oxygen affinity of Hb S Antilles than Hb S (P50 approximately 40 v 26.5 mm Hg), and the lower solubility of deoxygenated Hb S Antilles than Hb S (approximately 11 v 18 g/dL) would favor deoxygenation and polymerization of human Hb S Antilles in MHOAH mouse red blood cells (RBCs). The Tg58 x Tg98 mice produced have a high and balanced expression (approximately 50% each) of h alpha and h beta(S Antilles) globins, 25% to 35% of their RBCs are misshapen in vivo, and in vitro deoxygenation of their blood induces 30% to 50% of the RBCs to form classical looking, elongated sickle cells with pointed ends. Tg58 x Tg98 mice exhibit reticulocytosis, an elevated white blood cell count and lung and kidney pathology commonly found in sickle cell patients, which should make these mice useful for experimental studies on possible therapeutic intervention of sickle cell disease.

  14. Ligand and interfacial dynamics in a homodimeric hemoglobin

    PubMed Central

    Gupta, Prashant Kumar; Meuwly, Markus

    2016-01-01

    The structural dynamics of dimeric hemoglobin (HbI) from Scapharca inaequivalvis in different ligand-binding states is studied from atomistic simulations on the μs time scale. The intermediates are between the fully ligand-bound (R) and ligand-free (T) states. Tertiary structural changes, such as rotation of the side chain of Phe97, breaking of the Lys96–heme salt bridge, and the Fe–Fe separation, are characterized and the water dynamics along the R-T transition is analyzed. All these properties for the intermediates are bracketed by those determined experimentally for the fully ligand-bound and ligand-free proteins, respectively. The dynamics of the two monomers is asymmetric on the 100 ns timescale. Several spontaneous rotations of the Phe97 side chain are observed which suggest a typical time scale of 50–100 ns for this process. Ligand migration pathways include regions between the B/G and C/G helices and, if observed, take place in the 100 ns time scale. PMID:26958581

  15. Hemoglobin Brisbane: beta68 Leu replaced by His. A new high oxygen affinity variant.

    PubMed

    Brennan, S O; Wells, R M; Smith, H; Carrell, R W

    1981-01-01

    Hemoglobin Brisbane is a new hemoglobin variant which produces a mile erythrocytosis. It is not detectable by electrophoresis at pH 8.6 or by isoelectric focusing but it is mildly unstable and gives a positive result with standard stability tests. The new hemoglobin has increased oxygen affinity and reduced co-operativity with a normal Bohr effect and 2,3-DPG binding. Structural analysis shows that a histidine residue has replaced the leucine normally found at position beta 68 (E12).

  16. Cloning and characterization of a caesalpinoid (Chamaecrista fasciculata) hemoglobin: the structural transition from a nonsymbiotic hemoglobin to a leghemoglobin.

    PubMed

    Gopalasubramaniam, Sabarinathan K; Kovacs, Frank; Violante-Mota, Fernando; Twigg, Paul; Arredondo-Peter, Raúl; Sarath, Gautam

    2008-07-01

    Nonsymbiotic hemoglobins (nsHbs) and leghemoglobins (Lbs) are plant proteins that can reversibly bind O(2) and other ligands. The nsHbs are hexacoordinate and appear to modulate cellular concentrations of NO and maintain energy levels under hypoxic conditions. The Lbs are pentacoordinate and facilitate the diffusion of O(2) to symbiotic bacteroids within legume root nodules. Multiple lines of evidence suggest that all plant Hbs evolved from a common ancestor and that Lbs originated from nsHbs. However, little is known about the structural intermediates that occurred during the evolution of pentacoordinate Lbs from hexacoordinate nsHbs. We have cloned and characterized a Hb (ppHb) from the root nodules of the ancient caesalpinoid legume Chamaecrista fasciculata. Protein sequence, modeling data, and spectral analysis indicated that the properties of ppHb are intermediate between that of nsHb and Lb, suggesting that ppHb resembles a putative ancestral Lb. Predicted structural changes that appear to have occurred during the nsHb to Lb transition were a compaction of the CD-loop and decreased mobility of the distal His inhibiting its ability to coordinate directly with the heme-Fe, leading to a pentacoordinate protein. Other predicted changes include shortening of the N- and C-termini, compaction of the protein into a globular structure, disappearance of positive charges outside the heme pocket and appearance of negative charges in an area located between the N- and C-termini. A major consequence for some of these changes appears to be the decrease in O(2)-affinity of ancestral nsHb, which resulted in the origin of the symbiotic function of Lbs.

  17. A Theoretical Study of some Rheological Properties of the Aggregation of the Molecules Deoxy- Hemoglobin S

    NASA Astrophysics Data System (ADS)

    Mensah, Francis; Grant, Julius; Thorpe, Arthur

    2010-02-01

    Sickle cell disease is a serious public health problem that affects many people worldwide. In this paper, the Langevin equation is used for hemoglobin's aggregation in sickle cell anemia. Several parameters are explored such as the time-dependent deformation of the aggregates whose plot gives a sigmoid, the time-dependent expressions obtained for the coefficient of viscosity and the elastic modulus which characterize the aggregation of the sickle hemoglobin. Other properties such as the viscoelastic and the elasto-thixotropic properties of the sickle hemoglobin polymer are also described. An attempt is made to approach the polymerization process in terms of a dynamical system. )

  18. 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)

  19. Hemoglobin A1c in predicting progression to diabetes.

    PubMed

    Nakagami, Tomoko; Tajima, Naoko; Oizumi, Toshihide; Karasawa, Shigeru; Wada, Kiriko; Kameda, Wataru; Susa, Shinji; Kato, Takeo; Daimon, Makoto

    2010-01-01

    The predictive value of hemoglobin A1c (HbA1c) in comparison to fasting plasma glucose (FPG) is evaluated for 5-year incident diabetes (DM), as HbA1c may be more practical than FPG in the screening for DM in the future. Of 1189 non-DM subjects aged 35-89 years old from the Funagata Study, 57 subjects (4.8%) had developed DM on the WHO criteria at 5-year follow-up. The odds ratio (95% confidence interval: CI) for a one standard deviation increase in FPG/HbA1c was 3.40 (2.44-4.74)/3.49 (2.42-5.02). The area under the receiver operating characteristic curve for FPG/HbA1c was 0.786 (95% CI: 0.719-0.853)/0.785 (0.714-0.855). The HbA1c corresponding to FPG 5.56 mmol/l was HbA1c 5.3%. There was no statistical difference in sensitivity between FPG 5.56 mmol/l and HbA1c 5.3% (61.4% vs. 56.1%), while specificity was higher in HbA1c 5.3% than FPG 5.56 mmol/l (87.8% vs. 82.5%, p-value<0.001). The fraction of incident case from those with baseline IGT was similar between the groups, however the fraction of people above the cut-off was significantly lower in HbA1c 5.3% than FPG 5.56 mmol/l (14.3% vs. 19.6%, p-value<0.001). HbA1c is similar to FPG to evaluate DM risk, and HbA1c could be practical and efficient to select subjects for intervention.

  20. A novel dynamic heterogeneous phase polymerization reaction for poly-hemoglobin with narrow molecular weight distribution.

    PubMed

    Wang, Xiang; Huang, Lei; Wang, Jin-Feng; Yang, Cheng-Min

    2008-01-01

    A dynamic heterogeneous phase polymerization reaction is found to be efficient for controllable cross-link of hemoglobin with glutaraldehyde. The selective absorption of the immobile phase and asymmetry of protein concentration leads to narrowness of the molecular weight distribution and lowness of the average molecular weight. Using this method, 53% of hemoglobin obtained is intermolecular cross-linked with 12 molecular equivalents of glutaraldehyde. The majority of poly-hemoglobins is in the range of 128 kD to 258 kD.

  1. [A new case of hemoglobin J Capetown alpha 92 (FG 4) Arg replaced by gln].

    PubMed

    Gacon, G; Amegnizin, K E; Belkhodja, O; Denis, P; Krishnamoorthy, R; Labie, D; Lefrancois, R; Michel, Y; Pasquis, P; Wajcman, H

    1977-01-01

    Hemoglobin J Capetown was found incidentally in a patient of french origin suffering from urticaria with delayed pressure oedema. Using a preparative finger-print technique, the structural determination was easy. A functional study of the purified component confirmed the high oxygen affinity of hemoglobin J Capetown and demonstrated a low reactivity for organic phosphates. These results may explain the perturbations observed in the whole blood.

  2. Double-layer estimation of intra- and extracerebral hemoglobin concentration with a time-resolved system

    PubMed Central

    Gagnon, Louis; Gauthier, Claudine; Hoge, Rick D.; Lesage, Frédéric; Selb, Juliette; Boas, David A.

    2009-01-01

    We present in vivo measurements of baseline physiology from five subjects with a four-wavelength (690, 750, 800, and 850 nm) time-resolved optical system. The measurements were taken at four distances: 10, 15, 25, and 30 mm. All distances were fit simultaneously with a two-layered analytical model for the absorption and reduced scattering coefficient of both layers. The thickness of the first layer, comprising the skin, scalp, and cerebrospinal fluid, was obtained from anatomical magnetic resonance images. The fitting procedure was first tested with simulations before being applied to in vivo measurements and verified that this procedure permits accurate characterization of the hemoglobin concentrations in the extra- and intracerebral tissues. Baseline oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentrations and oxygen saturation were recovered from in vivo measurements and compared to the literature. We observed a noticeable intersubject variability of the hemoglobin concentrations, but constant values for the cerebral hemoglobin oxygen saturation. PMID:19021399

  3. Hemoglobin A1c and Self-Monitored Average Glucose

    PubMed Central

    Kovatchev, Boris P.; Breton, Marc D.

    2015-01-01

    Background: Previously we have introduced the eA1c—a new approach to real-time tracking of average glycemia and estimation of HbA1c from infrequent self-monitoring (SMBG) data, which was developed and tested in type 2 diabetes. We now test eA1c in type 1 diabetes and assess its relationship to the hemoglobin glycation index (HGI)—an established predictor of complications and treatment effect. Methods: Reanalysis of previously published 12-month data from 120 patients with type 1 diabetes, age 39.15 (14.35) years, 51/69 males/females, baseline HbA1c = 7.99% (1.48), duration of diabetes 20.28 (12.92) years, number SMBG/day = 4.69 (1.84). Surrogate fasting BG and 7-point daily profiles were derived from these unstructured SMBG data and the previously reported eA1c method was applied without any changes. Following the literature, we calculated HGI = HbA1c – (0.009 × Fasting BG + 6.8). Results: The correlation of eA1c with reference HbA1c was r = .75, and its deviation from reference was MARD = 7.98%; 95% of all eA1c values fell within ±20% from reference. The HGI was well approximated by a linear combination of the eA1c calibration factors: HGI = 0.007552*θ1 + 0.007645*θ2 – 3.154 (P < .0001); 73% of low versus moderate-high HGIs were correctly classified by the same factors as well. Conclusions: The eA1c procedure developed in type 2 diabetes to track in real-time changes in average glycemia and present the results in HbA1c-equivalent units has shown similar performance in type 1 diabetes. The eA1c calibration factors are highly predictive of the HGI, thereby explaining partially the biological variation causing discrepancies between HbA1c and its linear estimates from SMBG data. PMID:26553023

  4. Hypoxic survival requires a 2-on-2 hemoglobin in a process involving nitric oxide.

    PubMed

    Hemschemeier, Anja; Düner, Melis; Casero, David; Merchant, Sabeeha S; Winkler, Martin; Happe, Thomas

    2013-06-25

    Hemoglobins are recognized today as a diverse family of proteins present in all kingdoms of life and performing multiple reactions beyond O2 chemistry. The physiological roles of most hemoglobins remain elusive. Here, we show that a 2-on-2 ("truncated") hemoglobin, termed THB8, is required for hypoxic growth and the expression of anaerobic genes in Chlamydomonas reinhardtii. THB8 is 1 of 12 2-on-2 hemoglobins in this species. It belongs to a subclass within the 2-on-2 hemoglobin class I family whose members feature a remarkable variety of domain arrangements and lengths. Posttranscriptional silencing of the THB8 gene results in the mis-regulation of several genes and a growth defect under hypoxic conditions. The latter is intensified in the presence of an NO scavenger, which also impairs growth of wild-type cells. As recombinant THB8 furthermore reacts with NO, the results of this study indicate that THB8 is part of an NO-dependent signaling pathway.

  5. Hypoxic survival requires a 2-on-2 hemoglobin in a process involving nitric oxide

    PubMed Central

    Hemschemeier, Anja; Düner, Melis; Casero, David; Merchant, Sabeeha S.; Winkler, Martin; Happe, Thomas

    2013-01-01

    Hemoglobins are recognized today as a diverse family of proteins present in all kingdoms of life and performing multiple reactions beyond O2 chemistry. The physiological roles of most hemoglobins remain elusive. Here, we show that a 2-on-2 (“truncated”) hemoglobin, termed THB8, is required for hypoxic growth and the expression of anaerobic genes in Chlamydomonas reinhardtii. THB8 is 1 of 12 2-on-2 hemoglobins in this species. It belongs to a subclass within the 2-on-2 hemoglobin class I family whose members feature a remarkable variety of domain arrangements and lengths. Posttranscriptional silencing of the THB8 gene results in the mis-regulation of several genes and a growth defect under hypoxic conditions. The latter is intensified in the presence of an NO scavenger, which also impairs growth of wild-type cells. As recombinant THB8 furthermore reacts with NO, the results of this study indicate that THB8 is part of an NO-dependent signaling pathway. PMID:23754374

  6. A spectroscopic study on the interaction between gold nanoparticles and hemoglobin

    SciTech Connect

    Garabagiu, Sorina

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer The interaction was studied using UV-vis and fluorescence spectroscopy. Black-Right-Pointing-Pointer Gold nanoparticles quench the fluorescence emission of hemoglobin solution. Black-Right-Pointing-Pointer The binding and thermodynamic constants were calculated. Black-Right-Pointing-Pointer Major impact: electrochemical applications of the complex onto a substrate. -- Abstract: The interaction between horse hemoglobin and gold nanoparticles was studied using optical spectroscopy. UV-vis and fluorescence spectra show that a spontaneous binding process occurred between hemoglobin and gold nanoparticles. The Soret band of hemoglobin in the presence of gold nanoparticles does not show significant changes, which proves that the protein retained its biological function. A shift to longer wavelengths appears in the plasmonic band of gold nanoparticles upon the attachment of hemoglobin molecules. Gold nanoparticles quench the fluorescence emission of tryptophan residues in the structure of hemoglobin. The Stern-Volmer quenching constant, the binding constant and the number of binding sites were also calculated. Thermodynamic parameters indicate that the binding was mainly due to hydrophobic interactions.

  7. Evaluation and interference study of hemoglobin A1c measured by turbidimetric inhibition immunoassay.

    PubMed

    Chang, J; Hoke, C; Ettinger, B; Penerian, G

    1998-03-01

    The technical performance of the turbidimetric immunoinhibition (TI) assay for hemoglobin (Hb) A1c (Tina-quant Hb A1c, Boehringer Mannheim, Indianapolis, Ind) was evaluated by using the BM/Hitachi 911 analyzer. Intra-assay imprecision was less than 2.7%, and interassay imprecision was less than 2.8% as measured by coefficient of variation. In 93 subjects with diabetes who did not have hemoglobin variants, results of the TI assay for Hb A1c correlated strongly with those obtained by using a high-performance liquid chromatography analyzer (Diamat, BioRad Laboratories, Hercules, Calif). Among 241 subjects who had or did not have hemoglobin variants, the TI assay for Hb A1c correlated strongly with results of affinity chromatography for total glycated hemoglobin (Glyc-Affin GHb, IsoLab, Akron, Ohio). We also studied the effect of various percentages of hemoglobin S, C, E, and F on the accuracy of the TI Hb A1c assay. Only high hemoglobin F percentages caused interference. More than 14 times as many samples can be analyzed per hour by using the TI Hb A1c assay than can be analyzed by using the HPLC assay. For high-volume reference laboratories, using the fully automated TI Hb A1c assay to monitor glycemic control in patients with diabetes may be preferable to using the conventional ion-exchange high-performance liquid chromatography Hb A1c assay because the TI assay measures Hb A1c more accurately in patients with diabetes who have hemoglobin variants, and it requires less time.

  8. 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.

  9. Development of hemoglobin A1c certified reference material by liquid chromatography isotope dilution mass spectrometry.

    PubMed

    Bi, Jiaming; Wu, Liqing; Yang, Bin; Yang, Yi; Wang, Jing

    2012-04-01

    We report the development of a National Institute of Metrology (NIM) hemoglobin A(1c) (HbA(1c)) certified reference material (CRM). Each CRM unit contains about 10 μL of hemoglobin. Both hemoglobin and glycated hemoglobin were quantitatively determined by high-performance liquid chromatography (HPLC)-isotope dilution mass spectrometry (IDMS) with synthesized VHLTPE and glycated VHLTPE as standards. The mass fraction of synthesized VHLTPE or glycated VHLTPE was also quantitatively determined by HPLC-IDMS with NIM amino acid CRMs as standards. The homogeneity and stability of the CRMs were examined with a commercial HbA(1c) analyzer based on the HPLC principle. Fifteen units were randomly selected for homogeneity examination, and statistical analysis showed there was no inhomogeneity. Examination of the stability showed that the CRM was stable for at least 6 months at -80 °C. Uncertainty components of the balance, amino acid purity, hydrolysis and proteolysis efficiency, method reproducibility, homogeneity, and stability were taken into consideration for uncertainty evaluation. The certified value of NIM HbA(1c) CRM was expressed as the ratio of HbA(1c) to total hemoglobin in moles, and was (9.6 ± 1.9)%. The CRM can be used as a calibration or validation standard for clinical diagnostics. It is expected to improve the comparability for HbA(1c) measurement in China.

  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. Multichannel spectroreflectometry: a noninvasive method for assessment of on-line hemoglobin derivatives.

    PubMed

    Diaconu, Vasile

    2009-04-01

    The goal of the current study was to introduce a mathematical method to derive hemoglobin, oxyhemoglobin and carboxyl-hemoglobin absorption factors from full spectrum reflectometry measurements of retinal microcapillaries. The mathematical equation that describes the spectral reflectometry function was expressed as a linear combination of several terms of S(i)(lambda) representing the spectral signature functions of hemoglobin, oxyhemoglobin, carboxyl-hemoglobin, ocular media, melanin, and a scattering factor. Contrary to the classical model, where the reflectometry function was expressed as an absorbance Ab(lambda)=log?(incident light(lambda)/reflected light(lambda)), in this model and system, it is proposed to express the reflectometry function from the eye structures as an absorption factor A(lambda)%=incident light(lambda)/reflected light(lambda). To increase confidence in the estimation of hemoglobin derivatives, the mathematical model was applied to only a part of the spectral function of reflectometry, while the results of the model were used to explain the other part of the reflectometry function. The results demonstrate that for the visible spectral field, the model that explains the absorption of the light by the blood contained in the microcapillaries of biological structures is not compatible with the Beer-Lambert law.

  12. Iron bioavailability of maize hemoglobin in a Caco-2 cell culture model.

    PubMed

    Bodnar, Anastasia L; Proulx, Amy K; Scott, M Paul; Beavers, Alyssa; Reddy, Manju B

    2013-07-31

    Maize ( Zea mays ) 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. It was hypothesized that maize hemoglobin is a highly bioavailable iron source and that biofortification of maize with iron can be accomplished by overexpression of maize globin in the endosperm. Maize was transformed with a gene construct encoding a translational fusion of maize globin and green fluorescent protein under transcriptional control of the maize 27 kDa γ-zein promoter. Iron bioavailability of maize hemoglobin produced in Escherichia coli and of stably transformed seeds expressing the maize globin-GFP fusion was determined using an in vitro Caco-2 cell culture model. Maize flour fortified with maize hemoglobin was found to have iron bioavailability that is not significantly different from that of flour fortified with ferrous sulfate or bovine hemoglobin but is significantly higher than unfortified flour. Transformed maize grain expressing maize globin was found to have iron bioavailability similar to that of untransformed seeds. These results suggest that maize globin produced in E. coli may be an effective iron fortificant, but overexpressing maize globin in maize endosperm may require a different strategy to increase bioavailable iron content in maize.

  13. 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 ...

  14. Human hemoglobin structural and functional alterations and heme degradation upon interaction with benzene: A spectroscopic study.

    PubMed

    Hosseinzadeh, Reza; Moosavi-Movahedi, Ali Akbar

    2016-03-15

    Here, the effect of benzene on hemoglobin structure, stability and heme prosthetic group integrity was studied by different methods. These included UV-vis absorption spectrophotometry, normal and synchronous fluorescence techniques, and differential scanning calorimetry (DSC). Our results indicated that benzene has high hemolytic potential even at low concentrations. The UV-vis spectroscopic results demonstrated that benzene altered both the globin chain and the heme prosthetic group of hemoglobin increasing met- and deoxy-Hb, while decreasing oxy-Hb. However, with increasing benzene the concentration of all species decreased due to heme destruction. The spectrophotometric results show that benzene has a high potential for penetrating the hydrophobic pocket of hemoglobin. These results were consistent with the molecular docking simulation results of benzene-hHb. Aggregation and thermal denaturation studies show that the increased benzene concentration induced hemoglobin aggregation with a decrease in stability, which is consistent with the DSC results. Conventional fluorescence spectroscopy revealed that the heme degradation species were produced in the presence of benzene. The results of constant wavelength synchronous fluorescence spectroscopy (CWSFS) indicated that at least five heme-degraded species were produced. Together, our results indicated that benzene has adverse effects on hemoglobin structure and function, and heme degradation.

  15. Human hemoglobin structural and functional alterations and heme degradation upon interaction with benzene: A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, Reza; Moosavi-Movahedi, Ali Akbar

    2016-03-01

    Here, the effect of benzene on hemoglobin structure, stability and heme prosthetic group integrity was studied by different methods. These included UV-vis absorption spectrophotometry, normal and synchronous fluorescence techniques, and differential scanning calorimetry (DSC). Our results indicated that benzene has high hemolytic potential even at low concentrations. The UV-vis spectroscopic results demonstrated that benzene altered both the globin chain and the heme prosthetic group of hemoglobin increasing met- and deoxy-Hb, while decreasing oxy-Hb. However, with increasing benzene the concentration of all species decreased due to heme destruction. The spectrophotometric results show that benzene has a high potential for penetrating the hydrophobic pocket of hemoglobin. These results were consistent with the molecular docking simulation results of benzene-hHb. Aggregation and thermal denaturation studies show that the increased benzene concentration induced hemoglobin aggregation with a decrease in stability, which is consistent with the DSC results. Conventional fluorescence spectroscopy revealed that the heme degradation species were produced in the presence of benzene. The results of constant wavelength synchronous fluorescence spectroscopy (CWSFS) indicated that at least five heme-degraded species were produced. Together, our results indicated that benzene has adverse effects on hemoglobin structure and function, and heme degradation.

  16. Acute Splenic Sequestration Crisis in a 70-Year-Old Patient With Hemoglobin SC Disease

    PubMed Central

    Squiers, John J.; Edwards, Anthony G.; Parra, Alberto; Hofmann, Sandra L.

    2016-01-01

    A 70-year-old African American female with a past medical history significant for chronic bilateral shoulder pain and reported sickle cell trait presented with acute-onset bilateral thoracolumbar pain radiating to her left arm. Two days after admission, Hematology was consulted for severely worsening microcytic anemia and thrombocytopenia. Examination of the patient’s peripheral blood smear from admission revealed no cell sickling, spherocytes, or schistocytes. Some targeting was noted. A Coombs test was negative. The patient was eventually transferred to the medical intensive care unit in respiratory distress. Hemoglobin electrophoresis confirmed a diagnosis of hemoglobin SC disease. A diagnosis of acute splenic sequestration crisis complicated by acute chest syndrome was crystallized, and red blood cell exchange transfusion was performed. Further research is necessary to fully elucidate the pathophysiology behind acute splenic sequestration crisis, and the role of splenectomy to treat hemoglobin SC disease patients should be better defined. PMID:27047980

  17. Hemoglobin digestion in Blood-Feeding Ticks: Mapping a Multi-Peptidase Pathway by Functional Proteomics

    PubMed Central

    Horn, Martin; Nussbaumerová, Martina; Šanda, Miloslav; Kovářová, Zuzana; Srba, Jindřich; Franta, Zdeněk; Sojka, Daniel; Bogyo, Matthew; Caffrey, Conor R.; Kopáček, Petr; Mareš, Michael

    2009-01-01

    SUMMARY Hemoglobin digestion is an essential process for blood-feeding parasites. Using chemical tools, we deconvoluted the intracellular hemoglobinolytic cascade in the tick Ixodes ricinus, a vector of Lyme disease and tick-borne encephalitis. In tick gut tissue, a network of peptidases was demonstrated through imaging with specific activity-based probes and activity profiling with peptidic substrates/inhibitors. This peptidase network is induced upon blood feeding and degrades hemoglobin at acidic pH. Selective inhibitors were applied to dissect the roles of the individual peptidases and determine the peptidase-specific cleavage map of the hemoglobin molecule. The degradation pathway is initiated by endopeptidases of aspartic and cysteine class (cathepsin D supported by cathepsin L and legumain) and continued by cysteine amino- and carboxy-dipeptidases (cathepsins C and B). The identified enzymes are potential targets to developing novel anti-tick vaccines. PMID:19875079

  18. Development and characterization of K562 cell clones expressing BCL11A-XL: Decreased hemoglobin production with fetal hemoglobin inducers and its rescue with mithramycin

    PubMed Central

    Finotti, Alessia; Gasparello, Jessica; Breveglieri, Giulia; Cosenza, Lucia Carmela; Montagner, Giulia; Bresciani, Alberto; Altamura, Sergio; Bianchi, Nicoletta; Martini, Elisa; Gallerani, Eleonora; Borgatti, Monica; Gambari, Roberto

    2015-01-01

    Induction of fetal hemoglobin (HbF) is considered a promising strategy in the treatment of β-thalassemia, in which production of adult hemoglobin (HbA) is impaired by mutations affecting the β-globin gene. Recent results indicate that B-cell lymphoma/leukemia 11A (BCL11A) is a major repressor of γ-globin gene expression. Therefore, disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter provides a novel approach for inducing expression of the γ-globin genes. To develop a cellular screening system for the identification of BCL11A inhibitors, we produced K562 cell clones with integrated copies of a BCL11A-XL expressing vector. We characterized 12 K562 clones expressing different levels of BCL11A-XL and found that a clear inverse relationship does exist between the levels of BCL11A-XL and the extent of hemoglobinization induced by a panel of HbF inducers. Using mithramycin as an inducer, we found that this molecule was the only HbF inducer efficient in rescuing the ability to differentiate along the erythroid program, even in K562 cell clones expressing high levels of BCL11A-XL, suggesting that BCL11A-XL activity is counteracted by mithramycin. PMID:26342260

  19. A novel chimera: the "truncated hemoglobin-antibiotic monooxygenase" from Streptomyces avermitilis.

    PubMed

    Bonamore, Alessandra; Attili, Andrea; Arenghi, Fabio; Catacchio, Bruno; Chiancone, Emilia; Morea, Veronica; Boffi, Alberto

    2007-08-15

    Novel chimeric proteins made of a globin domain fused with a "cofactor free" monooxygenase domain have been identified within the Streptomyces avermitilis and Frankia sp. genomes by means of bioinformatics methods. Structure based sequence alignments show that the globin domains of both proteins can be unambiguously assigned to the truncated hemoglobin family, in view of the striking similarity to the truncated hemoglobins from Mycobacterium tuberculosis, Thermobifida fusca and Bacillus subtilis. In turn, the non-heme domains belong to a family of small (about 100 aminoacids) homodimeric proteins annotated as antibiotic biosynthesis monooxygenases, despite the lack of a cofactor (e.g., a metal, a flavin or a heme) necessary for oxygen activation. The chimeric protein from S. avermitilis has been cloned, expressed and characterized. The protein is a stable dimer in solution based on analytical ultracentrifugation experiments. The heme ligand binding properties with oxygen and carbonmonoxide resemble those of other Group II truncated hemoglobins. In addition, an oxygen dependent redox activity has been demonstrated towards easily oxidizable substrates such as menadiol and p-aminophenol. These findings suggest novel functional roles of truncated hemoglobins, which might represent a vast class of multipurpose oxygen activating/scavenging proteins whose catalytic action is mediated by the interaction with cofactor free monooxygenases.

  20. [Hemoglobins, XXXVII. The primary structure of a monomeric insect hemoglobin (Erythrocruorin), component CTT IIIa of Chironomus thummi thummi. An anomalous Heme complex: E7 Gln, E11 Ile].

    PubMed

    Steer, W; Braunitzer, G

    1981-01-01

    The primary structure of the monomeric hemoglobin CTT IIIa of the midge larva of Chironomus thummi thummi is presented. Cyanogenbromide peptides and tryptic peptides were used for sequence analysis. The primary structure was established with a small number of large peptides. The complete sequencing of the cyanogen bromide peptides was enabled by the C-terminal fixation of arginine. The primary structure of CTT IIIa is compared to the beta-chains of human and to the monomeric component CTT III: CTT IIIa possesses a "tail" of 9 amino acids on the N-terminus, and shows only a small number of identical residues compared to the number that other CTT hemoglobins share with each other. Also the heme complex is unusual: E7 Gln and E11 Ile.

  1. Challenges in HbA1c Analysis and Reporting in Patients with Variant Hemoglobins.

    PubMed

    Sultana, T A; Sheme, Z A; Sultana, G S; Sultana, B; Mishu, F A; Khan, N Z; Sarkar, B C; Muttalib, M A; Khan, S A; Choudhury, S; Mahtab, H

    2016-04-01

    Hemoglobin A1c (HbA(1)c) is a well-established indicator of mean glycemia. The presence of genetic variants of hemoglobin can profoundly affect the accuracy of HbA(1)c measurements. Variants of hemoglobin especially Hemoglobin E (HbE) is prevalent in South East Asia including Bangladesh. The objective of our study is to compare the HbA(1)c values measured on high performance liquid chromatography (HPLC) and Turbidimetric Inhibition Immunoassay (TINIA) in diabetic patients with variant hemoglobins including HbE. A total of 7595 diabetic patients receiving treatment at BIRDEM General Hospital were analyzed for HbA(1)c results within a period of two months from December 2013 to January 2014. Seventy two cases out of 7595 (0.95%) had either undetectable or below normal HbA(1)c levels (males-33 and females-39; ratio = 0.82:1) by HPLC method. In 34(0.45%) cases, HbA(1)c value was undetectable by HPLC method but was in the reportable range by TINIA method. In the other 38 (0.55%) cases, HbA(1)c levels were below the reportable range (<4%) by HPLC method but were in the normal or higher range by TINIA method. TINIA method did not agree with HPLC method on Bland Altman plot in the 38 cases with below normal HbA(1)c levels, [Mean bias -5.2(-9.3 to 1.0), 95% CI] but agreed very well [mean bias -0.21 (-0.84 to 0.42), y=1.1037+0.776X; r(2)=0.30, p<0.01] in controls. In control group mean MCV was 83.80±7.48 and in study group was 73.65±10.44. Alkaline electrophoresis confirmed the variant hemoglobin to be HbE. The fasting blood sugar levels of all the 72 cases correlated strongly with TINIA method (r(2) =0.75, p<0.0001) but not with HPLC (r = 0.24, p=0.13). In our regions where populations have a high prevalence of Hb variant, proper knowledge of hemoglobin variants which affect the measurements HbA(1)c level is essential. MCV of 80fl or below may serve as a rough guide to select samples that require analysis by TINIA method. Moreover, HPLC may be a convenient and inexpensive

  2. A mathematical model relating cortical oxygenated and deoxygenated hemoglobin flows and volumes to neural activity

    NASA Astrophysics Data System (ADS)

    Cornelius, Nathan R.; Nishimura, Nozomi; Suh, Minah; Schwartz, Theodore H.; Doerschuk, Peter C.

    2015-08-01

    Objective. To describe a toolkit of components for mathematical models of the relationship between cortical neural activity and space-resolved and time-resolved flows and volumes of oxygenated and deoxygenated hemoglobin motivated by optical intrinsic signal imaging (OISI). Approach. Both blood flow and blood volume and both oxygenated and deoxygenated hemoglobin and their interconversion are accounted for. Flow and volume are described by including analogies to both resistive and capacitive electrical circuit elements. Oxygenated and deoxygenated hemoglobin and their interconversion are described by generalization of Kirchhoff's laws based on well-mixed compartments. Main results. Mathematical models built from this toolkit are able to reproduce experimental single-stimulus OISI results that are described in papers from other research groups and are able to describe the response to multiple-stimuli experiments as a sublinear superposition of responses to the individual stimuli. Significance. The same assembly of tools from the toolkit but with different parameter values is able to describe effects that are considered distinctive, such as the presence or absence of an initial decrease in oxygenated hemoglobin concentration, indicating that the differences might be due to unique parameter values in a subject rather than different fundamental mechanisms.

  3. Hemoglobin-based oxygen carrier and convection enhanced oxygen transport in a hollow fiber bioreactor.

    PubMed

    Chen, Guo; Palmer, Andre F

    2009-04-15

    A mathematical model was developed to study O(2) transport in a convection enhanced hepatic hollow fiber (HF) bioreactor, with hemoglobin-based O(2) carriers (HBOCs) present in the flowing cell culture media stream of the HF lumen. In this study, four HBOCs were evaluated: PEG-conjugated human hemoglobin (MP4), human hemoglobin (hHb), bovine hemoglobin (BvHb) and polymerized bovine hemoglobin (PolyBvHb). In addition, two types of convective flow in the HF extra capillary space (ECS) were considered in this study. Starling flow naturally occurs when both of the ECS ports are closed. If one of the ECS ports is open, forced convective flow through the ECS will occur due to the imposed pressure difference between the lumen and ECS. This type of flow is referred to as cross-flow in this work, since some of the fluid entering the HF lumen will pass across the HF membrane and exit via the open ECS port. In this work, we can predict the dissolved O(2) concentration profile as well as the O(2) transport flux in an individual HF of the bioreactor by solving the coupled momentum and mass transport equations. Our results show that supplementation of the cell culture media with HBOCs can dramatically enhance O(2) transport to the ECS (containing hepatocytes) and lead to the formation of an in vivo-like O(2) spectrum for the optimal culture of hepatocytes. However, both Starling flow and cross-flow have a very limited effect on O(2) transport in the ECS. Taken together, this work represents a novel predictive tool that can be used to design or analyze HF bioreactors that expose cultured cells to defined overall concentrations and gradients of O(2).

  4. 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

  5. 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.

  6. 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

  7. Therapeutic Depletion of Iron Stores Is Not Associated with a Reduced Hemoglobin Mass in a Hemochromatosis Patient

    PubMed Central

    Wrobel, Nina; Pottgiesser, Torben; Birkner, Philipp; Deibert, Peter; Ahlgrim, Christoph

    2016-01-01

    Introduction Hereditary hemochromatosis features a dysregulated iron absorption leading to iron overload and organ damage. The regulation of total hemoglobin mass during depletion of iron deposits by therapeutic phlebotomy has not been studied. Case Presentation The initial ferritin level of the 52-year-old male subject was 1,276 μg/l. Despite successful depletion of iron stores (ferritinmin: 53 μg/l) through phlebotomies, total hemoglobin mass stabilized at the pretherapy level. However, regeneration of total hemoglobin mass was accelerated (up to 10.8 g/day). Conclusion In this hemochromatosis patient, the total hemoglobin mass was not altered in the long term, but regeneration was accelerated, possibly due to elevated body iron content. PMID:27721733

  8. Hemoglobin Villejuif [beta 123(H1) Thr----Ile]: a new variant found in coincidence with polycythemia vera.

    PubMed

    Wajcman, H; Mrad, A; Blouquit, Y; Parmentier, C; Riou, J; Galacteros, F

    1989-12-01

    A new abnormal hemoglobin, Hb Villejuif [beta 123(H1) Thr----Ile] has been discovered during the exploration of a polycythemia in a 87-year-old patient of French origin. The isoelectric focusing of the lysate revealed the presence of a variant hemoglobin with an isoelectric point very close to that of HbA. The oxygen binding properties of the patient's red blood cells being normal, it was clear that the polycythemia was not a consequence of the presence of this hemoglobin. In fact, the red blood cell morphology and the involvement of the other blood cell lines, demonstrating excessive hemopoiesis, led to the diagnosis of polycythemia vera.

  9. pH effects on the binding of oxygen to non-vertebrate monomeric hemoglobins. A linked function model.

    PubMed

    Saroff, Harry A

    2004-07-07

    Monomeric invertabrate hemoglobins with high oxygen affinity usually contain a tyrosine in the distal region of the heme. This feature has stimulated investigations revealing that one of the properties resulting from the presence of the distal tyrosines is a decreased off rate on the binding of oxygen, thus developing the high affinity. Despite that fact that the pK value of the tyrosine group differs significantly from the groups it replaces little attention has been paid to the pH dependence of the binding of oxygen to the high affinity hemoglobins. Such a pH dependence has been reported on two of the monomeric hemoglobins with relatively low oxygen affinity and one monomeric hemoglobin of intermediate affinity. The pH data of these hemoglobins has been analysed with a linked function model involving the hydrogen ion. pK values required for the low-affinity hemoglobins vary from 4.5 to 7.5. When applied to the high-affinity hemoglobins, the linked function model provides reasonable values for the binding parameters. These pK values vary from 3.0 to 9.0.

  10. Sulfide binding is mediated by zinc ions discovered in the crystal structure of a hydrothermal vent tubeworm hemoglobin.

    PubMed

    Flores, Jason F; Fisher, Charles R; Carney, Susan L; Green, Brian N; Freytag, John K; Schaeffer, Stephen W; Royer, William E

    2005-02-22

    Key to the remarkable ability of vestimentiferan tubeworms to thrive in the harsh conditions of hydrothermal vents are hemoglobins that permit the sequestration and delivery of hydrogen sulfide and oxygen to chemoautotrophic bacteria. Here, we demonstrate that zinc ions, not free cysteine residues, bind sulfide in vestimentiferan hemoglobins. The crystal structure of the C1 hemoglobin from the hydrothermal vent tubeworm Riftia pachyptila has been determined to 3.15 A and revealed the unexpected presence of 12 tightly bound Zn(2+) ions near the threefold axes of this D(3) symmetric hollow sphere. Chelation experiments on R. pachyptila whole-coelomic fluid and purified hemoglobins reveal a role for Zn(2+) ions in sulfide binding. Free cysteine residues, previously proposed as sulfide-binding sites in vestimentiferan hemoglobins, are found buried in surprisingly hydrophobic pockets below the surface of the R. pachyptila C1 molecule, suggesting that access of these residues to environmental sulfide is restricted. Attempts to reduce the sulfide-binding capacities of R. pachyptila hemoglobins by addition of a thiol inhibitor were also unsuccessful. These findings challenge the currently accepted paradigm of annelid hemoglobin evolution and adaptation to reducing environments.

  11. Diabetes mellitus, hemoglobin A1C, and the incidence of total joint arthroplasty infection.

    PubMed

    Iorio, Richard; Williams, Kelly M; Marcantonio, Andrew J; Specht, Lawrence M; Tilzey, John F; Healy, William L

    2012-05-01

    Patients with diabetes have a higher incidence of infection after total joint arthroplasty (TJA) than patients without diabetes. Hemoglobin A1c (HbA1c) levels are a marker for blood glucose control in diabetic patients. A total of 3468 patients underwent 4241 primary or revision total hip arthroplasty or total knee arthroplasty at one institution. Hemoglobin A1c levels were examined to evaluate if there was a correlation between the control of HbA1c and infection after TJA. There were a total of 46 infections (28 deep and 18 superficial [9 cellulitis and 9 operative abscesses]). Twelve (3.43%) occurred in diabetic patients (n = 350; 8.3%) and 34 (0.87%) in nondiabetic patients (n = 3891; 91.7%) (P < .001). There were 9 deep (2.6%) infections in diabetic patients and 19 (0.49%) in nondiabetic patients. In noninfected, diabetic patients, HbA1c level ranged from 4.7% to 15.1% (mean, 6.92%). In infected diabetic patients, HbA1c level ranged from 5.1% to 11.7% (mean, 7.2%) (P < .445). The average HbA1c level in patients with diabetes was 6.93%. Diabetic patients have a significantly higher risk for infection after TJA. Hemoglobin A1c levels are not reliable for predicting the risk of infection after TJA.

  12. Measurement of the refractive index of hemoglobin solutions for a continuous spectral region

    PubMed Central

    Wang, Jin; Deng, Zhichao; Wang, Xiaowan; Ye, Qing; Zhou, Wenyuan; Mei, Jianchun; Zhang, Chunping; Tian, Jianguo

    2015-01-01

    Determination of the refractive index of hemoglobin solutions over a wide wavelength range remains challenging. A famous detour approach is the Kramers-Kronig (KK) analysis which can resolve the real part of complex refractive index from the imaginary part. However, KK analysis is limited by the contradiction between the requirement of semi-infinite frequency range and limited measured range. In this paper, based on the Multi-curve fitting method (MFM), continuous refractive index dispersion (CRID) of oxygenated and deoxygenated hemoglobin solutions are measured using a homemade symmetrical arm-linked apparatus in the continuous wavelength range with spectral resolution of about 0.259nm. A novel method to obtain the CRID is proposed. PMID:26203379

  13. A new mode for heme-heme interactions in hemoglobin associated with distal perturbations.

    PubMed Central

    Levy, A; Sharma, V S; Zhang, L; Rifkind, J M

    1992-01-01

    The distal side of the heme pocket, known to regulate ligand affinity, is shown to be directly involved in subunit interactions. Valency hybrids with oxygen or carbon monoxide bound to the reduced chain are used to model R-state hemoglobin with different distal perturbations. Electron paramagnetic resonance of the oxidized chains shows that the carbon monoxide perturbation is transmitted between subunits to the distal histidine and the oxidized iron center. A comparison of hybrids with only one type of chain oxidized and hybrids with a single alpha beta dimer oxidized is consistent with this perturbation being transmitted across the alpha 1 beta 1 interface. This represents a new mode of subunit interactions in hemoglobin. Images FIGURE 3 FIGURE 4 PMID:1324020

  14. Hemoglobin A1c Testing and Amputation Rates in Black, Hispanic, and White Medicare Patients

    PubMed Central

    Suckow, Bjoern D.; Newhall, Karina A.; Bekelis, Kimon; Faerber, Adrienne E.; Gottlieb, Daniel J.; Skinner, Jonathan S.; Stone, David H.; Goodney, Philip P.

    2016-01-01

    Background Major (above-knee or below-knee) amputation is a complication of diabetes and is seen more common among black and Hispanic patients. While amputation rates have declined for patients with diabetes in the last decade, it remains unknown if these improvements have equitably extended across racial groups and if measures of diabetic care, such as hemoglobin A1c testing, are associated with these improvements. We set out to characterize secular changes in amputation rates among black, Hispanic, and white patients, and to determine associations between hemoglobin A1c testing and amputation risk. Methods We identified 11,942,840 Medicare patients (55% female) with diabetes over the age of 65 years between 2002 and 2012 and followed them for a mean of 6.6 years. Of these, 86% were white, 11.5% were black, and 2.5% were Hispanic. We recorded the occurrence of major amputation and hemoglobin A1c testing during this time period and studied secular changes in amputation rate by race (black, Hispanic, and white). Finally, we examined associations between amputation risk and hemoglobin A1c testing. We measured both the presence of any testing and testing consistency using 3 categories: poor consistency (hemoglobin A1c testing in 0–50% of years), medium consistency (testing in 50–90% of years), and high consistency (testing in >90% of the years in the cohort). Results Between 2002 and 2012, the average major lower-extremity amputation rate in diabetic Medicare patients was 1.78 per 1,000 per year for black patients, 1.15 per 1,000 per year for Hispanic patients, and 0.56 per 1,000 per year for white patients (P < 0.001). Over the study period, the incidence of major amputation in Medicare patients with diabetes declined by 54%, from 1.15 per 1,000 in 2002 to 0.53 per 1,000 in 2012 (rate ratio = 0.53, 95% CI = 0.51–0.54). The reduction in amputation rate was similar across racial groups: 52% for black patients, 61% for Hispanic patients, and 55% for white patients

  15. Upstream promoter mutation associated with a modest elevation of fetal hemoglobin expression in human adults.

    PubMed

    Gilman, J G; Mishima, N; Wen, X J; Kutlar, F; Huisman, T H

    1988-07-01

    In hereditary persistence of fetal hemoglobin, Hb F (alpha 2 gamma 2) is elevated after birth. Screening of sickle cell patients has revealed a family with elevated Hb F and high A gamma values. The propositus was a sickle cell patient with approximately 25% Hb F and 68.4% A gamma. He was heterozygous for the Benin (#19) and Mor beta S haplotypes. Five AS relatives with the Mor haplotype had 2.5% +/- 0.9% fetal hemoglobin and 92.8% +/- 2.8% A gamma, whereas two with the Benin haplotype had normal fetal hemoglobin (0.5%). The Mor haplotype is thus associated with the elevated Hb F in this family. The 13-kilobase (kb) Bg/II fragment containing the G gamma and A gamma genes of the Mor haplotype was cloned, and the G gamma and A gamma promoters sequenced from -383 to beyond the Cap sites. The Mor G gamma gene was normal, but the A gamma gene had a unique C----T mutation at -202. A different mutation at -202 of G gamma (C----G) was previously detected by other researchers in association with considerably higher Hb F in AS cases (15% to 25%). These data suggest either that -202 mutations affect the G gamma and A gamma promoters differently or that different nucleotide substitutions at -202 have divergent effects. Alternatively, additional unknown mutations could cause the differences in gene expression.

  16. Targeted O2 delivery by low-P50 hemoglobin: a new basis for O2 therapeutics.

    PubMed

    Tsai, Amy G; Vandegriff, Kim D; Intaglietta, Marcos; Winslow, Robert M

    2003-10-01

    To assess O2 delivery to tissue by a new surface-modified, polyethylene glycol-conjugated human hemoglobin [MP4; Po2 at 50% saturation of hemoglobin (P50); 5.4 mmHg], we studied microcirculatory hemodynamics and O2 release in golden Syrian hamsters hemodiluted with MP4 or polymerized bovine hemoglobin (PolyBvHb; P50 54.2 mmHg). Comparisons were made with the animals' hemodiluted blood with a non-O2 carrying plasma expander with similar solution properties (Dextran-70). Systemic hemodynamics (arterial blood pressure and heart rate) and acid-base parameters were not correlated with microhemodynamics (arteriolar and venular diameter, red blood cell velocity, and flow). Microscopic measurements of Po2 and the O2 equilibrium curves permitted analysis of O2 release in precapillary and capillary vessels by red blood cells and plasma hemoglobin separately. No significant differences between the groups of animals with respect to arteriolar diameter, flow, or flow velocity were observed, but the functional capillary density was significantly higher in the MP4-treated animals (67%) compared with PolyBvHb-treated animals (37%; P < 0.05) or dextran-treated animals (53%). In the PolyBvHb-treated animals, predominant O2 release (both red blood cells and plasma hemoglobin) occurred in precapillary vessels, whereas in MP4 animals most of the O2 was released from both red blood cells and plasma hemoglobin in capillaries. Base excess correlated directly with capillary O2 release but not systemic O2 content or total O2 release. Higher O2 extraction of both red blood cell and plasma hemoglobin in capillaries represents a new mechanism of action of cell-free hemoglobin. High O2 affinity appears to be an important property for cell-free hemoglobin solutions.

  17. Discovery of the magnetic behavior of hemoglobin: A beginning of bioinorganic chemistry

    PubMed Central

    Bren, Kara L.; Eisenberg, Richard; Gray, Harry B.

    2015-01-01

    Two articles published by Pauling and Coryell in PNAS nearly 80 years ago described in detail the magnetic properties of oxy- and deoxyhemoglobin, as well as those of closely related compounds containing hemes. Their measurements revealed a large difference in magnetism between oxygenated and deoxygenated forms of the protein and, along with consideration of the observed diamagnetism of the carbonmonoxy derivative, led to an electronic structural formulation of oxyhemoglobin. The key role of hemoglobin as the main oxygen carrier in mammalian blood had been established earlier, and its allosteric behavior had been described in the 1920s. The Pauling–Coryell articles on hemoglobin represent truly seminal contributions to the field of bioinorganic chemistry because they are the first to make connections between active site electronic structure and the function of a metalloprotein. PMID:26508205

  18. First report of successful stem cell transplantation in a patient with sickle cell hemoglobin D disease.

    PubMed

    Hamidieh, Amir Ali; Jalili, Mahdi; Khojasteh, Omid; Ghavamzadeh, Ardeshir

    2010-07-01

    Sickle cell hemoglobin D disease is a rare variant of sickle cell disease. Affected patients suffer from episodes of acute exacerbation of clinical course with a wide range of manifestations such as acute chest syndrome, stroke, painful vaso-occlusive crises, acute sequestration crises, joint necrosis, organ failure, infections, and temporary aplastic crises, collectively called sickling crises. Conventional treatments for patients with sickle cell disease include hydroxyurea therapy and prophylactic red blood cell transfusion. However, morbidity and mortality rates remain high with these remedies. In this article, we report hematopoietic stem cell transplantation as an alternative treatment in children with high-risk factors. According to our knowledge and an extensive review of the literature, stem cell transplantation in sickle cell hemoglobin D disease previously has not been reported in any published study and our patient is the first case.

  19. Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing

    PubMed Central

    Xu, Miao-Qing; Wu, Jian-Feng; Zhao, Guang-Chao

    2013-01-01

    A simple two-step method was employed for preparing nano-sized gold nanoparticles-graphene composite to construct a GNPs-GR-SDS modified electrode. Hemoglobin (Hb) was successfully immobilized on the surface of a basal plane graphite (BPG) electrode through a simple dropping technique. Direct electrochemistry and electrocatalysis of the hemoglobin-modified electrode was investigated. The as-prepared composites showed an obvious promotion of the direct electro-transfer between hemoglobin and the electrode. A couple of well-defined and quasi-reversible Hb CV peaks can be observed in a phosphate buffer solution (pH 7.0). The separation of anodic and cathodic peak potentials is 81 mV, indicating a fast electron transfer reaction. The experimental results also clarified that the immobilized Hb retained its biological activity for the catalysis toward NO. The biosensor showed high sensitivity and fast response upon the addition of NO, under the conditions of pH 7.0, potential -0.82 V. The time to reach the stable-state current was less than 3 s, and the linear response range of NO was 0.72-7.92 μM, with a correlation coefficient of 0.9991. PMID:23748173

  20. Synthesis and characterization of magnetite nanoparticles encapsulated in a bovine hemoglobin microgel

    NASA Astrophysics Data System (ADS)

    Mody, Puja J.

    This study shows the successful synthesis and characterization of a novel material that is composed of iron oxide particles within a protein gel. During the synthesis, bovine hemoglobin surrounds the forming Fe 3O4 nanoparticles, resulting in a biocompatible hydrogel, which has the potential to be used as a targeted drug delivery vehicle and as an MRI contrast agent. The structure, size, and thermal stability of these hydrogel complexes were analyzed using a range of techniques. Powder x-ray diffraction and infrared spectroscopy indicated the presence of Fe3O 4 and hemoglobin without significant interactions between particles in the solid state. Microscopy analysis determined the average size of these microgel complexes to be 4-9 mum2 in area (˜2-3 mum in diameter), and DSC analysis indicated that none of the microgels exhibited a denaturing or unfolding transition below 54°C regardless of the iron: hemoglobin ratio. Initial testing has been performed on the ability of these materials to act as magnetically activated drug delivery vehicles. Other pertinent tests (for magnetic properties and MRI applicability) are currently proceeding at external labs.

  1. A Critical Examination of the Reaction of Pyridoxal 5-Phosphate with Human Hemoglobin Ao

    DTIC Science & Technology

    1989-01-01

    Second, extracellular hemoglobin is quickly lost from the vascular system (vascular half-life - 3 h ), which is generally considered due to the...20,000 x g for 1 h . To avoid contamination with stroma, only the upper two-thirds of this solution was removed and passed through a mixed-bed ion...autoburette. Water’- saturated air or nitrogen was then flushed over the surface for periods of up to 4 h at room temperature. Deoxygenation was

  2. Effects of lead and cadmium co-exposure on hemoglobin in a Chinese population.

    PubMed

    Chen, Xiao; Zhou, Hao; Li, Xiaoshuang; Wang, Zhongqiu; Zhu, Guoying; Jin, Taiyi

    2015-03-01

    Cadmium (Cd) and lead (Pb) show adverse effects on hemoglobin. But most studies are focussed on one single agent. In this study, we observed the main and interactive effects of Cd and Pb on the hemoglobin level in a Chinese population. A total of 308 persons (202 women and 106 men), living in controlled and polluted areas, were included in this study. Blood and urine were collected to determine the levels of hemoglobin (Hb), Cd, Pb, and urinary N-acetyl-β-D-glucosaminidase (UNAG). The Cd and Pb level of subjects living in the polluted area were significantly higher compared to those living in the control area (p<0.05). The level of hemoglobin was declined with the increasing BPb (p<0.05) and BCd in women. The Hb of women and men with the highest level of BCd and BPb were decreased by 8.3g/L and 10.7 g/L compared to those with the lowest level of BCd and BPb, respectively. The Hb level of those women and men with the highest level of UNAG decreased by 4.2g/L and 17.2g/L compared with those with low level of UNAG, respectively. Hb was negatively associated with BPb, BCd, and UNAG. This study evidenced that Cd and Pb can influence Hb level. In addition, our study shows that Cd and Pb may have interactive effects on Hb and Hb level was correlated with tubular dysfunction caused by Cd and Pb exposure.

  3. Hemoglobin-derived porphyrins preserved in a Middle Eocene blood-engorged mosquito

    PubMed Central

    Greenwalt, Dale E.; Goreva, Yulia S.; Siljeström, Sandra M.; Rose, Tim; Harbach, Ralph E.

    2013-01-01

    Although hematophagy is found in ∼14,000 species of extant insects, the fossil record of blood-feeding insects is extremely poor and largely confined to specimens identified as hematophagic based on their taxonomic affinities with extant hematophagic insects; direct evidence of hematophagy is limited to four insect fossils in which trypanosomes and the malarial protozoan Plasmodium have been found. Here, we describe a blood-engorged mosquito from the Middle Eocene Kishenehn Formation in Montana. This unique specimen provided the opportunity to ask whether or not hemoglobin, or biomolecules derived from hemoglobin, were preserved in the fossilized blood meal. The abdomen of the fossil mosquito was shown to contain very high levels of iron, and mass spectrometry data provided a convincing identification of porphyrin molecules derived from the oxygen-carrying heme moiety of hemoglobin. These data confirm the existence of taphonomic conditions conducive to the preservation of biomolecules through deep time and support previous reports of the existence of heme-derived porphyrins in terrestrial fossils. PMID:24127577

  4. Hemoglobin Kansas as a Rare Cause of Cyanosis: A Case Report and Review of the Literature

    PubMed Central

    Nagayama, Yoshikuni; Yoshida, Minoru; Kohyama, Tadashi; Matsui, Katsuyuki

    2017-01-01

    Hemoglobin (Hb) Kansas is an inherited Hb variant with a low oxygen affinity that is associated with low oxygen saturation on pulse oximetry (SpO2). It leads to asymptomatic cyanosis. Patients with Hb Kansas do not require any specific treatment and the prognosis is good. In patients with unexplained cyanosis, we should thus consider Hb variants, including Hb Kansas and avoid unnecessary investigations and managements. We herein report the case of 65-year-old woman with Hb Kansas and review five other cases (three lineages) that have been reported in Japan. PMID:28090054

  5. 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.

  6. A Unified Approach to Sickle Hemoglobin Gelation and Phase Separation

    NASA Astrophysics Data System (ADS)

    Ferrone, F. A.; Palma, M. U.; Palma-Vittorelli, M. B.

    2006-03-01

    Protein aggregation has been identified as a major component in a number of diseases of which the earliest known and most thoroughly studied is sickle cell disease. Because of its direct bearing on pathophysiology, HbS polymer formation has been extensively described. The principal challenge now lies in the need of reconciling well documented but apparently contrasting properties of HbS solutions. These are the purely hard-sphere behavior of HbS under non-gelling conditions (extending to the 7th order in virial coefficients), and the equally well documented existence of a region of liquid-liquid demixing of the solution, from which notable deviations from hard-sphere behavior would be expected. We present a strategy to circumvent this impasse by including explicit and well known activity coefficients in a Flory-Huggins like term in the monomer chemical potential. This preserves the successful thermodynamic treatment of polymer formation while introducing a term leading to a spinodal. The formulation is consistent with known data, and implications for kinetics will be described.

  7. [Abnormal hemoglobins in a Negroid population in Peru].

    PubMed

    Ruiz Franco, O E; Villacorta Wettstein, M E; Zaga Catacora, R E; Márquez Torres, M C

    1990-08-01

    A study was performed on 100 blood samples from black people native of the Chincha province and living in Pueblo Nuevo Ica district, in Peru. No haematological abnormalities were seen in any of the cases. Upon haemoglobin electrophoresis, 8 carriers of abnormal haemoglobin were found, the A/S pattern appearing in 5 instances and the A/C pattern in 3. These 8 samples were subjected to deoxyhaemoglobin solubility tests and to differential solubility test with urea, the initial results being confirmed. These data correlate, in general terms with previous findings.

  8. Catechol-O-methyltransferase association with hemoglobin A1c

    PubMed Central

    Hall, Kathryn T.; Jablonski, Kathleen A.; Chen, Ling; Harden, Maegan; Tolkin, Benjamin R.; Kaptchuk, Ted J.; Bray, George A.; Ridker, Paul M.; Florez, Jose C.; Chasman, Daniel I.

    2016-01-01

    Aims Catecholamines have metabolic effects on blood pressure, insulin sensitivity and blood glucose. Genetic variation in catechol-O-methyltransferase (COMT), an enzyme that degrades catecholamines, is associated with cardiometabolic risk factors and incident cardiovascular disease (CVD). Here we examined COMT effects on glycemic function and type 2 diabetes. Methods We tested whether COMT polymorphisms were associated with baseline HbA1c in the Women’s Genome Health Study (WGHS), and Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC), and with susceptibility to type 2 diabetes in WGHS, DIAbetes Genetics Replication And Meta-analysis consortium (DIAGRAM), and the Diabetes Prevention Program (DPP). Given evidence that COMT modifies some drug responses, we examined association with type 2 diabetes and randomized metformin and aspirin treatment. Results COMT rs4680 high-activity G-allele was associated with lower HbA1c in WGHS (β = −0.032% [0.012], p = 0.008) and borderline significant in MAGIC (β = −0.006% [0.003], p = 0.07). Combined COMT per val allele effects on type 2 diabetes were significant (OR = 0.98 [0.96–0.998], p = 0.03) in fixed-effects analyses across WGHS, DIAGRAM, and DPP. Similar results were obtained for 2 other COMT SNPs rs4818 and rs4633. In the DPP, the rs4680 val allele was borderline associated with lower diabetes incidence among participants randomized to metformin (HR = 0.81 [0.65–1.00], p = 0.05). Conclusions COMT rs4680 high-activity G-allele was associated with lower HbA1c and modest protection from type 2 diabetes. The directionality of COMT associations was concordant with those previously observed for cardiometabolic risk factors and CVD. PMID:27282867

  9. A simple method to overcome the interference of hemoglobin in the detection of reporter genes in vivo.

    PubMed

    Reynier, Philippe; Lesage, Denis; Cao, An; Briane, Dominique; Coudert, Robert; Taillandier, Eliane

    2002-02-15

    The determination of chemiluminescent intensity of reporter gene expression in vivo is generally disturbed by the presence of hemoglobin. Current methods consist in using perfusion to eliminate blood from investigated tumors or organs. In this work we propose a simple method to overcome this difficulty. The method consists in establishing an absorbance-dependence plot of the ratio R% = phi/phi(0) between the chemiluminescent intensities measured when hemoglobin is present or absent. For every measurement of the luminescent intensity phi on sample containing blood, if the absorbance A of the hemoglobin is determined, it allows one to have the intensity ratio R% which in turn gives the corrected intensity phi(0) when the absorption by hemoglobin is eliminated. The method is particularly adapted for comparative measurements of transfection levels in tumors where perfusion cannot be easily performed.

  10. Free Energy of Sickle Hemoglobin Polymerization: A Scaled-Particle Treatment for Use with Dextran as a Crowding Agent

    PubMed Central

    Liu, Zenghui; Weng, Weijun; Bookchin, Robert M.; Lew, Virgilio L.; Ferrone, Frank A.

    2008-01-01

    Fundamental to the analysis of protein polymerization is the free energy of association, typically determined from solubility. It has been previously shown that concentrated 70 kDa dextran lowers the solubility of sickle hemoglobin, due to molecular crowding, and provides a useful ranking tool for the effects of inhibitors and molecular modifications. Because hemoglobin occupies a substantial volume as well, crowding effects of both hemoglobin and dextran contribute to the nonideality of the solution. We show how scaled-particle theory can be used to account for both types of crowding, thus allowing the determination of solubility in the absence of dextran, given data measured in its presence. The approach adopted approximates dextran as a sphere with a volume that decreases as the concentration of dextran increases. We use an asymptotic relation to describe the volume, which decreases nearly linearly by a factor of two over the range studied, from 60 to 230 mg/ml. This compression is similar to previously observed compression of sephadex beads and ficoll solutions. In the limit of low hemoglobin concentrations, the theory reduces to the previously-used approach of Ogston. Our method therefore provides a means of measuring the free energy of association of molecules that occupy significant volume fractions, even when assisted by the crowding of dextran and we present a tabulation of all known free energies of polymerization of sickle hemoglobin measured in the presence of dextran. PMID:18212015

  11. Testosterone Induces Erythrocytosis via Increased Erythropoietin and Suppressed Hepcidin: Evidence for a New Erythropoietin/Hemoglobin Set Point

    PubMed Central

    Travison, Thomas G.; Basaria, Shehzad; Davda, Maithili N.; Guo, Wen; Li, Michelle; Connor Westfall, John; Bae, Harold; Gordeuk, Victor; Bhasin, Shalender

    2014-01-01

    Background. The mechanisms by which testosterone increases hemoglobin and hematocrit remain unclear. Methods. We assessed the hormonal and hematologic responses to testosterone administration in a clinical trial in which older men with mobility limitation were randomized to either placebo or testosterone gel daily for 6 months. Results. The 7%–10% increase in hemoglobin and hematocrit, respectively, with testosterone administration was associated with significantly increased erythropoietin (EPO) levels and decreased ferritin and hepcidin levels at 1 and 3 months. At 6 months, EPO and hepcidin levels returned toward baseline in spite of continued testosterone administration, but EPO levels remained nonsuppressed even though elevated hemoglobin and hematocrit higher than at baseline, suggesting a new set point. Consistent with increased iron utilization, soluble transferrin receptor (sTR) levels and ratio of sTR/log ferritin increased significantly in testosterone-treated men. Hormonal and hematologic responses were similar in anemic participants. The majority of testosterone-treated anemic participants increased their hemoglobin into normal range. Conclusions. Testosterone-induced increase in hemoglobin and hematocrit is associated with stimulation of EPO and reduced ferritin and hepcidin concentrations. We propose that testosterone stimulates erythropoiesis by stimulating EPO and recalibrating the set point of EPO in relation to hemoglobin and by increasing iron utilization for erythropoiesis. PMID:24158761

  12. Purification and characterization of a hemoglobin degrading aspartic protease from the malarial parasite Plasmodium vivax.

    PubMed

    Sharma, Arun; Eapen, Alex; Subbarao, Sarala K

    2005-07-01

    Aspartic proteases of human malarial parasites are thought to play key roles in essential pathways of merozoite release, invasion and host cell hemoglobin degradation during the intraerythrocytic stages of their life cycle. Therefore, we have purified and characterized Plasmodium vivax aspartic protease, to determine if this enzyme can be used as potential drug target/immunogen, and its inhibitors as potential antimalarial drug. The P. vivax aspartic protease has been purified by a combination of ion exchange and size exclusion chromatographies and HPLC. Its properties were examined in order to define a role in the hemoglobin degradation process. The purified enzyme migrated as a single band on native PAGE and SDS/PAGE with a molecular mass of 40 kDa. Gelatin zymogram analyses revealed a clear zone of proteolytic activity corresponding to the band obtained on native PAGE and SDS/PAGE. The enzyme has an optimal pH of 4.0 and exhibits its highest activity at 37 degrees C. The enzyme is inhibited by pepstatin, but not by other inhibitors including o-phenanthroline, EDTA, PMSF or E-64, supporting its designation as an aspartic protease; its IC50 value was found to be 3.0 microM. A Lineweaver Burk double reciprocal plot with pepstatin shows that the inhibition is competitive with respect to the substrate. Ca2+ and Mg2+ ions enhance the protease activity, whereas Cu2+ and Hg2+ ions were found to be inhibitory. The pivotal role of aspartic protease in initiating hemoglobin degradation in P. vivax malaria parasite is also demonstrated.

  13. A biochemical--biophysical study of hemoglobins from woolly mammoth, Asian elephant, and humans.

    PubMed

    Yuan, Yue; Shen, Tong-Jian; Gupta, Priyamvada; Ho, Nancy T; Simplaceanu, Virgil; Tam, Tsuey Chyi S; Hofreiter, Michael; Cooper, Alan; Campbell, Kevin L; Ho, Chien

    2011-08-30

    This study is aimed at investigating the molecular basis of environmental adaptation of woolly mammoth hemoglobin (Hb) to the harsh thermal conditions of the Pleistocene ice ages. To this end, we have carried out a comparative biochemical-biophysical characterization of the structural and functional properties of recombinant hemoglobins (rHb) from woolly mammoth (rHb WM) and Asian elephant (rHb AE) in relation to human hemoglobins Hb A and Hb A(2) (a minor component of human blood). We have obtained oxygen equilibrium curves and calculated O(2) affinities, Bohr effects, and the apparent heat of oxygenation (ΔH) in the presence and absence of allosteric effectors [inorganic phosphate and inositol hexaphosphate (IHP)]. Here, we show that the four Hbs exhibit distinct structural properties and respond differently to allosteric effectors. In addition, the apparent heat of oxygenation (ΔH) for rHb WM is less negative than that of rHb AE, especially in phosphate buffer and the presence of IHP, suggesting that the oxygen affinity of mammoth blood was also less sensitive to temperature change. Finally, (1)H NMR spectroscopy data indicates that both α(1)(β/δ)(1) and α(1)(β/δ)(2) interfaces in rHb WM and rHb AE are perturbed, whereas only the α(1)δ(1) interface in Hb A(2) is perturbed compared to that in Hb A. The distinct structural and functional features of rHb WM presumably facilitated woolly mammoth survival in the Arctic environment.

  14. Bacillus cereus bacteremia and hemolytic anemia in a patient with hemoglobin SC disease.

    PubMed

    Rodgers, G M; Barrera, E; Martin, R R

    1980-08-01

    A patient with hemoglobin SC disease and cholelithiasis was found to have Bacillus cereus bacteremia. Hemolytic anemia developed, for which common causes of hemolysis were excluded, suggesting a relationship with the bacteremia. Following in vitro incubation, type O erythrocytes were hemolyzed by the culture, but not by a bacteria-free filtrate. This case confirms the association between sickle cell disorders and cholelithiasis with B cereus infections. In addition, it provides evidence for in vivo hemolysis with B cereus bacteremia, an organism not previously associated with hemolytic anemia.

  15. Hemoglobin level as a risk factor for lower respiratory tract infections in Lebanese children

    PubMed Central

    Mourad, Sawsan; Rajab, Mariam; Alameddine, Aouni; Fares, Mohammad; Ziade, Fouad; Merhi, Bassem Abou

    2010-01-01

    Background: Pneumonia is the biggest single cause of childhood death under the age of 5 years, and anemia affects approximately 30% of infants and children all over the world. Aim: Determination of the relationship between anemia and lower respiratory tract infection as a risk factor in Lebanese children. Patients and Methods: A total number of two hundred infants and children aged nine months to twelve years were included; One hundred cases were hospitalized for lower respiratory tract infection in Department of Pediatrics, Makassed General Hospital, and one hundred healthy, age and sex matched controls, were selected from outpatient department. Complete blood count, iron level, ferritin level, and total iron binding capacity were taken if hemoglobin level less than eleven gram per deci-liter. In addition peripheral blood smear, chest radiograph and C-reactive protein were done to hospitalized cases. Definition of iron deficiency anemia and normal laboratory values were predetermined. Results: Anemia was found in 32% of hospitalized cases and 16% of healthy controls. Mean hemoglobin level was 9.99 ± 0.62 gram per deci-liter and 11.99 ± 0.92 gram per deci-liter in anemic and non-anemic group respectively with a significant P-value of 0.001. C-reactive protein levels and number hospitalization days were similar among the anemic and non-anemic group. History of recurrent chest infections was significantly higher in both anemic group and hospitalized cases compared to non-anemic group and healthy controls. Low hemoglobin level was a risk factor for lower respiratory tract infection with a P-value of 0.008. Conclusion: Anemic children were two times more susceptible to lower respiratory tract infection compared to the control group, and iron deficiency anemia was predominating. Accurate diagnosis and prevention of anemia, whatever its etiology, is essential. PMID:22558548

  16. Hemopressin: a novel bioactive peptide derived from the alpha1-chain of hemoglobin.

    PubMed

    Dale, Camila Squarzoni; Pagano, Rosana de Lima; Rioli, Vanessa

    2005-03-01

    Hemopressin (PVNFKFLSH), a novel bioactive peptide derived from the alpha1-chain of hemoglobin, was originally isolated from rat brain homogenates. Hemopressin causes hypotension in anesthetized rats and is metabolized in vivo and in vitro by endopeptidase 24.15 (EP24.15), neurolysin (EP24.16), and angiotensin-converting enzyme (ACE). Hemopressin also exerts an antinociceptive action in experimental inflammatory hyperalgesia induced by carrageenin or bradykinin via a mechanism that is independent of opioids. These findings suggest that this peptide may have important regulatory physiological actions in vivo.

  17. Studies of the interaction between FNC and human hemoglobin: a spectroscopic analysis and molecular docking.

    PubMed

    Li, Huiyi; Dou, Huanjing; Zhang, Yuhai; Li, Zhigang; Wang, Ruiyong; Chang, Junbiao

    2015-02-05

    FNC (2'-deoxy-2'-bfluoro-4'-azidocytidine) is a novel nucleoside analogue with pharmacologic effects on several human diseases. In this work, the binding of FNC to human hemoglobin (HHb) have been investigated by absorption spectroscopy, fluorescence quenching technique, synchronous fluorescence, three-dimensional fluorescence and molecular modeling methods. Analysis of fluorescence data showed that the binding of FNC to HHb occurred via a static quenching mechanism. Thermodynamic analysis and molecular modeling suggest that hydrogen bond and van der Waals force are the mainly binding force in the binding of FNC to HHb.

  18. Rice (Oryza) hemoglobins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. [Rapid hemoglobin A1c determination (a new possibility in diabetes care)].

    PubMed

    Jermendy, G; Nádas, J; Farkas, K

    1999-05-30

    To assess the long-term metabolic control, immunochemical method was used for hemoglobin A1c (HbA1c) determinations in diabetic patients. The use of DCA 2000 device (Bayer) resulted in immediate (< 6 min) HbA1c values. The reproducibility of this method was acceptable (within-run coefficients of variations were 3.48% and 4.80%). A close, linear correlation (r = 0.974; p < 0.001; n = 106) between HbA1c-values measured simultaneously by DCA 2000 and DIAMAT (Bio-Rad, method: high pressure liquid chromatography) was observed in diabetic patients. The new immunochemical method proved to be simple and reliable. The immediate (within 6 min) result makes the therapeutic decision easier during the care of diabetic patients.

  20. Hemoglobin P50 During a Simulated Ascent of Mt. Everest, Operation Everest II

    DTIC Science & Technology

    2007-01-01

    Everest summit (West, 1983). Blood gas measurements were made at rest and HIGH ALTITUDE MEDICINE & BIOLOGY Volume 8, Number 1, 2007 © Mary Ann ... Liebert , Inc . DOI: 10.1089/ham.2006.1049 Hemoglobin P50 During a Simulated Ascent of Mt. Everest, Operation Everest II PETER D. WAGNER,1 HARRIETH E. WAGNER...Everest II). Arterial and venous blood was sampled at five “altitudes” ( PB 760, 429, 347, 282, 253 mmHg), and PO2, PCO2, pH, O2 saturation, [Hb] and

  1. Cloning and Characterization of a Caesalpinoid (Chamaecrista fasciculate) Hemoglobin: The Structural Transition from a Non-Symbiotic Hemoglobin to a Leghemoglobin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-symbiotic hemoglobins (nsHbs) and leghemoglobins (Lbs) are plant proteins that can reversibly bind O2 and other ligands. The nsHbs are hexacoordinate and appear to modulate cellular concentrations of NO and maintain energy levels under hypoxic conditions. The Lbs are pentacoordinate and facilita...

  2. 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

  3. Dehaloperoxidase-Hemoglobin from Amphitrite ornata Is Primarily a Monomer in Solution

    SciTech Connect

    M Thompson; S Franzen; M Davis; R Oliver; j Krueger; J Tredup; C Chang; J Khan; E Baldwin

    2011-12-31

    The crystal structures of the dehaloperoxidase-hemoglobin from A. ornata (DHP A) each report a crystallographic dimer in the unit cell. Yet, the largest dimer interface observed is 450 {angstrom}{sup 2}, an area significantly smaller than the typical value of 1200-2000 {angstrom}{sup 2} and in contrast to the extensive interface region of other known dimeric hemoglobins. To examine the oligomerization state of DHP A in solution, we used gel permeation by fast protein liquid chromatography and small-angle X-ray scattering (SAXS). Gel permeation experiments demonstrate that DHP A elutes as a monomer (15.5 kDa) and can be separated from green fluorescent protein, which has a molar mass of 27 kDa, near the 31 kDa expected for the DHP A dimer. By SAXS, we found that DHP A is primarily monomeric in solution, but with a detectable level of dimer (10%), under all conditions studied up to a protein concentration of 3.0 mM. These concentrations are likely 10-100-fold lower than the K{sub d} for dimer formation. Additionally, there was no significant effect either on the overall conformation of DHP A or its monomer-dimer equilibrium upon addition of the DHP A inhibitor, 4-iodophenol.

  4. An Order-Disorder Transition Plays a Role in Switching Off the Root Effect in Fish Hemoglobins*

    PubMed Central

    Vergara, Alessandro; Vitagliano, Luigi; Merlino, Antonello; Sica, Filomena; Marino, Katia; Verde, Cinzia; di Prisco, Guido; Mazzarella, Lelio

    2010-01-01

    The Root effect is a widespread property among fish hemoglobins whose structural basis remains largely obscure. Here we report a crystallographic and spectroscopic characterization of the non-Root-effect hemoglobin isolated from the Antarctic fish Trematomus newnesi in the deoxygenated form. The crystal structure unveils that the T state of this hemoglobin is stabilized by a strong H-bond between the side chains of Asp95α and Asp101β at the α1β2 and α2β1 interfaces. This unexpected finding undermines the accepted paradigm that correlates the presence of this unusual H-bond with the occurrence of the Root effect. Surprisingly, the T state is characterized by an atypical flexibility of two α chains within the tetramer. Indeed, regions such as the CDα corner and the EFα pocket, which are normally well ordered in the T state of tetrameric hemoglobins, display high B-factors and non-continuous electron densities. This flexibility also leads to unusual distances between the heme iron and the proximal and distal His residues. These observations are in line with Raman micro-spectroscopy studies carried out both in solution and in the crystal state. The findings here presented suggest that in fish hemoglobins the Root effect may be switched off through a significant destabilization of the T state regardless of the presence of the inter-aspartic H-bond. Similar mechanisms may also operate for other non-Root effect hemoglobins. The implications of the flexibility of the CDα corner for the mechanism of the T-R transition in tetrameric hemoglobins are also discussed. PMID:20610398

  5. Luminol chemiluminescence biosensor for glycated hemoglobin (HbA1c) in human blood samples.

    PubMed

    Ahn, Kwang-Soo; Lee, JungHoon; Park, Jong-Myeon; Choi, Han Nim; Lee, Won-Yong

    2016-01-15

    Luminol chemiluminescence (CL) biosensor based on boronic acid modified gold substrate has been developed for the determination of glycated hemoglobin (HbA1c) in human blood samples. In order to selectively capture HbA1c in sample, carboxy-EG6-undecanethiol was self-assembled on a gold thin-film substrate, followed by covalent coupling of 3-aminophenyl boronic acid (3-APBA). The captured HbA1c containing four iron heme groups plays as a catalyst for luminol CL reaction in the presence of hydrogen peroxide, and thus the luminol CL response is linearly proportional to the amount of HbA1c captured on the biosensor surface. The present biosensor showed linear dynamic range of HbA1c from 2.5% to 17.0%, which well covers the clinically important concentration range. In addition, the present biosensor exhibited negligible response to interfering species such as hemoglobin, fructose, and sorbitol. The present HbA1c biosensor was applied to the determination of HbA1c in human blood samples and the results were well agreed with that obtained with a conventional method.

  6. Secreted proteases from Actinobacillus pleuropneumoniae serotype 1 degrade porcine gelatin, hemoglobin and immunoglobulin A.

    PubMed Central

    Negrete-Abascal, E; Tenorio, V R; Serrano, J J; Garcia, C; de la Garza, M

    1994-01-01

    It was found that 48 hour cultures of Actinobacillus pleuropneumoniae secreted proteases into the medium. Electrophoresis in polyacrylamide gels (10%) copolymerized with porcine gelatin (0.1%), of the 70% (NH4)2SO4 precipitate from the culture supernatants, displayed protease activities of different molecular weights: > 200, 200, 90, 80, 70 and 50 kDa. They had activity over a broad range of pHs (4-8), with an optimal pH of 6-7. All were inhibited by 10 mM EDTA, and reactivated by 10 mM calcium. They were stable at -20 degrees C for more than a month. The proteases also degraded porcine IgA and porcine, human, and bovine hemoglobin, although they appeared to be less active against the hemoglobins. The IgA was totally cleaved in 48 h, using supernatants concentrated with polyvinyl pyrrolidone or the 70% (NH4)2SO4. Extracellular proteases could play a role in virulence. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:8004545

  7. Paenungulata: a comparison of the hemoglobin sequences from elephant, hyrax, and manatee.

    PubMed

    Kleinschmidt, T; Czelusniak, J; Goodman, M; Braunitzer, G

    1986-09-01

    Inspection of the amino acid differences among hemoglobin sequences of a wide range of mammalian species suggested that at alpha 19, alpha 110, alpha 111, beta 23, beta 44, and beta 56, synapomorphies group manatee (Trichechus inungius, Sirenia), Indian and African elephant (Elephas maximus and Loxodonta africana, Proboscidea), and rock hyrax (Procavia habessinica, Hyracoidea) into a monophyletic clade. Results obtained by parsimony analysis provide evidence for this grouping--and thus support for the genealogical validity of Simpson's superorder Paenungulata, which contains as the extant orders Proboscidea, Sirenia, and Hyracoidea. All of the 39 most, or nearly most, parsimonious of 10,395 trees constructed from a tandemly combined alpha- and beta-hemoglobin sequence for 103 vertebrate species (of which 79 were mammals from 16 extant orders), depicted Paenungulata as one of the most anciently separated branches of Eutheria. It was found on examining thousands of alternative trees that to not group Proboscidea, Hyracoidea, and Sirenia in a monophyletic clade required at least four additional substitutions.

  8. 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

  9. Safety Evaluation of Hemoglobin-Albumin Cluster "HemoAct" as a Red Blood Cell Substitute.

    PubMed

    Haruki, Risa; Kimura, Takuya; Iwasaki, Hitomi; Yamada, Kana; Kamiyama, Ikuo; Kohno, Mitsutomo; Taguchi, Kazuaki; Nagao, Saori; Maruyama, Toru; Otagiri, Masaki; Komatsu, Teruyuki

    2015-07-29

    A hemoglobin (Hb) wrapped covalently by human serum albumins (HSAs), a core-shell structured hemoglobin-albumin cluster designated as "HemoAct", is an O2-carrier designed for use as a red blood cell (RBC) substitute. This report describes the blood compatibility, hemodynamic response, and pharmacokinetic properties of HemoAct, and then explains its preclinical safety. Viscosity and blood cell counting measurements revealed that HemoAct has good compatibility with whole blood. Intravenous administration of HemoAct into anesthetized rats elicited no unfavorable increase in systemic blood pressure by vasoconstriction. The half-life of (125)I-labeled HemoAct in circulating blood is markedly longer than that of HSA. Serum biochemical tests conducted 7 days after HemoAct infusion yielded equivalent values to those observed in the control group with HSA. Histopathologic inspections of the vital organs revealed no marked abnormality in their tissues. All results indicate that HemoAct has sufficient preclinical safety as an alternative material for RBC transfusion.

  10. A probe to study the toxic interaction of tartrazine with bovine hemoglobin at the molecular level.

    PubMed

    Li, Yating; Wei, Haoran; Liu, Rutao

    2014-03-01

    Tartrazine is an artificial azo dye commonly used in food products, but tartrazine in the environment is potentially harmful. The toxic interaction between tartrazine and bovine hemoglobin (BHb) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption, circular dichroism (CD) and molecular modeling techniques under simulated physiological conditions. The fluorescence data showed that tartrazine can bind with BHb to form a complex. The binding process was a spontaneous molecular interaction, in which van der Waals' forces and hydrogen bonds played major roles. Molecular docking results showed that the hydrogen bonds exist between the oxygen atoms at position 31 of tartrazine and the nitrogen atom NZ7 on Lys99, and also between the oxygen atoms at position 15 of tartrazine and the nitrogen atom NZ7 on Lys104, Lys105. The results of UV-vis and CD spectra revealed that tartrazine led to conformational changes in BHb, including loosening of the skeleton structure and decreasing α helix in the secondary structure. The synchronous fluorescence experiment revealed that tartrazine binds into the hemoglobin central cavity, and this was verified using a molecular modeling study.

  11. Hemoglobin E Hemoglobinopathy in an Adult from Assam with Unusual Presentation: A Diagnostic Dilemma

    PubMed Central

    Kiran, Sunitha S; Aithal, Saraswathy; Belagavi, Charalingappa S

    2016-01-01

    Hemoglobin E (HbE) is estimated to affect at least one million people around the world. Carrier frequency of hemoglobin E/β-thalassemia (HbE/β-thalassemia) is highest in Southeast Asia, reaching as high as 60% in parts of Thailand, Laos, and Cambodia. In the Indian subcontinent, highest frequency is observed in The Northeast regions, but relatively rare in rest of the country. Increasing migration of population from highly affected areas is resulting in rising prevalence in The South and other parts of India. HbE/β-thalassemia is characterized by marked clinical diversity, phenotypic instability, and age-related changes in adaptation to anemia. This paper reports a case of HbE disease in an adult immigrant from Assam and documents the difficulties encountered in the definitive subtyping of HbE hemoglobinopathy. Distinguishing between homozygous HbE disease and HbE/β-thalassemia is a challenge to hematopathologist as both are clinically and hematologically similar. PMID:27365922

  12. Comparative analysis of cellulose acetate hemoglobin electrophoresis and high performance liquid chromatography for quantitative determination of hemoglobin A2

    PubMed Central

    Khosa, Shafi Mohammad; Moinuddin, Moinuddin; Mehmood, Hassan Osman; Qamar, Khansa

    2015-01-01

    Background The present study is designed to evaluate the reliability and cost effectiveness of cellulose acetate Hb electrophoresis and high performance liquid chromatography (HPLC) in the determination of HbA2 levels. Methods The test population comprised 160 individuals divided into four groups: normal individuals, β-thalassemia trait (BTT) patients, iron deficiency anemia (IDA) patients, and co-morbid patients (BTT with IDA). HbA2 levels determined using cellulose acetate Hb electrophoresis and HPLC were compared. Results HbA2 levels were found to be diagnostic for classical BTT using either method. In co-morbid cases, both techniques failed to diagnose all cases of BTT. The sensitivity, specificity, and Youden's index for detection of the co-morbid condition was 69% and 66% for HPLC and cellulose acetate Hb electrophoresis, respectively. Conclusion This study revealed that semi-automated cellulose acetate Hb electrophoresis is more suitable for use in β-thalassemia prevention programs in low-income countries like Pakistan. This technique is easily available, simple and cost effective. PMID:25830130

  13. A Study of the Interaction of Bovine Hemoglobin with Synthetic Dyes Using Spectroscopic Techniques and Molecular Docking

    PubMed Central

    Kamaljeet; Bansal, Saurabh; SenGupta, Uttara

    2017-01-01

    Synthetic dyes are a very efficient class of dyes that are ingested or come into contact with the skin from numerous sources (cosmetics, textiles, leather, paper, and drugs). An important component of their safety profile is the interactions that they form after they enter the body. Hemoglobin is a functionally important protein that can form multiple interactions with soluble compounds present in the blood, and hence forms an important aspect of the toxicological or safety profile of the dyes. Here we study the interaction between bovine hemoglobin and organic dyes using UV-Vis absorbance and fluorescence spectroscopy. Molecular modeling was used to visualize the binding site and partners of the dye molecules, within the hemoglobin molecule. We find that all four dyes studied form sufficiently strong interactions with hemoglobin to allow for the formation of potentially toxic interactions. Molecular modeling showed that all four dyes bind within the central cavity of the hemoglobin molecule. However, binding partners could not be identified as multiple binding conformations with very similar energies were possible for each dye. PMID:28119912

  14. A Quantitative Near-Infrared Spectroscopy Study: A Decrease in Cerebral Hemoglobin Oxygenation in Alzheimer's Disease and Mild Cognitive Impairment

    ERIC Educational Resources Information Center

    Arai, Heii; Takano, Maki; Miyakawa, Koichi; Ota, Tsuneyoshi; Takahashi, Tadashi; Asaka, Hirokazu; Kawaguchi, Tsuneaki

    2006-01-01

    A newly developed quantitative near-infrared spectroscopy (NIRS) system was used to measure changes in cortical hemoglobin oxygenation during the Verbal Fluency Task in 32 healthy controls, 15 subjects with mild cognitive impairment (MCI), and 15 patients with Alzheimer's disease (AD). The amplitude of changes in the waveform, which was…

  15. The amino-acid sequence of alpha A- and beta-chains from the major hemoglobin component of American flamingo (Phoenicopterus ruber ruber).

    PubMed

    Godovac-Zimmermann, J; Braunitzer, G

    1984-04-01

    The complete amino-acid sequence of alpha A- and beta-chains from the major hemoglobin component (HbA) of American Flamingo ( Phoenicopterus ruber ruber) is presented. The minor component (HbD) with alpha D-chains was detected in similar amounts (25%) as in chicken and pheasant hemoglobins. The comparison of American Flamingo and Greylag Goose (Anser anser) hemoglobins shows that alpha A-chains differ by 22 exchanges and beta-chains by only 4 exchanges. Two substitutions modify alpha 1 beta 1-contacts. Amino-acid replacements between American Flamingo and other bird hemoglobins are discussed.

  16. Determination of hemoglobin derivatives with IL 282 CO-oximeter as compared with a manual spectrophotometric five-wavelength method.

    PubMed

    Zwart, A; Buursma, A; Oeseburg, B; Zijlstra, W G

    1981-11-01

    Hemoglobin derivatives as determined with the IL 282 CO-Oximeter correlated well with results by a manual five-wavelength method, which in turn had been checked against established methods for one or two derivatives. Measurement of total hemoglobin yielded almost identical results with both methods. As for oxyhemoglobin, carboxyhemoglobin, and hemiglobin, agreement between the two methods was fair. Although the IL 282 CO-Oximeter has not been constructed for the determination of sulfhemoglobin, it appeared that the instrument can still give a strong indication as to the presence of this hemoglobin derivative. Results from the IL 282 for fetal human blood should be used with caution, especially because of the possibility of falsely high HbCO readings.

  17. 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.

  18. A case of hemoglobin Hiroshima (β146 histidine to aspartic acid) with compensatory erythremia and undetectable HbA₁c.

    PubMed

    Nishimori, Hisakazu; Harano, Keiko; Wada, Hideho; Takano, Satoshi; Fukuda, Shinji; Takehara, Yukihito; Matsumoto, Hiroshi; Kumagai, Isao; Tanimoto, Mitsune; Takeda, Sho

    2012-06-01

    Hemoglobin (Hb) Hiroshima is an Hb variant that travels rapidly on electrophoresis and shows a fourfold increase in oxygen affinity and a decreased Bohr effect. We encountered a 40-year-old male patient with erythremia and an undetectable HbA(1c) level. The presence of an abnormal hemoglobin molecule was suggested by the results of high-performance liquid chromatography analysis. Subsequent gene analysis by direct sequencing confirmed Hb Hiroshima (β146 histidine → aspartic acid). Caution should be exercised when diagnosing erythremia.

  19. Rates of energy transfer between tryptophans and hemes in hemoglobin, assuming that the heme is a planar oscillator.

    PubMed Central

    Gryczynski, Z; Tenenholz, T; Bucci, E

    1992-01-01

    Using the Förster equations we have estimated the rate of energy transfer from tryptophans to hemes in hemoglobin. Assuming an isotropic distribution of the transition moments of the heme in the plane of the porphyrin, we computed the orientation factors and the consequent transfer rates from the crystallographic coordinates of human oxy- and deoxy-hemoglobin. It appears that the orientation factors do not play a limiting role in regulating the energy transfer and that the rates are controlled almost exclusively by the intrasubunit separations between tryptophans and hemes. In intact hemoglobin tetramers the intrasubunit separations are such as to reduce lifetimes to 5 and 15 ps/ns of tryptophan lifetime. Lifetimes of several hundred picoseconds would be allowed by the intersubunit separations, but intersubunits transfer becomes important only when one heme per tetramer is absent or does not accept transfer. If more than one heme per tetramer is absent lifetimes of more than 1 ns would appear. PMID:1420905

  20. An erythroid enhancer of BCL11A subject to genetic variation determines fetal hemoglobin level

    PubMed Central

    Bauer, Daniel E.; Kamran, Sophia C.; Lessard, Samuel; Xu, Jian; Fujiwara, Yuko; Lin, Carrie; Shao, Zhen; Canver, Matthew C.; Smith, Elenoe C.; Pinello, Luca; Sabo, Peter J.; Vierstra, Jeff; Voit, Richard A.; Yuan, Guo-Cheng; Porteus, Matthew H.; Stamatoyannopoulos, John A.; Lettre, Guillaume; Orkin, Stuart H.

    2014-01-01

    Genome-wide association studies (GWAS) have ascertained numerous trait-associated common genetic variants, frequently localized to regulatory DNA. We find that common genetic variation at BCL11A associated with fetal hemoglobin (HbF) level lies in noncoding sequences decorated by an erythroid enhancer chromatin signature. Fine-mapping uncovers a motif-disrupting common variant associated with reduced transcription factor binding, modestly diminished BCL11A expression and elevated HbF. The surrounding sequences function in vivo as a developmental stage-specific lineage-restricted enhancer. Genome engineering reveals the enhancer is required in erythroid but not B-lymphoid cells for BCL11A expression. These findings illustrate how GWAS may expose functional variants of modest impact within causal elements essential for appropriate gene expression. We propose the GWAS-marked BCL11A enhancer represents an attractive target for therapeutic genome engineering for the β-hemoglobinopathies. PMID:24115442

  1. An erythroid enhancer of BCL11A subject to genetic variation determines fetal hemoglobin level.

    PubMed

    Bauer, Daniel E; Kamran, Sophia C; Lessard, Samuel; Xu, Jian; Fujiwara, Yuko; Lin, Carrie; Shao, Zhen; Canver, Matthew C; Smith, Elenoe C; Pinello, Luca; Sabo, Peter J; Vierstra, Jeff; Voit, Richard A; Yuan, Guo-Cheng; Porteus, Matthew H; Stamatoyannopoulos, John A; Lettre, Guillaume; Orkin, Stuart H

    2013-10-11

    Genome-wide association studies (GWASs) have ascertained numerous trait-associated common genetic variants, frequently localized to regulatory DNA. We found that common genetic variation at BCL11A associated with fetal hemoglobin (HbF) level lies in noncoding sequences decorated by an erythroid enhancer chromatin signature. Fine-mapping uncovers a motif-disrupting common variant associated with reduced transcription factor (TF) binding, modestly diminished BCL11A expression, and elevated HbF. The surrounding sequences function in vivo as a developmental stage-specific, lineage-restricted enhancer. Genome engineering reveals the enhancer is required in erythroid but not B-lymphoid cells for BCL11A expression. These findings illustrate how GWASs may expose functional variants of modest impact within causal elements essential for appropriate gene expression. We propose the GWAS-marked BCL11A enhancer represents an attractive target for therapeutic genome engineering for the β-hemoglobinopathies.

  2. Escaping the Hemoglobin A1c-Centric World in Evaluating Diabetes Mellitus Interventions

    PubMed Central

    Vigersky, Robert A.

    2015-01-01

    Any intervention in patients with diabetes must consider its effect on both the incidence of hypoglycemia and hemoglobin A1c. Yet, there is no single metric that expresses these key factors simultaneously. Such a composite metric would permit clinicians, regulators, manufacturers, payers, and researchers to more easily evaluate the merits of an intervention as well as enable the comparison of qualitatively different interventions. This article proposes a composite metric, the hypoglycemia-A1c score (HAS), as the basis for a more comprehensive approach for the stakeholders in diabetes treatment to better understand how an intervention affects diabetes management. The article also demonstrates how additional parameters such as effects on weight, quality of life, and costs could be included in such a scoring system. PMID:25697718

  3. Effect of Iron Deficiency Anemia on Hemoglobin A1c Levels

    PubMed Central

    Sinha, Nitin; Mishra, T.K.; Singh, Tejinder

    2012-01-01

    Background Iron deficiency anemia is the most common form of anemia in India. Hemoglobin A1c (HbA1c) is used in diabetic patients as an index of glycemic control reflecting glucose levels of the previous 3 months. Like blood sugar levels, HbA1c levels are also affected by the presence of variant hemoglobins, hemolytic anemias, nutritional anemias, uremia, pregnancy, and acute blood loss. However, reports on the effects of iron deficiency anemia on HbA1c levels are inconsistent. We conducted a study to analyze the effects of iron deficiency anemia on HbA1c levels and to assess whether treatment of iron deficiency anemia affects HbA1c levels. Methods Fifty patients confirmed to have iron deficiency anemia were enrolled in this study. HbA1c and absolute HbA1c levels were measured both at baseline and at 2 months after treatment, and these values were compared with those in the control population. Results The mean baseline HbA1c level in anemic patients (4.6%) was significantly lower than that in the control group (5.5%, p<0.05). A significant increase was observed in the patients' absolute HbA1c levels at 2 months after treatment (0.29 g/dL vs. 0.73 g/dL, p<0.01). There was a significant difference between the baseline values of patients and controls (0.29 g/dL vs. 0.74 g/dL, p<0.01). Conclusions In contrast to the observations of previous studies, ours showed that HbA1c levels and absolute HbA1c levels increased with treatment of iron deficiency anemia. This could be attributable to nutritional deficiency and/or certain unknown variables. Further studies are warranted. PMID:22259774

  4. Transcription factors LRF and BCL11A independently repress expression of fetal hemoglobin.

    PubMed

    Masuda, Takeshi; Wang, Xin; Maeda, Manami; Canver, Matthew C; Sher, Falak; Funnell, Alister P W; Fisher, Chris; Suciu, Maria; Martyn, Gabriella E; Norton, Laura J; Zhu, Catherine; Kurita, Ryo; Nakamura, Yukio; Xu, Jian; Higgs, Douglas R; Crossley, Merlin; Bauer, Daniel E; Orkin, Stuart H; Kharchenko, Peter V; Maeda, Takahiro

    2016-01-15

    Genes encoding human β-type globin undergo a developmental switch from embryonic to fetal to adult-type expression. Mutations in the adult form cause inherited hemoglobinopathies or globin disorders, including sickle cell disease and thalassemia. Some experimental results have suggested that these diseases could be treated by induction of fetal-type hemoglobin (HbF). However, the mechanisms that repress HbF in adults remain unclear. We found that the LRF/ZBTB7A transcription factor occupies fetal γ-globin genes and maintains the nucleosome density necessary for γ-globin gene silencing in adults, and that LRF confers its repressive activity through a NuRD repressor complex independent of the fetal globin repressor BCL11A. Our study may provide additional opportunities for therapeutic targeting in the treatment of hemoglobinopathies.

  5. Transcription factors LRF and BCL11A independently repress expression of fetal hemoglobin

    PubMed Central

    Masuda, Takeshi; Wang, Xin; Maeda, Manami; Canver, Matthew C.; Sher, Falak; Funnell, Alister P. W.; Fisher, Chris; Suciu, Maria; Martyn, Gabriella E.; Norton, Laura J.; Zhu, Catherine; Kurita, Ryo; Nakamura, Yukio; Xu, Jian; Higgs, Douglas R.; Crossley, Merlin; Bauer, Daniel E.; Orkin, Stuart H.; Kharchenko, Peter V.; Maeda, Takahiro

    2016-01-01

    Genes encoding human β-type globin undergo a developmental switch from embryonic to fetal to adult-type expression. Mutations in the adult form cause inherited hemoglobinopathies or globin disorders, including sickle cell disease and thalassemia. Some experimental results have suggested that these diseases could be treated by induction of fetal-type hemoglobin (HbF). However, the mechanisms that repress HbF in adults remain unclear. We found that the LRF/ZBTB7A transcription factor occupies fetal γ-globin genes and maintains the nucleosome density necessary for γ-globin gene silencing in adults, and that LRF confers its repressive activity through a NuRD repressor complex independent of the fetal globin repressor BCL11A. Our study may provide additional opportunities for therapeutic targeting in the treatment of hemoglobinopathies. PMID:26816381

  6. A micro-potentiometric hemoglobin immunosensor based on electropolymerized polypyrrole-gold nanoparticles composite.

    PubMed

    Qu, Lan; Xia, Shanhong; Bian, Chao; Sun, Jizhou; Han, Jinghong

    2009-08-15

    We report a novel micro-potentiometric hemoglobin (Hb) immunosensor based on electrochemically synthesized polypyrrole (PPy)-gold nanoparticles (AuNPs) composite. PPy-AuNPs film with AuNPs uniformly distributed in it was deposited on gold electrode surface by a simple and direct procedure, without the addition of any nanoparticles or reducing agent. And this generic method makes it possible to deposite different polymers on miniaturized electrodes. With the existence of AuNPs, the antibody immobilization onto the electrode surface was facilitated. Morphology study by field emission scanning electron microscope (FE-SEM) confirms the presence of AuNPs in PPy. Based on an ion-sensitive field-effect transistors (ISFETs) integrated chip, a micro-potentiometric immunosensor for Hb and hemoglobin-A1c (HbA1c) has been constructed. The sensor response was linear over the concentration range 60-180 microg/ml Hb and 4-18 microg/ml HbA1c. The Hb concentration in whole blood samples has also been analysed, with a linear dose-response behavior between 125 and 197 microg/ml and a sensitivity of 0.20 mV microg(-1)ml. The measuring ranges of the developed Hb and HbA1c immunosensors meet the clinical demand for measuring the HbA1c/Hb ratio of 5-20%. This sensor results in simple and rapid differential measurement of Hb and HbA1c, and has great potential to become an inexpensive and portable device for monitoring of diabetes.

  7. Molecular cloning and characterization of a moss (Ceratodon purpureus) nonsymbiotic hemoglobin provides insight into the early evolution of plant nonsymbiotic hemoglobins.

    PubMed

    Garrocho-Villegas, Verónica; Arredondo-Peter, Raúl

    2008-07-01

    Nonsymbiotic hemoglobins (nsHbs) are widespread in plants including bryophytes. Bryophytes (such as mosses) are among the oldest land plants, thus an analysis of a bryophyte nsHb is of interest from an evolutionary perspective. However, very little is known about bryophyte nsHbs. Here, we report the cloning and characterization of an nshb gene (cerhb) from the moss Ceratodon purpureus. Sequence analysis showed that cerhb is interrupted by 3 introns in identical position as all known plant nshb genes, which suggests that the ancestral nshb gene was interrupted by 3 introns. Expression analysis showed that cerhb expresses in protonemas and gametophytes growing in normal conditions and that it overexpresses in protonemas subjected to osmotic (sucrose), heat-shock, cold-, and nitrate-stress conditions. Also, modeling of the Ceratodon nsHb (CerHb) tertiary structure suggests that CerHb is hexacoordinate and that it binds O(2) with high affinity. Comparative analysis of the predicted CerHb with native rice Hb1 and soybean leghemoglobin a structures revealed that the major evolutionary changes that probably occurred during the evolution of plant Hbs were 1) a hexacoordinate to pentacoordinate transition at the heme prosthetic group, 2) a length decrease at the CD-loop and N- and C-termini regions, and 3) the compaction of the protein into a globular structure.

  8. Phenotypic expression of hemoglobin A2 in beta-thalassemia trait with iron deficiency.

    PubMed

    Madan, N; Sikka, M; Sharma, S; Rusia, U

    1998-09-01

    Iron status was estimated in 463 heterozygous beta-thalassemics to delineate the effect of iron deficiency on the expression of hemoglobin A2 (HbA2) in these patients. One hundred and twenty-six (27.2%) patients with the trait were iron deficient. These iron-deficient patients had a significantly (p < 0.0002) higher prevalence of anemia (90.5%) compared with iron-replete patients with the trait (71.5%). The mean hemoglobin (Hb) concentration, MCV, and MCH were significantly (p < 0.0001) lower in patients with beta-thalassemia traits (BTT) who had iron deficiency than in those without iron deficiency. Mean RBC count and MCHC did not differ in the two groups. Mean HbA2 was not significantly different in the two groups of patients with the trait and was elevated (>3.5%) in all but one heterozygote investigated. Mean HbA2/cell was significantly (p < 0.05) lower in BTT patients with iron deficiency than in patients without iron deficiency. The presence of iron deficiency did not preclude the detection of BTT in this population. The effect of iron deficiency in BTT was apparent as a significant lowering of the Hb concentration and an increased prevalence of anemia. Iron therapy is warranted for BTT patients with iron-deficiency traits and would help to significantly raise their Hb concentration. The elevation of HbA2 was striking and could be used with reliability in making the diagnosis of BTT even in the presence of iron deficiency.

  9. Novel Luminescent Probe Based on a Terbium(III) Complex for Hemoglobin Determination

    NASA Astrophysics Data System (ADS)

    Yegorova, A. V.; Leonenko, I. I.; Aleksandrova, D. I.; Scrypynets, Yu. V.; Antonovich, V. P.; Ukrainets, I. V.

    2014-09-01

    We have studied the spectral luminescent properties of Tb(III) and Eu(III) complexes with a number of novel derivatives of oxoquinoline-3-carboxylic acid amides (L1-L5 ). We have observed quenching of the luminescence of 1:1 Tb(III)-L1-5 complexes by hemoglobin (Hb), which is explained by resonance energy transfer of electronic excitation from the donor (Tb(III)-L1-5 ) to the acceptor (Hb). Using the novel luminescent probe Tb(III)-L1, we have developed a method for determining Hb in human blood. The calibration Stern-Volmer plot is linear in the Hb concentration range 0.6-36.0 μg/mL, detection limit 0.2 μg/mL (3·10-9 mol/L).

  10. Photometric sensor system for a non-invasive real-time hemoglobin monitoring

    NASA Astrophysics Data System (ADS)

    Timm, Ulrich; Kraitl, Jens; Schnurstein, Kirstin; Ewald, Hartmut

    2013-03-01

    Hemoglobin (Hb) is an important component of red blood cells. The primary function of Hb is the transport of oxygen from the lungs to the tissue and carbon dioxide back to the lungs. The Hb concentration in human blood is an important parameter in evaluating the physiological status of an individual and an essential parameter in every blood count. Invasive methods are used to measure the Hb concentration, whereby blood is taken from the patient and subsequently analyzed. Apart from the discomfort of drawing blood samples, an added disadvantage of this method is the delay between the blood collection and its analysis, which does not allow real time patient monitoring in critical situations. A non-invasive method allows pain free continuous on-line patient monitoring with minimum risk of infection and facilitates real time data monitoring allowing immediate clinical reaction to the measured data.

  11. Acrylamide Hemoglobin Adduct Levels and Ovarian Cancer Risk: a nested case-control study

    PubMed Central

    Xie, Jing; Terry, Kathryn L.; Poole, Elizabeth M.; Wilson, Kathryn M.; Rosner, Bernard A.; Willett, Walter C.; Vesper, Hubert W.; Tworoger, Shelley S.

    2013-01-01

    Background Acrylamide is a probable human carcinogen formed during cooking of starchy foods. Two large prospective cohort studies of dietary acrylamide intake and ovarian cancer risk observed a positive association, although two other studies reported no association. Methods We measured acrylamide exposure using red blood cell acrylamide and glycidamide hemoglobin adducts among women in two large prospective cohorts: the Nurses’ Health Study and Nurses’ Health Study II. Between blood collection and 2010, we identified 263 incident cases of epithelial ovarian cancer, matching two controls per case. We used logistic regression models to examine the association between acrylamide exposure and ovarian cancer risk, adjusting for matching factors, family history of ovarian cancer, tubal ligation, oral contraceptive use, body mass index (BMI), parity, alcohol intake, smoking, physical activity, and caffeine intake. Results The multivariate-adjusted relative risk (RR) of ovarian cancer comparing the highest versus lowest tertile of total acrylamide adducts was 0.79 (95% CI: 0.50–1.24, P trend = 0.08). The comparable RR of ovarian cancer among non-smokers at blood draw was 0.85 (95% CI: 0.57–1.27, P trend =0.14). The association did not differ by tumor histology (serous invasive versus not), P for heterogeneity=0.41. Individual adduct types (acrylamide or glycidamide) were not associated with risk. Conclusions We observed no evidence that acrylamide exposure as measured by adducts to hemoglobin is associated with an increased risk of ovarian cancer. Impact Our finding indicates that acrylamide intake may not increase risk of ovarian cancer. PMID:23417989

  12. 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.

  13. 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)

  14. 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.

  15. 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

  16. Immunizing pigs with Ascaris suum hemoglobin increases the inflammatory response in the liver but fails to induce a protective immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine whether purified Ascaris suum hemoglobin (AsHb) is a suitable vaccine candidate for the control of Ascaris infections, pigs were 30 vaccinated with AsHb in combination with QuilA adjuvant and challenged with A. suum eggs. The number of liver lesions and worms in the intestine was assess...

  17. Microchromatography of hemoglobins. VIII. A general qualitative and quantitative method in plastic drinking straws and the quantitative analysis of Hb-F.

    PubMed

    Schroeder, W A; Pace, L A

    1978-03-01

    The microchromatographic procedure for the quantitative analysis of the hemoglobin components in a hemolysate uses columns of DEAE-cellulose in a plastic drinking straw with a glycine-KCN-NaCl developer. Not only may the method be used for the quantitative analysis of Hb-F but also for the analysis of the varied components in mixtures of hemoglobins.

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. Diffuse reflectance spectra of the palpebral conjunctiva and its utility as a noninvasive indicator of total hemoglobin

    NASA Astrophysics Data System (ADS)

    McMurdy, John W., III; Jay, Gregory D.; Suner, Selim; Trespalacios, Flor; Crawford, Gregory P.

    2006-01-01

    The palpebral conjunctiva is an attractive location to qualitatively examine for the presence of anemia; however, this method of diagnosis has not been shown to be accurate. A spectroscopic examination of the palpebral conjunctiva enables the use of a quantitative parameter as a basis for diagnoses. Visible range diffuse reflectance spectra from the palpebral conjunctiva are examined from 30 patients and hemoglobin levels are extracted from these signatures using both a partial least-squares (PLS) multivariate regression model and a discrete spectral region model. Hemoglobin concentration derived from both these models is compared to an in vitro measurement of hemoglobin. Root mean squared errors of cross validation for the two analytical methods are 0.67 g/dL and 1.07 g/dL, respectively. Conjunctival reflectance spectra coupled with a PLS analysis achieve an enhanced specificity and sensitivity for anemia diagnoses over reported observational studies using the palpebral conjunctiva and achieve improved accuracy to other reported methods of noninvasive hemoglobin measurement.

  8. 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)....

  9. 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)....

  10. 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)....

  11. 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)....

  12. 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)....

  13. 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)....

  14. 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)....

  15. 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)....

  16. 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)....

  17. 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)....

  18. Hemoglobin: a gas transport molecule that is hormonally regulated in the ovarian follicle in mice and humans.

    PubMed

    Brown, Hannah M; Anastasi, Marie R; Frank, Laura A; Kind, Karen L; Richani, Dulama; Robker, Rebecca L; Russell, Darryl L; Gilchrist, Robert B; Thompson, Jeremy G

    2015-01-01

    An increasing number of nonerythroid tissues are found to express hemoglobin mRNA and protein. Hemoglobin is a well-described gas transport molecule, especially for O2, but also for NO, CO2, and CO, and also acts as a reactive oxygen species scavenger. We previously found Hba-a1 and Hbb mRNA and protein at high levels within mouse periovulatory cumulus cells, but not in cumulus following in vitro maturation. This led us to investigate the temporal and spatial regulation in follicular cells during the periovulatory period. Cumulus-oocyte complexes were collected from equine chorionic gonadotropin/human chorionic gonadotropin-treated peripubertal SV129 female mice and collected and analyzed for gene expression and protein localization at a variety of time points over the periovulatory period. A further cohort matured in vitro with different forms of hemoglobin (ferro- and ferrihemoglobin) under different O2 atmospheric conditions (2%, 5%, and 20% O2) were subsequently fertilized in vitro and cultured to the blastocyst stage. Murine mRNA transcripts for hemoglobin were regulated by stimulation of the ovulatory cascade, in both granulosa and cumulus cells, and expression of HBA1 and HBB was highly significant in human granulosa and cumulus, but erythrocyte cell marker genes were not. Several other genes involved in hemoglobin function were similarly luteinizing hormone-regulated, including genes for heme biosynthesis. Immunohistochemistry revealed a changing localization pattern of HBA-A1 protein in murine cumulus cells and oocytes following the ovulatory signal. Significantly, no positive staining for HBA-A1 protein was observed within in vitro-matured oocytes, but, if coincubated with ferro- or ferrihemoglobin, cytoplasmic HBA-A1 was observed, similar to in vivo-derived oocytes. Addition of ferro-, but not ferrihemoglobin, had a small, positive effect on blastocyst yield, but only under either 2% or 20% O2 gas atmosphere. The identification of hemoglobin within

  19. Combined hemoglobin and fluorescence diffuse optical tomography for breast tumor diagnosis: a pilot study on time-domain methodology

    PubMed Central

    Zhang, Wei; Wu, Linhui; Li, Jiao; Yi, Xi; Wang, Xin; Lu, Yiming; Chen, Weiting; Zhou, Zhongxing; Zhang, Limin; Zhao, Huijuan; Gao, Feng

    2013-01-01

    A combined time-domain fluorescence and hemoglobin diffuse optical tomography (DOT) system and the image reconstruction methods are proposed for enhancing the reliability of breast-dedicated optical measurement. The system equipped with two pulsed laser diodes at wavelengths of 780 nm and 830 nm that are specific to the peak excitation and emission of the FDA-approved ICG agent, and works with a 4-channel time-correlated single photon counting device to acquire the time-resolved distributions of the light re-emissions at 32 boundary sites of tissues in a tandem serial-to-parallel mode. The simultaneous reconstruction of the two optical (absorption and scattering) and two fluorescent (yield and lifetime) properties are achieved with the respective featured-data algorithms based on the generalized pulse spectrum technique. The performances of the methodology are experimentally assessed on breast-mimicking phantoms for hemoglobin- and fluorescence-DOT alone, as well as for fluorescence-guided hemoglobin-DOT. The results demonstrate the efficacy of improving the accuracy of hemoglobin-DOT based on a priori fluorescence localization. PMID:23412647

  20. Configuration of the Hemoglobin Oxygen Dissociation Curve Demystified: A Basic Mathematical Proof for Medical and Biological Sciences Undergraduates

    ERIC Educational Resources Information Center

    Leow, Melvin Khee-Shing

    2007-01-01

    The oxygen dissociation curve (ODC) of hemoglobin (Hb) has been widely studied and mathematically described for nearly a century. Numerous mathematical models have been designed to predict with ever-increasing accuracy the behavior of oxygen transport by Hb in differing conditions of pH, carbon dioxide, temperature, Hb levels, and…

  1. Assessment of Microcirculatory Hemoglobin Levels in Normal and Diabetic Subjects using Diffuse Reflectance Spectroscopy in the Visible Region — a Pilot Study

    NASA Astrophysics Data System (ADS)

    Sujatha, N.; Anand, B. S. Suresh; Nivetha, K. Bala; Narayanamurthy, V. B.; Seshadri, V.; Poddar, R.

    2015-07-01

    Light-based diagnostic techniques provide a minimally invasive way for selective biomarker estimation when tissues transform from a normal to a malignant state. Spectroscopic techniques based on diffuse reflectance characterize the changes in tissue hemoglobin/oxygenation levels during the tissue transformation process. Recent clinical investigations have shown that changes in tissue oxygenation and microcirculation are observed in diabetic subjects in the initial and progressive stages. In this pilot study, we discuss the potential of diffuse reflectance spectroscopy (DRS) in the visible (Vis) range to differentiate the skin microcirculatory hemoglobin levels between normal and advanced diabetic subjects with and without neuropathy. Average concentration of hemoglobin as well as hemoglobin oxygen saturation within the probed tissue volume is estimated for a total of four different sites in the foot sole. The results indicate a statistically significant decrease in average total hemoglobin and increase in hemoglobin oxygen saturation levels for diabetic foot compared with a normal foot. The present study demonstrates the ability of reflectance spectroscopy in the Vis range to determine and differentiate the changes in tissue hemoglobin and hemoglobin oxygen saturation levels in normal and diabetic subjects.

  2. A quantitative framework for the design of acellular hemoglobins as blood substitutes: implications of dynamic flow conditions

    PubMed Central

    Cole, Russell; Vandegriff, Kim; Szeri, Andrew; Savas, Omer; Baker, Dale; Winslow, Robert

    2007-01-01

    The delivery of oxygen to tissue by cell-free carriers eliminates intraluminal barriers associated with red blood cells. This is important in arterioles, since arteriolar tone controls capillary perfusion. We describe a mathematical model for O2 transport by hemoglobin solutions and red blood cells flowing through arteriolar-sized tubes to optimize values of p50, Hill number, hemoglobin molecular diffusivity and concentration. Oxygen release is evaluated by including an extra-luminal resistance term to reflect tissue oxygen consumption. For low consumption (i.e., high resistance to O2 release) a hemoglobin solution with p50=15 mmHg, Hill n=1, DHBO2=3×10−7 cm2/s delivers O2 at a rate similar to that of red blood cells. For high consumption, the p50 must be decreased to 5 mmHg. The model predicts that regardless of size, hemoglobin solutions with higher p50 will present excess O2 to arteriolar walls. Oversupply of O2 to arteriolar walls may cause constriction and paradoxically reduced capillary perfusion. PMID:17418478

  3. Glycated Hemoglobin (HbA1c): Clinical Applications of a Mathematical Concept

    PubMed Central

    Leow, Melvin Khee Shing

    2016-01-01

    Background and purpose: Glycated hemoglobin (HbA1c) reflects the cumulative glucose exposure of erythrocytes over a preceding time frame proportional to erythrocyte survival. HbA1c is thus an areal function of the glucose-time curve, an educationally useful concept to aid teaching and clinical judgment. Methods: An ordinary differential equation is formulated as a parsimonious model of HbA1c. The integrated form yields HbA1c as an area-under-the-curve (AUC) of a glucose-time profile. The rate constant of the HbA1c model is then derived using the validated regression equation in the ADAG study that links mean blood glucose and HbA1c with a very high degree of goodness-of-fit. Results: This model has didactic utility to enable patients, biomedical students and clinicians to appreciate how HbA1c may be conceptually inferred from discrete blood glucose values using continuous glucose monitoring system (CGMS) or self-monitored blood glucose (SMBG) glucometer readings as shown in the examples. It can be appreciated how hypoglycemia can occur with rapid HbA1c decline despite poor glycemic control. Conclusions: Being independent of laboratory assay pitfalls, computed ‘virtual’ HbA1c serves as an invaluable internal consistency cross-check against laboratory-measured HbA1c discordant with SMBG readings suggestive of inaccurate/fraudulent glucometer records or hematologic disorders including thalassemia and hemoglobinopathy. This model could be implemented within portable glucometers, CGMS devices and even smartphone apps for deriving tentative ‘virtual’ HbA1c from serial glucose readings as an adjunct to measured HbA1c. Such predicted ‘virtual’ HbA1c readily accessible via glucometers may serve as feedback to modify behavior and empower diabetic patients to achieve better glycemic control. PMID:27708483

  4. 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)...

  5. 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)...

  6. 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)...

  7. 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)...

  8. 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)...

  9. IlsA, a unique surface protein of Bacillus cereus required for iron acquisition from heme, hemoglobin and ferritin.

    PubMed

    Daou, Nadine; Buisson, Christophe; Gohar, Michel; Vidic, Jasmina; Bierne, Hélène; Kallassy, Mireille; Lereclus, Didier; Nielsen-LeRoux, Christina

    2009-11-01

    The human opportunistic pathogen Bacillus cereus belongs to the B. cereus group that includes bacteria with a broad host spectrum. The ability of these bacteria to colonize diverse hosts is reliant on the presence of adaptation factors. Previously, an IVET strategy led to the identification of a novel B. cereus protein (IlsA, Iron-regulated leucine rich surface protein), which is specifically expressed in the insect host or under iron restrictive conditions in vitro. Here, we show that IlsA is localized on the surface of B. cereus and hence has the potential to interact with host proteins. We report that B. cereus uses hemoglobin, heme and ferritin, but not transferrin and lactoferrin. In addition, affinity tests revealed that IlsA interacts with both hemoglobin and ferritin. Furthermore, IlsA directly binds heme probably through the NEAT domain. Inactivation of ilsA drastically decreases the ability of B. cereus to grow in the presence of hemoglobin, heme and ferritin, indicating that IlsA is essential for iron acquisition from these iron sources. In addition, the ilsA mutant displays a reduction in growth and virulence in an insect model. Hence, our results indicate that IlsA is a key factor within a new iron acquisition system, playing an important role in the general virulence strategy adapted by B. cereus to colonize susceptible hosts.

  10. Cell-specific expression of the promoters of two nonlegume hemoglobin genes in a transgenic legume, Lotus corniculatus.

    PubMed

    Andersson, C R; Llewellyn, D J; Peacock, W J; Dennis, E S

    1997-01-01

    The promoters of the hemoglobin genes from the nitrogen-fixing tree Parasponia andersonii and the related nonnitrogen-fixing Trema tomentosa both confer beta-glucuronidase reporter gene expression to the central zone of the nodules of a transgenic legume, Lotus corniculatus. beta-Glucuronidase expression was high in the uninfected interstitial cells and parenchyma of the surrounding boundary layer and was low in the Rhizobium-infected cells. This contrasts with the expression of both the P. andersonii hemoglobin protein in P. andersonii nodules and the endogenous Lotus leghemoglobins that are expressed in the infected cells at very high levels. The expression pattern of the P. andersonii and T. tomentosa hemoglobin promoters in L. corniculatus resembles that of a nonsymbiotic hemoglobin gene from Casuarina glauca, which was introduced into this legume, and suggests that only the nonsymbiotic functions of the P. andersonii promoter are being recognized. Deletion of the distal segments of both the P. andersonii and T. tomentosa promoters identified regions important for the control of their tissue-specific and temporal activity in Lotus. Potential regulatory elements, which enhance nodule expression and suppress nonnodule expression, were also identified and localized to a distal promoter segment. A proximal AAGAG motif is present in the P. andersonii, T. tomentosa, and nonsymbiotic Casuarina hemoglobin genes. Mutation of this motif in the P. andersonii promoter resulted in a significant reduction in both the nodule and root expression levels in L. corniculatus. Some of the regulatory motifs characterized are similar to, but different from, the nodulin motifs of the leghemoglobins.

  11. Krüppel-like factor 1 mutations and expression of hemoglobins F and A2 in homozygous hemoglobin E syndrome.

    PubMed

    Tepakhan, Wanicha; Yamsri, Supawadee; Fucharoen, Goonnapa; Sanchaisuriya, Kanokwan; Fucharoen, Supan

    2015-07-01

    The basis for variability of hemoglobin (Hb) F in homozygous Hb E disease is not well understood. We have examined multiple mutations of the Krüppel-like factor 1 (KLF1) gene; an erythroid specific transcription factor and determined their associations with Hbs F and A2 expression in homozygous Hb E. Four KLF1 mutations including G176AfsX179, T334R, R238H, and -154 (C-T) were screened using specific PCR assays on 461 subjects with homozygous Hb E and 100 normal controls. None of these four mutations were observed in 100 normal controls. Among 461 subjects with homozygous Hb E, 306 had high (≥5 %) and 155 had low (<5 %) Hb F. DNA analysis identified the KLF1 mutations in 35 cases of the former group with high Hb F, including the G176AfsX179 mutation (17/306 = 5.6 %), T334R mutation (9/306 = 2.9 %), -154 (C-T) mutation (7/306 = 2.3 %), and R328H mutation (2/306 = 0.7 %). Only two subjects in the latter group with low Hb F carried the G176AfsX179 and -154 (C-T) mutations. Significant higher Hb A2 level was observed in those of homozygous Hb E with the G176AfsX179 mutation as compared to those without KLF1 mutations. These results indicate that KLF1 is among the genetic factors associated with increased Hbs F and A2, and in combination with other factors could explain the variabilities of these Hb expression in Hb E syndrome.

  12. Hematocrit and Hemoglobin Levels of Nonhuman Apes at Moderate Altitudes: A Comparison with Humans.

    PubMed

    Mortola, Jacopo P; Wilfong, DeeAnn

    2016-12-01

    Mortola, Jacopo P. and DeeAnn Wilfong. Hematocrit and hemoglobin levels of nonhuman apes at moderate altitudes: a comparison with humans. High Alt Med Biol. 17:323-335, 2016.-We asked to what extent the hematologic response (increase in hematocrit [Hct] and in blood hemoglobin concentration [Hb]) of humans to altitude hypoxia was shared by our closest relatives, the nonhuman apes. Data were collected from 29 specimens of 7 species of apes at 2073 m altitude (barometric pressure Pb = 598 mm Hg); additional data originated from apes located at a lower altitude (1493 m, Pb = 639 mm Hg). The human altitude profiles of Hct and Hb between sea level and 3000 m were constructed from a compilation of literature sources that (all combined) comprised data sets of 10,000-12,000 subjects for each gender. These human data were binned for 0-250 m altitude (sea level) and for each 500 m of progressively higher altitudes. Values of Hb and Hct of both men and women were significantly higher than at sea level at the 1500 bin (1250-1750 m); hence, the altitude threshold for the human hematological responses must be between 1000 and 1500 m. In the nonhuman apes, no increase in Hct or Hb was apparent at 1500 m; at 2000 m, the increase was significant only for the Hb of females. At either altitude in the group of nonhuman apes, the increase in Hct was much less than in humans, and that of Hb was significantly less at 1500 m. We conclude that lack of, or minimal, hematopoietic response to moderate altitude can occur in mammalian species that are not genetically adapted to high altitudes. Polycythemia is not a common response to altitude hypoxia and, at least at moderate altitudes, the degree of the human response may represent the exception among apes rather than the rule.

  13. Contribution of a mutational hot spot to hemoglobin adaptation in high-altitude Andean house wrens

    PubMed Central

    Galen, Spencer C.; Natarajan, Chandrasekhar; Moriyama, Hideaki; Weber, Roy E.; Fago, Angela; Benham, Phred M.; Chavez, Andrea N.; Cheviron, Zachary A.; Storz, Jay F.; Witt, Christopher C.

    2015-01-01

    A key question in evolutionary genetics is why certain mutations or certain types of mutation make disproportionate contributions to adaptive phenotypic evolution. In principle, the preferential fixation of particular mutations could stem directly from variation in the underlying rate of mutation to function-altering alleles. However, the influence of mutation bias on the genetic architecture of phenotypic evolution is difficult to evaluate because data on rates of mutation to function-altering alleles are seldom available. Here, we report the discovery that a single point mutation at a highly mutable site in the βA-globin gene has contributed to an evolutionary change in hemoglobin (Hb) function in high-altitude Andean house wrens (Troglodytes aedon). Results of experiments on native Hb variants and engineered, recombinant Hb mutants demonstrate that a nonsynonymous mutation at a CpG dinucleotide in the βA-globin gene is responsible for an evolved difference in Hb–O2 affinity between high- and low-altitude house wren populations. Moreover, patterns of genomic differentiation between high- and low-altitude populations suggest that altitudinal differentiation in allele frequencies at the causal amino acid polymorphism reflects a history of spatially varying selection. The experimental results highlight the influence of mutation rate on the genetic basis of phenotypic evolution by demonstrating that a large-effect allele at a highly mutable CpG site has promoted physiological differentiation in blood O2 transport capacity between house wren populations that are native to different elevations. PMID:26460028

  14. Contribution of a mutational hot spot to hemoglobin adaptation in high-altitude Andean house wrens.

    PubMed

    Galen, Spencer C; Natarajan, Chandrasekhar; Moriyama, Hideaki; Weber, Roy E; Fago, Angela; Benham, Phred M; Chavez, Andrea N; Cheviron, Zachary A; Storz, Jay F; Witt, Christopher C

    2015-11-10

    A key question in evolutionary genetics is why certain mutations or certain types of mutation make disproportionate contributions to adaptive phenotypic evolution. In principle, the preferential fixation of particular mutations could stem directly from variation in the underlying rate of mutation to function-altering alleles. However, the influence of mutation bias on the genetic architecture of phenotypic evolution is difficult to evaluate because data on rates of mutation to function-altering alleles are seldom available. Here, we report the discovery that a single point mutation at a highly mutable site in the β(A)-globin gene has contributed to an evolutionary change in hemoglobin (Hb) function in high-altitude Andean house wrens (Troglodytes aedon). Results of experiments on native Hb variants and engineered, recombinant Hb mutants demonstrate that a nonsynonymous mutation at a CpG dinucleotide in the β(A)-globin gene is responsible for an evolved difference in Hb-O2 affinity between high- and low-altitude house wren populations. Moreover, patterns of genomic differentiation between high- and low-altitude populations suggest that altitudinal differentiation in allele frequencies at the causal amino acid polymorphism reflects a history of spatially varying selection. The experimental results highlight the influence of mutation rate on the genetic basis of phenotypic evolution by demonstrating that a large-effect allele at a highly mutable CpG site has promoted physiological differentiation in blood O2 transport capacity between house wren populations that are native to different elevations.

  15. Allosteric action in real time: Time-resolved crystallographic studies of a cooperative dimeric hemoglobin

    PubMed Central

    Knapp, James E.; Pahl, Reinhard; Šrajer, Vukica; Royer, William E.

    2006-01-01

    Protein allostery provides mechanisms for regulation of biological function at the molecular level. We present here an investigation of global, ligand-induced allosteric transition in a protein by time-resolved x-ray diffraction. The study provides a view of structural changes in single crystals of Scapharca dimeric hemoglobin as they proceed in real time, from 5 ns to 80 μs after ligand photodissociation. A tertiary intermediate structure forms rapidly (<5 ns) as the protein responds to the presence of an unliganded heme within each R-state protein subunit, with key structural changes observed in the heme groups, neighboring residues, and interface water molecules. This intermediate lays a foundation for the concerted tertiary and quaternary structural changes that occur on a microsecond time scale and are associated with the transition to a low-affinity T-state structure. Reversal of these changes shows a considerable lag as a T-like structure persists well after ligand rebinding, suggesting a slow T-to-R transition. PMID:16684887

  16. Enzymatic function of hemoglobin as a nitrite reductase that produces NO under allosteric control

    PubMed Central

    Huang, Zhi; Shiva, Sruti; Kim-Shapiro, Daniel B.; Patel, Rakesh P.; Ringwood, Lorna A.; Irby, Cynthia E.; Huang, Kris T.; Ho, Chien; Hogg, Neil; Schechter, Alan N.; Gladwin, Mark T.

    2005-01-01

    Hypoxic vasodilation is a fundamental, highly conserved physiological response that requires oxygen and/or pH sensing coupled to vasodilation. While this process was first characterized more than 80 years ago, the precise identity and mechanism of the oxygen sensor and mediators of vasodilation remain uncertain. In support of a possible role for hemoglobin (Hb) as a sensor and effector of hypoxic vasodilation, here we show biochemical evidence that Hb exhibits enzymatic behavior as a nitrite reductase, with maximal NO generation rates occurring near the oxy-to-deoxy (R-to-T) allosteric structural transition of the protein. The observed rate of nitrite reduction by Hb deviates from second-order kinetics, and sigmoidal reaction progress is determined by a balance between 2 opposing chemistries of the heme in the R (oxygenated conformation) and T (deoxygenated conformation) allosteric quaternary structures of the Hb tetramer — the greater reductive potential of deoxyheme in the R state tetramer and the number of unligated deoxyheme sites necessary for nitrite binding, which are more plentiful in the T state tetramer. These opposing chemistries result in a maximal nitrite reduction rate when Hb is 40–60% saturated with oxygen (near the Hb P50), an apparent ideal set point for hypoxia-responsive NO generation. These data suggest that the oxygen sensor for hypoxic vasodilation is determined by Hb oxygen saturation and quaternary structure and that the nitrite reductase activity of Hb generates NO gas under allosteric and pH control. PMID:16041407

  17. Cyanide binding to hexacoordinate cyanobacterial hemoglobins: hydrogen-bonding network and heme pocket rearrangement in ferric H117A Synechocystis hemoglobin.

    PubMed

    Vu, B Christie; Nothnagel, Henry J; Vuletich, David A; Falzone, Christopher J; Lecomte, Juliette T J

    2004-10-05

    The truncated hemoglobin (Hb) from the cyanobacterium Synechocystis sp. PCC 6803 is a bis-histidyl hexacoordinate complex in the absence of exogenous ligands. This protein can form a covalent cross-link between His117 in the H-helix and the heme 2-vinyl group. Cross-linking, the physiological importance of which has not been established, is avoided with the His117Ala substitution. In the present work, H117A Hb was used to explore exogenous ligand binding to the heme group. NMR and thermal denaturation data showed that the replacement was of little consequence to the structural and thermodynamic properties of ferric Synechocystis Hb. It did, however, decelerate the association of cyanide ions with the heme iron. Full complexation required hours, instead of minutes, of incubation at optical and NMR concentrations. At neutral pH and in the presence of excess cyanide, binding occurred with a first-order dependence on cyanide concentration, eliminating distal histidine decoordination as the rate-limiting step. The cyanide complex of the H117A variant was characterized for the conformational changes occurring as the histidine on the distal side, His46 (E10), was displaced. Extensive rearrangement allowed Tyr22 (B10) to insert in the heme pocket and Gln43 (E7) and Gln47 (E11) to come in contact with it. H-bond formation to the bound cyanide was identified in solution with the use of (1)H(2)O/(2)H(2)O mixtures. Cyanide binding also resulted in a change in the ratio of heme orientational isomers, in a likely manifestation of heme environment reshaping. Similar observations were made with the related Synechococcus sp. PCC 7002 H117A Hb, except that cyanide binding was rapid in this protein. In both cases, the (15)N chemical shift of bound cyanide was reminiscent of that in peroxidases and the orientation of the proximal histidine was as in other truncated Hbs. The ensemble of the data provided insight into the structural cooperativity of the heme pocket scaffold and pointed

  18. 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.

  19. Optical imaging of hemoglobin oxygen saturation using a small number of spectral images for endoscopic application

    NASA Astrophysics Data System (ADS)

    Saito, Takaaki; Yamaguchi, Hiroshi

    2015-12-01

    Tissue hypoxia is associated with tumor and inflammatory diseases, and detection of hypoxia is potentially useful for their detailed diagnosis. An endoscope system that can optically observe hemoglobin oxygen saturation (StO2) would enable minimally invasive, real-time detection of lesion hypoxia in vivo. Currently, point measurement of tissue StO2 via endoscopy is possible using the commercial fiber-optic oximeter T-Stat, which is based on visible light spectroscopy at many wavelengths. For clinical use, however, imaging of StO2 is desirable to assess the distribution of tissue oxygenation around a lesion. Here, we describe our StO2 imaging technique based on a small number of wavelength ranges in the visible range. By assuming a homogeneous tissue, we demonstrated that tissue StO2 can be obtained independently from the scattering property and blood concentration of tissue using four spectral bands. We developed a prototype endoscope system and used it to observe tissue-simulating phantoms. The StO2 (%) values obtained using our technique agreed with those from the T-Stat within 10%. We also showed that tissue StO2 can be derived using three spectral band if the scattering property is fixed at preliminarily measured values.

  20. Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin.

    PubMed

    Mittermayr, Rainer; Osipov, Anatoly; Piskernik, Christina; Haindl, Susanne; Dungel, Peter; Weber, Carina; Vladimirov, Yuri A; Redl, Heinz; Kozlov, Andrey V

    2007-01-01

    It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 microM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes.

  1. Staphylococcus aureus Uses a Novel Multidomain Receptor to Break Apart Human Hemoglobin and Steal Its Heme*

    PubMed Central

    Spirig, Thomas; Malmirchegini, G. Reza; Zhang, Jiang; Robson, Scott A.; Sjodt, Megan; Liu, Mengyao; Krishna Kumar, Kaavya; Dickson, Claire F.; Gell, David A.; Lei, Benfang; Loo, Joseph A.; Clubb, Robert T.

    2013-01-01

    Staphylococcus aureus is a leading cause of life-threatening infections in the United States. It requires iron to grow, which must be actively procured from its host to successfully mount an infection. Heme-iron within hemoglobin (Hb) is the most abundant source of iron in the human body and is captured by S. aureus using two closely related receptors, IsdH and IsdB. Here we demonstrate that each receptor captures heme using two conserved near iron transporter (NEAT) domains that function synergistically. NMR studies of the 39-kDa conserved unit from IsdH (IsdHN2N3, Ala326–Asp660) reveals that it adopts an elongated dumbbell-shaped structure in which its NEAT domains are properly positioned by a helical linker domain, whose three-dimensional structure is determined here in detail. Electrospray ionization mass spectrometry and heme transfer measurements indicate that IsdHN2N3 extracts heme from Hb via an ordered process in which the receptor promotes heme release by inducing steric strain that dissociates the Hb tetramer. Other clinically significant Gram-positive pathogens capture Hb using receptors that contain multiple NEAT domains, suggesting that they use a conserved mechanism. PMID:23132864

  2. Optimal hemoglobin concentration and high altitude: a theoretical approach for Andean men at rest.

    PubMed

    Villafuerte, Francisco C; Cárdenas, Rosa; Monge-C, Carlos

    2004-05-01

    The beneficial role of erythrocytosis for O2 transport has been questioned by evidence from bloodletting and hemodilution research as well as by studies suggesting the existence of an "optimal" hematocrit (Hct) or hemoglobin concentration ([Hb]) value. To assess to what extent erythrocytosis is beneficial in Andean men at high altitude, we examined and discussed optimal [Hb] using a mathematical approach by modeling the mixed (mean) venous Po2 (Pv(O2)) and arterial O2 content, considering for both the relation between [Hb] and arterial Po2. Relations of [Hb] to other physiological variables such as cardiac output and convective arterial O2 transport were also discussed, revealing the importance of Pv(O2) in this model. Our theoretical analysis suggests that increasing [Hb] allows increase and maintenance of Pv(O2) with only moderate declines in arterial Po2 as a consequence of moderate increases in altitude, reaching its maximum at the optimal [Hb] of 14.7 g/dl. Our analysis also shows that [Hb] corresponding to high arterial O2 content and O2 transport values is apparently not quite advantageous for improvement of oxygenation. Furthermore, chronic mountain sickness is discussed as an insightful example of the effects of excessive erythrocytosis at high altitude.

  3. Characterization of Spbhp-37, a Hemoglobin-Binding Protein of Streptococcus pneumoniae

    PubMed Central

    Romero-Espejel, María E.; Rodríguez, Mario A.; Chávez-Munguía, Bibiana; Ríos-Castro, Emmanuel; Olivares-Trejo, José de Jesús

    2016-01-01

    Streptococcus pneumoniae is a Gram-positive microorganism that is the cause of bacterial pneumonia, sinusitis and otitis media. This human pathogen also can cause invasive diseases such as meningitis, bacteremia and septicemia. Hemoglobin (Hb) and haem can support the growth and viability of S. pneumoniae as sole iron sources. Unfortunately, the acquisition mechanism of Hb and haem in this bacterium has been poorly studied. Previously we identified two proteins of 37 and 22 kDa as putative Hb- and haem-binding proteins (Spbhp-37 and Spbhp-22, respectively). The sequence of Spbhp-37 protein was database annotated as lipoprotein without any function or localization. Here it was immunolocalized in the surface cell by transmission electron microscopy using specific antibodies produced against the recombinant protein. The expression of Spbhp-37 was increased when bacteria were grown in media culture supplied with Hb. In addition, the affinity of Sphbp-37 for Hb was determined. Thus, in this work we are presenting new findings that attempt to explain the mechanism involved in iron acquisition of this pathogen. In the future these results could help to develop new therapy targets in order to avoid the secondary effects caused by the traditional therapies. PMID:27200302

  4. 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.

  5. Axolotl hemoglobin: cDNA-derived amino acid sequences of two alpha globins and a beta globin from an adult Ambystoma mexicanum.

    PubMed

    Shishikura, Fumio; Takeuchi, Hiro-aki; Nagai, Takatoshi

    2005-11-01

    Erythrocytes of the adult axolotl, Ambystoma mexicanum, have multiple hemoglobins. We separated and purified two kinds of hemoglobin, termed major hemoglobin (Hb M) and minor hemoglobin (Hb m), from a five-year-old male by hydrophobic interaction column chromatography on Alkyl Superose. The hemoglobins have two distinct alpha type globin polypeptides (alphaM and alpham) and a common beta globin polypeptide, all of which were purified in FPLC on a reversed-phase column after S-pyridylethylation. The complete amino acid sequences of the three globin chains were determined separately using nucleotide sequencing with the assistance of protein sequencing. The mature globin molecules were composed of 141 amino acid residues for alphaM globin, 143 for alpham globin and 146 for beta globin. Comparing primary structures of the five kinds of axolotl globins, including two previously established alpha type globins from the same species, with other known globins of amphibians and representatives of other vertebrates, we constructed phylogenetic trees for amphibian hemoglobins and tetrapod hemoglobins. The molecular trees indicated that alphaM, alpham, beta and the previously known alpha major globin were adult types of globins and the other known alpha globin was a larval type. The existence of two to four more globins in the axolotl erythrocyte is predicted.

  6. Polymerized and polyethylene glycol-conjugated hemoglobins: a globin-based calibration curve for dynamic light scattering analysis.

    PubMed

    Faggiano, Serena; Ronda, Luca; Bruno, Stefano; Jankevics, Hanna; Mozzarelli, Andrea

    2010-06-15

    Dynamic light scattering (DLS) is a technique capable of determining the hydrodynamic radius of proteins. From this parameter, a molecular weight can be assessed provided that an appropriate calibration curve is available. To this goal, a globin-based calibration curve was used to determine the polymerization state of a recombinant hemoglobin-based oxygen carrier and to assess the equivalent molecular weight of hemoglobins conjugated with polyethylene glycol molecules. The good agreement between DLS values and those obtained from gel filtration chromatography is a consequence of the high similarity in structure, shape, and density within the globin superfamily. Moreover, globins and heme proteins in general share similar spectroscopic properties, thereby reducing possible systematic errors associated with the absorption of the probe radiation by the chromophore.

  7. Immune safety evaluation of polymerized porcine hemoglobin (pPolyHb): a potential red blood cell substitute.

    PubMed

    Zhu, Hongli; Yan, Kunping; Dang, Xiaodong; Huang, He; Chen, Erfang; Chen, Bang; Luo, Chao; Chang, Thomas Ming Swi; Dai, Penggao; Chen, Chao

    2011-12-01

    Polymerized Porcine Hemoglobin (pPolyHb), a hemoglobin-based oxygen carrier (HBOC), was developed as a potential red blood substitute for clinical applications. Assessment of its effects on the immune system is an important component of the overall safety evaluation of HBOC. For this purpose, we assessed three inflammation indicators, including complement C3a, IL-6, and TNF-? in cultured cells and in a rat model when pPolyHb was incubated or administrated with the cells/animals. Our results suggested that the levels of these three indicators were not statistically changed upon pPolyHb stimulation, indicating that pPolyHb is not immunotoxic to cells and animals in this aspect.

  8. Higher sensitivity of capillary electrophoresis in detecting hemoglobin A2'compared to traditional gel electrophoresis.

    PubMed

    Oleske, Deanna Alicia; Huang, Richard Sheng Poe; Dasgupta, Amitava; Nguyen, Andy; Wahed, Amer

    2014-01-01

    HbA2' (also called Hb B2) is the most common delta-globin chain defect and is reported to occur in 1-2% of the African American population. The major clinical significance of HbA2' is that the failure to detect it might lead to an underestimation of the total HbA2, leading to failure to diagnose β-thalassemia minor. In order to diagnose β-thalassemia minor, both HbA2 and HbA2' levels must be combined.Hb A2' accounts for a small percentage (1-2%) of the total hemoglobin in heterozygotes. It is difficult to detect this small amount by traditional gel electrophoresis. Using HPLC Hb A2' is easily detected as it produces a minor peak in the S window. Other conditions which might interfere with detection of HbA2' by HPLC include Hb S trait or Hb SS disease (Hb A2' hidden in the S peak), transfused Hb SS (Hb S peak may be very small), Hb C trait or Hb CC disease (glycosylated Hb C elutes in the S window), and Hb G (Hb G2 elutes in the S window). All of the above conditions, including Hb A2', occur most commonly in the same ethnic group (African American). We reviewed 654 consecutive cases over a period of three months for the presence of Hb A2' in our laboratory where capillary electrophoresis is used as the primary diagnostic tool. We detected seven cases (1.07 %) of HbA2'. In contrast, we did not detect any HbA2' using conventional gel electrophoresis in the last one year (2,580 cases). Although in none of the seven cases the sum of Hb A2 and Hb A2' exceeded 3.5%, we believe that capillary electrophoresis allows for a better detection of Hb A2' than gel electrophoresis and HPLC.

  9. Higher minor hemoglobin A2 levels in multiple sclerosis patients correlate with lesser disease severity

    PubMed Central

    Ozcan, Muhammed Emin; Ince, Bahri; Karadeli, Hasan Huseyin; Gedikbasi, Asuman; Asil, Talip; Altinoz, Meric A

    2016-01-01

    Objective To define whether minor adult hemoglobin A2 (HbA2, α2δ2) exerts any protective activity in multiple sclerosis (MS). Methods HbA2 levels were measured in 146 MS patients with high performance liquid chromatography and association with MS Severity Scores (MSSS) were determined. HbA2 associations with blood count parameters were also studied using blood counts evaluated on the same day of high performance liquid chromatography sampling. Routine biochemical parameters were also determined to rule out elusively influential factors, such as anemia and thyroid disorders. Results HbA2 levels negatively correlated with MSSS (Spearman correlation, R: −0.186, P=0.025). Exclusion of confounding factors with a generalized linear model revealed an even stronger negative correlation between HbA2 and MSSS (P<0.001). HbA2 positively correlated with red blood cells (RBCs) (R=0.350, P<0.001) and in turn, RBCs negatively correlated with MSSS (R=−0.180, P=0.031). Average HbA2 levels were highest among patients treated with interferon β1a. Conclusion RBC fragility is increased in MS, and recent data suggest that circulating free Hb contributes to neural injury in MS. HbA2 and its oxidative denaturation product hemichrome A2 enhance RBC membrane stability to a greater extent than do major HbA or hemichrome A. Reductions in ischemic cerebrovascular vascular events are reported in β-thalassemia carriers and HbA2 levels are considerably higher in this population. Episodic declines of cerebral blood flow were shown in bipolar disorder, and we have recently shown a protective role of HbA2 against postpartum episodes in females with bipolar disorder. HbA2’s erythroprotective functions may reduce free Hb and long-term neural injury in MS. PMID:27578976

  10. A micronutrient-fortified beverage prevents iron deficiency, reduces anemia and improves the hemoglobin concentration of pregnant Tanzanian women.

    PubMed

    Makola, Diklar; Ash, Deborah M; Tatala, Simon R; Latham, Michael C; Ndossi, Godwin; Mehansho, Haile

    2003-05-01

    Maternal malnutrition continues to be a major contributor to adverse reproductive outcomes in developing countries, despite longstanding efforts to fortify foods or to distribute medicinal supplements to pregnant women. The objective of this study was to test the effect of a micronutrient-fortified beverage containing 11 micronutrients (iron, iodine, zinc, vitamin A, vitamin C, niacin, riboflavin, folate, vitamin B-12, vitamin B-6 and vitamin E) on the hemoglobin, iron and vitamin A status of pregnant women in Tanzania. A group of 259 pregnant women with gestational ages of 8 to 34 wk were enrolled in a randomized double-blind controlled trial in which study women received 8 wk of supplementation. Hemoglobin, ferritin and dried blood spot retinol were measured at baseline and at the end of the supplementation period. The supplement resulted in a 4.16 g/L increase in hemoglobin concentration and a 3 micro g/L increase in ferritin and reduced the risk of anemia and iron deficiency anemia by 51 and 56%, respectively. The risk of iron deficiency was reduced by 70% among those who had iron deficiency at baseline and by 92% among those who had adequate stores. The micronutrient-fortified beverage may be a useful and convenient preventative measure, one that could help improve the nutritional status of women both before and during pregnancy and thereby help avoid some of the potential maternal and fetal consequences of micronutrient deficiencies.

  11. Evaluation of Hemoglobin A1c Criteria to Assess Preoperative Diabetes Risk in Cardiac Surgery Patients

    PubMed Central

    Saberi, Sima; Zrull, Christina A.; Patil, Preethi V.; Jha, Leena; Kling-Colson, Susan C.; Gandia, Kenia G.; DuBois, Elizabeth C.; Plunkett, Cynthia D.; Bodnar, Tim W.; Pop-Busui, Rodica

    2011-01-01

    Abstract Objective Hemoglobin A1c (A1C) has recently been recommended for diagnosing diabetes mellitus and diabetes risk (prediabetes). Its performance compared with fasting plasma glucose (FPG) and 2-h post-glucose load (2HPG) is not well delineated. We compared the performance of A1C with that of FPG and 2HPG in preoperative cardiac surgery patients. Methods Data from 92 patients without a history of diabetes were analyzed. Patients were classified with diabetes or prediabetes using established cutoffs for FPG, 2HPG, and A1C. Sensitivity and specificity of the new A1C criteria were evaluated. Results All patients diagnosed with diabetes by A1C also had impaired fasting glucose, impaired glucose tolerance, or diabetes by other criteria. Using FPG as the reference, sensitivity and specificity of A1C for diagnosing diabetes were 50% and 96%, and using 2HPG as the reference they were 25% and 95%. Sensitivity and specificity for identifying prediabetes with FPG as the reference were 51% and 51%, respectively, and with 2HPG were 53% and 51%, respectively. One-third each of patients with prediabetes was identified using FPG, A1C, or both. When testing A1C and FPG concurrently, the sensitivity of diagnosing dysglycemia increased to 93% stipulating one or both tests are abnormal; specificity increased to 100% if both tests were required to be abnormal. Conclusions In patients before cardiac surgery, A1C criteria identified the largest number of patients with diabetes and prediabetes. For diagnosing prediabetes, A1C and FPG were discordant and characterized different groups of patients, therefore altering the distribution of diabetes risk. Simultaneous measurement of FGP and A1C may be a more sensitive and specific tool for identifying high-risk individuals with diabetes and prediabetes. PMID:21854260

  12. HbQ-India associated with microcytosis: An uncommon hemoglobin variant associated with a common hematologic condition.

    PubMed

    Kumar Yadav, Amit; Rusia, Usha

    2010-09-05

    HbQ-India is a rare alpha chain variant that usually presents in the heterozygous state. Normally, HbQ-India is clinically silent. It becomes symptomatic when present in association with other conditions. We report a case of HbQ-India with concomitant presence of iron deficiency anemia. A 16-year-old female presented with weakness and pallor intermittently for six years. Complete blood count showed severe microcytic hypochromic anemia. Hemoglobin electrophoresis showed a prominent band in the S,D,G region. Tests for sickling were negative. High performance liquid chromatography (HPLC) showed a peak in the unknown window (4.70-4.90 min) suggestive of HbQ-India. Serum iron profile was suggestive of iron deficiency anemia. Based on the above findings, a diagnosis of coexistent HbQ-India-iron deficiency anemia was made. A family study revealed the father as having moderate anemia with similar findings while the mother was normal. Abnormal hemoglobin in the patient was confirmed by molecular diagnosis. HbQ variants are the alpha globin chain variants due to structural mutations (α64 Asp→His) inherited in autosomal dominant fashion. Three molecular variant types have been documented, namely HbQ-India, HbQ-Thailand and HbQ-Iran. Normally, HbQ is clinically silent. Therefore, careful screening of the samples using routine techniques like Hb electrophoresis and HPLC are needed for identification of such abnormal hemoglobin variants like HbQ-India.

  13. Whole Blood Donation Affects the Interpretation of Hemoglobin A1c

    PubMed Central

    Lenters-Westra, Erna; de Kort, Wim; Bokhorst, Arlinke G.; Bilo, Henk J. G.; Slingerland, Robbert J.; Vos, Michel J.

    2017-01-01

    Introduction Several factors, including changed dynamics of erythrocyte formation and degradation, can influence the degree of hemoglobin A1c (HbA1c) formation thereby affecting its use in monitoring diabetes. This study determines the influence of whole blood donation on HbA1c in both non-diabetic blood donors and blood donors with type 2 diabetes. Methods In this observational study, 23 non-diabetic blood donors and 21 blood donors with type 2 diabetes donated 475 mL whole blood and were followed prospectively for nine weeks. Each week blood samples were collected and analyzed for changes in HbA1c using three secondary reference measurement procedures. Results Twelve non-diabetic blood donors (52.2%) and 10 (58.8%) blood donors with type 2 diabetes had a significant reduction in HbA1c following blood donation (reduction >-4.28%, P < 0.05). All non-diabetic blood donors with a normal ferritin concentration predonation had a significant reduction in HbA1c. In the non-diabetic group the maximum reduction was -11.9%, in the type 2 diabetes group -12.0%. When eligible to donate again, 52.2% of the non-diabetic blood donors and 41.2% of the blood donors with type 2 diabetes had HbA1c concentrations significantly lower compared to their predonation concentration (reduction >-4.28%, P < 0.05). Conclusion Patients with type 2 diabetes contributing to whole blood donation programs can be at risk of falsely lowered HbA1c. This could lead to a wrong interpretation of their glycemic control by their general practitioner or internist. PMID:28118412

  14. Heme orientational disorder in human adult hemoglobin reconstituted with a ring fluorinated heme and its functional consequences

    SciTech Connect

    Nagao, Satoshi; Hirai, Yueki; Kawano, Shin; Imai, Kiyohiro; Suzuki, Akihiro; Yamamoto, Yasuhiko . E-mail: yamamoto@chem.tsukuba.ac.jp

    2007-03-16

    A ring fluorinated heme, 13,17-bis(2-carboxylatoethyl)-3,8-diethyl-2-fluoro-7,12, 18-trimethyl-porphyrin-atoiron(III), has been incorporated into human adult hemoglobin (Hb A). The heme orientational disorder in the individual subunits of the protein has been readily characterized using {sup 19}F NMR and the O{sub 2} binding properties of the protein have been evaluated through the oxygen equilibrium analysis. The equilibrated orientations of hemes in {alpha}- and {beta}- subunits of the reconstituted protein were found to be almost completely opposite to each other, and hence were largely different from those of the native and the previously reported reconstituted proteins [T. Jue, G.N. La Mar, Heme orientational heterogeneity in deuterohemin-reconstituted horse and human hemoglobin characterized by proton nuclear magnetic resonance spectroscopy, Biochem. Biophys. Res. Commun. 119 (1984) 640-645]. Despite the large difference in the degree of the heme orientational disorder in the subunits of the proteins, the O{sub 2} affinity and the cooperativity of the protein reconstituted with 2-MF were similar to those of the proteins reconstituted with a series of hemes chemically modified at the heme 3- and 8-positions [K. Kawabe, K. Imaizumi, Z. Yoshida, K. Imai, I. Tyuma, Studies on reconstituted myoglobins and hemoglobins II. Role of the heme side chains in the oxygenation of hemoglobin, J. Biochem. 92 (1982) 1713-1722], whose O{sub 2} affinity and cooperativity were higher and lower, respectively, relative to those of native protein. These results indicated that the heme orientational disorder could exert little effect, if any, on the O{sub 2} affinity properties of Hb A. This finding provides new insights into structure-function relationship of Hb A.

  15. A rapid paper-based test for quantifying sickle hemoglobin in blood samples from patients with sickle cell disease.

    PubMed

    Piety, Nathaniel Z; Yang, Xiaoxi; Lezzar, Dalia; George, Alex; Shevkoplyas, Sergey S

    2015-06-01

    Quantification of sickle hemoglobin (HbS) in patients with sickle cell disease (SCD) undergoing hydroxyurea or chronic transfusion therapy is essential to monitoring the effectiveness of these therapies. The clinical monitoring of %HbS using conventional laboratory methods is limited by high per-test costs and long turnaround times usually associated with these methods. Here we demonstrate a simple, rapid, inexpensive paper-based assay capable of quantifying %HbS in blood samples from patients with SCD. A 20 μL droplet of whole blood and hemoglobin solubility buffer was deposited on chromatography paper. The relative color intensities of regions of the resulting blood stain, determined by automated image analysis, are used to estimate %HbS. We compared the paper-based assay with hemoglobin electrophoresis (comparison method) using blood samples from 88 subjects. The test shows high correlation (R(2)  = 0.86) and strong agreement (standard deviation of difference = 7%HbS) with conventional Hb electrophoresis measurement of %HbS, and closely approximates clinically predicted change in %HbS with transfusion therapy (mean difference 2.6%HbS, n = 5). The paper-based assay can be completed in less than 35 min and has a per-test cost less than $0.25. The assay is accurate across a wide range of HbS levels (10-97%) and hemoglobin concentrations (5.6-12.9 g/dL) and is unaffected by high levels of HbF (up to 80.6%). This study demonstrates the feasibility of the paper-based %HbS assay. The paper-based test could improve clinical care for SCD, particularly in resource-limited settings, by enabling more rapid and less expensive %HbS monitoring.

  16. A near infrared instrument to monitor relative hemoglobin concentrations of human bone tissue in vitro and in vivo.

    PubMed

    Aziz, Syed Mahfuzul; Khambatta, Faram; Vaithianathan, Tharshan; Thomas, John C; Clark, Jillian M; Marshall, Ruth

    2010-04-01

    A continuous wave near infrared instrument has been developed to monitor in vivo changes in the hemoglobin concentration of the trabecular compartment of human bone. The transmitter uses only two laser diodes of wavelengths 685 and 830 nm, and the receiver uses a single silicon photodiode operating in the photovoltaic mode. The functioning of the instrument and the depth of penetration of the near infrared signals was determined in vitro using tissue-equivalent phantoms. The instrument achieves a depth of penetration of approximately 2 cm for an optode separation of 4 cm and, therefore, has the capacity to interrogate the trabecular compartment of human bone. The functioning of the instrument was tested in vivo to evaluate the relative oxy-hemoglobin (HbO(2)) and deoxy-hemoglobin (Hb) concentrations of the proximal tibial bone of apparently healthy, normal weight, adult subjects in response to a 3 min on, 5 min off, vascular occlusion protocol. The traces of the relative Hb and HbO(2) concentrations obtained were reproducible in controlled conditions. The instrument is relatively simple and flexible, and offers an inexpensive platform for further studies to obtain normative data for healthy cohorts, and to evaluate disease-specific performance characteristics for cohorts with vasculopathies of bone.

  17. A comparative analysis of clustering algorithms: O2 migration in truncated hemoglobin I from transition networks

    NASA Astrophysics Data System (ADS)

    Cazade, Pierre-André; Zheng, Wenwei; Prada-Gracia, Diego; Berezovska, Ganna; Rao, Francesco; Clementi, Cecilia; Meuwly, Markus

    2015-01-01

    The ligand migration network for O2-diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k-means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k-means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.

  18. A comparative analysis of clustering algorithms: O2 migration in truncated hemoglobin I from transition networks.

    PubMed

    Cazade, Pierre-André; Zheng, Wenwei; Prada-Gracia, Diego; Berezovska, Ganna; Rao, Francesco; Clementi, Cecilia; Meuwly, Markus

    2015-01-14

    The ligand migration network for O2-diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k-means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k-means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.

  19. A preliminary study on the antibacterial mechanism of Tegillarca granosa hemoglobin by derived peptides and peroxidase activity.

    PubMed

    Bao, Yongbo; Wang, Juanjuan; Li, Chenghua; Li, Peifen; Wang, Sufang; Lin, Zhihua

    2016-04-01

    The blood clam, Tegillarca granosa, is one of the few bivalve molluscs containing hemoglobin (Hb). In the present study, we purified two types of T. granosa hemoglobin, Tg-HbI and Tg-HbII, using size exclusion chromatography and measured their antibacterial and peroxidase activities. We also tested antibacterial activities of peptides prepared by trypsin digestion of purified Tg-Hb and reversed-phase high-performance liquid chromatography purification. Purified Tg-HbI and Tg-HbII showed antibacterial activity against Escherichia coli, Pseudomonas putida, Bacillus subtilis, and Bacillus firmus, with differences in minimal inhibitory concentrations (MICs), but lacked antibacterial activity against Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi and Staphylococcus aureus. In contrast, 7 Tg-Hb derived peptides exhibited varying degrees of antibacterial activity against V. alginolyticus (MICs: 12-200 μg/ml), V. parahaemolyticus (11-100 μg/ml) and V. harveyi (1-200 μg/ml). The antibacterial activity of Hb derived peptides was confirmed by fluorescence microscopy. In addition, peroxidase activity was detected in Tg-HbI and Tg-HbII. The results indicated that in addition to functioning as a respiratory protein T. granosa hemoglobins likely play a role in host antibacterial defense probably via a peroxidase activity of native molecules and some internal peptides released from the proteins.

  20. Effects of Sleep Disorders on Hemoglobin A1c Levels in Type 2 Diabetic Patients

    PubMed Central

    Keskin, Ahmet; Ünalacak, Murat; Bilge, Uğur; Yildiz, Pinar; Güler, Seda; Selçuk, Engin Burak; Bilgin, Muzaffer

    2015-01-01

    Background: Studies have reported the presence of sleep disorders in approximately 50–70% of diabetic patients, and these may contribute to poor glycemic control, diabetic neuropathy, and overnight hypoglycemia. The aim of this study was to determine the frequency of sleep disorders in diabetic patients, and to investigate possible relationships between scores of these sleep disorders and obstructive sleep apnea syndrome (OSAS) and diabetic parameters (fasting blood glucose, glycated hemoglobin A1c [HbA1c], and lipid levels). Methods: We used the Berlin questionnaire (BQ) for OSAS, the Epworth Sleepiness Scale (ESS), and the Pittsburgh Sleep Quality Index (PSQI) to determine the frequency of sleep disorders and their possible relationships with fasting blood glucose, HbA1c, and lipid levels. Results: The study included 585 type 2 diabetic patients admitted to family medicine clinics between October and December 2014. Sleep, sleep quality, and sleep scores were used as the dependent variables in the analysis. The ESS scores showed that 54.40% of patients experienced excessive daytime sleepiness, and according to the PSQI, 64.30% experienced poor-quality sleep. The BQ results indicated that 50.20% of patients were at high-risk of OSAS. HbA1c levels correlated significantly with the ESS and PSQI results (r = 0.23, P < 0.001 and r = 0.14, P = 0.001, respectively), and were significantly higher in those with high-risk of OSAS as defined by the BQ (P < 0.001). These results showed that HbA1c levels were related to sleep disorders. Conclusions: Sleep disorders are common in diabetic patients and negatively affect the control of diabetes. Conversely, poor diabetes control is an important factor disturbing sleep quality. Addressing sleep disturbances in patients who have difficulty controlling their blood glucose has dual benefits: Preventing diabetic complications caused by sleep disturbance and improving diabetes control. PMID:26668142

  1. Unraveling the interaction of hemoglobin with a biocompatible and cleavable oxy-diester-functionalized gemini surfactant.

    PubMed

    Akram, Mohd; Anwar, Sana; Bhat, Imtiyaz Ahmad; Kabir-Ud-Din

    2017-03-01

    Surfactant-protein mixtures have attracted considerable research interest in recent years at the interface of chemical biology and medicinal chemistry. Herein, the interaction between a green gemini surfactant (C16-E2O-C16) and a redox protein hemoglobin was examined through a series of in vitro experimental techniques with an attempt to provide a comprehensive knowledge of the surfactant-protein binding interactions. Quantitative appraisal of the fluorescence/CV data showed that the binding of C16-E2O-C16 to Hb leads to the formation of thermodynamically favorable non-covalent adduct with 1:1 stoichiometry. UV-vis spectra demonstrated that the effect of C16-E2O-C16 on Hb is highly concentration dependent. Far-UV and near-UV CD spectra together elucidated the formation of molten globule state of Hb upon C16-E2O-C16 addition. Temperature dependent CD explicated the effect of C16-E2O-C16 on the thermal stability of Hb. Furthermore, the structural investigation of Hb via pyrene/synchronous/three-dimensional fluorescence and FT-IR spectroscopy provided the complementary information related to its microenvironmental and conformational changes. Computational studies delineated that C16-E2O-C16 binds in the vicinity of β-37 Trp at the α1β2 interface of Hb. Overall, this study is expected to clarify the binding mechanism between Hb/other congeners and surfactant at the molecular level that are known to have immense potential in biomedical and industrial areas.

  2. A new insight into fecal hemoglobin concentration-dependent predictor for colorectal neoplasia.

    PubMed

    Yen, Amy Ming-Fang; Chen, Sam Li-Sheng; Chiu, Sherry Yueh-Hsia; Fann, Jean Ching-Yuan; Wang, Po-En; Lin, Sheng-Che; Chen, Yao-Der; Liao, Chao-Sheng; Yeh, Yen-Po; Lee, Yi-Chia; Chiu, Han-Mo; Chen, Hsiu-Hsi

    2014-09-01

    We sought to assess how much of the variation in incidence of colorectal neoplasia is explained by baseline fecal hemoglobin concentration (FHbC) and also to assess the additional predictive value of conventional risk factors. We enrolled subjects aged 40 years and over who attended screening for colorectal cancer with the fecal immunochemical test (FIT) in Keelung community-based integrated screening program. The accelerated failure time model was used to train the clinical weights of covariates in the prediction model. Datasets from two external communities were used for external validation. The area under curve (AUC) for the model containing only FHbC was 83.0% (95% CI: 81.5-84.4%), which was considerably greater than the one containing only conventional risk factors (65.8%, 95% CI: 64.2-67.4%). Adding conventional risk factors did not make significant additional contribution (p = 0.62, AUC = 83.5%, 95% CI: 82.1-84.9%) to the predictive model with FHbC only. Males showed a stronger linear dose-response relationship than females, yielding gender-specific FHbC predictive models. External validation confirms these results. The high predictive ability supported by a dose-dependent relationship between baseline FHbC and the risk of developing colorectal neoplasia suggests that FHbC may be useful for identifying cases requiring closer postdiagnosis clinical surveillance as well as being an early indicator of colorectal neoplasia risk in the general population. Our findings may also make contribution to the development of the FHbC-guided screening policy but its pros and cons in connection with cost and effectiveness of screening should be evaluated before it can be applied to population-based screening for colorectal cancer.

  3. Vitamin D Supplementation and Hemoglobin Levels in Hypertensive Patients: A Randomized Controlled Trial

    PubMed Central

    Ernst, Jana B.; Tomaschitz, Andreas; Grübler, Martin R.; Gaksch, Martin; Kienreich, Katharina; Verheyen, Nicolas; März, Winfried; Pilz, Stefan; Zittermann, Armin

    2016-01-01

    Epidemiological evidence suggests that circulating 25-hydroxyvitamin D (25OHD) levels are inversely associated with hemoglobin (Hb) levels and anemia risk. We evaluated whether vitamin D supplementation improves Hb levels and reduces anemia risk in hypertensive patients. Two hundred patients with 25OHD levels <75 nmol/L who attended the Styrian Vitamin D Hypertension Trial were included, of whom 188 completed the trial. Patients randomly received 2800 IU vitamin D3 daily or a matching placebo for eight weeks. Initially, the prevalence of anemic status (Hb levels <12.5 g/dL) and deficient 25OHD levels (<30 nmol/L) was 6.5% and 7.5%, respectively. All anemic patients had 25OHD levels >50 nmol/L. The mean (95% confidence interval) vitamin D effect on Hb levels was 0.04 (−0.14 to 0.22) g/dL (P = 0.661). Moreover, vitamin D treatment did not influence anemic status significantly (P > 0.999). Likewise, vitamin D had no significant effect on Hb levels in the subgroups of anemic patients or in patients with initial 25OHD levels <30 nmol/L. In conclusion, a daily vitamin D supplement of 2800 IU for eight weeks did not improve Hb levels or anemic status in hypertensive patients. Future trials should focus on anemic patients with deficient 25OHD levels (e.g., <30 nmol/L). This trial is registered with clinicaltrials.gov [NCT02136771]. PMID:27006655

  4. Kinetic study of the inhibition mechanism of dehaloperoxidase-hemoglobin a by 4-bromophenol.

    PubMed

    Zhao, Jing; Franzen, Stefan

    2013-07-18

    The mechanism of dehaloperoxidase-hemoglobin (DHP) inhibition by 4-bromophenol (4-BP) was investigated using Michealis-Menten and transient-state kinetic analyses. Transient-state kinetics using the stopped-flow technique to mix DHP and H2O2 in the presence of inhibitor concentrations less than 10-fold greater than the enzyme concentration show that 4-BP does not fully impede H2O2 entering the distal pocket to activate DHP. It is not clear whether an oxoferryl intermediate is formed under these conditions and there may be alternative pathways for H2O2 reaction in the 4-BP bound form of DHP. Two new species have been identified during the reaction of 4-BP bound form of DHP in the transient-state kinetic experiment by using Singular Value Decomposition (SVD) and global-fitting analysis. Rather than forming Compound ES in the unbound form, an inhibitor bound intermediate that possesses blue-shifted Soret band and a double peaked Q-band is observed. This intermediate is subsequently converted to the end-point species that is distinguished from Compound RH formed in the uninhibited enzyme. Bench-top mixing kinetics of DHP were conducted in order to determine the inhibitor binding constant and to understand the enzyme inhibition mechanism from a thermodynamic perspective. It was found that the inhibition constant, Ki, decreased from 2.56 mM to 0.15 mM over the temperature range from 283 to 298 K, which permits determination of the enthalpy and entropy for inhibitor binding as -135.5 ± 20.9 kJ/mol and 526.1 ± 71.9 J/(mol·K), respectively, leading to the conclusion that inhibitor binding is entropically driven.

  5. Reactivating Fetal Hemoglobin Expression in Human Adult Erythroblasts Through BCL11A Knockdown Using Targeted Endonucleases

    PubMed Central

    Bjurström, Carmen F; Mojadidi, Michelle; Phillips, John; Kuo, Caroline; Lai, Stephen; Lill, Georgia R; Cooper, Aaron; Kaufman, Michael; Urbinati, Fabrizia; Wang, Xiaoyan; Hollis, Roger P; Kohn, Donald B

    2016-01-01

    We examined the efficiency, specificity, and mutational signatures of zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 systems designed to target the gene encoding the transcriptional repressor BCL11A, in human K562 cells and human CD34+ progenitor cells. ZFNs and TALENs were delivered as in vitro transcribed mRNA through electroporation; CRISPR/Cas9 was codelivered by Cas9 mRNA with plasmid-encoded guideRNA (gRNA) (pU6.g1) or in vitro transcribed gRNA (gR.1). Analyses of efficacy revealed that for these specific reagents and the delivery methods used, the ZFNs gave rise to more allelic disruption in the targeted locus compared to the TALENs and CRISPR/Cas9, which was associated with increased levels of fetal hemoglobin in erythroid cells produced in vitro from nuclease-treated CD34+ cells. Genome-wide analysis to evaluate the specificity of the nucleases revealed high specificity of this specific ZFN to the target site, while specific TALENs and CRISPRs evaluated showed off-target cleavage activity. ZFN gene-edited CD34+ cells had the capacity to engraft in NOD-PrkdcSCID-IL2Rγnull mice, while retaining multi-lineage potential, in contrast to TALEN gene-edited CD34+ cells. CRISPR engraftment levels mirrored the increased relative plasmid-mediated toxicity of pU6.g1/Cas9 in hematopoietic stem/progenitor cells (HSPCs), highlighting the value for the further improvements of CRISPR/Cas9 delivery in primary human HSPCs. PMID:28131278

  6. Pretreatment Hematocrit Is Superior to Hemoglobin as a Prognostic Factor for Triple Negative Breast Cancer

    PubMed Central

    Ai, Xiaohong; Chen, Xi; Zhang, Xiaoyan; Li, Zhiyan; Xie, Xiaoming

    2016-01-01

    Background Anemia usually refers to low hemoglobin (Hb) levels. Previous studies indicated that anemia negatively influence the survival in various cancers. Hematocrit (HCT) is the volume percentage of red blood cells in blood, which could indicate anemia in both individuals and populations. This study compared the value of HCT with that of Hb for predicting outcomes of patients who underwent treatment for triple negative breast cancer (TNBC). Methods A retrospective study of 293 triple negative breast cancer patients, accepting treatment from January 2004 to December 2009 at Sun Yat-sen University Cancer Center, was conducted. Kaplan-Meier curves and multivariate Cox proportional models were used to calculate disease free survival (DFS) and overall survival (OS). Results The cut-off value of HCT was 35.9% determined by X-tile software analysis. The cut-off value of Hb was 12.0 g/dl based on the World Health Organization (WHO) criteria. In univariate analysis, low HCT and low Hb were both significantly associated with decreased DFS and OS. In multivariate analysis, HCT (HR: 0.570; 95% CI: 0.331–0.981, P = 0.042 for DFS; HR: 0.456; 95% CI: 0.256–0.813, P = 0.008 for OS) was still identified as independent predictor of outcome, but not Hb. Conclusion Pretreatment low HCT is independently associated with poor prognosis in TNBC patients. However, HCT was found to be superior to Hb in terms of predicting breast cancer mortality. In the future, large-scale prospective studies or validation studies are needed to verify our findings. PMID:27851755

  7. 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.

  8. ESA and iron therapy in chronic kidney disease: a balance between patient safety and hemoglobin target.

    PubMed

    Hung, Szu-Chun; Tarng, Der-Cherng

    2014-10-01

    Optimal treatment algorithms for erythropoiesis-stimulating agent (ESA) and iron therapy in anemic CKD patients are lacking. Kuragano et al. evaluated hemodialysis patients over two years and report increased mortality risk and/or adverse events in those with high serum ferritin levels and high ferritin fluctuations, and an increase in adverse events in iron users. Clinical practice should avoid disproportionately high ESA or iron doses to achieve hemoglobin targets, particularly in those with significant comorbidity or ESA resistance.

  9. Hemoglobin and hemin induce DNA damage in human colon tumor cells HT29 clone 19A and in primary human colonocytes.

    PubMed

    Glei, Michael; Klenow, Stefanie; Sauer, Julia; Wegewitz, Uta; Richter, Konrad; Pool-Zobel, Beatrice L

    2006-02-22

    Epidemiological findings have indicated that red meat increases the likelihood of colorectal cancer. Aim of this study was to investigate whether hemoglobin, or its prosthetic group heme, in red meat, is a genotoxic risk factor for cancer. Human colon tumor cells (HT29 clone 19A) and primary colonocytes were incubated with hemoglobin/hemin and DNA damage was investigated using the comet assay. Cell number, membrane damage, and metabolic activity were measured as parameters of cytotoxicity in both cell types. Effects on cell growth were determined using HT29 clone 19A cells. HT29 clone 19A cells were also used to explore possible pro-oxidative effects of hydrogen peroxide (H2O2) and antigenotoxic effects of the radical scavenger dimethyl sulfoxide (DMSO). Additionally we determined in HT29 clone 19A cells intracellular iron levels after incubation with hemoglobin/hemin. We found that hemoglobin increased DNA damage in primary cells (> or =10 microM) and in HT29 clone 19A cells (> or =250 microM). Hemin was genotoxic in both cell types (500-1000 microM) with concomitant cytotoxicity, detected as membrane damage. In both cell types, hemoglobin and hemin (> or =100 microM) impaired metabolic activity. The growth of HT29 clone 19A cells was reduced by 50 microM hemoglobin and 10 microM hemin, indicating cytotoxicity at genotoxic concentrations. Hemoglobin or hemin did not enhance the genotoxic activity of H2O2 in HT29 clone 19A cells. On the contrary, DMSO reduced the genotoxicity of hemoglobin, which indicated that free radicals were scavenged by DMSO. Intracellular iron increased in hemoglobin/hemin treated HT29 clone 19A cells, reflecting a 40-50% iron uptake for each compound. In conclusion, our studies show that hemoglobin is genotoxic in human colon cells, and that this is associated with free radical mechanisms and with cytotoxicity, especially for hemin. Thus, hemoglobin/hemin, whether available from red meat or from bowel bleeding, may pose genotoxic and

  10. Interpreting Hemoglobin A1C in Combination With Conventional Risk Factors for Prediction of Cardiovascular Risk

    PubMed Central

    Jarmul, Jamie A.; Pignone, Michael; Pletcher, Mark J.

    2015-01-01

    Background Hemoglobin A1C (HbA1C) is associated with increased risk of cardiovascular events, but its use for prediction of cardiovascular disease (CVD) events in combination with conventional risk factors has not been well defined. Methods and Results To understand the effect of HbA1C on CVD risk in the context of other CVD risk factors, we analyzed HbA1C and other CVD risk factor measurements in 2000 individuals aged 40-79 years old without pre-existing diabetes or cardiovascular disease from the 2011-2012 NHANES survey. The resulting regression model was used to predict the HbA1C distribution based on individual patient characteristics. We then calculated post-test 10-year atherosclerotic cardiovascular disease (ASCVD) risk incorporating the actual versus predicted HbA1C, according to established methods, for a set of example scenarios. Age, gender, race/ethnicity and traditional cardiovascular risk factors were significant predictors of HbA1C in our model, with the expected HbA1C distribution being significantly higher in non-Hispanic black, non-Hispanic Asian and Hispanic individuals than non-Hispanic white/other individuals. Incorporating the expected HbA1C distribution into pretest ASCVD risk has a modest effect on post-test ASCVD risk. In the patient examples we assessed, having an HbA1C < 5.7% reduced post-test risk by 0.4%-2.0% points, whereas having an HbA1C ≥ 6.5% increased post-test risk by 1.0%-2.5% points, depending on the scenario. The post-test risk increase from having an HbA1C ≥ 6.5 % tends to approximate the risk increase from being five years older in age. Conclusions HbA1C has modest effects on predicted ASCVD risk when considered in the context of conventional risk factors. PMID:26349840

  11. Protein characterization by LC-MS/MS may be required for the DNA identification of a fusion hemoglobin: the example of Hb P-Nilotic.

    PubMed

    Zanella-Cleon, Isabelle; Delolme, Frédéric; Lacan, Philippe; Garcia, Caroline; Vinatier, Isabelle; Francina, Alain; Joly, Philippe

    2012-02-01

    DNA analysis is currently the easiest way to identify a hemoglobin variant in most cases. Nevertheless, in case of complex gene rearrangements, mass spectrometry studies may be required to orientate the DNA diagnosis. The present report shows the use of mass spectrometry techniques prior to DNA analysis for the identification of the rare P-Nilotic fusion hemoglobin. Complete protein analysis is performed by liquid chromatography-tandem mass spectrometry on the abnormal globin chain isolated by reversed-phase liquid chromatography.

  12. Hypoglycemia Reduction and Changes in Hemoglobin A1c in the ASPIRE In-Home Study

    PubMed Central

    Weiss, Ram; Garg, Satish K.; Bode, Bruce W.; Bailey, Timothy S.; Ahmann, Andrew J.; Schultz, Kenneth A.; Welsh, John B.

    2015-01-01

    Abstract Background: ASPIRE In-Home randomized 247 subjects with type 1 diabetes to sensor-augmented pump therapy with or without the Threshold Suspend (TS) feature, which interrupts insulin delivery at a preset sensor glucose value. We studied the effects of TS on nocturnal hypoglycemia (NH) in relation to baseline hemoglobin A1c (A1C) and change in A1C during the study. Materials and Methods: NH event rates and mean area under curve (AUC) of NH events were evaluated at different levels of baseline A1C (<7%, 7–8%, and >8%) and at different levels of changes in A1C (less than −0.3% [decreased], −0.3% to 0.3% [stable], and >0.3% [increased]), in the TS Group compared with the Control Group (sensor-augmented pump only). Results: In the TS Group, 27.9% of the NH events were accompanied by a confirmatory blood glucose value, compared with 39.3% in the Control Group. Among subjects with baseline A1C levels of <7% or 7–8%, those in the TS Group had significantly lower NH event rates than those in the Control Group (P=0.001 and P=0.004, respectively). Among subjects with decreased or stable A1C levels, those in the TS Group had significantly lower NH event rates, and the events had lower AUCs (P≤0.001 for each). Among subjects with increased A1C levels, those in the TS Group had NH events with significantly lower AUCs (P<0.001). Conclusions: Use of the TS feature was associated with decreases in the rate and severity (as measured by AUC) of NH events in many subjects, including those with low baseline A1C levels and those whose A1C values decreased during the study period. Use of the TS feature can help protect against hypoglycemia in those wishing to intensify diabetes management to achieve target glucose levels. PMID:26237308

  13. Glycated Hemoglobin Level and Mortality in a Nondiabetic Population with CKD

    PubMed Central

    Metzger, Marie; Haymann, Jean-Philippe; Boffa, Jean-Jacques; Flamant, Martin; Vrtovsnik, François; Houillier, Pascal; Stengel, Benedicte; Thervet, Eric

    2015-01-01

    Background and objectives Glycated hemoglobin (HbA1c) is used to diagnose diabetes mellitus (DM) and guide its management. The association between higher HbA1c and progression to ESRD and mortality has been demonstrated in populations with DM. This study examined the association between HbA1c and these end points in a population with CKD and without DM. Design, setting, participants, & measurements In the hospital-based NephroTest cohort study, measured GFR (mGFR) was taken by 51Cr-EDTA renal clearance and HbA1c in 1165 adults with nondialysis CKD stages 1–5 and without DM between January 2000 and December 2010. The median follow-up was 3.48 years (interquartile range, 1.94–5.82) for the competing events of ESRD and pre-ESRD mortality. Time-fixed and time-dependent Cox models were used to estimate hazard ratios (HRs) for ESRD and mortality according to HbA1c, treated continuously or in tertiles. Results At inclusion, the mean mGFR was 42.2±19.9 ml/min per 1.73 m2, and the mean HbA1c value was 5.5%±0.5%. During follow-up, 109 patients died, and 162 patients reached ESRD. Pre-ESRD mortality was significantly associated with HbA1c treated continuously: for every 1% higher HbA1c, the crude HR was 2.16 (95% confidence interval [95% CI], 1.27 to 3.68), and it was 1.85 (95% CI, 1.05 to 3.24) after adjustment for mGFR and other risk factors of death. After excluding incident diabetes over time, the updated mean of HbA1c remained significantly associated with higher mortality risk: adjusted HR for the highest (5.7%–6.4%) versus the lowest tertile (<5.3%) was 2.62 (95% CI, 1.16 to 5.91). There was no association with ESRD risk after adjustment for risk factors of CKD progression. Conclusions In a CKD cohort, HbA1c values in the prediabetes range are associated with mortality. Such values should be therefore included among the risk factors for negative outcomes in CKD populations. PMID:25979978

  14. BIOMARKERS IN DIABETES: HEMOGLOBIN A1c, VASCULAR AND TISSUE MARKERS

    PubMed Central

    Lyons, Timothy J; Basu, Arpita

    2012-01-01

    Biomarkers are conventionally defined as ‘biological molecules that represent health and disease states.’ They typically are measured in readily available body fluids (blood or urine), lie outside the causal pathway, are able to detect sub-clinical disease, and are used to monitor clinical and sub-clinical disease burden and response to treatments. Biomarkers can be “direct” endpoints of the disease itself, or “indirect” or surrogate endpoints. New technologies (such as metabolomics, proteomics, genomics) bring a wealth of opportunity to develop new biomarkers. Other new technologies enable the development of non-molecular, functional or bio-physical tissue-based biomarkers. Diabetes mellitus is a complex disease affecting almost every tissue and organ system, with metabolic ramifications extending far beyond impaired glucose metabolism. Biomarkers may reflect the presence and severity of hyperglycemia (i.e. diabetes itself), or the presence and severity of the vascular complications of diabetes. Illustrative examples are considered in this brief review. In blood, hemoglobin A1c (HbA1c) may be considered as a biomarker for the presence and severity of hyperglycemia, implying diabetes or pre-diabetes, or, over time, as a “biomarker for a risk factor”, i.e. hyperglycemia as a risk factor for diabetic retinopathy, nephropathy, and other vascular complications of diabetes. In tissues, glycation and oxidative stress resulting from hyperglycemia and dyslipidemia lead to widespread modification of biomolecules by advanced glycation end products (AGEs). Some of these altered species may serve as biomarkers, whereas others may lie in the causal pathway for vascular damage. New non-invasive technologies can detect tissue damage mediated by AGE formation: these include indirect measures such as pulse wave analysis (a marker of vascular dysfunction) and more direct markers such as skin autofluorescence (a marker of long-term accumulation of AGEs). In the future

  15. Local Population Characteristics and Hemoglobin A1c Testing Rates among Diabetic Medicare Beneficiaries

    PubMed Central

    Yasaitis, Laura C.; Bubolz, Thomas; Skinner, Jonathan S.; Chandra, Amitabh

    2014-01-01

    Background Proposed payment reforms in the US healthcare system would hold providers accountable for the care delivered to an assigned patient population. Annual hemoglobin A1c (HbA1c) tests are recommended for all diabetics, but some patient populations may face barriers to high quality healthcare that are beyond providers' control. The magnitude of fine-grained variations in care for diabetic Medicare beneficiaries, and their associations with local population characteristics, are unknown. Methods HbA1c tests were recorded for 480,745 diabetic Medicare beneficiaries. Spatial analysis was used to create ZIP code-level estimated testing rates. Associations of testing rates with local population characteristics that are outside the control of providers – population density, the percent African American, with less than a high school education, or living in poverty – were assessed. Results In 2009, 83.3% of diabetic Medicare beneficiaries received HbA1c tests. Estimated ZIP code-level rates ranged from 71.0% in the lowest decile to 93.1% in the highest. With each 10% increase in the percent of the population that was African American, associated HbA1c testing rates were 0.24% lower (95% CI −0.32–−0.17); for identical increases in the percent with less than a high school education or the percent living in poverty, testing rates were 0.70% lower (−0.95–−0.46) and 1.6% lower (−1.8–−1.4), respectively. Testing rates were lowest in the least and most densely populated ZIP codes. Population characteristics explained 5% of testing rate variations. Conclusions HbA1c testing rates are associated with population characteristics, but these characteristics fail to explain the vast majority of variations. Consequently, even complete risk-adjustment may have little impact on some process of care quality measures; much of the ZIP code-related variations in testing rates likely result from provider-based differences and idiosyncratic local factors not related to

  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. 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.

  18. 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

  19. 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.

  20. Association between Inflammation and Biological Variation in Hemoglobin A1c in U.S. Nondiabetic Adults

    PubMed Central

    Liu, Shuqian; Hempe, James M.; McCarter, Robert J.; Li, Shengxu

    2015-01-01

    Context: Inflammation is associated with higher glycated hemoglobin (HbA1c) levels. Whether the relationship is independent of blood glucose concentration remains unclear. Objective: The hemoglobin glycation index (HGI) was used to test the hypothesis that interindividual variation in HbA1c is associated with inflammation. Participants: This study used nondiabetic adults from the National Health and Nutrition Examination Survey (1999–2008). Main Outcome Measures: A subsample of participants was used to estimate the linear regression relationship between HbA1c and fasting plasma glucose (FPG). Predicted HbA1c were calculated for 7323 nondiabetic participants by inserting FPG into the equation, HbA1c = 0.017× FPG (mg/dL) + 3.7. HGI was calculated as the difference between the observed and predicted HbA1c and the population was divided into low, moderate, and high HGI subgroups. Polymorphonuclear leukocytes (PMNL), monocytes, and C-reactive protein (CRP) were used as biomarkers of inflammation. Results: Mean HbA1c, CRP, monocyte, and PMNL levels, but not FPG, progressively increased in the low, moderate, and high HGI subgroups. There were disproportionately more Blacks than whites in the high HGI subgroup. CRP (ß, 0.009; 95% confidence interval [CI], 0.0001–0.017), PMNL (ß, 0.036; 95% CI, 0.010–0.062), and monocyte count (ß, 0.072; 95% CI, 0.041–0.104) were each independent predictors of HGI after adjustment for age, sex, race, triglycerides, hemoglobin level, mean corpuscular volume, red cell distribution width, and obesity status. Conclusions: HGI reflects the effects of inflammation on HbA1c in a nondiabetic population of U.S. adults and may be a marker of risk associated with inflammation independent of FPG, race, and obesity. PMID:25867810

  1. A new alpha chain hemoglobin variant: Hb Al-Hammadi Riyadh [alpha75(EF4)Asp-->Val (alpha2)].

    PubMed

    Burnichon, Nelly; Lacan, Philippe; Becchi, Michel; Zanella-Cleon, Isabelle; Aubry, Martine; Mowafy, Mohammed; Couprie, Nicole; Francina, Alain

    2006-01-01

    A new hemoglobin (Hb) variant in the heterozygous state, Hb Al-Hammadi Riyadh [codon 75 (GAC-->GTC); alpha75(EF4)Asp-->Val (alpha2)] corresponding to an A-->T transversion on the second exon of the alpha2-globin gene, is described. The variant was characterized by DNA sequencing and mass spectrometry (MS). The variant was found during a routine Hb analysis for anemia in a 16-month-old boy who lived in Riyadh, Kingdom of Saudi Arabia.

  2. Hemoglobin Kirklareli (α H58L), a New Variant Associated with Iron Deficiency and Increased CO Binding.

    PubMed

    Bissé, Emmanuel; Schaeffer-Reiss, Christine; Van Dorsselaer, Alain; Alayi, Tchilabalo Dilezitoko; Epting, Thomas; Winkler, Karl; Benitez Cardenas, Andres S; Soman, Jayashree; Birukou, Ivan; Samuel, Premila P; Olson, John S

    2017-02-10

    Mutations in hemoglobin can cause a wide range of phenotypic outcomes, including anemia due to protein instability and red cell lysis. Uncovering the biochemical basis for these phenotypes can provide new insights into hemoglobin structure and function as well as identify new therapeutic opportunities. We report here a new hemoglobin α chain variant in a female patient with mild anemia, whose father also carries the trait and is from the Turkish city of Kirklareli. Both the patient and her father had a His-58(E7) → Leu mutation in α1. Surprisingly, the patient's father is not anemic, but he is a smoker with high levels of HbCO (∼16%). To understand these phenotypes, we examined recombinant human Hb (rHb) Kirklareli containing the α H58L replacement. Mutant α subunits containing Leu-58(E7) autoxidize ∼8 times and lose hemin ∼200 times more rapidly than native α subunits, causing the oxygenated form of rHb Kirklareli to denature very rapidly under physiological conditions. The crystal structure of rHb Kirklareli shows that the α H58L replacement creates a completely apolar active site, which prevents electrostatic stabilization of bound O2, promotes autoxidation, and enhances hemin dissociation by inhibiting water coordination to the Fe(III) atom. At the same time, the mutant α subunit has an ∼80,000-fold higher affinity for CO than O2, causing it to rapidly take up and retain carbon monoxide, which prevents denaturation both in vitro and in vivo and explains the phenotypic differences between the father, who is a smoker, and his daughter.

  3. Biophysical Characterisation of Neuroglobin of the Icefish, a Natural Knockout for Hemoglobin and Myoglobin. Comparison with Human Neuroglobin

    PubMed Central

    Giordano, Daniela; Boron, Ignacio; Abbruzzetti, Stefania; Van Leuven, Wendy; Nicoletti, Francesco P.; Forti, Flavio; Bruno, Stefano; Cheng, C-H. Christina; Moens, Luc; di Prisco, Guido; Nadra, Alejandro D.; Estrin, Darío; Smulevich, Giulietta; Dewilde, Sylvia; Viappiani, Cristiano; Verde, Cinzia

    2012-01-01

    The Antarctic icefish Chaenocephalus aceratus lacks the globins common to most vertebrates, hemoglobin and myoglobin, but has retained neuroglobin in the brain. This conserved globin has been cloned, over-expressed and purified. To highlight similarities and differences, the structural features of the neuroglobin of this colourless-blooded fish were compared with those of the well characterised human neuroglobin as well as with the neuroglobin from the retina of the red blooded, hemoglobin and myoglobin-containing, closely related Antarctic notothenioid Dissostichus mawsoni. A detailed structural and functional analysis of the two Antarctic fish neuroglobins was carried out by UV-visible and Resonance Raman spectroscopies, molecular dynamics simulations and laser-flash photolysis. Similar to the human protein, Antarctic fish neuroglobins can reversibly bind oxygen and CO in the Fe2+ form, and show six-coordination by distal His in the absence of exogenous ligands. A very large and structured internal cavity, with discrete docking sites, was identified in the modelled three-dimensional structures of the Antarctic neuroglobins. Estimate of the free-energy barriers from laser-flash photolysis and Implicit Ligand Sampling showed that the cavities are accessible from the solvent in both proteins. Comparison of structural and functional properties suggests that the two Antarctic fish neuroglobins most likely preserved and possibly improved the function recently proposed for human neuroglobin in ligand multichemistry. Despite subtle differences, the adaptation of Antarctic fish neuroglobins does not seem to parallel the dramatic adaptation of the oxygen carrying globins, hemoglobin and myoglobin, in the same organisms. PMID:23226490

  4. 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.

  5. 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...

  6. Association Between the Presence of Iron Deficiency Anemia and Hemoglobin A1c in Korean Adults

    PubMed Central

    Hong, Jae W.; Ku, Cheol R.; Noh, Jung H.; Ko, Kyung S.; Rhee, Byoung D.; Kim, Dong-Jun

    2015-01-01

    Abstract Few studies have investigated the clinical effect of iron deficiency anemia (IDA) on the use of the Hemoglobin A1c (HbA1c) as a screening parameter for diabetes or prediabetes. We investigated the association between IDA and HbA1c levels in Korean adults. Among the 11,472 adults (≥19 years of age) who participated in the 2011–2012 Korea National Health and Nutrition Examination Survey (a cross-sectional and nationally representative survey conducted by the Korean Center for Disease Control for Health Statistics), 807 patients with diabetes currently taking anti-diabetes medications were excluded from this study. We compared the weighted HbA1c levels and weighted proportion (%) of HbA1c levels of ≥5.7%, ≥6.1%, and ≥6.5% according to the range of fasting plasma glucose (FPG) levels and the presence of IDA. Among 10,665 participants (weighted n = 35,229,108), the prevalence of anemia and IDA was 7.3% and 4.3%, respectively. The HbA1c levels were higher in participants with IDA (5.70% ± 0.02%) than in normal participants (5.59% ± 0.01%; P < 0.001), whereas there was no significant difference in FPG levels. In participants with an FPG level of <100 mg/dL and 100 to 125 mg/dL, the weighted HbA1c level was higher in those with IDA (5.59% ± 0.02% and 6.00% ± 0.05%) than in normal participants (5.44% ± 0.01% and 5.82% ± 0.01%) after adjusting for confounders such as age, sex, FPG level, heavy alcohol drinking, waist circumference, and smoking status as well as after exclusion of an estimated glomerular filtration rate of <60 mL/min/1.73 m2 (P < 0.001, <0.01). The weighted proportions (%) of an HbA1c level of ≥5.7% and ≥6.1% were also higher in participants with IDA than in normal participants (P < 0.001, <0.05). However, the weighted HbA1c levels in individuals with an FPG level ≥126 mg/dL and a weighted proportion (%) of an HbA1c level of ≥6.5% showed no significant differences according to

  7. 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

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. Optical noninvasive calculation of hemoglobin components concentrations and fractional oxygen saturation using a ring-scattering pulse oximeter

    NASA Astrophysics Data System (ADS)

    Abdallah, Omar; Stork, Wilhelm; Muller-Glaser, Klaus

    2004-06-01

    The deficiencies of the currently used pulse oximeter are discussed in diverse literature. A hazardous pitfalls of this method is that the pulse oximeter will not detect carboxyhemoglobin (COHb) and methemoglobin (metHb) concentrations. This leads to incorrect measurement of oxygen saturation by carbon monoxide poisoning and methemoglobinemia. Also the total hemoglobin concentration will not be considered and can only be measured in-vitro up to now. A second pitfall of the standard pulse oximetry is that it will not be able to show a result by low perfusion of tissues. This case is available inter alia when the patient is under shock or has a low blood pressure. The new non-invasive system we designed measures the actual (fractional) oxygen saturation and hemoglobin concentration. It will enable us also to measure COHb and metHb. The measurement can be applied at better perfused body central parts. Four or more light emitting diodes (LEDs) or laser diodes (LDs) and five photodiodes (PDs) are used. The reflected light signal detected by photodiodes is processed using a modified Lambert-Beer law (I=I0×e-α.d ). According to this law, when a non scattering probe is irradiated with light having the incident intensity I0, the intensity of transmitted light I decays exponentially with the absorption coefficient a of that probe and its thickness d. Modifications of this law have been performed following the theoretical developed models in literature, Monte Carlo simulation and experimental measurement.

  13. Thrombocytopenia and erythrocytosis in mice with a mutation in the gene encoding the hemoglobin β minor chain

    PubMed Central

    Kauppi, Maria; Hilton, Adrienne A.; Metcalf, Donald; Ng, Ashley P.; Hyland, Craig D.; Collinge, Janelle E.; Kile, Benjamin T.; Hilton, Douglas J.; Alexander, Warren S.

    2012-01-01

    Diverse mutations in the genes encoding hemoglobin (Hb) have been characterized in human disease. We describe here a mutation in the mouse Hbb-b2 gene, denoted Plt12, that precisely mimics the human hemoglobin Hotel Dieu variant. The mutation results in increased affinity of Hb for oxygen and Plt12 mutant mice exhibited reduced partial pressure of O2 in the blood, accompanied by erythrocytosis characterized by elevated erythropoietin levels and splenomegaly with excess erythropoiesis. Most homozygous Hbb-b2Plt12/Plt12 mice succumbed to early lethality associated with emphysema, cardiac abnormalities, and liver degeneration. Survivors displayed a marked thrombocytopenia without significant deficiencies in the numbers of megakaryocytes or megakaryocyte progenitor cells. The lifespan of platelets in the circulation of Hbb-b2Plt12/Plt12 mice was normal, and splenectomy did not correct the thrombocytopenia, suggesting that increased sequestration was unlikely to be a major contributor. These data, together with the observation that megakaryocytes in Hbb-b2Plt12/Plt12 mice appeared smaller and deficient in cytoplasm, support a model in which hypoxia causes thrombocytopenia as a consequence of an inability of megakaryocytes, once formed, to properly mature and produce sufficient platelets. The Plt12 mouse is a model of high O2-affinity hemoglobinopathy and provides insights into hematopoiesis under conditions of chronic hypoxia. PMID:22203977

  14. Estimation of regional hemoglobin concentration in biological tissues using diffuse reflectance spectroscopy with a novel spectral interpretation algorithm.

    PubMed

    Chen, P; Fernald, B; Lin, W

    2011-07-07

    Both in medical research and clinical settings, regional hemoglobin concentrations ([Hb]) in the microcirculation of biological tissues are highly sought. Diffuse reflectance spectroscopy has been proven to be a favorable method by which to detect regional [Hb]. This paper introduces a new algorithm to retrieve [Hb] information from diffuse reflectance spectra. The proposed algorithm utilizes the natural logarithmic operation and the differential wavelet transform to effectively quench the scattering effects, and then employs the concept of isosbestic wavelength in the transformed spectra to reduce the effects of hemoglobin oxygenation. As a result, the intensity at the defined isosbestic wavelength of the transformed spectra is a good indicator of [Hb] estimation. The algorithm was derived and validated using theoretical spectra produced by Monte Carlo simulation of photon migration. Its accuracy was further evaluated using liquid tissue phantoms, and its clinical utility with an in vivo clinical study of brain tumors. The results demonstrate the applicability of the algorithm for real-time [Hb] estimations from diffuse reflectance spectra, acquired by means of a fiber-optic spectroscopy system.

  15. Large scale production of vesicles by hollow fiber extrusion: a novel method for generating polymersome encapsulated hemoglobin dispersions.

    PubMed

    Rameez, Shahid; Bamba, Ibrahim; Palmer, Andre F

    2010-04-06

    Vesicles, which include both liposomes and polymersomes (polymer vesicles), are being developed as therapeutic drug carriers. In this study, we present a fully scalable low pressure extrusion methodology for preparing vesicles. Vesicles were generated by continuous extrusion through a 200 nm pore diameter hollow fiber (HF) membrane. The first half of this study describes a method for generating empty polymersomes composed of different molecular weight amphiphilic poly(butadiene-b-ethylene oxide) (PBD-b-PEO) diblock copolymers on a large scale (50-100 mL) using a HF membrane. Monodisperse empty polymersomes were formed with particle diameters slightly less than 200 nm, which were close to the rated 200 nm pore size of the HF membrane. The second half of this study describes the successful encapsulation of hemoglobin (Hb) inside the aqueous core of polymersomes using the HF extrusion methodology. We demonstrate that polymersome encapsulated hemoglobin (PEH) particles formed by this technique had similar oxygen affinity, cooperativity coefficient, and methemoglobin (metHb) level compared to PEH particles formed by the 1 mL volume small scale manual extrusion method. Most notably, Hb encapsulation inside the polymer vesicles formed by the HF extrusion method increased 2-fold compared to the manual extrusion method. This work is important, since it will enable facile scale-up of homogeneous vesicle dispersions that are typically required for preclinical and clinical studies as well as industrial use.

  16. Safety Evaluation of Hemoglobin-Albumin Cluster “HemoAct” as a Red Blood Cell Substitute

    PubMed Central

    Haruki, Risa; Kimura, Takuya; Iwasaki, Hitomi; Yamada, Kana; Kamiyama, Ikuo; Kohno, Mitsutomo; Taguchi, Kazuaki; Nagao, Saori; Maruyama, Toru; Otagiri, Masaki; Komatsu, Teruyuki

    2015-01-01

    A hemoglobin (Hb) wrapped covalently by human serum albumins (HSAs), a core–shell structured hemoglobin-albumin cluster designated as “HemoAct”, is an O2-carrier designed for use as a red blood cell (RBC) substitute. This report describes the blood compatibility, hemodynamic response, and pharmacokinetic properties of HemoAct, and then explains its preclinical safety. Viscosity and blood cell counting measurements revealed that HemoAct has good compatibility with whole blood. Intravenous administration of HemoAct into anesthetized rats elicited no unfavorable increase in systemic blood pressure by vasoconstriction. The half-life of 125I-labeled HemoAct in circulating blood is markedly longer than that of HSA. Serum biochemical tests conducted 7 days after HemoAct infusion yielded equivalent values to those observed in the control group with HSA. Histopathologic inspections of the vital organs revealed no marked abnormality in their tissues. All results indicate that HemoAct has sufficient preclinical safety as an alternative material for RBC transfusion. PMID:26220366

  17. Reproducing the Hemoglobin Saturation Profile, a Marker of the Blood Oxygenation Level Dependent (BOLD) fMRI Effect, at the Microscopic Level.

    PubMed

    Hadjistassou, Constantinos; Moyle, Keri; Ventikos, Yiannis

    2016-01-01

    The advent of functional MRI in the mid-1990s has catalyzed progress pertaining to scientific discoveries in neuroscience. With the prospect of elucidating the physiological aspect of the Blood Oxygenation Level Dependent (BOLD) effect we present a computational capillary-tissue system capable of mapping venous hemoglobin saturation- a marker of the BOLD hemodynamic response. Free and facilitated diffusion and convection for hemoglobin and oxygen are considered in the radial and axial directions. Hemoglobin reaction kinetics are governed by the oxyhemoglobin dissociation curve. Brain activation, mimicked by dynamic transitions in cerebral blood velocity (CBv) and oxidative metabolism (CMRO2), is simulated by normalized changes in m = (ΔCBv/CBv)/(ΔCMRO2/CMRO2) of values 2, 3 and 4. Venous hemoglobin saturation profiles and peak oxygenation results, for m = 2, based upon a 50% and a 25% increase in CBv and CMRO2, respectively, lie within physiological limits exhibiting excellent correlation with the BOLD signal, for short-duration stimuli. Our analysis suggests basal CBv and CMRO2 values of 0.6 mm/s and 200 μmol/100g/min. Coupled CBv and CMRO2 responses, for m = 3 and m = 4, overestimate peak hemoglobin saturation, confirming the system's responsiveness to changes in hematocrit, CBv and CMRO2. Finally, factoring in neurovascular effects, we show that no initial dip will be observed unless there is a time delay in the onset of increased CBv relative to CMRO2.

  18. Mycobacterium tuberculosis hemoglobin N displays a protein tunnel suited for O2 diffusion to the heme

    PubMed Central

    Milani, Mario; Pesce, Alessandra; Ouellet, Yannick; Ascenzi, Paolo; Guertin, Michel; Bolognesi, Martino

    2001-01-01

    Macrophage-generated oxygen- and nitrogen-reactive species control the development of Mycobacterium tuberculosis infection in the host. Mycobacterium tuberculosis ‘truncated hemoglobin’ N (trHbN) has been related to nitric oxide (NO) detoxification, in response to macrophage nitrosative stress, during the bacterium latent infection stage. The three-dimensional structure of oxygenated trHbN, solved at 1.9 Å resolution, displays the two-over-two α-helical sandwich fold recently characterized in two homologous truncated hemoglobins, featuring an extra N-terminal α-helix and homodimeric assembly. In the absence of a polar distal E7 residue, the O2 heme ligand is stabilized by two hydrogen bonds to TyrB10(33). Strikingly, ligand diffusion to the heme in trHbN may occur via an apolar tunnel/cavity system extending for ∼28 Å through the protein matrix, connecting the heme distal cavity to two distinct protein surface sites. This unique structural feature appears to be conserved in several homologous truncated hemoglobins. It is proposed that in trHbN, heme Fe/O2 stereochemistry and the protein matrix tunnel may promote O2/NO chemistry in vivo, as a M.tuberculosis defense mechanism against macrophage nitrosative stress. PMID:11483493

  19. Adduct formation of Thimerosal with human and rat hemoglobin: a study using liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC/ESI-TOF-MS).

    PubMed

    Janzen, Rasmus; Schwarzer, Miriam; Sperling, Michael; Vogel, Martin; Schwerdtle, Tanja; Karst, Uwe

    2011-08-01

    Thimerosal (THI) is used as a preservative in many vaccines throughout the world. Ethylmercury (EtHg(+)), released from THI in aqueous media, has a high affinity to thiol functions of proteins. In blood, hemoglobin is a likely target protein because of its high abundance and its several free thiol functions. In comparison to hemoglobin of human origin, hemoglobin of rats exhibits almost twice as many free thiol groups, which might lead to different binding behavior and therefore a limited comparability between the situation in man and in rats, which are frequently used as models for mercury species toxicity investigations. Thus, the adduct formation of EtHg(+) with hemoglobin of humans and rats was compared under simulated physiological conditions by using gradient reversed-phase liquid chromatography (LC) with electrospray time-of-flight mass spectrometry (ESI-TOF-MS) detection. The binding stoichiometry correlated with the number of free thiols in the α- and β-chain of hemoglobin. The use of rats to verify the safety of additives in vaccines like Thimerosal is therefore doubtful and should be reevaluated.

  20. A biophysical investigation on the binding of proflavine with human hemoglobin: Insights from spectroscopy, thermodynamics and AFM studies.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2016-12-01

    Interaction of proflavine with hemoglobin (Hgb) was studied employing spectroscopy, calorimetry, and atomic force microscopy. The equilibrium constant was found to be of the order 10(4)M(-1). The quenching of Hgb fluorescence by proflavine was due to the complex formation. Calculation of the molecular distance (r) between the donor (β-Trp37 of Hgb) and acceptor (proflavine) suggested that energy can be efficiently transferred from the β-Trp37 residue at the α1β2 interface of the protein to the dye. Proflavine induced significant secondary structural changes in Hgb. Synchronous fluorescence studies showed that proflavine altered the microenvironment around the tryptophan residues to a greater extent than the tyrosine residues. Circular dichroism spectral studies showed that proflavine caused significant reduction in the α-helical content of Hgb. The esterase activity assay further complemented the circular dichroism data. The Soret band intensity of Hgb decreased upon complexation. Differential scanning calorimetry and circular dichroism melting results revealed that proflavine induced destabilization of Hgb. The binding was driven by both positive entropy and negative enthalpy. Atomic force microscopy studies revealed that the essential morphological features of hemoglobin were retained in the presence of proflavine. Overall, insights on the photophysical aspects and energetics of the binding of proflavine with Hgb are presented.

  1. The effects of ginger on fasting blood sugar, hemoglobin a1c, apolipoprotein B, apolipoprotein a-I and malondialdehyde in type 2 diabetic patients.

    PubMed

    Khandouzi, Nafiseh; Shidfar, Farzad; Rajab, Asadollah; Rahideh, Tayebeh; Hosseini, Payam; Mir Taheri, Mohsen

    2015-01-01

    Diabetes mellitus is the most common endocrine disorder, causes many complications such as micro- and macro-vascular diseases. Anti-diabetic, hypolipidemic and anti-oxidative properties of ginger have been noticed in several researches. The present study was conducted to investigate the effects of ginger on fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, and malondialdehyde in type 2 diabetic patients. In a randomized, double-blind, placebo-controlled, clinical trial, a total of 41 type 2 diabetic patients randomly were assigned to ginger or placebo groups (22 in ginger group and 19 in control group), received 2 g/day of ginger powder supplement or lactose as placebo for 12 weeks. The serum concentrations of fasting blood sugar, Hemoglobin A1c, apolipoprotein B, apolipoprotein A-I and malondialdehyde were analyzed before and after the intervention. Ginger supplementation significantly reduced the levels of fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein B/apolipoprotein A-I and malondialdehyde in ginger group in comparison to baseline, as well as control group, while it increased the level of apolipoprotein A-I (p<0.05). It seems that oral administration of ginger powder supplement can improves fasting blood sugar, hemoglobin A1c, apolipoprotein B, apolipoprotein A-I, apolipoprotein B/apolipoprotein A-I and malondialdehyde in type 2 diabetic patients. So it may have a role in alleviating the risk of some chronic complications of diabetes.

  2. Hb East Timor [β80(EF4)Asn→His, AAC>CAC (HBB c.241A>C)], a variant hemoglobin associated with normal hematology.

    PubMed

    Finlayson, Jill; Ghassemifar, Reza; Holmes, Paula; Grey, Dianne; Figliomeni, Lisa; Newbound, Christopher; Pell, Nicole; Kersten, Michael; Jennens, Michelle; Macaulay, Claire; Greenwood, Laura; Beilby, John

    2010-01-01

    Routine hemoglobin (Hb) analyses identified a new β-globin variant in a family from East Timor. The red cell indices were within normal limits for all affected family members. The variant is due to a missense mutation at amino acid codon 80 (AAC>CAC) which results in the substitution of histidine for asparagine.

  3. Analysis of Hemoglobin Glycation Using Microfluidic CE-MS: A Rapid, Mass Spectrometry Compatible Method for Assessing Diabetes Management.

    PubMed

    Redman, Erin A; Ramos-Payan, Maria; Mellors, J Scott; Ramsey, J Michael

    2016-05-17

    Diabetes has become a significant health problem worldwide with the rate of diagnosis increasing rapidly in recent years. Measurement of glycated blood proteins, particularly glycated hemoglobin (HbA1c), is an important diagnostic tool used to detect and manage the condition in patients. Described here is a method using microfluidic capillary electrophoresis with mass spectrometry detection (CE-MS) to assess hemoglobin glycation in whole blood lysate. Using denaturing conditions, the hemoglobin (Hb) tetramer dissociates into the alpha and beta subunits (α- and β-Hb), which are then separated via CE directly coupled to MS detection. Nearly baseline resolution is achieved between α-Hb, β-Hb, and glycated β-Hb. A second glycated β-Hb isomer that is partially resolved from β-Hb is detected in extracted ion electropherograms for glycated β-Hb. Glycation on α-Hb is also detected in the α-Hb mass spectrum. Additional modifications to the β-Hb are detected, including acetylation and a +57 Da species that could be the addition of a glyoxal moiety. Patient blood samples were analyzed using the microfluidic CE-MS method and a clinically used immunoassay to measure HbA1c. The percentage of glycated α-Hb and β-Hb was calculated from the microfluidic CE-MS data using peak areas generated from extracted ion electropherograms. The values for glycated β-Hb were found to correlate well with the HbA1c levels derived in the clinic, giving a slope of 1.20 and an R(2) value of 0.99 on a correlation plot. Glycation of human serum albumin (HSA) can also be measured using this technique. It was observed that patients with elevated glycated Hb levels also had higher levels of HSA glycation. Interestingly, the sample with the highest HbA1c levels did not have the highest levels of glycated HSA. Because the lifetime of HSA is shorter than Hb, this could indicate a recent lapse in glycemic control for that patient. The ability to assess both Hb and HSA glycation has the potential

  4. 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

  5. Long-Term Stored Hemoglobin-Vesicles, a Cellular Type of Hemoglobin-Based Oxygen Carrier, Has Resuscitative Effects Comparable to That for Fresh Red Blood Cells in a Rat Model with Massive Hemorrhage without Post-Transfusion Lung Injury

    PubMed Central

    Yamasaki, Keishi; Sakai, Hiromi; Otagiri, Masaki

    2016-01-01

    Hemoglobin-vesicles (HbV), encapsulating highly concentrated human hemoglobin in liposomes, were developed as a substitute for red blood cells (RBC) and their safety and efficacy in transfusion therapy has been confirmed in previous studies. Although HbV suspensions are structurally and physicochemically stabile for least 1-year at room temperature, based on in vitro experiments, the issue of whether the use of long-term stored HbV after a massive hemorrhage can be effective in resuscitations without adverse, post-transfusion effects remains to be clarified. We report herein on a comparison of the systemic response and the induction of organ injuries in hemorrhagic shock model rats resuscitated using 1-year-stored HbV, freshly packed RBC (PRBC-0) and by 28-day-stored packed RBC (PRBC-28). The six-hour mortality after resuscitation was not significantly different among the groups. Arterial blood pressure and blood gas parameters revealed that, using HbV, recovery from the shock state was comparable to that when PRBC-0 was used. Although no significant change was observed in serum parameters reflecting liver and kidney injuries at 6 hours after resuscitation among the three resuscitation groups, results based on Evans Blue and protein leakage in bronchoalveolar lavage fluid, the lung wet/dry weight ratio and histopathological findings indicated that HbV as well as PRBC-0 was less predisposed to result in a post-transfusion lung injury than PRBC-28, as evidenced by low levels of myeloperoxidase accumulation and subsequent oxidative damage in the lung. The findings reported herein indicate that 1-year-stored HbV can effectively function as a resuscitative fluid without the induction of post-transfused lung injury and that it is comparable to fresh PRBC, suggesting that HbV is a promising RBC substitute with a long shelf-life. PMID:27798697

  6. Hemoglobin Riyadh--alpha2beta2 (120(GH3)Lys replaced by Asn). A new variant found in association with alpha-thalassemia and iron deficiency.

    PubMed

    El-Hazmi, M A; Lehmann, H

    On a field trip toSaudi Arabia (M.A.F.E.H.) in which the relationship between alpha-thalassemia and iron deficiency was studied, a fast moving hemoglobin variant was noted in a 30 year old Saudi Arabian woman. Analysis of the hemoglobin variant showed that the amino acid substitution was beta120 Lys replaced by Asn. This variant had not been described previously and has been named Hb Riyadh. There was also present an alpha-thalassemia and details are given of the imbalance of globin chain synthesis. It was possible to improve considerably the balance in vitro by the addition of hemin.

  7. The 2.4-A crystal structure of Scapharca dimeric hemoglobin. Cooperativity based on directly communicating hemes at a novel subunit interface.

    PubMed

    Royer, W E; Hendrickson, W A; Chiancone, E

    1989-12-15

    The crystal structure of the cooperative dimeric hemoglobin from the arcid clam, Scapharca inaequivalvis, has been determined in the carbonmonoxy state. The phase problem was solved for reflections with Bragg spacings greater than 3 A using anomalous scattering from the porphyrin iron atoms measured at a single wavelength in combination with molecular averaging. The model built into this electron density map has been refined at 2.4 A resolution by means of stereochemically restrained least squares minimization to a conventional R-value of 0.156. The root mean square deviation from ideal bond lengths and angles are 0.013 A and 1.7 degrees, respectively. In addition to the 2336 hemoglobin atoms, 214 water molecules have been incorporated into the model. This structure reveals the details of an assemblage of two identical myoglobin-like subunits that is radically different from vertebrate hemoglobins. The subunit interface is formed by direct apposition of the E and F helices, whereas these surfaces are external in vertebrate hemoglobins. The interface has both hydrophobic and hydrophilic character. Two symmetrically related hydrophobic regions are formed between subunits. Six residues are involved in each of these regions that pack tightly enough to exclude water but have only a few atoms in close van der Waals contact. A number of ordered water molecules line the interface and form bridging hydrogen bonds between subunits. Four intersubunit ionic interactions are formed, two of which involve negatively charged propionate groups of the porphyrin. In contrast to cooperative vertebrate hemoglobins, a hydrogen bond network provides a direct route for communication between the two heme groups.

  8. Performance of a Predictive Model for Long-Term Hemoglobin Response to Darbepoetin and Iron Administration in a Large Cohort of Hemodialysis Patients.

    PubMed

    Barbieri, Carlo; Bolzoni, Elena; Mari, Flavio; Cattinelli, Isabella; Bellocchio, Francesco; Martin, José D; Amato, Claudia; Stopper, Andrea; Gatti, Emanuele; Macdougall, Iain C; Stuard, Stefano; Canaud, Bernard

    2016-01-01

    Anemia management, based on erythropoiesis stimulating agents (ESA) and iron supplementation, has become an increasingly challenging problem in hemodialysis patients. Maintaining hemodialysis patients within narrow hemoglobin targets, preventing cycling outside target, and reducing ESA dosing to prevent adverse outcomes requires considerable attention from caregivers. Anticipation of the long-term response (i.e. at 3 months) to the ESA/iron therapy would be of fundamental importance for planning a successful treatment strategy. To this end, we developed a predictive model designed to support decision-making regarding anemia management in hemodialysis (HD) patients treated in center. An Artificial Neural Network (ANN) algorithm for predicting hemoglobin concentrations three months into the future was developed and evaluated in a retrospective study on a sample population of 1558 HD patients treated with intravenous (IV) darbepoetin alfa, and IV iron (sucrose or gluconate). Model inputs were the last 90 days of patients' medical history and the subsequent 90 days of darbepoetin/iron prescription. Our model was able to predict individual variation of hemoglobin concentration 3 months in the future with a Mean Absolute Error (MAE) of 0.75 g/dL. Error analysis showed a narrow Gaussian distribution centered in 0 g/dL; a root cause analysis identified intercurrent and/or unpredictable events associated with hospitalization, blood transfusion, and laboratory error or misreported hemoglobin values as the main reasons for large discrepancy between predicted versus observed hemoglobin values. Our ANN predictive model offers a simple and reliable tool applicable in daily clinical practice for predicting the long-term response to ESA/iron therapy of HD patients.

  9. Direct evidence for interaction between human erythroid progenitor cells and a hemoglobin switching activity present in fetal sheep serum.

    PubMed Central

    Stamatoyannopoulos, G; Nakamoto, B; Kurachi, S; Papayannopoulou, T

    1983-01-01

    An activity that induces Hb F to Hb A switching in human cells is present in fetal sheep serum. To test directly the role of cell-to-environment interactions in hemoglobin switching and to define the level of erythroid cell differentiation at which this activity operates, colony transfer experiments were done. Clones grown in the presence of switching activity-containing medium (fetal sheep serum) or control medium (fetal calf serum) were transferred, at the 16- to 30-cell stage, to either fetal sheep serum or fetal calf serum plates and Hb F synthesis was determined in the fully mature erythroid bursts. Fetal calf serum-to-fetal calf serum transfers produced colonies with the high Hb F levels characteristic of undisturbed fetal calf serum-grown clones. Fetal sheep serum-to-fetal calf serum transfers resulted in significant decrease in Hb F synthesis, revealing an interaction between hemoglobin switching activity and cells at an early stage of progenitor cell development. The reduction of Hb F synthesis in fetal calf serum-to-fetal sheep serum transfers indicated that hemoglobin switching activity interacts with cells at later stages of progenitor cell development. Maximal decrease in Hb F synthesis was observed in fetal sheep serum-to-fetal sheep serum transfers, indicating that optimal effects on Hb switching are obtained when the environment that induces Hb switching is present throughout the development of progenitor cells. By splitting single early clones into two parts and transferring them to either a fetal sheep serum or a fetal calf serum environment, these interactions were further demonstrated in the progeny of a single erythroid burst-forming unit. Since all clone transfers were done on cell-free plates, the results of fetal calf serum-to-fetal sheep serum and of fetal sheep serum-to-fetal sheep serum transfers indicated that the switching activity does not require helper cells for its action. These studies show directly that (i) Hb F synthesis is

  10. Development of a simple assay system for protein-stabilizing efficiency based on hemoglobin protection against denaturation and measurement of the cooperative effect of mixing protein stabilizers.

    PubMed

    Chen, Siyu; Manabe, Yoshiyuki; Minamoto, Naoya; Saiki, Naoka; Fukase, Koichi

    2016-10-01

    We have elucidated the cooperative stabilization of proteins by sugars, amino acids, and other protein-stabilizing agents using a new and simple assay system. Our system determines the protein-stabilizing ability of various compounds by measuring their ability to protect hemoglobin from denaturation. Hemoglobin denaturation was readily measured by quantitative changes in its ultraviolet-visible absorption spectrum. The efficiency of our assay was confirmed using various sugars such as trehalose and sucrose that are known to be good protein stabilizers. We have also found that mixtures of two different types of protein stabilizers resulted in a cooperative stabilizing effect on protein.

  11. Diabetes mellitus, hyperglycemia, hemoglobin A1C and the risk of prosthetic joint infections in total hip and knee arthroplasty.

    PubMed

    Maradit Kremers, Hilal; Lewallen, Laura W; Mabry, Tad M; Berry, Daniel J; Berbari, Elie F; Osmon, Douglas R

    2015-03-01

    Diabetes mellitus is an established risk factor for infections but evidence is conflicting to what extent perioperative hyperglycemia, glycemic control and treatment around the time of surgery modify the risk of prosthetic joint infections (PJIs). In a cohort of 20,171 total hip and knee arthroplasty procedures, we observed a significantly higher risk of PJIs among patients with a diagnosis of diabetes mellitus (hazard ratio [HR] 1.55, 95% CI 1.11, 2.16), patients using diabetes medications (HR 1.56, 95% CI 1.08, 2.25) and patients with perioperative hyperglycemia (HR 1.59, 95% CI 1.07, 2.35), but the effects were attenuated after adjusting for body mass index, type of surgery, ASA score and operative time. Although data were limited, there was no association between hemoglobin A1c values and PJIs.

  12. Analysis of the accuracy and precision of the Axis-Shield Afinion hemoglobin A1c measurement device.

    PubMed

    Little, Randie R

    2012-03-01

    Point-of-care (POC) hemoglobin A1c measurement is now used by many physicians to make more timely decisions on therapy changes. A few studies have highlighted the drawbacks of some POC methods, e.g., poor precision and lot-to-lot variability. Evaluating performance in the clinical setting is difficult because there is minimal proficiency testing data on POC methods. In this issue of Journal of Diabetes Science and Technology, Wood and colleagues describe their experience with the Afinion method in a pediatric clinic network, comparing these results to another POC method as well as to a laboratory high-performance liquid chromatography method. Although they conclude that the Afinion exhibits adequate performance, they do not evaluate lot-to-lot variability. As with laboratory methods, potential assay interferences must also be considered.

  13. 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.

  14. Properties of a recombinant human hemoglobin with aspartic acid 99(beta), an important intersubunit contact site, substituted by lysine.

    PubMed Central

    Yanase, H.; Cahill, S.; Martin de Llano, J. J.; Manning, L. R.; Schneider, K.; Chait, B. T.; Vandegriff, K. D.; Winslow, R. M.; Manning, J. M.

    1994-01-01

    Site-directed mutagenesis of an important subunit contact site, Asp-99(beta), by a Lys residue (D99K(beta)) was proven by sequencing the entire beta-globin gene and the mutant tryptic peptide. Oxygen equilibrium curves of the mutant hemoglobin (Hb) (2-15 mM in heme) indicated that it had an increased oxygen affinity and a lowered but significant amount of cooperativity compared to native HbA. However, in contrast to normal HbA, oxygen binding of the recombinant mutant Hb was only marginally affected by the allosteric regulators 2,3-diphosphoglycerate or inositol hexaphosphate and was not at all responsive to chloride. The efficiency of oxygen binding by HbA in the presence of allosteric regulators was limited by the mutant Hb. At concentrations of 0.2 mM or lower in heme, the mutant D99K(beta) Hb was predominantly a dimer as demonstrated by gel filtration, haptoglobin binding, fluorescence quenching, and light scattering. The purified dimeric recombinant Hb mutant exists in 2 forms that are separable on isoelectric focusing by about 0.1 pH unit, in contrast to tetrameric hemoglobin, which shows 1 band. These mutant forms, which were present in a ratio of 60:40, had the same masses for their heme and globin moieties as determined by mass spectrometry. The elution positions of the alpha- and beta-globin subunits on HPLC were identical. Circular dichroism studies showed that one form of the mutant Hb had a negative ellipticity at 410 nm and the other had positive ellipticity at this wavelength. The findings suggest that the 2 D99K(beta) recombinant mutant forms have differences in their heme-protein environments. PMID:7987216

  15. Ultrafast heme-ligand recombination in truncated hemoglobin HbO from Mycobacterium tuberculosis: A ligand cage

    NASA Astrophysics Data System (ADS)

    Jasaitis, Audrius; Ouellet, Hugues; Lambry, Jean-Christophe; Martin, Jean-Louis; Friedman, Joel M.; Guertin, Michel; Vos, Marten H.

    2012-03-01

    Truncated hemoglobin HbO from Mycobacterium tuberculosis displays very slow exchange of diatomic ligands with its environment. Using femtosecond spectroscopy, we show that upon photoexcitation, ligands rebind with unusual speed and efficiency. Only ˜1% O2 can escape from the heme pocket and less than 1% NO. Most remarkably, CO rebinding occurs for 95%, predominantly in 1.2 ns. The general CO rebinding properties are unexpectedly robust against changes in the interactions with close by aromatic residues Trp88 (G8) and Tyr36 (CD1). Molecular dynamics simulations of the CO complex suggest that interactions of the ligand with structural water molecules as well as its rotational freedom play a role in the high reactivity of the ligand and the heme. The slow exchange of ligands between heme and environment may result from a combination of hindered ligand access to the heme pocket by the network of distal aromatic residues, and low escape probability from the pocket.

  16. Configuration of the hemoglobin oxygen dissociation curve demystified: a basic mathematical proof for medical and biological sciences undergraduates.

    PubMed

    Leow, Melvin Khee-Shing

    2007-06-01

    The oxygen dissociation curve (ODC) of hemoglobin (Hb) has been widely studied and mathematically described for nearly a century. Numerous mathematical models have been designed to predict with ever-increasing accuracy the behavior of oxygen transport by Hb in differing conditions of pH, carbon dioxide, temperature, Hb levels, and 2,3-diphosphoglycerate concentrations that enable their applications in various clinical situations. The modeling techniques employed in many existing models are notably borrowed from advanced and highly sophisticated mathematics that are likely to surpass the comprehensibility of many medical and bioscience students due to the high level of "mathematical maturity" required. It is, however, a worthy teaching point in physiology lectures to illustrate in simple mathematics the fundamental reason for the crucial sigmoidal configuration of the ODC such that the medical and bioscience undergraduates can readily appreciate it, which is the objective of this basic dissertation.

  17. Enhanced resting-state dynamics of the hemoglobin signal as a novel biomarker for detection of breast cancer

    PubMed Central

    Graber, Harry L.; Al abdi, Rabah; Xu, Yong; Asarian, Armand P.; Pappas, Peter J.; Dresner, Lisa; Patel, Naresh; Jagarlamundi, Kuppuswamy; Solomon, William B.; Barbour, Randall L.

    2015-01-01

    Purpose: The work presented here demonstrates an application of diffuse optical tomography (DOT) to the problem of breast-cancer diagnosis. The potential for using spatial and temporal variability measures of the hemoglobin signal to identify useful biomarkers was studied. Methods: DOT imaging data were collected using two instrumentation platforms the authors developed, which were suitable for exploring tissue dynamics while performing a simultaneous bilateral exam. For each component of the hemoglobin signal (e.g., total, oxygenated), the image time series was reduced to eight scalar metrics that were affected by one or more dynamic properties of the breast microvasculature (e.g., average amplitude, amplitude heterogeneity, strength of spatial coordination). Receiver-operator characteristic (ROC) analyses, comparing groups of subjects with breast cancer to various control groups (i.e., all noncancer subjects, only those with diagnosed benign breast pathology, and only those with no known breast pathology), were performed to evaluate the effect of cancer on the magnitudes of the metrics and of their interbreast differences and ratios. Results: For women with known breast cancer, simultaneous bilateral DOT breast measures reveal a marked increase in the resting-state amplitude of the vasomotor response in the hemoglobin signal for the affected breast, compared to the contralateral, noncancer breast. Reconstructed 3D spatial maps of observed dynamics also show that this behavior extends well beyond the tumor border. In an effort to identify biomarkers that have the potential to support clinical aims, a group of scalar quantities extracted from the time series measures was systematically examined. This analysis showed that many of the quantities obtained by computing paired responses from the bilateral scans (e.g., interbreast differences, ratios) reveal statistically significant differences between the cancer-positive and -negative subject groups, while the

  18. Enhanced resting-state dynamics of the hemoglobin signal as a novel biomarker for detection of breast cancer

    SciTech Connect

    Graber, Harry L. Xu, Yong; Barbour, Randall L.; Al abdi, Rabah; Asarian, Armand P.; Pappas, Peter J.; Dresner, Lisa; Patel, Naresh; Jagarlamundi, Kuppuswamy; Solomon, William B.

    2015-11-15

    Purpose: The work presented here demonstrates an application of diffuse optical tomography (DOT) to the problem of breast-cancer diagnosis. The potential for using spatial and temporal variability measures of the hemoglobin signal to identify useful biomarkers was studied. Methods: DOT imaging data were collected using two instrumentation platforms the authors developed, which were suitable for exploring tissue dynamics while performing a simultaneous bilateral exam. For each component of the hemoglobin signal (e.g., total, oxygenated), the image time series was reduced to eight scalar metrics that were affected by one or more dynamic properties of the breast microvasculature (e.g., average amplitude, amplitude heterogeneity, strength of spatial coordination). Receiver-operator characteristic (ROC) analyses, comparing groups of subjects with breast cancer to various control groups (i.e., all noncancer subjects, only those with diagnosed benign breast pathology, and only those with no known breast pathology), were performed to evaluate the effect of cancer on the magnitudes of the metrics and of their interbreast differences and ratios. Results: For women with known breast cancer, simultaneous bilateral DOT breast measures reveal a marked increase in the resting-state amplitude of the vasomotor response in the hemoglobin signal for the affected breast, compared to the contralateral, noncancer breast. Reconstructed 3D spatial maps of observed dynamics also show that this behavior extends well beyond the tumor border. In an effort to identify biomarkers that have the potential to support clinical aims, a group of scalar quantities extracted from the time series measures was systematically examined. This analysis showed that many of the quantities obtained by computing paired responses from the bilateral scans (e.g., interbreast differences, ratios) reveal statistically significant differences between the cancer-positive and -negative subject groups, while the

  19. A Novel Glycated Hemoglobin A1c-Lowering Traditional Chinese Medicinal Formula, Identified by Translational Medicine Study

    PubMed Central

    Li, Tsai-Chung; Li, Chia-Cheng; Huang, Hui-Chi; Chen, Jaw-Chyun; Ho, Tin-Yun

    2014-01-01

    Diabetes is a chronic metabolic disorder that has a significant impact on the health care system. The reduction of glycated hemoglobin A1c is highly associated with the improvements of glycemic control and diabetic complications. In this study, we identified a traditional Chinese medicinal formula with a HbA1c-lowering potential from clinical evidences. By surveying 9,973 diabetic patients enrolled in Taiwan Diabetic Care Management Program, we found that Chu-Yeh-Shih-Kao-Tang (CYSKT) significantly reduced HbA1c values in diabetic patients. CYSKT reduced the levels of HbA1c and fasting blood glucose, and stimulated the blood glucose clearance in type 2 diabetic mice. CYSKT affected the expressions of genes associated with insulin signaling pathway, increased the amount of phosphorylated insulin receptor in cells and tissues, and stimulated the translocation of glucose transporter 4. Moreover, CYSKT affected the expressions of genes related to diabetic complications, improved the levels of renal function indexes, and increased the survival rate of diabetic mice. In conclusion, this was a translational medicine study that applied a “bedside-to-bench” approach to identify a novel HbA1c-lowering formula. Our findings suggested that oral administration of CYSKT affected insulin signaling pathway, decreased HbA1c and blood glucose levels, and consequently reduced mortality rate in type 2 diabetic mice. PMID:25133699

  20. A combination of dynamic light scattering and polarized resonance Raman scattering applied in the study of Arenicola Marina extracellular hemoglobin

    NASA Astrophysics Data System (ADS)

    Jernshøj, K. D.; Hassing, S.; Olsen, L. F.

    2013-08-01

    Arenicola Marina extracellular hemoglobin (Hbl Hb) is considered to be a promising candidate as a blood substitute. To entangle some of the properties of extracellular giant hexagonal bilayer hemoglobin (Hbl Hb) of Arenicola Marina, we combined polarized resonance Raman scattering (532 nm excitation) with dynamic light scattering (DLS) (632.8 nm). An analysis of the depolarization ratio of selected a2g skeletal modes of the heme in native Hbl Hb and porcine Hb, shows that the distortion of the heme group away from its ideal fourfold symmetry is much smaller for heme groups bound in the Hbl Hb than for heme groups bound in porcine Hb. Using DLS, the average hydrodynamic diameter (⟨dh⟩) of Hbl Hb was measured at pH = 5, 7, 8, 9, and 10. At pH = 5 to 7, the Hbl Hb was found in its native form with ⟨dh⟩ equal to 24.2 nm, while at pH = 8 and 9, a dissociation process starts to take place resulting in ⟨dh⟩ = 9 nm. At pH = 10, only large aggregates of fragmented Hbl Hb with ⟨dh⟩ larger than 1000 nm was detected, however, a comparison of the DLS results with the polarized resonance Raman scattering (RRS) revealed that the coupling between the fragments did not involve direct interaction between the heme groups, but also that the local heme environment seems to be comparable in the aggregates and in the native Hbl Hb. By comparing the unpolarized RRS results obtained for erythrocytes (RBC) with those for Hbl Hb, led us to the important conclusion that Hbl Hb is much easier photolyzed than porcine RBC.

  1. A combination of dynamic light scattering and polarized resonance Raman scattering applied in the study of Arenicola Marina extracellular hemoglobin.

    PubMed

    Jernshøj, K D; Hassing, S; Olsen, L F

    2013-08-14

    Arenicola Marina extracellular hemoglobin (Hbl Hb) is considered to be a promising candidate as a blood substitute. To entangle some of the properties of extracellular giant hexagonal bilayer hemoglobin (Hbl Hb) of Arenicola Marina, we combined polarized resonance Raman scattering (532 nm excitation) with dynamic light scattering (DLS) (632.8 nm). An analysis of the depolarization ratio of selected a(2g) skeletal modes of the heme in native Hbl Hb and porcine Hb, shows that the distortion of the heme group away from its ideal fourfold symmetry is much smaller for heme groups bound in the Hbl Hb than for heme groups bound in porcine Hb. Using DLS, the average hydrodynamic diameter () of Hbl Hb was measured at pH = 5, 7, 8, 9, and 10. At pH = 5 to 7, the Hbl Hb was found in its native form with equal to 24.2 nm, while at pH = 8 and 9, a dissociation process starts to take place resulting in = 9 nm. At pH = 10, only large aggregates of fragmented Hbl Hb with larger than 1000 nm was detected, however, a comparison of the DLS results with the polarized resonance Raman scattering (RRS) revealed that the coupling between the fragments did not involve direct interaction between the heme groups, but also that the local heme environment seems to be comparable in the aggregates and in the native Hbl Hb. By comparing the unpolarized RRS results obtained for erythrocytes (RBC) with those for Hbl Hb, led us to the important conclusion that Hbl Hb is much easier photolyzed than porcine RBC.

  2. Detection of a major gene for heterocellular hereditary persistence of fetal hemoglobin after accounting for genetic modifiers

    SciTech Connect

    Thein, S.L.; Weatherall, D.J. ); Sampietro, M.; Rohde, K.; Rochette, J.; Lathrop, G.M.; Demenais, F.

    1994-02-01

    [open quotes]Heterocellular hereditary persistence of fetal hemoglobin[close quotes] (HPFH) is the term used to describe the genetically determined persistence of fetal hemoglobin (Hb F) production into adult life, in the absence of any related hematological disorder. Whereas some forms are caused by mutations in the [beta]-globin gene cluster on chromosome 11, others segregate independently. While the latter are of particular interest with respect to the regulation of globin gene switching, it has not been possible to determine their chromosomal location, mainly because their mode of inheritance is not clear, but also because several other factors are known to modify Hb F production. The authors have examined a large Asian Indian pedigree which includes individuals with heterocellular HPFH associated with [beta]-thalassemia and/or [alpha]-thalassemia. Segregation analysis was conducted on the HPFH trait FC, defined to be the percentage of Hb F-containing cells (F-cells), using the class D regressive model. The results provide evidence for the presence of a major gene, dominant or codominant, which controls the FC values with residual familial correlations. The major gene was detected when the effects of genetic modifiers, notably [beta]-thalassemia and the XmnI-[sup G][gamma] polymorphism, are accounted for in this analysis. Linkage with the [beta]-globin gene cluster is excluded. The transmission of the FC values in this pedigree is informative enough to allow detection of linkage with an appropriate marker(s). The analytical approach outlined in this study, using simple regression to allow for genetic modifiers and thus allowing the mode of inheritance of a trait to be dissected out, may be useful as a model for segregation and linkage analyses of other complex phenotypes. 39 refs., 4 figs., 6 tabs.

  3. 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.

  4. A molecular study of a family with Greek hereditary persistence of fetal hemoglobin and beta-thalassemia.

    PubMed

    Giglioni, B; Casini, C; Mantovani, R; Merli, S; Comi, P; Ottolenghi, S; Saglio, G; Camaschella, C; Mazza, U

    1984-11-01

    A family was studied in which two inherited defects of the non-alpha-globin cluster segregate: Greek hereditary persistence of fetal hemoglobin (HPFH) and beta-thalassemia. Fragments of the non-alpha-globin cluster from two patients were cloned in cosmid and phage lambda vectors, and assigned to either the HPFH or beta-thalassemic chromosome on the basis of the demonstration of a polymorphic BglII site in the HPFH gamma-globin cluster. The thalassemic beta-globin gene carries a mutation at nucleotide 1 of the intervening sequence I, known to cause beta zero-thalassemia; the beta-globin gene from the HPFH chromosome is entirely normal, both in the intron-exon sequence and in 5' flanking regions required for transcription. As the compound HPFH/beta-thalassemia heterozygote synthesizes HbA, these data prove that the HPFH beta-globin gene is functional, although at a decreased rate; its lower activity is likely to be due to a distant mutation. The HPFH A gamma-globin gene shows only two mutations: a T----C substitution in the large intervening sequence (responsible for the BglII polymorphic site) and a C----T substitution 196 nucleotides 5' to the cap site; the 5' flanking sequence is normal up to -1350 nucleotides upstream from the gene. Circumstantial evidence suggests that the mutation at -196 may be responsible for the abnormally high expression of the A gamma-globin gene.

  5. A comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals.

    PubMed

    Fago, Angela; Parraga, Daniel Garcia; Petersen, Elin E; Kristensen, Niels; Giouri, Lea; Jensen, Frank B

    2017-03-01

    The ability of marine mammals to hunt prey at depth is known to rely on enhanced oxygen stores and on selective distribution of blood flow, but the molecular mechanisms regulating blood flow and oxygen transport remain unresolved. To investigate the molecular mechanisms that may be important in regulating blood flow, we measured concentration of nitrite and S-nitrosothiols (SNO), two metabolites of the vasodilator nitric oxide (NO), in the blood of 5 species of marine mammals differing in their dive duration: bottlenose dolphin, South American sea lion, harbor seal, walrus and beluga whale. We also examined oxygen affinity, sensitivity to 2,3-diphosphoglycerate (DPG) and nitrite reductase activity of the hemoglobin (Hb) to search for possible adaptive variations in these functional properties. We found levels of plasma and red blood cells nitrite similar to those reported for terrestrial mammals, but unusually high concentrations of red blood cell SNO in bottlenose dolphin, walrus and beluga whale, suggesting enhanced SNO-dependent signaling in these species. Purified Hbs showed similar functional properties in terms of oxygen affinity and sensitivity to DPG, indicating that reported large variations in blood oxygen affinity among diving mammals likely derive from phenotypic variations in red blood cell DPG levels. The nitrite reductase activities of the Hbs were overall slightly higher than that of human Hb, with the Hb of beluga whale, capable of longest dives, having the highest activity. Taken together, these results underscore adaptive variations in circulatory NO metabolism in diving mammals but not in the oxygenation properties of the Hb.

  6. 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.

  7. A candidate transacting modulator of fetal hemoglobin gene expression in the Arab-Indian haplotype of sickle cell anemia.

    PubMed

    Vathipadiekal, Vinod; Farrell, John J; Wang, Shuai; Edward, Heather L; Shappell, Heather; Al-Rubaish, A M; Al-Muhanna, Fahad; Naserullah, Z; Alsuliman, A; Qutub, Hatem Othman; Simkin, Irene; Farrer, Lindsay A; Jiang, Zhihua; Luo, Hong-Yuan; Huang, Shengwen; Mostoslavsky, Gustavo; Murphy, George J; Patra, Pradeep K; Chui, David H K; Alsultan, Abdulrahman; Al-Ali, Amein K; Sebastiani, Paola; Steinberg, Martin H

    2016-11-01

    Fetal hemoglobin (HbF) levels are higher in the Arab-Indian (AI) β-globin gene haplotype of sickle cell anemia compared with African-origin haplotypes. To study genetic elements that effect HbF expression in the AI haplotype we completed whole genome sequencing in 14 Saudi AI haplotype sickle hemoglobin homozygotes-seven selected for low HbF (8.2% ± 1.3%) and seven selected for high HbF (23.5% ± 2.6%). An intronic single nucleotide polymorphism (SNP) in ANTXR1, an anthrax toxin receptor (chromosome 2p13), was associated with HbF. These results were replicated in two independent Saudi AI haplotype cohorts of 120 and 139 patients, but not in 76 Saudi Benin haplotype, 894 African origin haplotype and 44 AI haplotype patients of Indian origin, suggesting that this association is effective only in the Saudi AI haplotype background. ANTXR1 variants explained 10% of the HbF variability compared with 8% for BCL11A. These two genes had independent, additive effects on HbF and together explained about 15% of HbF variability in Saudi AI sickle cell anemia patients. ANTXR1 was expressed at mRNA and protein levels in erythroid progenitors derived from induced pluripotent stem cells (iPSCs) and CD34(+) cells. As CD34(+) cells matured and their HbF decreased ANTXR1 expression increased; as iPSCs differentiated and their HbF increased, ANTXR1 expression decreased. Along with elements in cis to the HbF genes, ANTXR1 contributes to the variation in HbF in Saudi AI haplotype sickle cell anemia and is the first gene in trans to HBB that is associated with HbF only in carriers of the Saudi AI haplotype. Am. J. Hematol. 91:1118-1122, 2016. © 2016 Wiley Periodicals, Inc.

  8. 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

  9. 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.

  10. Perioperative hemoglobin area under the curve is an independent predictor of renal failure after cardiac surgery. Results from a Spanish multicenter retrospective cohort study

    PubMed Central

    Duque-Sosa, Paula; Iribarren, María Josefa; Rábago, Gregorio

    2017-01-01

    Perioperative anemia is an important risk factor for cardiac surgery-associated acute kidney injury (CSA-AKI). Nonetheless, the severity of the anemia and the time in the perioperative period in which the hemoglobin level should be considered as a risk factor is conflicting. The present study introduces the concept of perioperative hemoglobin area under the curve (pHb-AUC) as a surrogate marker of the evolution of perioperative hemoglobin concentration. Through a retrospective analysis of prospectively collected data, we assessed this new variable as a risk factor for the development of acute kidney injury after cardiac surgery in 966 adult patients who underwent cardiac surgery with cardiopulmonary bypass, at twenty-three academic hospitals in Spain. Exclusion criteria were patients on renal replacement therapy, who needed a reoperation because of bleeding and/or with missing perioperative hemoglobin or creatinine values. Using a multivariate regression analysis, we found that a pHb-AUC <19 g/dL was an independent risk factor for CSA-AKI even after adjustment for intraoperative red blood cell transfusion (OR 1.41, p <0.05). It was also associated with mortality (OR 2.48, p <0.01) and prolonged hospital length of stay (4.67 ± 0.99 days, p <0.001) PMID:28225801

  11. Complex interaction of Hb Q-Thailand and Hb E with alpha(0)-thalassemia and hereditary persistence of fetal hemoglobin in a Chinese family.

    PubMed

    Zheng, Weidong; Liu, Yanhui; Chen, Dong; Rong, Kabin; Ge, Yanfen; Gong, Caiping; Chen, Heping

    2010-09-01

    Hemoglobin (Hb) Q-Thailand, Hb E, and other forms of thalassemia are prevalent in Southeast Asia including China. We report a hitherto undescribed condition in which four forms of Hb defects co-segregate. The proband was a 20-year-old Chinese man who presented with moderate hypochromic microcytosis with Hb 73 g/l, hematocrit (Hct) 27.0%, mean corpuscular volume 57.6 fl, mean corpuscular hemoglobin 15.5 pg, and mean corpuscular hemoglobin concentration (MCHC) 268.0 g/l. Both Hb electrophoresis and high-performance liquid chromatography analysis revealed abnormal Hbs. DNA analysis demonstrated that the proband was a double heterozygote of Hb Q-Thailand and Hb E in combination with alpha(0)-thalassemia and Southeast Asian-type hereditary persistence of fetal hemoglobin (SEA-HPFH). Family study identified that her father was a double heterozygote for Hb Q-Thailand and Hb E, whereas her mother was a heterozygote for SEA-HPFH with alpha(0)-thalassemia. Moreover, his brother was a classical Hb QH disease patient. The genotype-phenotype relationship observed in this Chinese family with complex thalassemia syndromes is presented. This work will provide some clinical implications for molecular diagnosis for complex hemoglobinopathies.

  12. MicroRNA-15a and -16-1 act via MYB to elevate fetal hemoglobin expression in human trisomy 13.

    PubMed

    Sankaran, Vijay G; Menne, Tobias F; Šćepanović, Danilo; Vergilio, Jo-Anne; Ji, Peng; Kim, Jinkuk; Thiru, Prathapan; Orkin, Stuart H; Lander, Eric S; Lodish, Harvey F

    2011-01-25

    Many human aneuploidy syndromes have unique phenotypic consequences, but in most instances it is unclear whether these phenotypes are attributable to alterations in the dosage of specific genes. In human trisomy 13, there is delayed switching and persistence of fetal hemoglobin (HbF) and elevation of embryonic hemoglobin in newborns. Using partial trisomy cases, we mapped this trait to chromosomal band 13q14; by examining the genes in this region, two microRNAs, miR-15a and -16-1, appear as top candidates for the elevated HbF levels. Indeed, increased expression of these microRNAs in primary human erythroid progenitor cells results in elevated fetal and embryonic hemoglobin gene expression. Moreover, we show that a direct target of these microRNAs, MYB, plays an important role in silencing the fetal and embryonic hemoglobin genes. Thus we demonstrate how the developmental regulation of a clinically important human trait can be better understood through the genetic and functional study of aneuploidy syndromes and suggest that miR-15a, -16-1, and MYB may be important therapeutic targets to increase HbF levels in patients with sickle cell disease and β-thalassemia.

  13. Role of Breastfeeding and Complementary Food on Hemoglobin and Ferritin Levels in a Cambodian Cross-Sectional Sample of Children Aged 3 to 24 Months

    PubMed Central

    Reinbott, Anika; Jordan, Irmgard; Herrmann, Johannes; Kuchenbecker, Judith; Kevanna, Ou; Krawinkel, Michael B.

    2016-01-01

    Background Iron deficiency derives from a low intake of dietary iron, poor absorption of iron, and high requirements due to growth as well as blood loss. An estimated number of about 50% of all anemia may be attributed to iron deficiency among young children in Cambodia. Methods A cross-sectional survey was conducted in rural Cambodia in September 2012. Villages in pre-selected communes were randomly chosen using stunting as a primary indicator of nutritional status. In total, 928 randomly selected households with children aged 3–23 months were included. Hemoglobin, ferritin, soluble transferrin receptor (sTfR), and retinol binding protein (RBP) were assessed from capillary blood samples. In addition, length/height and weight of mothers and children were taken and data on dietary diversity was collected. A child feeding index (CFI) was created. Associations between biomarkers of iron and vitamin A status and nutritional status or food intake were explored. Results Anemia prevalence was highest among 6- to 12-months-olds (71%). Ferritin and sTfR inversely correlated and were significantly associated with hemoglobin concentrations. The consumption of animal source foods (ASF) significantly impacts on the interaction between ferritin, sTfR and hemoglobin. Concentrations of RBP were significantly higher in children who had received a vitamin A supplement. The CFI was associated with sTfR and hemoglobin. Lower length and weight were associated with lower ferritin levels and showed an indirect effect on hemoglobin through ferritin. Conclusion Nutrition programs targeting children under 2 years of age need to focus on the preparation of complementary foods with high nutrient density to sustainably prevent micronutrient deficiency and generally improve nutritional status. Future assessments of the micronutrient status should include identification of hemoglobinopathies and parasitic infections to better understand all causes of anemia in Cambodian infants and young

  14. The Monod-Wyman-Changeux allosteric model accounts for the quaternary transition dynamics in wild type and a recombinant mutant human hemoglobin

    PubMed Central

    Levantino, Matteo; Spilotros, Alessandro; Cammarata, Marco; Schirò, Giorgio; Ardiccioni, Chiara; Vallone, Beatrice; Brunori, Maurizio; Cupane, Antonio

    2012-01-01

    The acknowledged success of the Monod-Wyman-Changeux (MWC) allosteric model stems from its efficacy in accounting for the functional behavior of many complex proteins starting with hemoglobin (the paradigmatic case) and extending to channels and receptors. The kinetic aspects of the allosteric model, however, have been often neglected, with the exception of hemoglobin and a few other proteins where conformational relaxations can be triggered by a short and intense laser pulse, and monitored by time-resolved optical spectroscopy. Only recently the application of time-resolved wide-angle X-ray scattering (TR-WAXS), a direct structurally sensitive technique, unveiled the time scale of hemoglobin quaternary structural transition. In order to test the generality of the MWC kinetic model, we carried out a TR-WAXS investigation in parallel on adult human hemoglobin and on a recombinant protein (HbYQ) carrying two mutations at the active site [Leu(B10)Tyr and His(E7)Gln]. HbYQ seemed an ideal test because, although exhibiting allosteric properties, its kinetic and structural properties are different from adult human hemoglobin. The structural dynamics of HbYQ unveiled by TR-WAXS can be quantitatively accounted for by the MWC kinetic model. Interestingly, the main structural change associated with the R–T allosteric transition (i.e., the relative rotation and translation of the dimers) is approximately 10-fold slower in HbYQ, and the drop in the allosteric transition rate with ligand saturation is steeper. Our results extend the general validity of the MWC kinetic model and reveal peculiar thermodynamic properties of HbYQ. A possible structural interpretation of the characteristic kinetic behavior of HbYQ is also discussed. PMID:22927385

  15. A molecular study of a family with Greek hereditary persistence of fetal hemoglobin and beta-thalassemia.

    PubMed Central

    Giglioni, B; Casini, C; Mantovani, R; Merli, S; Comi, P; Ottolenghi, S; Saglio, G; Camaschella, C; Mazza, U

    1984-01-01

    A family was studied in which two inherited defects of the non-alpha-globin cluster segregate: Greek hereditary persistence of fetal hemoglobin (HPFH) and beta-thalassemia. Fragments of the non-alpha-globin cluster from two patients were cloned in cosmid and phage lambda vectors, and assigned to either the HPFH or beta-thalassemic chromosome on the basis of the demonstration of a polymorphic BglII site in the HPFH gamma-globin cluster. The thalassemic beta-globin gene carries a mutation at nucleotide 1 of the intervening sequence I, known to cause beta zero-thalassemia; the beta-globin gene from the HPFH chromosome is entirely normal, both in the intron-exon sequence and in 5' flanking regions required for transcription. As the compound HPFH/beta-thalassemia heterozygote synthesizes HbA, these data prove that the HPFH beta-globin gene is functional, although at a decreased rate; its lower activity is likely to be due to a distant mutation. The HPFH A gamma-globin gene shows only two mutations: a T----C substitution in the large intervening sequence (responsible for the BglII polymorphic site) and a C----T substitution 196 nucleotides 5' to the cap site; the 5' flanking sequence is normal up to -1350 nucleotides upstream from the gene. Circumstantial evidence suggests that the mutation at -196 may be responsible for the abnormally high expression of the A gamma-globin gene. Images Fig. 1. Fig. 3. Fig. 4. Fig. 5. PMID:6210198

  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. Hb A1c Determination by Capillary Electrophoresis is an Efficient Method for Detecting β-Thalassemias and Hemoglobin Variants.

    PubMed

    Orts, Juan A; Zúñiga, Ángel; Bello, Yanis; Fabregat, Aleix B; Vicente, Ana I

    2016-09-01

    Glycated hemoglobin (Hb A1c) determination by multicapillary zone electrophoresis (MZE) can additionally be used to detect Hb A2, Hb F and most common hemoglobin (Hb) variants. We assessed the effectiveness of this method for detecting β-thalassemia (β-thal), δβ-thalassemia (δβ-thal) and most common Hb variants. Moreover, Hb F/Hb A2 is evaluated as an index for discriminating between β- and δβ-thal traits. The theoretical β-thalassemia major (β-TM) birth rate in our healthcare area is calculated and contrasted with real data. A MZE technique was used for Hb A1c measurements in 27,724 patients. Previous criteria for carrier detection were established and subsequently confirmed by molecular biology techniques. Positive predictive value (PPV) was 100.0%. The prevalence of β-thal trait (including δβ-thal) was 0.34%. The most prevalent mutations (estimated per 100,000 population) were HBB: c.118C > T (57.7%), HBB: c.93-21G>A (50.5%), HBB: c.92 + 1G > A (43.3%), HBB: c.92 + 6T > C (32.5%) and HBB: c.20delA (18.0%) for β-thalassemias, and Hb S (HBB: c.20A > T) (32.5%) and Hb J-Baltimore (HBB:c.3880T>A) (28.9%) for Hb variants. We found a paradoxical result between the theoretical β-TM birth rate and real data. We calculated an optimal Hb F/Hb A2 index cutoff of 0.71 for discriminating between β- and δβ-thal traits. This method is highly cost-effective for detecting β-thalassemias and common Hb variants. Prevalence results match previous data for the Spanish population. Heterogeneity of mutations in Spain has markedly increased as a consequence of migration. The Hb F/Hb A2 index cutoff could be used to predict δβ-thal trait.

  18. 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.

  19. Genetic heterogeneity of hemoglobin AEBart's disease: a large cohort data from a single referral center in northeast Thailand.

    PubMed

    Chaibunruang, Attawut; Karnpean, Rossarin; Fucharoen, Goonnapa; Fucharoen, Supan

    2014-04-01

    AEBart's disease is a thalassemia intermedia usually characterized by the interaction of α(0)-thalassemia with either deletional or non-deletional α(+)-thalassemia in Hb E heterozygote. Genotypic and phenotypic features are heterogeneous. We studied the hematologic and molecular characteristics of this disease in a cohort of 173 Thai patients encountered at our center in northeast Thailand. Hemoglobin and DNA analyses identified patients with deletional AEBart's disease (n=84), Hb Constant Spring AEBart's disease (n=81), Hb Paksé-AEBart's disease (n=5), AEBart's disease with codon 30 mutation (n=1) and two hitherto un-described forms of AEBart's disease due to interaction of Hb E heterozygote and α(0)-thalassemia with the -α(16.6)kb deletional α(+)-thalassemia (n=1) and Hb Q-Thailand (n=1). Different phenotypic expression of these AEBart's diseases with low Hb, Hct and MCV and increased RDW values with marked reduction in Hb E levels were observed. It was found that all these forms of AEBart's disease showed similar thalassemia intermedia phenotypes but those with non-deletional forms were relatively more anemic. Our data confirm that in such area with high prevalence of hemoglobinopathies such as Southeast Asia, identification of rare thalassemia alleles in a thalassemia intermedia patient should not be ignored. Careful consideration of different phenotypic expression may help in providing presumptive diagnosis of this disease where access to molecular testing is limited. However, molecular diagnostic is useful for predicting the clinical outcome and improving genetic counseling of these complex hemoglobinopathies.

  20. 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)....

  1. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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)....

  2. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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)....

  3. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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)....

  4. 21 CFR 864.7470 - Glycosylated hemoglobin assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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)....

  5. 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

  6. What Do We Need beyond Hemoglobin A1c to Get the Complete Picture of Glycemia in People with Diabetes?

    PubMed Central

    Hinzmann, Rolf; Schlaeger, Christof; Tran, Cam Tuan

    2012-01-01

    Hemoglobin A1c (HbA1c) is currently the most commonly used marker for the determination of the glycemic status in people with diabetes and it is frequently used to guide therapy and especially medical treatment of people with diabetes. The measurement of HbA1c has reached a high level of analytical quality and, therefore, this biomarker is currently also suggested to be used for the diagnosis of diabetes. Nevertheless, it is crucial for people with diabetes and their treating physicians to be aware of possible interferences during its measurement as well as physiological or pathological factors that contribute to the HbA1c concentration without being related to glycemia, which are discussed in this review. We performed a comprehensive review of the literature based on PubMed searches on HbA1c in the treatment and diagnosis of diabetes including its most relevant limitations, glycemic variability and self-monitoring of blood glucose (SMBG). Although the high analytical quality of the HbA1c test is widely acknowledged, the clinical relevance of this marker regarding risk reduction of cardiovascular morbidity and mortality is still under debate. In this respect, we argue that glycemic variability as a further risk factor should deserve more attention in the treatment of diabetes. PMID:23055818

  7. A Blue Spectral Shift of the Hemoglobin Soret Band Correlates with the Age (Time Since Deposition) of Dried Bloodstains

    PubMed Central

    Hanson, Erin K.; Ballantyne, Jack

    2010-01-01

    The ability to determine the time since deposition of a bloodstain found at a crime scene could prove invaluable to law enforcement investigators, defining the time frame in which the individual depositing the evidence was present. Although various methods of accomplishing this have been proposed, none has gained widespread use due to poor time resolution and weak age correlation. We have developed a method for the estimation of the time since deposition (TSD) of dried bloodstains using UV-VIS spectrophotometric analysis of hemoglobin (Hb) that is based upon its characteristic oxidation chemistry. A detailed study of the Hb Soret band (λmax = 412 nm) in aged bloodstains revealed a blue shift (shift to shorter wavelength) as the age of the stain increases. The extent of this shift permits, for the first time, a distinction to be made between bloodstains that were deposited minutes, hours, days and weeks prior to recovery and analysis. The extent of the blue shift was found to be a function of ambient relative humidity and temperature. The method is extremely sensitive, requiring as little as a 1 µl dried bloodstain for analysis. We demonstrate that it might be possible to perform TSD measurements at the crime scene using a portable low-sample-volume spectrophotometer. PMID:20877468

  8. miRNA-embedded shRNAs for Lineage-specific BCL11A Knockdown and Hemoglobin F Induction

    PubMed Central

    Guda, Swaroopa; Brendel, Christian; Renella, Raffaele; Du, Peng; Bauer, Daniel E; Canver, Matthew C; Grenier, Jennifer K; Grimson, Andrew W; Kamran, Sophia C; Thornton, James; de Boer, Helen; Root, David E; Milsom, Michael D; Orkin, Stuart H; Gregory, Richard I; Williams, David A

    2015-01-01

    RNA interference (RNAi) technology using short hairpin RNAs (shRNAs) expressed via RNA polymerase (pol) III promoters has been widely exploited to modulate gene expression in a variety of mammalian cell types. For certain applications, such as lineage-specific knockdown, embedding targeting sequences into pol II-driven microRNA (miRNA) architecture is required. Here, using the potential therapeutic target BCL11A, we demonstrate that pol III-driven shRNAs lead to significantly increased knockdown but also increased cytotoxcity in comparison to pol II-driven miRNA adapted shRNAs (shRNAmiR) in multiple hematopoietic cell lines. We show that the two expression systems yield mature guide strand sequences that differ by a 4 bp shift. This results in alternate seed sequences and consequently influences the efficacy of target gene knockdown. Incorporating a corresponding 4 bp shift into the guide strand of shRNAmiRs resulted in improved knockdown efficiency of BCL11A. This was associated with a significant de-repression of the hemoglobin target of BCL11A, human γ-globin or the murine homolog Hbb-y. Our results suggest the requirement for optimization of shRNA sequences upon incorporation into a miRNA backbone. These findings have important implications in future design of shRNAmiRs for RNAi-based therapy in hemoglobinopathies and other diseases requiring lineage-specific expression of gene silencing sequences. PMID:26080908

  9. MP4CO, a pegylated hemoglobin saturated with carbon monoxide, is a modulator of HO-1, inflammation, and vaso-occlusion in transgenic sickle mice.

    PubMed

    Belcher, John D; Young, Mark; Chen, Chunsheng; Nguyen, Julia; Burhop, Kenneth; Tran, Phuc; Vercellotti, Gregory M

    2013-10-10

    Transgenic sickle mice expressing β(S) hemoglobin have activated vascular endothelium in multiple organs that exhibits enhanced expression of NF-ĸB and adhesion molecules and promotes microvascular stasis in sickle, but not normal, mice in response to hypoxia/reoxygenation (H/R), or heme. Induction of heme oxygenase-1 (HO-1) or administration of its products, carbon monoxide (CO) or biliverdin, inhibits microvascular stasis in sickle mice. Infusion of human hemoglobin conjugated with polyethylene glycol and saturated with CO (MP4CO) markedly induced hepatic HO-1 activity and inhibited NF-ĸB activation and H/R-induced microvascular stasis in sickle mice. These effects were mediated by CO; saline or MP4 saturated with O2 (MP4OX) had little to no effect on H/R-induced stasis, though unmodified oxyhemoglobin exacerbated stasis. The HO-1 inhibitor, tin protoporphyrin, blocked MP4CO protection, consistent with HO-1 involvement in the protection afforded by MP4CO. MP4CO also induced nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), an important transcriptional regulator of HO-1 and other antioxidant genes. In a heterozygous (hemoglobin-AS) sickle mouse model, intravenous hemin induced cardiovascular collapse and mortality within 120 minutes, which was significantly reduced by MP4CO, but not MP4OX. These data demonstrate that MP4CO induces cytoprotective Nrf2 and HO-1 and decreases NF-ĸB activation, microvascular stasis, and mortality in transgenic sickle mouse models.

  10. Are the ADA hemoglobin A(1c) criteria relevant for the diagnosis of type 2 diabetes in youth?

    PubMed

    Kapadia, Chirag R

    2013-02-01

    Diagnostic criteria for diabetes in children have not been established with nearly the rigor as that employed in adults. Recently revised American Diabetes Association (ADA) criteria allowed utilization of hemoglobin A(1c) (HbA1c) ≥ 6.5 % for diagnosis of diabetes. A recent series of pediatric studies appear to show that HbA1c has lower sensitivity than Fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT). However, FPG and OGTT have themselves never been validated in children. Studies to validate diagnostic thresholds in children appear unlikely to take place. Thus, accepting the major ADA diagnostic criteria appears to be the best course of action for the pediatric community. One area in which correlation studies between HbA1c and FPG or OGTT might shed light is in the definition of criteria for intervention in 'pre-diabetes,' as the Diabetes Prevention Program Trial did not use HbA1c. However, such treatment, and the exact diagnostic thresholds at which it should be initiated in children, remains unproven.

  11. Heterologous coexpression of Vitreoscilla hemoglobin and Bacillus megaterium glucanase in Streptomyces lydicus A02 enhanced its production of antifungal metabolites.

    PubMed

    Wu, Huiling; Li, Jinjin; Dong, Dan; Liu, Ting; Zhang, Taotao; Zhang, Dianpeng; Liu, Weicheng

    2015-12-01

    Streptomyces lydicus A02 is a novel producer of commercially important polyene macrocyclic antibiotic natamycin and a potential biocontrol agent to several plant fungal diseases, including wilt caused by Fusarium oxysporum f. spp. To improve the natamycin production and the antifungal activity of S. lydicus A02, we coexpressed gene vgb encoding Vitreoscilla hemoglobin (VHb) and bglC encoding Bacillus megaterium L103 glucanase, both under the control of the strong constitutive ermE* promoter, in S. lydicus A02. Our results showed that coexpressing VHb and glucanase improved cell growth, and the engineered strain produced 26.90% more biomass than the wild-type strain after 72h fermentation in YSG medium. In addition, coexpressing genes encoding VHb and glucanase led to increased natamycin production, higher endogenous chitinase activity and exogenous glucanase activity, as well as enhanced antifungal activity in the engineered S. lydicus AVG02 and AGV02, regardless of the position of the two genes on the plasmids. Compared with model strains, few reports have successfully coexpressed VHb and other foreign proteins in industrial strains. Our results illustrated an effective approach for improving antifungal activity in an industrial strain by the rational engineering of combined favorable factors.

  12. Sustained decrease in oxygenated hemoglobin during video games in the dorsal prefrontal cortex: a NIRS study of children.

    PubMed

    Matsuda, Goh; Hiraki, Kazuo

    2006-02-01

    Traditional neuroimaging studies have mainly focused on brain activity derived from a simple stimulus and task. Therefore, little is known about brain activity during daily operations. In this study, we investigated hemodynamic changes in the dorsal prefrontal cortex (DPFC) during video games as one of daily amusements, using near infrared spectroscopy technique. It was previously reported that oxygenated hemoglobin (oxyHb) in adults' DPFC decreased during prolonged game playing time. In the present study, we examined whether similar changes were observed in children. Twenty children (7-14 years old) participated in our study, but only 13 of them were eventually subject to analysis. They played one or two commercially available video games; namely a fighting and a puzzle game, for 5 min. We used changes in concentration of oxyHb as an indicator of brain activity and consequently, most of the children exhibited a sustained game-related oxyHb decrease in DPFC. Decrease patterns of oxyHb in children during video game playing time did not differ from those in adults. There was no significant correlation between ages or game performances and changes in oxyHb. These findings suggest that game-related oxyHb decrease in DPFC is a common phenomenon to adults and children at least older than 7 years old, and we suggest that this probably results from attention demand from the video games rather than from subject's age and performance.

  13. A recombinant polymeric hemoglobin with conformational, functional, and physiological characteristics of an in vivo O2 transporter.

    PubMed

    Bobofchak, Kevin M; Mito, Toshiaki; Texel, Sarah J; Bellelli, Andrea; Nemoto, Masaaki; Traystman, Richard J; Koehler, Raymond C; Brinigar, William S; Fronticelli, Clara

    2003-08-01

    With the objective of developing a recombinant oxygen carrier suitable for therapeutic applications, we have employed an Escherichia coli expression system to synthesize in high-yield hemoglobin (Hb) Minotaur, containing alpha-human and beta-bovine chains. Polymerization of Hb Minotaur through S-S intermolecular cross-linking was obtained by introducing a Cys at position beta9 and substituting the naturally occurring Cys. This homogeneous polymer, Hb Polytaur, has a molecular mass of approximately 500 kDa and was resistant toward reducing agents present in blood. In mice, the circulating half-time (3 h) was fivefold greater than adult human Hb (HbA). The half-time of autooxidation measured in blood (46 h) exceeded the circulating retention time. Hypervolemic exchange transfusion resulted in increased arterial blood pressure similar to that with albumin. The increase in pressure was less than that obtained by transfusion of cross-linked tetrameric Hb known to undergo renovascular extravasation. The nitric oxide reactivity of Hb Polytaur was similar to HbA, suggesting that the diminished pressor response to Hb Polytaur was probably related to diminished extravasation. Transfusion of 3% Hb Polytaur during focal cerebral ischemia reduced infarct volume by 22%. Therefore, site-specific Cys insertion on the Hb surface results in uniform size polymers that do not produce the large pressor response seen with tetrameric Hb. Polymerization maintains physiologically relevant oxygen and heme affinity, stability toward denaturation and oxidation, and effective oxygen delivery as indicated by reduced cerebral ischemic damage.

  14. Evaluation of Gallium as a Tracer of Exogenous Hemoglobin-Haptoglobin Complexes for Targeted Drug Delivery Applications

    NASA Astrophysics Data System (ADS)

    Xu, Shengsheng; Kaltashov, Igor A.

    2016-12-01

    Haptoglobin (Hp) is a plasma glycoprotein that generates significant interest in the drug delivery community because of its potential for delivery of antiretroviral medicines with high selectivity to macrophages and monocytes, the latent reservoirs of human immunodeficiency virus. As is the case with other therapies that exploit transport networks for targeted drug delivery, the success of the design and optimization of Hp-based therapies will critically depend on the ability to accurately localize and quantitate Hp-drug conjugates on the varying and unpredictable background of endogenous proteins having identical structure. In this work, we introduce a new strategy for detecting and quantitating exogenous Hp and Hp-based drugs with high sensitivity in complex biological samples using gallium as a tracer of this protein and inductively coupled plasma mass spectrometry (ICP MS) as a method of detection. Metal label is introduced by reconstituting hemoglobin (Hb) with gallium(III)-protoporphyrin IX followed by its complexation with Hp. Formation of the Hp/Hb assembly and its stability are evaluated with native electrospray ionization mass spectrometry. Both stable isotopes of Ga give rise to an abundant signal in ICP MS of a human plasma sample spiked with the metal-labeled Hp/Hb complex. The metal label signal exceeds the spectral interferences' contributions by more than an order of magnitude even with the concentration of the exogenous protein below 10 nM, the level that is more than adequate for the planned pharmacokinetic studies of Hp-based therapeutics.

  15. Non-thermal radio frequency and static magnetic fields increase rate of hemoglobin deoxygenation in a cell-free preparation.

    PubMed

    Muehsam, David; Lalezari, Parviz; Lekhraj, Rukmani; Abruzzo, Provvidenza M; Abruzzo, Provvidenza; Bolotta, Alessandra; Marini, Marina; Bersani, Ferdinando; Aicardi, Giorgio; Pilla, Arthur; Casper, Diana

    2013-01-01

    The growing body of clinical and experimental data regarding electromagnetic field (EMF) bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF) signal, and a static magnetic field (SMF), applied independently, increased the rate of deoxygenation of human hemoglobin (Hb) in a cell-free assay. Deoxygenation of Hb was initiated using the reducing agent dithiothreitol (DTT) in an assay that allowed the time for deoxygenation to be controlled (from several min to several hours) by adjusting the relative concentrations of DTT and Hb. The time course of Hb deoxygenation was observed using visible light spectroscopy. Exposure for 10-30 min to either PRF or SMF increased the rate of deoxygenation occurring several min to several hours after the end of EMF exposure. The sensitivity and biochemical simplicity of the assay developed here suggest a new research tool that may help to further the understanding of basic biophysical EMF transduction mechanisms. If the results of this study were to be shown to occur at the cellular and tissue level, EMF-enhanced oxygen availability would be one of the mechanisms by which clinically relevant EMF-mediated enhancement of growth and repair processes could occur.

  16. [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.

  17. Ligation and quaternary structure induced changes in the heme pocket of hemoglobin: a transient resonance Raman study.

    PubMed

    Friedman, J M; Stepnoski, R A; Stavola, M; Ondrias, M R; Cone, R L

    1982-04-27

    The extent to which ligation and quaternary structure modify the heme-heme pocket configuration is determined by generating and analyzing transient resonance Raman spectra from various photolyzed and partially photolyzed hemoglobins (Hb). From small frequently shifts in Raman band I (approximately 1355 cm-1) it is determined that ligation induces a configurational change about the heme. The extent to which ligation modifies the heme pocket is influenced by the quaternary structure. With respect to the structural parameter responsible for variations in the pi orbital electron density of the porphyrin, the degree of alteration of the heme pocket configuration relative to deoxy-Hb(T) follows the sequence: liganded Hb(R) greater than liganded Hb(R) + IHP greater than liganded Hb(T) [alpha chain greater than beta chain] greater than deoxy-Hb(R). This progression of configurations also forms a sequence with respect to the "retentiveness" of the heme pocket as reflected in the ligand dynamics associated with geminate recombination. The results indicate that the heme-heme pocket of the R-state Hb's, relative to those of the T-state species, favors ligand retention in a dynamic, as well as thermodynamic, sense. The analysis of these and other related data implicates a ligation and quaternary structure modulated electronic and/or electrostatic interaction between the pi system of the porphyrin and the surrounding heme pocket as the basis for this variation in ligand dynamics as well as for the energetics of cooperativity.

  18. The evolution of polar fish hemoglobin: a phylogenetic analysis of the ancestral amino acid residues linked to the root effect.

    PubMed

    Verde, Cinzia; Parisi, Elio; di Prisco, Guido

    2003-01-01

    Originating from a benthic ancestor, the suborder Notothenioidei (the dominant fish fauna component of the Antarctic sea) underwent a remarkable radiation, which led notothenioids to fill several niches. The ecological importance of notothenioids in Antarctica and their biochemical adaptations have prompted great efforts to study their physiology and phylogeny, with special attention to the evolutionary adaptation of the oxygen-transport system. We herewith report the evolutionary history of alpha- and beta-globins under the assumption of the molecular clock hypothesis as a basis for reconstructing the phylogenetic relationships among species. These studies have been extended to fish species of other latitudes, including the Arctic region. The northern and southern polar oceans have very different characteristics; indeed, in many respects the Antarctic and Arctic ichthyofaunas are more dissimilar than similar. Our results show that the inferred phylogeny of Arctic and Antarctic globins is different. Taking advantage of the wealth of information collected on structure and function of hemoglobins, we have attempted to investigate the evolutionary history of an important physiological feature in fish, the Root effect. The results suggest that the amino acid residues reported to play a key role in the Root effect may be regarded as ancestor characters, but the lack of this effect in extant species can hardly be associated with the presence of synapomorphies.

  19. Molecular cloning and characterization of a nonsymbiotic hemoglobin gene (GLB1) from Malus hupehensis Rehd. with heterologous expression in tomato.

    PubMed

    Shi, Xingzheng; Wang, Xinliang; Peng, Futian; Zhao, Yu

    2012-08-01

    Nonsymbiotic hemoglobins (nsHbs) are involved in a variety of cellular processes in plants. Previous studies indicate that nsHb expression improves plant tolerance during waterlogging and hypoxia. In the present work, the nsHb class-1 coding sequence was cloned from Malus hupehensis Rehd. var. pinyiensis Jiang and subsequently named MhGLB1. The results elucidated the expressed characteristics and physiological effects of MhGLB1. The full-length cDNA contained a 477 bp open reading frame encoding a protein with a molecular mass of 17.8 KDa with 158 amino acids. Quantitative real-time PCR analysis showed that MhGLB1 expresses in roots, stems and leaves growing under normal and nitrate-induced conditions. Hypoxic stress induced accumulation of MhGLB1 within 12 h, and abscisic acid significantly induced expression of MhGLB1 in roots. The photosynthetic, transpiration and stomatal conductance rates of transgenic MhGLB1 tomato plants decreased more slowly than that of wild-type plants under waterlogging treatment. These results indicated that the MhGLB1 gene has an important role in hypoxia.

  20. A novel two-over-two α-helical sandwich fold is characteristic of the truncated hemoglobin family

    PubMed Central

    Pesce, Alessandra; Couture, Manon; Dewilde, Sylvia; Guertin, Michel; Yamauchi, Kiyoshi; Ascenzi, Paolo; Moens, Luc; Bolognesi, Martino

    2000-01-01

    Small hemoproteins displaying amino acid sequences 20–40 residues shorter than (non-)vertebrate hemoglobins (Hbs) have recently been identified in several pathogenic and non-pathogenic unicellular organisms, and named ‘truncated hemoglobins’ (trHbs). They have been proposed to be involved not only in oxygen transport but also in other biological functions, such as protection against reactive nitrogen species, photosynthesis or to act as terminal oxidases. Crystal structures of trHbs from the ciliated protozoan Paramecium caudatum and the green unicellular alga Chlamydomonas eugametos show that the tertiary structure of both proteins is based on a ‘two-over-two’ α-helical sandwich, reflecting an unprecedented editing of the classical ‘three-over-three’ α-helical globin fold. Based on specific Gly–Gly motifs the tertiary structure accommodates the deletion of the N-terminal A-helix and replacement of the crucial heme-binding F-helix with an extended polypeptide loop. Additionally, concerted structural modifications allow burying of the heme group and define the distal site, which hosts a TyrB10, GlnE7 residue pair. A set of structural and amino acid sequence consensus rules for stabilizing the fold and the bound heme in the trHbs homology subfamily is deduced. PMID:10835341

  1. 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.

  2. 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.

  3. Pulmonary thromboembolism in a child with sickle cell hemoglobin d disease in the setting of acute chest syndrome.

    PubMed

    Villanueva, Hazel; Kuril, Sandeepkumar; Krajewski, Jennifer; Sedrak, Aziza

    2013-01-01

    Introduction. Sickle cell hemoglobin D disease (HbSD) is a rare variant of sickle cell disease (SCD). Incidence of pulmonary thromboembolism (PE) and deep venous thrombosis (DVT) in children with HbSD is unknown. PE and DVT are known complications of SCD in adults but have not been reported in the literature in children with HbSD. Case Report. We are reporting a case of a 12-year-old boy with HbSD with acute chest syndrome (ACS) complicated by complete thrombosis of the branch of the right pulmonary artery and multiple small pulmonary artery emboli seen on computed tomography (CT) pulmonary angiogram and thrombosis of the right brachial vein seen on Doppler ultrasound. Our patient responded to treatment with anticoagulant therapy. Conclusion. There are no cases reported in children with HbSD disease presenting as ACS with pulmonary thromboembolism. We suggest that PE should be suspected in patients presenting with ACS who do not show improvement with standard management. CT pulmonary angiogram should be utilized for early diagnosis and appropriate management as there is no current protocol for management of PE/DVT in pediatric patients with SCD.

  4. Pulmonary Thromboembolism in a Child with Sickle Cell Hemoglobin D Disease in the Setting of Acute Chest Syndrome

    PubMed Central

    Villanueva, Hazel; Kuril, Sandeepkumar; Krajewski, Jennifer; Sedrak, Aziza

    2013-01-01

    Introduction. Sickle cell hemoglobin D disease (HbSD) is a rare variant of sickle cell disease (SCD). Incidence of pulmonary thromboembolism (PE) and deep venous thrombosis (DVT) in children with HbSD is unknown. PE and DVT are known complications of SCD in adults but have not been reported in the literature in children with HbSD. Case Report. We are reporting a case of a 12-year-old boy with HbSD with acute chest syndrome (ACS) complicated by complete thrombosis of the branch of the right pulmonary artery and multiple small pulmonary artery emboli seen on computed tomography (CT) pulmonary angiogram and thrombosis of the right brachial vein seen on Doppler ultrasound. Our patient responded to treatment with anticoagulant therapy. Conclusion. There are no cases reported in children with HbSD disease presenting as ACS with pulmonary thromboembolism. We suggest that PE should be suspected in patients presenting with ACS who do not show improvement with standard management. CT pulmonary angiogram should be utilized for early diagnosis and appropriate management as there is no current protocol for management of PE/DVT in pediatric patients with SCD. PMID:24159402

  5. Rice hemoglobins. Gene cloning, analysis, and O2-binding kinetics of a recombinant protein synthesized in Escherichia coli.

    PubMed Central

    Arredondo-Peter, R; Hargrove, M S; Sarath, G; Moran, J F; Lohrman, J; Olson, J S; Klucas, R V

    1997-01-01

    Although nonsymbiotic hemoglobins (Hbs) are found in different tissues of dicots and monocots, very little is known about hb genes in monocots and the function of Hbs in nonsymbiotic tissues. We report the cloning and analysis of two rice (Oryza sativa L.) hb genes, hb1 and hb2, that code for plant Hbs. Rice hb1 and hb2 genes contain four exons and three introns, as with all of the known plant hb genes. At least three copies of the hb gene were detected in rice DNA, and analysis of gene expression shows that hb1 and hb2 are expressed in leaves but only hb1 is expressed in roots. A cDNA for rice Hb1 was expressed in Escherichia coli, and the recombinant Hb (rHb1) shows an unusually high affinity for O2 because of a very low dissociation constant. The absorbance spectra of the ferric and deoxyferrous rHb1 indicate that, in contrast to symbiotic Hbs, a distal ligand is coordinated to the ligand-binding site. Mutation of the distal His demonstrates that this residue coordinates the heme Fe of ferric and deoxyferrous rHb1 and stabilizes O2 in oxy-rHb1. The biochemical properties of rice rHb1 suggest that this protein probably does not function to facilitate the diffusion of O2. PMID:9390447

  6. Evaluation of hemoglobin A1c measurement from filter paper using high-performance liquid chromatography and immunoturbidimetric assay.

    PubMed

    Wu, Yonghua; Yang, Xu; Wang, Haining; Li, Zhenrong; Wang, Tiancheng

    2017-04-01

    Glycated hemoglobin (HbA1c) measurement from whole blood (WB) samples is inconvenient for epidemic surveillance and self-monitoring of glycemic level. We evaluated HbA1c measurement from WB blotted on filter paper (FP), which can be easily transported to central laboratories, with high-performance liquid chromatography (HPLC) and immunoturbidimetric assay (ITA). WB was applied to Whatman filter paper. By using HPLC and WB samples as reference methods, these FP samples were evaluated on HPLC and ITA. Inter- and intra-assay variation, WB vs. FP agreement and sample stability at 20-25 °C and -70 °C were assessed by statistical analysis. Results showed that the coefficient of variation (CV, %) of FP samples for HPLC and ITA were 0.44-1.02% and 1.47-2.72%, respectively (intra-assay); 2.13-3.56% and 3.21-4.82%, respectively (inter-assay). The correlation of WB HPLC with FP analyzed using HPLC and ITA are both significant (p < 0.001). Sample stability showed that FP method up to 5 days at 20-25 °C and 5 weeks at -70 °C is accurate and reproducible. In conclusion, FP samples analyzed by HPLC and ITA can both provide an alternative to WB for HbA1c measurement, supporting the use of FP method in epidemic surveillance and healthcare units.

  7. The brain metabolic activity after resuscitation with liposome-encapsulated hemoglobin in a rat model of hypovolemic shock.

    PubMed

    Rao, Geeta; Hedrick, Andria F; Yadav, Vivek R; Xie, Jun; Hussain, Alamdar; Awasthi, Vibhudutta

    2015-09-01

    We examined the effect of resuscitation with liposome-encapsulated hemoglobin (LEH) on cerebral bioenergetics in a rat model of 45% hypovolemia. The rats were resuscitated with isovolemic LEH or saline after 15 minutes of shock and followed up to 6 hours. Untreated hypovolemic rats received no fluid. The cerebral uptake of F-18-fluorodeoxyglucose (FDG) was measured by PET, and at 6 hours, the brain was collected for various assays. Hypovolemia decreased cellular adenosine triphosphate (ATP), phosphocreatine, nicotinamide adenine dinucleotide (NAD)/NADH ratio, citrate synthase activity, glucose-6-phosphate, and nerve growth factor (NGF), even when FDG uptake remained unchanged. The FDG uptake was reduced by saline, but not by LEH infusion. The reduced FDG uptake in saline group was associated with a decrease in hexokinase I expression. The LEH infusion effectively restored ATP content, NAD/NADH ratio, and NGF expression, and reduced the hypovolemia-induced accumulation of pyruvate and ubiquitinated proteins; in comparison, saline was significantly less effective. The LEH infusion was associated with low pH and high anion gap, indicating anionic gap acidosis. The results suggest that hypovolemic shock perturbs glucose metabolism at the level of pyruvate utilization, resulting in deranged cerebral energy stores. The correction of volume and oxygen deficits by LEH recovers the cerebral metabolism and creates a prosurvival phenotype.

  8. Molecular Cloning and Characterization of a (Lys)6-Tagged Sulfide-Reactive Hemoglobin I from Lucina pectinata

    PubMed Central

    Díaz-Ayala, Ramonita; Moya-Rodríguez, Andrés; Pietri, Ruth; Cadilla, Carmen L.

    2016-01-01

    A poly-Lys tag was fused to the Lucina pectinata hemoglobin I (HbI) coding sequence and purified using an efficient and fast process. HbI is a hemeprotein that binds hydrogen sulfide (H2S) with high affinity and it has been used to understand physiologically relevant reactions of this signaling molecule. The (Lys)6-tagged rHbI construct was expressed in E. coli and purified by immobilization on a cation exchange matrix, followed by size-exclusion chromatography. The identity, structure, and function of the (Lys)6-tagged rHbI were assessed by mass spectrometry, small and wide X-ray scattering, optical spectroscopy, and kinetic analysis. The scattering and spectroscopic results showed that the (Lys)6-tagged rHbI is structurally and functionally analogous to the native protein as well as to the (His)6-tagged rHbI. Kinetics studies with H2S indicated that the association (kon) and dissociation (koff) rate constants were 1.4 × 105/M/s and 0.1 × 10−3/s, respectively. This results confirmed that the (Lys)6-tagged rHbI binds H2S with the same high affinity as its homologue. PMID:26482241

  9. 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.

  10. Spatial distributions of hemoglobin signals from superficial layers in the forehead during a verbal-fluency task

    NASA Astrophysics Data System (ADS)

    Kohno, Satoru; Hoshi, Yoko

    2016-06-01

    Functional near-infrared spectroscopy (fNIRS) signals originate in hemoglobin changes in both the superficial layer of the head and the brain. Under the assumption that the changes in the blood flow in the scalp are spatially homogeneous in the region of interest, a variety of methods for reducing the superficial signals has been proposed. To clarify the spatial distributions of the superficial signals, the superficial signals from the forehead during a verbal-fluency task were investigated by using ten source-detector pairs separated by 5 mm, whereas fNIRS signals were also detected from two source-detector pairs separated by 30 mm. The fNIRS signals strongly correlated with the superficial signals at some channels on the forehead. Hierarchical cluster analysis was performed on the temporal cross-correlation coefficients for two channels of both the NIRS signals, and the analysis results demonstrate spatially heterogeneous distributions and network structures of the superficial signals from within the forehead. The results also show that the assumption stated above is invalid for homogeneous superficial signals from any region of interest of 15-mm diameter or larger on the forehead. They also suggest that the spatially heterogeneous distributions may be attributable to vascular networks, including supraorbital, supratrochlear, and superficial temporal vessels.

  11. Synthesis of Hemoglobin Conjugated Polymeric Micelle: A ZnPc Carrier with Oxygen Self-Compensating Ability for Photodynamic Therapy.

    PubMed

    Wang, Shasha; Yuan, Fang; Chen, Kui; Chen, Gaojian; Tu, Kehua; Wang, Hongjun; Wang, Li-Qun

    2015-09-14

    Photodynamic therapy (PDT) is a promising singlet oxygen ((1)O2) mediated clinical treatment for many tumors. As the source of (1)O2, oxygen plays an important role in the curative effect of PDT. However, the facts of photochemical depletion of oxygen and the intrinsic hypoxic microenvironment of tumors remain the major challenges. In this work, a novel photosensitizer carrier with oxygen self-compensating ability was designed for PDT. It was synthesized via chemical conjugation of hemoglobin (Hb) to polymeric micelles formed by triblock copolymers of poly(ethylene glycol)-block-poly(acrylic acid)-block-polystyrene (PEG-b-PAA-b-PS). The PEG-b-PAA-b-PS and resultant micelles in aqueous solution were comprehensively characterized by means of FTIR, (1)H NMR, GPC, DLS, TEM, and fluorescence spectroscopy. The oxygen-binding capacity and antioxidative activity of the Hb conjugated micelles were evaluated via UV-vis spectroscopy. In addition, compared with the control micelles without Hb, the Hb conjugated photosensitizer carrier was able to generate more (1)O2 and exert greater photocytotoxicity on Hela cells in vitro.

  12. Improved polysaccharide production in a submerged culture of Ganoderma lucidum by the heterologous expression of Vitreoscilla hemoglobin gene.

    PubMed

    Li, Huan-Jun; Zhang, De-Huai; Yue, Tong-Hui; Jiang, Lu-Xi; Yu, Xuya; Zhao, Peng; Li, Tao; Xu, Jun-Wei

    2016-01-10

    Expression of Vitreoscilla hemoglobin (VHb) gene was used to improve polysaccharide production in Ganoderma lucidum. The VHb gene, vgb, under the control of the constitutive glyceraldehyde-3-phosphate dehydrogenase gene promoter was introduced into G. lucidum. The activity of expressed VHb was confirmed by the observation of VHb specific CO-difference spectrum with a maximal absorption at 419 nm for the transformant. The effects of VHb expression on intracellular polysaccharide (IPS) content, extracellular polysaccharide (EPS) production and transcription levels of three genes encoding the enzymes involved in polysaccharide biosynthesis, including phosphoglucomutase (PGM), uridine diphosphate glucose pyrophosphorylase (UGP), and β-1,3-glucan synthase (GLS), were investigated. The maximum IPS content and EPS production in the vgb-bearing G. lucidum were 26.4 mg/100mg dry weight and 0.83 g/L, respectively, which were higher by 30.5% and 88.2% than those of the wild-type strain. The transcription levels of PGM, UGP and GLS were up-regulated by 1.51-, 1.55- and 3.83-fold, respectively, in the vgb-bearing G. lucidum. This work highlights the potential of VHb to enhance G. lucidum polysaccharide production by large scale fermentation.

  13. Insufficient Sensitivity of Hemoglobin A1C (A1C) Determination in Diagnosis or Screening of Early Diabetic States

    PubMed Central

    Fajans, Stefan S.; Herman, William H.; Oral, Elif A.

    2010-01-01

    An International Expert Committee made recommendations for using the hemoglobin A1C (A1C) assay as the preferred method for diagnosis of diabetes in nonpregnant individuals. A concentration of ≥ 6.5% was considered as diagnostic. It is the aim of this study to compare the sensitivity of A1C with that of plasma glucose concentrations in subjects with early diabetes or IGT. We chose two groups of subjects who had A1C of ≤ 6.4%. The first group of 89 subjects had family histories of diabetes (MODY or T2DM) and had OGTT and A1C determinations. They included 36 subjects with diabetes or IGT and 53 with normal OGTT. The second group of 58 subjects was screened for diabetes in our Diabetes Clinic by FPG or 2HPG or OGTT and A1C and similar comparisons were made. Subjects with diabetes or IGT, including those with fasting hyperglycemia, had A1C ranging from 5.0 – 6.4%, mean 5.8%. The subjects with normal OGTT had A1C of 4.2 – 6.3%, mean 5.4% or 5.5% for the two groups. A1C may be in the normal range in subjects with diabetes or IGT, including those with fasting hyperglycemia. Approximately one third of subjects with early diabetes and IGT have A1C <5.7%, the cut-point that ADA recommends as indicating the onset of risk of developing diabetes in the future. The results of our study are similar to those obtained by a large Dutch epidemiological study. If our aim is to recognize early diabetic states to apply effective prophylactic procedures to prevent or delay progression to more severe diabetes, A1C is not sufficiently sensitive or reliable for diagnosis of diabetes or IGT. A combination of A1C and plasma glucose determinations, where necessary, are recommended for diagnosis or screening of diabetes or IGT. PMID:20723948

  14. 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.

  15. Detection of total and A1c-glycosylated hemoglobin in human whole blood using sandwich immunoassays on polydimethylsiloxane-based antibody microarrays.

    PubMed

    Chen, Huang-Han; Wu, Chih-Hsing; Tsai, Mei-Ling; Huang, Yi-Jing; Chen, Shu-Hui

    2012-10-16

    The percentage of glycosylated hemoglobin A1c (%GHbA1c) in human whole blood indicates the average plasma glucose concentration over a prolonged period of time and is used to diagnose diabetes. However, detecting GHbA1c in the whole blood using immunoassays has limited detection sensitivity due to its low percentage in total hemoglobin (tHb) and interference from various glycan moieties in the sample. We have developed a sandwich immunoassay using an antibody microarray on a polydimethylsiloxane (PDMS) substrate modified with fluorinated compounds to detect tHb and glycosylated hemoglobin A1c (GHbA1c) in human whole blood without sample pretreatment. A polyclonal antibody against hemoglobin (Hb) immobilized on PDMS is used as a common capture probe to enrich all forms of Hb followed by detection via monoclonal anti-Hb and specific monoclonal anti-GHbA1c antibodies for tHb and GHbA1c detection, respectively. This method prevents the use of glycan binding molecules and dramatically reduces the background interference, yielding a detection limit of 3.58 ng/mL for tHb and 0.20 ng/mL for GHbA1c. The fluorinated modification on PDMS is superior to the glass substrate and eliminates the need for the blocking step which is required in commercial enzyme linked immunosorbent assay (ELISA) kits. Moreover, the detection sensitivity for GHbA1c is 4-5 orders of magnitude higher, but the required sample amount is 25 times less than the commercial method. On the basis of patient sample data, a good linear correlation between %GHbA1c values determined by our method and the certified high performance liquid chromatography (HPLC) standard method is shown with R(2) > 0.98, indicating the great promise of the developed method for clinical applications.

  16. 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

  17. Positive impact of a weekly iron-folic acid supplement delivered with social marketing to Cambodian women: compliance, participation, and hemoglobin levels increase with higher socioeconomic status.

    PubMed

    Crape, Byron L; Kenefick, Eric; Cavalli-Sforza, Tommaso; Busch-Hallen, Jennifer; Milani, Silvano; Kanal, Koum

    2005-12-01

    A social marketing program promoting weekly iron-folic acid supplementation improved hemoglobin levels in women of reproductive age in Cambodia. Supplementation was increasingly effective among women of higher socioeconomic status (SES). Among higher SES schoolgirls, 58% took the supplements, compared with 49% for lower SES (P = 0.07). Garment factory workers with an 11th- or 12th-grade education had a mean improvement in hemoglobin of 0.72 g/dL over those with a 5th-grade education or less (P = 0.04). The percentage of rural village women taking supplements increased with increasing SES (linear trend P = 0.046). These results suggest that women with lower SES be given special attention for future programs.

  18. Effects of egg and vitamin A supplementation on hemoglobin, retinol status and physical growth levels of primary and middle school students in Chongqing, China.

    PubMed

    Cao, Jiaoyang; Wei, Xiaoping; Tang, Xianqiang; Jiang, Hongpeng; Fan, Zhen; Yu, Qin; Chen, Jie; Liu, Youxue; Li, Tingyu

    2013-01-01

    Lack of protein and vitamin A influences the growth of student in impoverished mountain areas. The aim of the study was to assess the effects of egg and vitamin A supplementation on hemoglobin, serum retinol and anthropometric indices of 10-18 years old students of a low socioeconomic status. A total number of 288 students from four boarding schools were randomly selected by using cluster sampling method in Chongqing, and they were assigned into supplement group and control group non-randomly. Students in supplement group received a single 200,000 international units vitamin A and 1 egg/day (including weekends) for 6 months. The control group did not receive any supplementation. We measured hemoglobin, serum retinol and height and weight at baseline and after supplementation. The supplementation increased the mean hemoglobin concentration by 7.13 g/L compared with 1.38 g/L in control group (p<0.001), the mean serum retinol concentration by 0.31 μmol/L compared with 0.09 μmol/L in the control group (p=0.005), the mean height-for-age z score by 0.05 compared with 0.03 in the control group (p=0.319), the mean weight-for-age z score by 0.05 compared with -0.12 in the control group (p<0.001). Our results revealed that egg and vitamin A supplementation is an effective, convenient, and practical method to improve the levels of hemoglobin, serum retinol and prevent the deterioration of growth in terms of weight for primary and middle school students from outlying poverty-stricken areas. Our intervention did not have a beneficial effect on linear growth.

  19. An immunogenic, surface-exposed domain of Haemophilus ducreyi outer membrane protein HgbA is involved in hemoglobin binding.

    PubMed

    Nepluev, Igor; Afonina, Galyna; Fusco, William G; Leduc, Isabelle; Olsen, Bonnie; Temple, Brenda; Elkins, Christopher

    2009-07-01

    HgbA is the sole TonB-dependent receptor for hemoglobin (Hb) acquisition of Haemophilus ducreyi. Binding of Hb to HgbA is the initial step in heme acquisition from Hb. To better understand this step, we mutagenized hgbA by deletion of each of the 11 putative surface-exposed loops and expressed each of the mutant proteins in trans in host strain H. ducreyi FX547 hgbA. All mutant proteins were expressed, exported, and detected on the surface by anti-HgbA immunoglobulin G (IgG). Deletion of sequences in loops 5 and 7 of HgbA abolished Hb binding in two different formats. In contrast, HgbA proteins containing deletions in the other nine loops retained the ability to bind Hb. None of the clones expressing mutant proteins were able to grow on plates containing low concentrations of Hb. Previously we demonstrated in a swine model of chancroid infection that an HgbA vaccine conferred complete protection from a challenge infection. Using anti-HgbA IgG from this study and the above deletion mutants, we show that loops 4, 5, and 7 of HgbA were immunogenic and surface exposed and that IgG directed against loops 4 and 5 blocked Hb binding. Furthermore, loop 6 was cleaved by protease on intact H. ducreyi, suggesting surface exposure. These data implicate a central domain of HgbA (in respect to the primary amino acid sequence) as important in Hb binding and suggest that this region of the molecule might have potential as a subunit vaccine.

  20. Evaluation of hemoglobin performance in the assessment of iron stores in feto-maternal pairs in a high-risk population: receiver operating characteristic curve analysis

    PubMed Central

    Jaime-Pérez, José Carlos; García-Arellano, Gisela; Méndez-Ramírez, Nereida; González-Llano, Óscar; Gómez-Almaguer, David

    2015-01-01

    Objective By applying receiver operating characteristic curve analysis, the objective of this study was to see whether hemoglobin levels reflect body iron stores in a group of pregnant women at term who, by using serum ferritin as the reference test, had a high pre-test probability of having iron deficiency anemia. Likewise, we evaluated the ability of hemoglobin and maternal serum ferritin levels to predict iron deficiency anemia in newborns. Methods Hemoglobin and serum ferritin were measured in 187 pregnant women at term belonging to a group with a high pre-test probability of iron deficiency anemia and their newborns. Women with Hb <11.0 g/dL and newborns with cord Hb <13.0 g/dL were classified as anemic. A serum ferritin <12.0 μg/L in women and a cord blood serum ferritin <35.0 μg/L were considered to reflect empty iron stores. Receiver operating characteristic curve analysis was applied to select the cut-off points that better reflected iron stores. Results The Hb cut-off point selected by receiver operating characteristic curve analysis in women was <11.5 g/dL (sensitivity: 60.82, specificity: 53.33%, Youden Index: 0.450). Most of the newborns had normal Hb which precluded this analysis. Maternal Hb <11.0 g/dL was the cut-off point that best reflected iron deficiency anemia in newborns (sensitivity: 55.88%, specificity: 57.24%, Youden Index: 0.217). The best cut-off point of maternal serum ferritin to reflect empty iron stores in newborns was <6.0 μg/L (sensitivity: 76.47%, specificity: 31.58%, Youden Index: 0.200). Conclusion Hemoglobin concentration performed poorly to detect iron deficiency anemia in women at term with high risk for iron deficiency and their newborns. PMID:26041420

  1. Common Variants at 10 Genomic Loci Influence Hemoglobin A1C Levels via Glycemic and Nonglycemic Pathways

    PubMed Central

    Soranzo, Nicole; Sanna, Serena; Wheeler, Eleanor; Gieger, Christian; Radke, Dörte; Dupuis, Josée; Bouatia-Naji, Nabila; Langenberg, Claudia; Prokopenko, Inga; Stolerman, Elliot; Sandhu, Manjinder S.; Heeney, Matthew M.; Devaney, Joseph M.; Reilly, Muredach P.; Ricketts, Sally L.

    2010-01-01

    OBJECTIVE Glycated hemoglobin (HbA1c), used to monitor and diagnose diabetes, is influenced by average glycemia over a 2- to 3-month period. Genetic factors affecting expression, turnover, and abnormal glycation of hemoglobin could also be associated with increased levels of HbA1c. We aimed to identify such genetic factors and investigate the extent to which they influence diabetes classification based on HbA1c levels. RESEARCH DESIGN AND METHODS We studied associations with HbA1c in up to 46,368 nondiabetic adults of European descent from 23 genome-wide association studies (GWAS) and 8 cohorts with de novo genotyped single nucleotide polymorphisms (SNPs). We combined studies using inverse-variance meta-analysis and tested mediation by glycemia using conditional analyses. We estimated the global effect of HbA1c loci using a multilocus risk score, and used net reclassification to estimate genetic effects on diabetes screening. RESULTS Ten loci reached genome-wide significant association with HbA1c, including six new loci near FN3K (lead SNP/P value, rs1046896/P = 1.6 × 10−26), HFE (rs1800562/P = 2.6 × 10−20), TMPRSS6 (rs855791/P = 2.7 × 10−14), ANK1 (rs4737009/P = 6.1 × 10−12), SPTA1 (rs2779116/P = 2.8 × 10−9) and ATP11A/TUBGCP3 (rs7998202/P = 5.2 × 10−9), and four known HbA1c loci: HK1 (rs16926246/P = 3.1 × 10−54), MTNR1B (rs1387153/P = 4.0 × 10−11), GCK (rs1799884/P = 1.5 × 10−20) and G6PC2/ABCB11 (rs552976/P = 8.2 × 10−18). We show that associations with HbA1c are partly a function of hyperglycemia associated with 3 of the 10 loci (GCK, G6PC2 and MTNR1B). The seven nonglycemic loci accounted for a 0.19 (% HbA1c) difference between the extreme 10% tails of the risk score, and would reclassify ∼2% of a general white population screened for diabetes with HbA1c. CONCLUSIONS GWAS identified 10 genetic loci reproducibly associated with HbA1c. Six are novel and seven map to loci where rarer variants cause hereditary anemias and iron

  2. High-risk glycated hemoglobin trajectories established by mid-20s: findings from a birth cohort study

    PubMed Central

    Shearer, Dara M; Thomson, W Murray; Broadbent, Jonathan M; McLean, Rachael; Poulton, Richie; Mann, Jim

    2016-01-01

    Objective To describe the natural history of glycemia (as measured by glycated hemoglobin (HbA1c)) over 12 years using group-based trajectory modeling (GBTM), and to examine baseline predictors of trajectory. Research design and methods HbA1c data collected at ages 26, 32 and 38 in the long-running, prospective Dunedin Multidisciplinary Health and Development Study were used to assign study members (n=893) to trajectories applying GBTM. A generalization of the model allowed the statistical linking of baseline demographic, smoking and anthropometric characteristics to group membership probability. Results Mean HbA1c increased with age, as did prevalence of prediabetes, diabetes and dysglycemia. The greatest increase occurred between ages 26 and 32. Glycemic health status at age 26 predicted glycemic health status at age 38. 3 HbA1c trajectory groups were identified: ‘low’ (n=98, 11.0%); ‘medium’ (n=482, 54.0%); and ‘high’ (n=313, 35.0%) with mean HbA1c of 29.6, 34.1, and 38.7 mmol/mol, respectively, at age 38. High waist circumference (≥880 mm for women and ≥1020 mm for men), high waist-height ratio (≥0.50), and being a smoker at age 26 predicted membership of the least favorable trajectory over the next 12 years. High body mass index (≥30) at age 26 did not predict of trajectory. Conclusions Trajectories of HbA1c are established relatively early in adulthood. HbA1c levels, waist circumference, waist-height ratio, and smoking status at age 26 are valid clinical predictors for future dysglycemic risk. The identification of HbA1c trajectories and their predictors introduces the possibility of an individualized approach to prevention at an earlier stage than is currently done. PMID:27648291

  3. A Swiss family with hemoglobin P Galveston beta117His leads to Arg, including two patients with hb P/beta thalassemia.

    PubMed

    Di Iorio, E E; Winterhalter, K H; Wilson, K; Rosenmund, A; Marti, H R

    1975-08-01

    The mutant Hb P Galveston (beta117His leads to Arg) is observed in two heterozygotes for beta thalassemia and by itself does not cause clinical symptoms. Some of the physico-chemical properties of Hb P Galveston are identical to the onemical properties of Hb P Galveston are identical to the ones hemoglobin Zurich (beta 63 His leads to Arg) so that only a detailed analysis led to its proper identification.

  4. Body fat percentage and hemoglobin levels are related to blood lead, cadmium, and mercury concentrations in a Korean Adult Population (KNHANES 2008-2010).

    PubMed

    Park, Sunmin; Lee, Byung-Kook

    2013-03-01

    Body stores of lead, cadmium, and mercury are determined by the levels in the circulation, and their levels in blood may be related to hemoglobin levels and their absorption by soft tissue and bone. We investigated the association of body fat percentage, hemoglobin levels, and nutrient intakes with the blood concentrations of lead, cadmium, and mercury in a Korean adult population. This study was based on data from the 2008-2010 Korean National Health and Nutritional Examination Survey (n = 4,522, aged ≥ 20 years), which examined nutritional, biochemical, and health-related parameters. A multiple regression analysis after controlling for covariates of age, body mass index, residence area, education level, smoking and drinking status, and bone mineral density for men, with menopausal status added for women in addition to covariates for men indicated that blood lead and mercury levels were negatively associated with body fat percentage only in men, and blood lead, cadmium, and mercury levels were positively related to hemoglobin levels in both genders. Additionally, blood lead levels were negatively associated with fat and carbohydrate intake in both men and women but blood mercury levels were only in men, but not women. Sodium intake was a positive predictor of blood lead levels in both genders but was a positive predictor of blood cadmium levels only in men. In conclusion, body fat percentage and hemoglobin levels need to be recognized as confounding factors when considering blood levels of lead, cadmium and mercury as biomarkers for their exposure. Fat, carbohydrates and sodium intakes are also associated with heavy metal levels in the circulation.

  5. Serum retinol levels are positively correlated with hemoglobin concentrations, independent of iron homeostasis: a population-based study.

    PubMed

    Jafari, Seyed Mojtaba; Heidari, Gholamreza; Nabipour, Iraj; Amirinejad, Roya; Assadi, Majid; Bargahi, Afshar; Akbarzadeh, Samad; Tahmasebi, Rahim; Sanjdideh, Zahra

    2013-04-01

    Micronutrient interactions give rise to complex issues that have an impact on preventive strategies when multiple micronutrient deficiencies coexist. The aim of this population-based study was to determine the prevalence of vitamins A and E and iron deficiencies among women 15 to 49 years of age in the northern Persian Gulf region. We hypothesized that serum retinol levels may show correlations with hemoglobin (Hb) concentrations, independent of iron status. A total of 1242 nonpregnant women of reproductive age were selected via a multistage stratified random cluster sampling technique. Serum ferritin and soluble transferrin receptor levels were measured using enzyme immunoassay techniques. Serum retinol (vitamin A) and α-tocopherol (vitamin E) were determined for 727 women by high-performance liquid chromatography. The prevalence of anemia (Hb <12 g/dL), iron deficiency (serum ferritin <15 μg/L), and iron deficiency anemia was 8.7%, 25.4%, and 4.6%, respectively. Vitamin A (<0.7 μmol/L) and vitamin E (<11.6 μmol/L) deficiencies were found in 1.2% and 5.9% of the studied population, respectively. Multiple regression analysis revealed that serum retinol levels exhibit a significant association with Hb concentrations after controlling for serum ferritin levels, anemia associated with chronic disease, and risk factors for anemia. Therefore, most nonpregnant women of reproductive age in the northern Persian Gulf were found to have adequate serum vitamin A and E levels. However, the status of anemia and iron deficiency anemia could be considered a mild public health problem in this region. On the basis of multivariate analyses, we conclude that low serum retinol levels may contribute to anemia, independent of iron homeostasis.

  6. The Associations Between Smoking Habits and Serum Triglyceride or Hemoglobin A1c Levels Differ According to Visceral Fat Accumulation

    PubMed Central

    Koda, Michiko; Kitamura, Itsuko; Okura, Tomohiro; Otsuka, Rei; Ando, Fujiko; Shimokata, Hiroshi

    2016-01-01

    Background Whether smokers and former smokers have worse lipid profiles or glucose levels than non-smokers remains unclear. Methods The subjects were 1152 Japanese males aged 42 to 81 years. The subjects were divided according to their smoking habits (nonsmokers, former smokers, and current smokers) and their visceral fat area (VFA) (<100 cm2 and ≥100 cm2). Results The serum triglyceride (TG) levels of 835 males were assessed. In the VFA ≥100 cm2 group, a significantly greater proportion of current smokers (47.3%) exhibited TG levels of ≥150 mg/dL compared with former smokers (36.4%) and non-smokers (18.8%). The difference in TG level distribution between former smokers and non-smokers was also significant. However, among the subjects with VFA of <100 cm2, the TG levels of the three smoking habit groups did not differ. The serum hemoglobin A1c (HbA1c) levels of 877 males were also assessed. In the VFA <100 cm2 group, significantly higher proportions of current smokers (17.9%) and former smokers (14.9%) demonstrated HbA1c levels of ≥5.6% compared with non-smokers (6.3%). In contrast, in the VFA ≥100 cm2 group, significantly fewer former smokers displayed HbA1c levels of ≥5.6% compared with non-smokers and current smokers. Furthermore, the interaction between smoking habits and VFA was associated with the subjects’ TG and HbA1c concentrations, and the associations of TG and HbA1c concentrations and smoking habits varied according to VFA. Conclusions Both smoking habits and VFA exhibited associations with TG and HbA1c concentrations. The associations between smoking habits and these parameters differed according to VFA. PMID:26616395

  7. miRNA-embedded shRNAs for Lineage-specific BCL11A Knockdown and Hemoglobin F Induction.

    PubMed

    Guda, Swaroopa; Brendel, Christian; Renella, Raffaele; Du, Peng; Bauer, Daniel E; Canver, Matthew C; Grenier, Jennifer K; Grimson, Andrew W; Kamran, Sophia C; Thornton, James; de Boer, Helen; Root, David E; Milsom, Michael D; Orkin, Stuart H; Gregory, Richard I; Williams, David A

    2015-09-01

    RNA interference (RNAi) technology using short hairpin RNAs (shRNAs) expressed via RNA polymerase (pol) III promoters has been widely exploited to modulate gene expression in a variety of mammalian cell types. For certain applications, such as lineage-specific knockdown, embedding targeting sequences into pol II-driven microRNA (miRNA) architecture is required. Here, using the potential therapeutic target BCL11A, we demonstrate that pol III-driven shRNAs lead to significantly increased knockdown but also increased cytotoxcity in comparison to pol II-driven miRNA adapted shRNAs (shRNA(miR)) in multiple hematopoietic cell lines. We show that the two expression systems yield mature guide strand sequences that differ by a 4 bp shift. This results in alternate seed sequences and consequently influences the efficacy of target gene knockdown. Incorporating a corresponding 4 bp shift into the guide strand of shRNA(miR)s resulted in improved knockdown efficiency of BCL11A. This was associated with a significant de-repression of the hemoglobin target of BCL11A, human γ-globin or the murine homolog Hbb-y. Our results suggest the requirement for optimization of shRNA sequences upon incorporation into a miRNA backbone. These findings have important implications in future design of shRNA(miR)s for RNAi-based therapy in hemoglobinopathies and other diseases requiring lineage-specific expression of gene silencing sequences.

  8. Effect of low glycemic load diet on glycated hemoglobin (HbA1c) in poorly-controlled diabetes patients.

    PubMed

    Ziaee, Amir; Afaghi, Ahmad; Sarreshtehdari, Majied

    2011-12-29

    Different carbohydrate diets have been administrated to diabetic patients to evaluate the glycemic response, while Poor-controlled diabetes is increasing world wide. To investigate the role of an alternative carbohydrate diet on glycemic control, we explored the effect of a low glycemic load (Low GL)-high fat diet on glycemic response and also glycated hemoglobin (HbA1c) of poor-controlled diabetes patients. Hundred poorly-controlled diabetes patients, HbA1c > 8, age 52.8 ± 4.5 y, were administrated a low GL diet , GL = 67 (Energy 1800 kcal; total fat 36%; fat derived from olive oil and nuts 15%; carbohydrate 42%; protein 22%) for 10 weeks. Patients did their routine life style program during intervention. Fasting blood glucose and HbA1c before and after intervention with significant reduction were: 169 ± 17, 141 ± 12; 8.85% (73 mmol/mol) ± 0.22%, and 7.81% (62 mmol/mol) ± 0.27%; respectively (P < 0.001). Mean fasting blood glucose reduced by 28.1 ± 12.5 and HbA1c by 1.1% (11 mmol/mol) ± 0.3% (P=0.001). There was positive moderate correlation between HbA1c concentration before intervention and FBS reduction after intervention (P < 0.001, at 0.01 level, R =0.52), and strong positive correlation between FBS before intervention and FBS reduction (P < 0.001, at 0.01 level, R = 0.70). This study demonstrated that our alternative low glycemic load diet can be effective in glycemic control.

  9. A comparative analysis of clustering algorithms: O{sub 2} migration in truncated hemoglobin I from transition networks

    SciTech Connect

    Cazade, Pierre-André; Berezovska, Ganna; Meuwly, Markus; Zheng, Wenwei; Clementi, Cecilia; Prada-Gracia, Diego; Rao, Francesco

    2015-01-14

    The ligand migration network for O{sub 2}–diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k–means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k–means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.

  10. An international effort to cure a global health problem: A report on the 19th Hemoglobin Switching Conference.

    PubMed

    Blobel, Gerd A; Bodine, David; Brand, Marjorie; Crispino, John; de Bruijn, Marella F T R; Nathan, David; Papayannopoulou, Thalia; Porcher, Catherine; Strouboulis, John; Zon, Len; Higgs, Douglas R; Stamatoyannopoulos, George; Engel, James Douglas

    2015-10-01

    Every 2 years since 1978, an international group of scientists, physicians, and other researchers meet to discuss the latest developments in the underlying etiology, mechanisms of action, and developmental acquisition of cellular and systemic defects exhibited and elicited by the most common inherited human disorders, the hemoglobinopathies. The 19th Hemoglobin Switching Conference, held in September 2014 at St. John's College in Oxford, once again exceeded all expectations by describing cutting edge research in cellular, molecular, developmental, and genomic advances focused on these diseases. The conference comprised about 60 short talks over 3 days by leading investigators in the field. This meeting report describes the highlights of the conference.

  11. Cation-exchange high-performance liquid chromatography for variant hemoglobins and HbF/A2: What must hematopathologists know about methodology?

    PubMed Central

    Sharma, Prashant; Das, Reena

    2016-01-01

    Cation-exchange high-performance liquid chromatography (CE-HPLC) is a widely used laboratory test to detect variant hemoglobins as well as quantify hemoglobins F and A2 for the diagnosis of thalassemia syndromes. It’s versatility, speed, reproducibility and convenience have made CE-HPLC the method of choice to initially screen for hemoglobin disorders. Despite its popularity, several methodological aspects of the technology remain obscure to pathologists and this may have consequences in specific situations. This paper discusses the basic principles of the technique, the initial quality control steps and the interpretation of various controls and variables that are available on the instrument output. Subsequent sections are devoted to methodological considerations that arise during reporting of cases. For instance, common problems of misidentified peaks, totals crossing 100%, causes of total area being above or below acceptable limits and the importance of pre-integration region peaks are dealt with. Ultimately, CE-HPLC remains an investigation, the reporting of which combines in-depth knowledge of the biological basics with more than a working knowledge of the technological aspects of the technique. PMID:27019794

  12. Serological characteristics of autoimmune pancreatitis and its differential diagnosis from pancreatic cancer by using a combination of carbohydrate antigen 19-9, globulin, eosinophils and hemoglobin.

    PubMed

    Yan, Tianlian; Ke, Yini; Chen, Yi; Xu, Chengfu; Yu, Chaohui; Li, Youming

    2017-01-01

    Autoimmune pancreatitis (AIP) is a special type of chronic pancreatitis, which may be misdiagnosed as pancreatic carcinoma. This study aims to verify new biomarkers for AIP and propose a serological pattern to differentiate AIP from pancreatic adenocarcinoma with routinely performed tests. In this study, data of serum samples were collected and compared between 25 patients with AIP and 100 patients with pancreatic carcinoma. Receiver operating characteristic analysis and logistic regression was performed to evaluate the diagnostic effect of serum parameters in differentiating AIP from pancreatic carcinoma alone or in combination. Among several serum markers observed in the two groups, carbohydrate antigen 19-9 (Ca19-9), globulin, eosinophils and hemoglobin were selected as the independent markers. Serum levels of Globulin, Eosinophil percentage in AIP group were significantly higher than in pancreatic cancer group (P<0.05), while hemoglobin and tumor marker CA19-9 levels were lower (P <0.05). The combination of these markers identified patients with AIP with 92% sensitivity and 79% specificity, which indicated relatively high diagnostic value. Elevated serum eosinophils, globulin, together with decreased hemoglobin level can be used as a preoperative indicator for AIP and can help to initiate diagnosis of AIP in time.

  13. Serological characteristics of autoimmune pancreatitis and its differential diagnosis from pancreatic cancer by using a combination of carbohydrate antigen 19-9, globulin, eosinophils and hemoglobin

    PubMed Central

    Chen, Yi; Xu, Chengfu; Yu, Chaohui; Li, Youming

    2017-01-01

    Autoimmune pancreatitis (AIP) is a special type of chronic pancreatitis, which may be misdiagnosed as pancreatic carcinoma. This study aims to verify new biomarkers for AIP and propose a serological pattern to differentiate AIP from pancreatic adenocarcinoma with routinely performed tests. In this study, data of serum samples were collected and compared between 25 patients with AIP and 100 patients with pancreatic carcinoma. Receiver operating characteristic analysis and logistic regression was performed to evaluate the diagnostic effect of serum parameters in differentiating AIP from pancreatic carcinoma alone or in combination. Among several serum markers observed in the two groups, carbohydrate antigen 19–9 (Ca19-9), globulin, eosinophils and hemoglobin were selected as the independent markers. Serum levels of Globulin, Eosinophil percentage in AIP group were significantly higher than in pancreatic cancer group (P<0.05), while hemoglobin and tumor marker CA19-9 levels were lower (P <0.05). The combination of these markers identified patients with AIP with 92% sensitivity and 79% specificity, which indicated relatively high diagnostic value. Elevated serum eosinophils, globulin, together with decreased hemoglobin level can be used as a preoperative indicator for AIP and can help to initiate diagnosis of AIP in time. PMID:28369140

  14. MALDI-ISD Mass Spectrometry Analysis of Hemoglobin Variants: a Top-Down Approach to the Characterization of Hemoglobinopathies

    NASA Astrophysics Data System (ADS)

    Théberge, Roger; Dikler, Sergei; Heckendorf, Christian; Chui, David H. K.; Costello, Catherine E.; McComb, Mark E.

    2015-08-01

    Hemoglobinopathies are the most common inherited disorders in humans and are thus the target of screening programs worldwide. Over the past decade, mass spectrometry (MS) has gained a more important role as a clinical means to diagnose variants, and a number of approaches have been proposed for characterization. Here we investigate the use of matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF MS) with sequencing using in-source decay (MALDI-ISD) for the characterization of Hb variants. We explored the effect of matrix selection using super DHB or 1,5-diaminonaphthalene on ISD fragment ion yield and distribution. MALDI-ISD MS of whole blood using super DHB simultaneously provided molecular weights for the alpha and beta chains, as well as extensive fragmentation in the form of sequence defining c-, (z + 2)-, and y-ion series. We observed sequence coverage on the first 70 amino acids positions from the N- and C-termini of the alpha and beta chains in a single experiment. An abundant beta chain N-terminal fragment ion corresponding to βc34 was determined to be a diagnostic marker ion for Hb S (β6 Glu→Val, sickle cell), Hb C (β6 Glu→Lys), and potentially for Hb E (β26 Glu→Lys). The MALDI-ISD analysis of Hb S and HbSC yielded mass shifts corresponding to the variants, demonstrating the potential for high-throughput screening. Characterization of an alpha chain variant, Hb Westmead (α122 His→Gln), generated fragments that established the location of the variant. This study is the first clinical application of MALDI-ISD MS for the determination and characterization of hemoglobin variants.

  15. Insights into the properties of the two enantiomers of trans-δ-viniferin, a resveratrol derivative: antioxidant activity, biochemical and molecular modeling studies of its interactions with hemoglobin.

    PubMed

    Ficarra, Silvana; Tellone, Ester; Pirolli, Davide; Russo, Annamaria; Barreca, Davide; Galtieri, Antonio; Giardina, Bruno; Gavezzotti, Paolo; Riva, Sergio; De Rosa, Maria Cristina

    2016-04-01

    Resveratrol is widely known as an antioxidant and anti-inflammatory molecule. The present study first reports the effects of trans-δ-viniferin (TVN), a dimer of resveratrol, on human erythrocytes. The antioxidant activity of TVN was tested using in vitro model systems such as hydroxy radical scavenging, DPPH and lipid peroxidation. In addition we have examined the influence of the 15R,22R- and 15S,22S-enantiomers (abbreviated R,R-TVN, and S,S-TVN, respectively) on anion transport, ATP release, caspase 3 activation. Given that hemoglobin (Hb) redox reactions are the major source of RBC oxidative stress, we also explored the effects of TVN on hemoglobin function. TVN showed moderate antioxidant properties and good protective activity from hemoglobin oxidation. Potential binding sites of R,R-TVN and S,S-TVN with oxy- and deoxy-Hb were also investigated through an extensive in silico docking approach and molecular dynamics calculations. The whole molecular modeling studies indicate that binding of R,R-TVN and S,S-TVN to Hb lacks of specific ligand-target interactions. This is the first report on the biological activity of the individual enantiomers of a resveratrol-related dimer.

  16. Hollow TiO2 modified reduced graphene oxide microspheres encapsulating hemoglobin for a mediator-free biosensor.

    PubMed

    Liu, Hui; Guo, Kai; Duan, Congyue; Dong, Xiaonan; Gao, Jiaojiao

    2017-01-15

    Hollow TiO2 modified reduced graphene oxide microspheres (hollow TiO2-rGO microspheres or H-TiO2-rGO MS) have been synthesized and then be used to immobilize hemoglobin (Hb) to fabricate a mediator-free biosensor. The morphology and structure of hollow TiO2-rGO microspheres were characterized by scanning electron microscopy, transmission electronic microscopy and X-ray diffraction. Results of spectroscopy and electrochemistry tests revealed that hollow TiO2-rGO microsphere is an excellent immobilization matrix with biocompatibility for redox protein, affording good protein bioactivity and stability. The hollow TiO2-rGO microspheres with special structure and component enhance the immobilization efficiency of proteins and facilitate the direct electron transfer, which result in the better H2O2 detection performance-the wide linear range of 0.1-360μM for H2O2 (sensitivity of 417.6 μA mM(-1) cm(-2)) and the extremely low detection limit of 10nM for H2O2. Moreover, the hollow microsphere can provide a protective microenvironment for Hb to make the as-prepared biosensor improve long-term stability. The as-prepared biosensor retains 95.4% of the initial response to H2O2 after 60-d storage. Hence, this work suggests that if can be fabricated a mediator-free biosensor, hollow TiO2-rGO microspheres will find wide potential applications in environmental analysis and biomedical detection.

  17. TSAT is a better predictor than ferritin of hemoglobin response to Epoetin alfa in US dialysis patients.

    PubMed

    Gaweda, Adam E; Bhat, Premila; Maglinte, Gregory A; Chang, Chun-Lan; Hill, Jerrold; Park, Grace S; Ashfaq, Akhtar; Gitlin, Matthew

    2014-01-01

    Clinical guidelines recommend concurrent treatment of anemia in end-stage renal disease with erythropoiesis-stimulating agents (ESAs) and iron. However, there are mixed data about optimal iron supplementation. To help address this gap, the relationship between iron markers and hemoglobin (Hb) response to ESA (Epoetin alfa) dose was examined. Electronic medical records of 1902 US chronic hemodialysis patients were analyzed over a 12-month period between June 2009 and June 2010. The analysis included patients who had at least one Hb value during each 4-week interval for four consecutive intervals (k - 2, k - 1, k, and k + 1; k is the index interval), received at least one ESA dose during intervals k - 1 or k, had at least one transferrin saturation (TSAT) value at interval k, and at least one ferritin value during intervals k - 2, k - 1, or k. Effect modification by TSAT and ferritin on Hb response was evaluated using the generalized estimating equations approach. Patients had a mean (standard deviation) age of 62 (15) years; 41% were Caucasian, 34% African American, 65% had hypertension, and 39% diabetes. Transferrin saturation, but not ferritin, had a statistically significant (P < 0.05) modifying effect on Hb response. Maximum Hb response was achieved when TSAT was 34%, with minimal incremental effect beyond these levels. Of the two standard clinical iron markers, TSAT should be used as the primary marker of the modifying effect of iron on Hb response to ESA. Long-term safety of iron use to improve Hb response to ESA warrants further study.

  18. [Contributions and prospects of hemoglobin derivatives].

    PubMed

    Remy, B; Deby-Dupont, G; Lamy, M

    1997-06-21

    Anoxia-reoxygenation leads to severe metabolic alterations, which result in a generalized inflammatory reaction and multiple organ dysfunction. Direct blood transfusion limits these alterations, but is accompanied by risk of transmission of infections or viral diseases. To avoid these risks, "blood substitutes" have been designed. The modified hemoglobins are not true blood substitutes because they do not possess the complex functions of erythrocytes. They are only oxygen carriers, with a short intravascular life, adapted for temporary use. They are stable, devoid of toxicity and antigenicity, and are able to carry and deliver O2 without regulation of this oxygen transport and without chemical reaction with O2. They possess rheologic properties and an oncotic pressure like those of blood. The use of natural hemoglobin solutions, obtained after lysis of erythrocytes, remains "at risk" because these solutions easily form methemoglobin, increase the oncotic pressure, present renal toxicity, and possess a too high affinity for O2. For these reasons, 5 types of modified hemoglobin solutions have been designed, prepared from human or bovine hemoglobin or by genetic engineering. These hemoglobins are highly purified to eliminate trace amounts of stroma, lipids and endotoxins, which are responsible for acute toxicity. They are modified by internal cross-linking between the monomers, or by binding to macromolecules. Afterwards, they can be polymerized or encapsulated in liposomes. The purpose of these modifications is to modulate the affinity for O2 (by decreasing the binding of O2 and increasing its delivery to tissue), to reduce the dissociation into monomers and to guard against oxidation into methemoglobin. Encapsulation in liposomes allows co-encapsulation of effector molecules and protective substances. Genetic engineering allows the production of recombinant hemoglobin with selective modifications. The modified hemoglobin solutions are essentially used in hemorrhagic

  19. Is there a "magic" hemoglobin number? Clinical decision support promoting restrictive blood transfusion practices.

    PubMed

    Goodnough, Lawrence Tim; Shah, Neil

    2015-10-01

    Blood transfusion has been identified as one of the most frequently performed therapeutic procedures, with a significant percentage of transfusions identified to be inappropriate. Recent key clinical trials in adults have provided Level 1 evidence to support restrictive red blood cell (RBC) transfusion practices. However, some advocates have attempted to identify a "correct" Hb threshold for RBC transfusion; whereas others assert that management of anemia, including transfusion decisions, must take into account clinical patient variables, rather than simply one diagnostic laboratory test. The heterogeneity of guidelines for blood transfusion by a number of medical societies reflects this controversy. Clinical decision support (CDS) uses a Hb threshold number in a smart Best Practices Alert (BPA) upon physician order, to trigger a concurrent utilization self-review for whether blood transfusion therapy is appropriate. This review summarizes Level 1 evidence in seven key clinical trials in adults that support restrictive transfusion practices, along strategies made possible by CDS that have demonstrated value in improving blood utilization by promoting restrictive transfusion practices.

  20. Chromatography paper as a low-cost medium for accurate spectrophotometric assessment of blood hemoglobin concentration.

    PubMed

    Bond, Meaghan; Elguea, Carlos; Yan, Jasper S; Pawlowski, Michal; Williams, Jessica; Wahed, Amer; Oden, Maria; Tkaczyk, Tomasz S; Richards-Kortum, Rebecca

    2013-06-21

    Anemia affects a quarter of the world's population, and a lack of appropriate diagnostic tools often prevents treatment in low-resource settings. Though the HemoCue 201+ is an appropriate device for diagnosing anemia in low-resource settings, the high cost of disposables ($0.99 per test in Malawi) limits its availability. We investigated using spectrophotometric measurement of blood spotted on chromatography paper as a low-cost (<$0.01 per test) alternative to HemoCue cuvettes. For this evaluation, donor blood was diluted with plasma to simulate anemia, a micropipette spotted blood on paper, and a bench-top spectrophotometer validated the approach before the development of a low-cost reader. We optimized impregnating paper with chemicals to lyse red blood cells, paper type, drying time, wavelengths measured, and sensitivity to variations in volume of blood, and we validated our approach using patient samples. Lysing the blood cells with sodium deoxycholate dried in Whatman Chr4 chromatography paper gave repeatable results, and the absorbance difference between 528 nm and 656 nm was stable over time in measurements taken up to 10 min after sample preparation. The method was insensitive to the amount of blood spotted on the paper over the range of 5 μL to 25 μL. We created a low-cost, handheld reader to measure the transmission of paper cuvettes at these optimal wavelengths. Training and validating our method with patient samples on both the spectrometer and the handheld reader showed that both devices are accurate to within 2 g dL(-1) of the HemoCue device for 98% and 95% of samples, respectively.

  1. Immunization with the Haemophilus ducreyi Hemoglobin Receptor HgbA with Adjuvant Monophosphoryl Lipid A Protects Swine from a Homologous but Not a Heterologous Challenge▿

    PubMed Central

    Fusco, William G.; Afonina, Galyna; Nepluev, Igor; Cholon, Deborah M.; Choudhary, Neelima; Routh, Patricia A.; Almond, Glenn W.; Orndorff, Paul E.; Staats, Herman; Hobbs, Marcia M.; Leduc, Isabelle; Elkins, Christopher

    2010-01-01

    Haemophilus ducreyi, the etiological agent of chancroid, has a strict requirement for heme, which it acquires from its only natural host, humans. Previously, we showed that a vaccine preparation containing the native hemoglobin receptor HgbA purified from H. ducreyi class I strain 35000HP (nHgbAI) and administered with Freund's adjuvant provided complete protection against a homologous challenge. In the current study, we investigated whether nHgbAI dispensed with monophosphoryl lipid A (MPL), an adjuvant approved for use in humans, offered protection against a challenge with H. ducreyi strain 35000HP expressing either class I or class II HgbA (35000HPhgbAI and 35000HPhgbAII, respectively). Pigs immunized with the nHgbAI/MPL vaccine were protected against a challenge from homologous H. ducreyi strain 35000HPhgbAI but not heterologous strain 35000HPhgbAII, as evidenced by the isolation of only strain 35000HPhgbAII from nHgbAI-immunized pigs. Furthermore, histological analysis of the lesions showed striking differences between mock-immunized and nHgbAI-immunized animals challenged with strains 35000HPhgbAI but not those challenged with strain 35000HPhgbAII. Mock-immunized pigs were not protected from a challenge by either strain. The enzyme-linked immunosorbent assay (ELISA) activity of the nHgbAI/MPL antiserum was lower than the activity of antiserum from animals immunized with the nHgbAI/Freund's vaccine; however, anti-nHgbAI from both studies bound whole cells of 35000HPhgbAI better than 35000HPhgbAII and partially blocked hemoglobin binding to nHgbAI. In conclusion, despite eliciting lower antibody ELISA activity than the nHgbAI/Freund's, the nHgbAI/MPL vaccine provided protection against a challenge with homologous but not heterologous H. ducreyi, suggesting that a bivalent HgbA vaccine may be needed. PMID:20584974

  2. Immunization with the Haemophilus ducreyi hemoglobin receptor HgbA with adjuvant monophosphoryl lipid A protects swine from a homologous but not a heterologous challenge.

    PubMed

    Fusco, William G; Afonina, Galyna; Nepluev, Igor; Cholon, Deborah M; Choudhary, Neelima; Routh, Patricia A; Almond, Glenn W; Orndorff, Paul E; Staats, Herman; Hobbs, Marcia M; Leduc, Isabelle; Elkins, Christopher

    2010-09-01

    Haemophilus ducreyi, the etiological agent of chancroid, has a strict requirement for heme, which it acquires from its only natural host, humans. Previously, we showed that a vaccine preparation containing the native hemoglobin receptor HgbA purified from H. ducreyi class I strain 35000HP (nHgbAI) and administered with Freund's adjuvant provided complete protection against a homologous challenge. In the current study, we investigated whether nHgbAI dispensed with monophosphoryl lipid A (MPL), an adjuvant approved for use in humans, offered protection against a challenge with H. ducreyi strain 35000HP expressing either class I or class II HgbA (35000HPhgbAI and 35000HPhgbAII, respectively). Pigs immunized with the nHgbAI/MPL vaccine were protected against a challenge from homologous H. ducreyi strain 35000HPhgbAI but not heterologous strain 35000HPhgbAII, as evidenced by the isolation of only strain 35000HPhgbAII from nHgbAI-immunized pigs. Furthermore, histological analysis of the lesions showed striking differences between mock-immunized and nHgbAI-immunized animals challenged with strains 35000HPhgbAI but not those challenged with strain 35000HPhgbAII. Mock-immunized pigs were not protected from a challenge by either strain. The enzyme-linked immunosorbent assay (ELISA) activity of the nHgbAI/MPL antiserum was lower than the activity of antiserum from animals immunized with the nHgbAI/Freund's vaccine; however, anti-nHgbAI from both studies bound whole cells of 35000HPhgbAI better than 35000HPhgbAII and partially blocked hemoglobin binding to nHgbAI. In conclusion, despite eliciting lower antibody ELISA activity than the nHgbAI/Freund's, the nHgbAI/MPL vaccine provided protection against a challenge with homologous but not heterologous H. ducreyi, suggesting that a bivalent HgbA vaccine may be needed.

  3. Is hemoglobin A1c level effective in predicting the prognosis of Fournier gangrene?

    PubMed Central

    Sen, Haluk; Bayrak, Omer; Erturhan, Sakip; Borazan, Ersin; Koc, Mustafa Nihat

    2016-01-01

    Objectives: To evaluate the effect of immune failure and/or diabetes mellitus (DM) association on the mortality and morbidity of the Fournier's Gangrene (FG), and interrelatedly, the usability of HbA1c level in the prediction of prognosis. Materials and Methods: The data of 38 patients with the diagnosis of FG were investigated retrospectively. The patients were divided into two groups as patients with DM (Group 1, n = 18) and non-diabetics (Group 2, n = 20). The patients in group 1 were also divided into two subgroups as patients with HbA1c value ≥7 (Group 1a) and HbA1c value <7 (Group 1b). Results: The mean age of all 38 male patients was 66.3 ± 6.4 years. The initial symptoms were scrotal rash and swelling (n = 20, 52.6%), high fever (>38°C) (n = 22, 57.8%), purulent discharge from genital or perineal areas (n = 13, 34.2%), skin bruises (n = 11, 28.9%) and general state disorder in five patients that were admitted from day care center (13.1%). DM, as the most often comorbid disease, was detected in 18 patients (47.3%). Six patients (15.7%) were deceased during the follow-up period. Conclusion: In the present study, the researchers determined that diabetic patients with HbA1c level of 7 or higher had worse prognosis, and increased mortality. PMID:27453658

  4. A comparative study on the functional properties of the wild European mouflon and domestic sheep hemoglobins.

    PubMed

    Corda, M; Giardina, B; Pellegrini, M; Manca, L; Olianas, A; Sanna, M T; Fais, A; Masala, B

    1997-07-01

    The functional properties of Hb B of the wild European mouflon (Ovis gmelini musimon), Hb B of domestic sheep (Ovis aries), and Hb C isolated from anemic mouflon were investigated. Mouflon and sheep Hbs appear to be very similar in their response to organic anions and protons, whereas sheep Hb B displays an oxygen affinity lower than that of mouflon Hb B and sheep Hb A. Mouflon Hb B and Hb C, like sheep Hb A and Hb C, have similar efficiencies in transporting oxygen to the tissues. As in other ruminant Hbs, the effect of temperature on the oxygen affinity is slight. Data suggest that mouflon Hb B is not only structurally, but even functionally, more similar to sheep Hb A than to sheep Hb B.

  5. Case report of hemoglobin a1c and weight reduction in integrative health coaching.

    PubMed

    Moore, Cynthia

    2013-05-01

    Integrative health coaching (IHC) offers significant health improvement in biometric measures without pharmaceuticals. In this case of newly diagnosed impaired glucose tolerance (IGT) with obesity, IHC used the patient's strengths to reverse IGT, prevent frank diabetes, and reduce weight by 40 lbs or 21% of her original weight. This intervention included a client self-assessment and 14 in-person health coaching sessions over 11 months. IHC provides a framework to accomplish short-term goals and identify and overcome barriers while drawing on the strengths and aims of the individual.

  6. Kinetic studies on photolysis-induced gelation of sickle cell hemoglobin suggest a new mechanism

    SciTech Connect

    Ferrone, F.A.; Hofrichter, J.; Sunshine, H.R.; Eaton, W.A.

    1980-10-01

    The kinetics of deoxyhemoglobin S gelation have been investigated using photolytic dissociation of the carbon monoxide complex to initiate the process. Measurements over a wide range of times, 10/sup -3/ -10/sup 4/s, show that both the concentration dependence of the tenth-time (i.e., the time required to complete one-tenth the reaction) and the time dependence of the process decrease as gelation speeds up. In slowly gelling samples, where single domains of polymers are formed in the small sample volumes employed with this technique (1 to 2 x 10/sup -9/ cm/sup 3/), there is a marked increase in the variability of the tenth-times. These results are explained by a mechanism in which gelation is initiated by homogeneous nucleation of polymers in the bulk solution phase, followed by heterogeneous nucleation on the surface of existing polymers. At the lowest concentrations, homogeneous nucleation is so improbable that stochastic behavior is observed in the small sample volumes, and heterogeneous nucleation is the dominant pathway for polymer formation, thereby accounting for the high time dependence. At the highest concentrations homogeneous nucleation becomes much more probable, and the time dependence decreases. The decrease in concentration dependence of the tenth-time with increasing concentration results from a decrease in size of both the homogeneous and heterogeneous critical nuclei. The model rationalizes the major observations on the kinetics of gelation of deoxyhemoglobin S, and is readily testable by further experiments.

  7. Impact of Multi-Micronutrient Fortified Rice on Hemoglobin, Iron and Vitamin A Status of Cambodian Schoolchildren: a Double-Blind Cluster-Randomized Controlled Trial

    PubMed Central

    Perignon, Marlène; Fiorentino, Marion; Kuong, Khov; Dijkhuizen, Marjoleine A.; Burja, Kurt; Parker, Megan; Chamnan, Chhoun; Berger, Jacques; Wieringa, Frank T.

    2016-01-01

    In Cambodia, micronutrient deficiencies remain a critical public health problem. Our objective was to evaluate the impact of multi-micronutrient fortified rice (MMFR) formulations, distributed through a World Food Program school-meals program (WFP-SMP), on the hemoglobin concentrations and iron and vitamin A (VA) status of Cambodian schoolchildren. The FORISCA-UltraRice+NutriRice study was a double-blind, cluster-randomized, placebo-controlled trial. Sixteen schools participating in WFP-SMP were randomly assigned to receive extrusion-fortified rice (UltraRice Original, UltraRice New (URN), or NutriRice) or unfortified rice (placebo) six days a week for six months. Four additional schools not participating in WFP-SMP were randomly selected as controls. A total of 2440 schoolchildren (6–16 years old) participated in the biochemical study. Hemoglobin, iron status, estimated using inflammation-adjusted ferritin and transferrin receptors concentrations, and VA status, assessed using inflammation-adjusted retinol-binding protein concentration, were measured at the baseline, as well as at three and six months. Baseline prevalence of anemia, depleted iron stores, tissue iron deficiency, marginal VA status and VA deficiency were 15.6%, 1.4%, 51.0%, 7.9%, and 0.7%, respectively. The strongest risk factors for anemia were hemoglobinopathy, VA deficiency, and depleted iron stores (all p < 0.01). After six months, children receiving NutriRice and URN had 4 and 5 times less risk of low VA status, respectively, in comparison to the placebo group. Hemoglobin significantly increased (+0.8 g/L) after three months for the URN group in comparison to the placebo group; however, this difference was no longer significant after six months, except for children without inflammation. MMFR containing VA effectively improved the VA status of schoolchildren. The impact on hemoglobin and iron status was limited, partly by sub-clinical inflammation. MMFR combined with non-nutritional approaches

  8. Impact of Multi-Micronutrient Fortified Rice on Hemoglobin, Iron and Vitamin A Status of Cambodian Schoolchildren: a Double-Blind Cluster-Randomized Controlled Trial.

    PubMed

    Perignon, Marlène; Fiorentino, Marion; Kuong, Khov; Dijkhuizen, Marjoleine A; Burja, Kurt; Parker, Megan; Chamnan, Chhoun; Berger, Jacques; Wieringa, Frank T

    2016-01-07

    In Cambodia, micronutrient deficiencies remain a critical public health problem. Our objective was to evaluate the impact of multi-micronutrient fortified rice (MMFR) formulations, distributed through a World Food Program school-meals program (WFP-SMP), on the hemoglobin concentrations and iron and vitamin A (VA) status of Cambodian schoolchildren. The FORISCA-UltraRice+NutriRice study was a double-blind, cluster-randomized, placebo-controlled trial. Sixteen schools participating in WFP-SMP were randomly assigned to receive extrusion-fortified rice (UltraRice Original, UltraRice New (URN), or NutriRice) or unfortified rice (placebo) six days a week for six months. Four additional schools not participating in WFP-SMP were randomly selected as controls. A total of 2440 schoolchildren (6-16 years old) participated in the biochemical study. Hemoglobin, iron status, estimated using inflammation-adjusted ferritin and transferrin receptors concentrations, and VA status, assessed using inflammation-adjusted retinol-binding protein concentration, were measured at the baseline, as well as at three and six months. Baseline prevalence of anemia, depleted iron stores, tissue iron deficiency, marginal VA status and VA deficiency were 15.6%, 1.4%, 51.0%, 7.9%, and 0.7%, respectively. The strongest risk factors for anemia were hemoglobinopathy, VA deficiency, and depleted iron stores (all p < 0.01). After six months, children receiving NutriRice and URN had 4 and 5 times less risk of low VA status, respectively, in comparison to the placebo group. Hemoglobin significantly increased (+0.8 g/L) after three months for the URN group in comparison to the placebo group; however, this difference was no longer significant after six months, except for children without inflammation. MMFR containing VA effectively improved the VA status of schoolchildren. The impact on hemoglobin and iron status was limited, partly by sub-clinical inflammation. MMFR combined with non-nutritional approaches

  9. Liposomal-Encapsulated Stroma-Free Hemoglobin as a Potential Blood Substitute.

    DTIC Science & Technology

    1983-03-31

    throuoh March 31, 1983 Supnorted by U.S. Army ’lledical Research and Development Command Acquisition Group Fort Detrick, Frederick, !. D . 21701 Contract No...PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION U .S. Armyv Medic a O ~f appikable) .- ici& DtoveIowpment Commiiand D ,)𔃻DI 7-79-C-9045 8c...ADDRESS (City, State. and ZIP Code) 10 SOURCE OF FUNDINGNUBR Jr t D lt ri Lk, Fr vdtor ic k, MD1 21701-5012 PROGRAM PROJECT TS WORK UNIT ELEMENT NO. NO

  10. Model of a Plasmonic Phase Interrogation Probe for Optical Sensing of Hemoglobin in Blood Samples

    NASA Astrophysics Data System (ADS)

    Sharma, Anuj K.

    2015-11-01

    Phase interrogation based surface plasmon resonance (SPR) biosensor is proposed for the determination of Hb concentration. Previous experimental results describing variation of refractive index of human blood with Hb concentration at different wavelengths are considered for design simulations. The biosensor design with silica substrate and gold layer is considered. The sensor's performance is closely analyzed in terms of phase sensitivity and resolution. The influence of operating wavelength on biosensor's performance for Hb measurement is critically investigated, which points to carry out the Hb measurement at a shorter wavelength as phase sensitivity and resolution increase significantly with decrease in wavelength. The results are explained in terms of suitable physical concepts such as radiation damping. Use of contamination-preventing biochemical layer ascertains the stability of measurement with the intended SPR biosensor probe. The simulation results also highlight that the resolution of Hb measurement achievable with the proposed biosensor is much higher compared with several existing methods.

  11. Does carboxy-hemoglobin serve as a stress-induced inflammatory marker reflecting surgical insults?

    PubMed

    Sakamoto, Atsuhiro; Nakanishi, Kazuhiro; Takeda, Shinhiro; Ogawa, Ryo

    2005-02-01

    Endogenous carbon monoxide (CO) production has been recently observed to be an index of the inflammatory response, reflecting various insults in critically ill patients. Major surgery is supposed to modulate the production of CO by transcriptional regulation of heme oxygenase (HO). CO is easy to measure as carboxyhemoglobin (CO-Hb) by spectrophotometry; however, whether CO-Hb can be used as an index reflecting surgical insults is unknown. We investigated changes in CO generation during coronary artery bypass graft by measuring CO-Hb concentrations and the expression of HO in circulating blood as well as the expressions of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta). The expression ratios of heme oxygenase-1 (HO-1), TNF-alpha, and IL-1 beta significantly increased after surgery, and these values correlated significantly with one another. CO-Hb concentrations significantly increased after surgery; however, many of those values during artificial ventilation with high inspired oxygen fraction were within normal limits. Furthermore, changes in CO-Hb concentrations were small when preoperative values were high. On the whole, CO-Hb concentrations significantly but weakly correlated with the expression ratios of the inflammatory mediators. However, they did not correlate in the patients who showed higher preoperative CO-Hb concentrations. These data indicate that CO-Hb concentrations can, in general, reflect the inflammatory response induced by surgical insult; however, CO-Hb measurement may not be a useful form of clinical monitoring because of the limited degree of changes, the variation of baseline values, and the necessity for the management under fixed conditions.

  12. 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.

  13. Passive immunization with a polyclonal antiserum to the hemoglobin receptor of Haemophilus ducreyi confers protection against a homologous challenge in the experimental swine model of chancroid.

    PubMed

    Leduc, Isabelle; Fusco, William G; Choudhary, Neelima; Routh, Patty A; Cholon, Deborah M; Hobbs, Marcia M; Almond, Glen W; Orndorff, Paul E; Elkins, Christopher

    2011-08-01

    Haemophilus ducreyi, the etiologic agent of chancroid, has an obligate requirement for heme. Heme is acquired by H. ducreyi from its human host via TonB-dependent transporters expressed at its bacterial surface. Of 3 TonB-dependent transporters encoded in the genome of H. ducreyi, only the hemoglobin receptor, HgbA, is required to establish infection during the early stages of the experimental human model of chancroid. Active immunization with a native preparation of HgbA (nHgbA) confers complete protection in the experimental swine model of chancroid, using either Freund's or monophosphoryl lipid A as adjuvants. To determine if transfer of anti-nHgbA serum is sufficient to confer protection, a passive immunization experiment using pooled nHgbA antiserum was conducted in the experimental swine model of chancroid. Pigs receiving this pooled nHgbA antiserum were protected from a homologous, but not a heterologous, challenge. Passively transferred polyclonal antibodies elicited to nHgbA bound the surface of H. ducreyi and partially blocked hemoglobin binding by nHgbA, but were not bactericidal. Taken together, these data suggest that the humoral immune response to the HgbA vaccine is protective against an H. ducreyi infection, possibly by preventing acquisition of the essential nutrient heme.

  14. 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

  15. 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.

  16. 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.

  17. Serum Uric Acid Levels were Dynamically Coupled with Hemoglobin A1c in the Development of Type 2 Diabetes

    NASA Astrophysics Data System (ADS)

    Wei, Fengjiang; Chang, Baocheng; Yang, Xilin; Wang, Yaogang; Chen, Liming; Li, Wei-Dong

    2016-06-01

    The aim of the study was to decipher the relationship between serum uric acid (SUA) and glycated hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG) in both type 2 diabetes mellitus (T2DM) patients and normal subjects. A total of 2,250 unrelated T2DM patients and 4,420 Han Chinese subjects from a physical examination population were recruited for this study. In T2DM patients SUA levels were negatively correlated with HbA1c (rs = ‑0.109, P = 0.000) and 2 h plasma glucose levels (rs = ‑0.178, P = 0.000). In the physical examination population, SUA levels were inversely correlated with HbA1c (rs = ‑0.175, P = 0.000) and FPG (rs = ‑0.131, P = 0.009) in T2DM patients but positively correlated with HbA1c (rs = 0.040, P = 0.012) and FPG (rs = 0.084, P = 0.000) in normal-glucose subjects. Multivariate analyses showed that HbA1c was significantly negatively associated with HUA both in T2DM patients (OR = 0.872, 95% CI: 0.790~0.963) and in the physical examination T2DM patients (OR = 0.722, 95% CI: 0.539~0.968). Genetic association studies in T2DM patients showed that alleles of two glucose-uric acid transporter genes, ABCG2 and SLC2A9 were significantly associated with SUA levels (P < 0.05). SUA level is inversely correlated with HbA1c in T2DM patients but positively correlated with HbA1c in normal-glucose subjects. The reverse transporting of uric acid and glucose in renal tubules might be accounted for these associations.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. Gold nanoparticles-coated magnetic microspheres as affinity matrix for detection of hemoglobin A1c in blood by microfluidic immunoassay.

    PubMed

    Chen, Shao-Peng; Yu, Xiao-Dong; Xu, Jing-Juan; Chen, Hong-Yuan

    2011-08-15

    A novel microfluidic immunoassay system for specific detection of hemoglobin A1c (HbA1c) was developed based on a three-component shell/shell/core structured magnetic nanocomposite Au/chitosan/Fe(3)O(4), which was synthesized with easy handling feature of Fe(3)O(4) by magnet, high affinity for gold nanoparticles of chitosan and good immobilization ability for anti-human hemoglobin-A1c antibody (HbA1c mAb) of assembled colloidal gold nanoparticles. The resulting HbA1c mAb/Au/chitosan/Fe(3)O(4) magnetic nanoparticles were then introduced into microfluidic devices coupled with a gold nanoband microelectrode as electrochemical detector. After that, three-step rapid immunoreactions were carried out in the sequence of HbA1c, anti-human hemoglobin antibodies (Hb mAb) and the secondary alkaline phosphatase (AP)-conjugated antibody within 20 min. The current response of 1-naphtol obtained from the reaction between the secondary AP-conjugated antibody and 1-naphthyl phosphate (1-NP) increased proportionally to the HbA1c concentration. Under optimized electrophoresis and detection conditions, HbA1c responded linearly in the concentration of 0.05-1.5 μg mL(-1), with the detection limit of 0.025 μg mL(-1). This system was successfully employed for detection of HbA1c in blood with good accuracy and renewable ability. The proposed method proved its potential use in clinical immunoassay of HbA1c.

  9. 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

  10. Effects of crosslinking on the thermal stability of hemoglobins. II. The stabilization of met-, cyanomet-, and carbonmonoxyhemoglobins A and S with bis(3,5-dibromosalicyl) fumarate.

    PubMed

    Yang, T; Olsen, K W

    1988-03-01

    Hemoglobins A and S were crosslinked between Lys 82 beta 1 and Lys 82 beta 2 using bis (3,5-dibromosalicyl) fumarate (J. A. Walder et al. (1979) Biochemistry 18, 4265). Thermal denaturation experiments were used to compare the stabilities of the met, cyanomet, and carbonmonoxy forms of these crosslinked hemoglobins to the corresponding uncrosslinked proteins. Uncrosslinked carbonmonoxy- and cyanomethemoglobins had transition temperatures about 11 degrees C higher than the corresponding met samples. The increase in denaturation temperature (Tm) due to crosslinking was 15 degrees C for the methemoglobins, 10 degrees C for the cyanomethemoglobins, and 4 degrees C for the carbonmonoxy ones. There was no significant difference in stability between the met and carbonmonoxy crosslinked proteins. In order of increasing stability the samples were: met Hb S less than met Hb A less than CO Hb S less than CO Hb A = CN-met Hb A less than met XL-Hb S = CO XL-Hb S less than met XL-Hb A = CO XL-Hb A less than CN-met XL-Hb A. The slight decrease in the stability of Hb S (beta 6 Glu----Val) compared to Hb A can be explained by the replacement of an external ionic group by a hydrophobic residue in Hb S. In mixtures of crosslinked and normal Hb A, the Tm of the uncrosslinked material was slightly increased by the presence of the more stable crosslinked hemoglobin. The effects of both crosslinking and cyanide or carbon monoxide binding can be explained by Le Chatelier's principle since both would favor the native form of the protein.

  11. 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.

  12. 76 FR 51041 - Hemoglobin Standards and Maintaining Adequate Iron Stores in Blood Donors; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... HUMAN SERVICES Food and Drug Administration Hemoglobin Standards and Maintaining Adequate Iron Stores in... workshop. The Food and Drug Administration (FDA) is announcing a public workshop entitled: ``Hemoglobin... discuss blood donor hemoglobin and hematocrit qualification standards in the United States, its impact...

  13. 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.

  14. In vivo biodistribution of a radiolabeled blood substitute: 99mTc-labeled liposome-encapsulated hemoglobin in an anesthetized rabbit.

    PubMed Central

    Rudolph, A S; Klipper, R W; Goins, B; Phillips, W T

    1991-01-01

    Liposome-encapsulated hemoglobin (LEH) is an erythrocyte substitute that is a potential resuscitative fluid for the in vivo delivery of oxygen. We have noninvasively imaged radiolabeled LEH in vivo with technetium-99m (99mTc) to study the biodistribution in an anesthetized rabbit. Rabbits (2.5 kg, n = 8) were infused with 30 ml of LEH (200 mg of phospholipid, 2.5 g of hemoglobin per kg of body weight) and imaged with a gamma camera continuously for 2 hr. At 20 hr postinfusion, the animals were imaged again and sacrificed; the organs were weighted and their radioactivity was determined for autopsy organ distribution. Organ uptake from the images was corrected for organ-associated blood pool, which was determined by infusion of 99mTc-labeled rabbit erythrocytes. Blood pool and decay-corrected biodistribution data reveal the kinetics of LEH distribution, with an initial rapid uptake by the liver, 8% at 30 min and 15% at 2 hr. The spleen accumulates less LEH initially, 3% at 30 min and 7% at 2 hr, with an apparent linear uptake of LEH over this time period. Image biodistribution data was also validated at 20 hr by tissue sampling. At 20 hr postinfusion, autopsy biodistribution data reveals approximately 42.6% of the total counts remaining in the blood, 15.4% in the liver, 18.1% in spleen, 3.2% in the lungs, 2.4% in muscle, 1.6% in urine, and trace levels in the kidney, brain, and heart (less than 1%). There is no evidence of hemoglobin release from LEH or kidney dysfunction (normal creatinine and blood urea nitrogen) at any time over the course of the study. Images PMID:1961766

  15. 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.

  16. 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.

  17. Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients

    PubMed Central

    Lebsir, Melissa; Dubroca, Christian; Fabrigoule, Martine; Jordana, Sylvie; Signouret, Thomas; Castanier, Matthias; Thomas, Guillemette; Soundaravelou, Rettinavelou; Lepidi, Anne; Delapierre, Laurence; Penaranda, Guillaume; Halfon, Philippe; Seghboyan, Jean-Marie

    2017-01-01

    Introduction Rapid detection of abnormal biological values using point-of-care (POC) testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose. Methods 314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800). BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability. Results Biases, limits of agreement (±1.96 SD) and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936) for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944) for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967) for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968) for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972) for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985) for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981) for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin. Conclusions Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement. PMID:28072822

  18. [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).

  19. Endothelin plays a role in contractions of isolated pig pulmonary vessels induced by diaspirin cross-linked hemoglobin.

    PubMed

    Ledvina, M A; Hart, J; Bina, S; Jing, M; Muldoon, S

    1999-05-01

    The current studies were undertaken to investigate the role of endothelin-1 (ET-1) and its receptors in contractions of isolated pulmonary vessels of the pig induced by diaspirin cross-linked hemoglobin (DCLHb). Second-order pulmonary arteries (PAs) and veins (PVs) were isolated from pigs, cut into rings (4 to 5 mm), and mounted at optimal passive tension in 37 degrees C Krebs-filled tissue baths bubbled with 95% O2/5% CO2. Isometric tension was recorded continuously. In paired rings, concentration responses to ET-1 (10(-10) to 10(-7) mol/L), DCLHb (10(-9) to 3x10(-6) mol/L), and N-nitro-L-arginine (LNA) (10(-6) to 5x10(-5) mol/L) in the presence and absence of the ET(A) receptor antagonist BQ123 (3x10(-5) mol/L) were determined. PVs and PAs with intact endothelium and rings from which the endothelium was removed (denuded) were pretreated with the ET(B) receptor antagonist BQ788 to determine the contribution of ET(B) receptors to ET-1, DCLHb, and LNA responses. ET-1, DCLHb, and LNA caused concentration-dependent increases in tension in all vessels. In the presence of BQ123, the 50% effective concentration (EC50) of ET-1 was significantly increased (by 5-fold to 10-fold) in all vessels. DCLHb concentration responses were significantly attenuated-in the PVs by 45% and in the PAs by 79%-during treatment with BQ123. BQ123 attenuated LNA responses in PVs by 35% and in PAs by 87%. Treatment with BQ788 had no effect on endothelium-intact PVs or PAs but significantly increased ET-1 EC50 (log of the molar concentration) from -9.0+/-0.22 to -7.8+/-0.05 in denuded PAs. The ET-1 EC50 was significantly decreased in denuded PAs (-9.0+/-0.22) as compared with responses in endothelium-intact PAs (-8.1+/-0.18). DCLHb concentration responses were attenuated by 71% and LNA responses by 80% during antagonism with BQ788 in the intact PAs only. These data demonstrate that ET-1 plays a role in DCLHb-induced contractions in the PA and PV. The contributions of ET are mediated by both ET(A

  20. Weekly supplementation with iron and vitamin A during pregnancy increases hemoglobin concentration but decreases serum ferritin concentration in Indonesian pregnant women.

    PubMed

    Muslimatun, S; Schmidt, M K; Schultink, W; West, C E; Hautvast, J A; Gross, R; Muhilal

    2001-01-01

    We investigated whether weekly iron supplementation was as effective as the national daily iron supplementation program in Indonesia in improving iron status at near term in pregnancy. In addition, we examined whether weekly vitamin A and iron supplementation was more efficacious than weekly supplementation with iron alone. One group of pregnant women (n = 122)was supplemented weekly with iron (120 mg Fe as FeSO4) and folic acid (500 microg); another group (n = 121) received the same amount of iron and folic acid plus vitamin A [4800 retinol equivalents (RE)]. A third ("daily") group (n = 123), participating in the national iron plus folic acid supplementation program, was also recruited. Data on subjects with complete biochemical data are reported (n = 190). At near term, hemoglobin concentrations increased, whereas serum ferritin concentrations decreased significantly in the weekly vitamin A and iron group, suggesting that vitamin A improved utilization of iron for hematopoiesis. Iron status in the weekly iron group was not different from that of the "daily" group. However, iron status decreased with daily supplementation if <50 iron tablets were ingested. Serum transferrin receptor concentrations increased in all groups (P < 0.01). Serum retinol concentrations were maintained in the weekly vitamin A and iron group, but decreased in the other two groups (P < 0.01). Thus, delivery of iron supplements on a weekly basis can be as effective as ona daily basis if compliance can be ensured. Addition of vitamin A to the supplement improved hemoglobin concentration.

  1. 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.

  2. Genome annotation of a 1.5 Mb region of human chromosome 6q23 encompassing a quantitative trait locus for fetal hemoglobin expression in adults

    PubMed Central

    Close, James; Game, Laurence; Clark, Barnaby; Bergounioux, Jean; Gerovassili, Ageliki; Thein, Swee Lay

    2004-01-01

    Background Heterocellular hereditary persistence of fetal hemoglobin (HPFH) is a common multifactorial trait characterized by a modest increase of fetal hemoglobin levels in adults. We previously localized a Quantitative Trait Locus for HPFH in an extensive Asian-Indian kindred to chromosome 6q23. As part of the strategy of positional cloning and a means towards identification of the specific genetic alteration in this family, a thorough annotation of the candidate interval based on a strategy of in silico / wet biology approach with comparative genomics was conducted. Results The ~1.5 Mb candidate region was shown to contain five protein-coding genes. We discovered a very large uncharacterized gene containing WD40 and SH3 domains (AHI1), and extended the annotation of four previously characterized genes (MYB, ALDH8A1, HBS1L and PDE7B). We also identified several genes that do not appear to be protein coding, and generated 17 kb of novel transcript sequence data from re-sequencing 97 EST clones. Conclusion Detailed and thorough annotation of this 1.5 Mb interval in 6q confirms a high level of aberrant transcripts in testicular tissue. The candidate interval was shown to exhibit an extraordinary level of alternate splicing – 19 transcripts were identified for the 5 protein coding genes, but it appears that a significant portion (14/19) of these alternate transcripts did not have an open reading frame, hence their functional role is questionable. These transcripts may result from aberrant rather than regulated splicing. PMID:15169551

  3. Fabrication of a facile electrochemical biosensor for hydrogen peroxide using efficient catalysis of hemoglobin on the porous Pd@Fe3O4-MWCNT nanocomposite.

    PubMed

    Baghayeri, Mehdi; Veisi, Hojat

    2015-12-15

    In this work, a sensitive amperometric biosensor for hydrogen peroxide based on synergetic catalysis of hemoglobin and porous Pd@Fe3O4-MWCNT nanocomposite has been constructed. With attention to the utilities of large surface area and outstanding catalytic performance, Pd@Fe3O4-MWCNT nanocomposite was employed as the nano-stabilizer for the immobilization of hemoglobin (Hb). The immobilized Hb on the surface of nanocomposite as an electrochemical biosensor efficiently catalyzed the reduction of hydrogen peroxide, amplified the electrochemical signal and enhanced the sensitivity. Results of voltammetry and electrochemical impedance examinations showed that the nanocomposite could enhance the electron conductivity and provide more sites for the immobilization of Hb. A linear response from 0.2-500 µM with detection limit of 0.063 µM for hydrogen peroxide was achieved. The apparent Michaelis-Menten constant Kapp(M) value was 21 µM. Thus, the nanocomposite could be applied for fabrication of a third generation biosensor for hydrogen peroxide with high sensitivity, selectivity and low detection limit. The excellent performance of the biosensor indicated its promising prospect as a valuable tool in simple and fast hydrogen peroxide detection in environmental and clinical applications.

  4. 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%.

  5. 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.

  6. Fetal Hemoglobin Inducers from the Natural World: A Novel Approach for Identification of Drugs for the Treatment of β-Thalassemia and Sickle-Cell Anemia

    PubMed Central

    Bianchi, Nicoletta; Zuccato, Cristina; Lampronti, Ilaria; Borgatti, Monica; Gambari, Roberto

    2009-01-01

    The objective of this review is to present examples of lead compounds identified from biological material (fungi, plant extracts and agro-industry material) and of possible interest in the field of a pharmacological approach to the therapy of β-thalassemia using molecules able to stimulate production of fetal hemoglobin (HbF) in adults. Concerning the employment of HbF inducers as potential drugs for pharmacological treatment of β-thalassemia, the following conclusions can be reached: (i) this therapeutic approach is reasonable, on the basis of the clinical parameters exhibited by hereditary persistence of fetal hemoglobin patients, (ii) clinical trials (even if still limited) employing HbF inducers were effective in ameliorating the symptoms of β-thalassemia patients, (iii) good correlation of in vivo and in vitro results of HbF synthesis and γ-globin mRNA accumulation indicates that in vitro testing might be predictive of in vivo responses and (iv) combined use of different inducers might be useful to maximize HbF, both in vitro and in vivo. In this review, we present three examples of HbF inducers from the natural world: (i) angelicin and linear psoralens, contained in plant extracts from Angelica arcangelica and Aegle marmelos, (ii) resveratrol, a polyphenol found in grapes and several plant extracts and (iii) rapamycin, isolated from Streptomyces hygroscopicus. PMID:18955291

  7. High-Affinity Binding of the Staphylococcal HarA Protein to Haptoglobin and Hemoglobin Involves a Domain with an Antiparallel Eight-Stranded β-Barrel Fold▿

    PubMed Central

    Dryla, Agnieszka; Hoffmann, Bernd; Gelbmann, Dieter; Giefing, Carmen; Hanner, Markus; Meinke, Andreas; Anderson, Annaliesa S.; Koppensteiner, Walter; Konrat, Robert; von Gabain, Alexander; Nagy, Eszter

    2007-01-01

    Iron scavenging from the host is essential for the growth of pathogenic bacteria. In this study, we further characterized two staphylococcal cell wall proteins previously shown to bind hemoproteins. HarA and IsdB harbor homologous ligand binding domains, the so called NEAT domain (for “near transporter”) present in several surface proteins of gram-positive pathogens. Surface plasmon resonance measurements using glutathione S-transferase (GST)-tagged HarAD1, one of the ligand binding domains of HarA, and GST-tagged full-length IsdB proteins confirmed high-affinity binding to hemoglobin and haptoglobin-hemoglobin complexes with equilibrium dissociation constants (KD) of 5 to 50 nM. Haptoglobin binding could be detected only with HarA and was in the low micromolar range. In order to determine the fold of this evolutionarily conserved ligand binding domain, the untagged HarAD1 protein was subjected to nuclear magnetic resonance spectroscopy, which revealed an eight-stranded, purely antiparallel β-barrel with the strand order (-β1↓-β2↑-β3↓-β6↑-β5↓-β4↑-β7↓-β8↑), forming two Greek key motifs. Based on structural-homology searches, the topology of the HarAD1 domain resembles that of the immunoglobulin (Ig) fold family, whose members are involved in protein-protein interactions, but with distinct structural features. Therefore, we consider that the HarAD1/NEAT domain fold is a novel variant of the Ig fold that has not yet been observed in other proteins. PMID:17041047

  8. [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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Acquired hemoglobin variants and exposure to glucose-6-phosphate dehydrogenase deficient red blood cell units during exchange transfusion for sickle cell disease in a patient requiring antigen-matched blood.

    PubMed

    Raciti, Patricia M; Francis, Richard O; Spitalnik, Patrice F; Schwartz, Joseph; Jhang, Jeffrey S

    2013-08-01

    Red blood cell exchange (RBCEx) is frequently used in the management of patients with sickle cell disease (SCD) and acute chest syndrome or stroke, or to maintain target hemoglobin S (HbS) levels. In these settings, RBCEx is a category I or II recommendation according to guidelines on the use of therapeutic apheresis published by the American Society for Apheresis. Matching donor red blood cells (RBCs) to recipient phenotypes (e.g., C, E, K-antigen negative) can decrease the risk of alloimmunization in patients with multi-transfused SCD. However, this may select for donors with a higher prevalence of RBC disorders for which screening is not performed. This report describes a patient with SCD treated with RBCEx using five units negative for C, E, K, Fya, Fyb (prospectively matched), four of which were from donors with hemoglobin variants and/or glucose-6-phosphate dehydrogenase (G6PD) deficiency. Pre-RBCEx HbS quantification by high performance liquid chromatography (HPLC) demonstrated 49.3% HbS and 2.8% hemoglobin C, presumably from transfusion of a hemoglobin C-containing RBC unit during a previous RBCEx. Post-RBCEx HPLC showed the appearance of hemoglobin G-Philadelphia. Two units were G6PD-deficient. The patient did well, but the consequences of transfusing RBC units that are G6PD-deficient and contain hemoglobin variants are unknown. Additional studies are needed to investigate effects on storage, in-vivo RBC recovery and survival, and physiological effects following transfusion of these units. Post-RBCEx HPLC can monitor RBCEx efficiency and detect the presence of abnormal transfused units.

  15. 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

  16. 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

  17. 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

  18. [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.

  19. 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

  20. Hemoglobin glycation index as a useful predictor of therapeutic responses to dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes

    PubMed Central

    Chen, Yu-Wei; Wang, Jun-Sing; Sheu, Wayne H-H; Lin, Shih-Yi; Lee, I-Te; Song, Yuh-Min; Fu, Chia-Po; Lee, Chia-Lin

    2017-01-01

    Introduction A high hemoglobin glycation index (HGI) and glycated hemoglobin (HbA1c) level are associated with greater inflammatory status, and dipeptidyl peptidase-4 (DPP-4) inhibitors can suppress inflammation. We aimed to evaluate the relationship between HGI and the therapeutic effect of DPP-4 inhibitors. Methods This retrospective cohort study followed 468 patients with type 2 diabetes receiving DPP-4 inhibitor treatment for 1 year. Estimated HbA1c was calculated using a linear regression equation derived from another 2969 randomly extracted patients with type 2 diabetes based on fasting plasma glucose (FPG) level. The subjects were divided into two groups based on HGI (HGI = observed HbA1c - estimated HbA1c). Mixed model repeated measures were used to compare the treatment efficacy after 1 year in patients with a low (HGI<0, n = 199) and high HGI (HGI≧0, n = 269). Results There were no significant group differences in mean changes of FPG after 1 year (-12.8 and -13.4 mg/dL in the low and high HGI groups, respectively). However, the patients with a high HGI had a significantly greater reduction in HbA1c from baseline compared to those with a low HGI (-1.9 versus -0.3% [-20.8 versus -3.3 mmol/mol]). Improvements in glycemic control were statistically significantly associated with the tested DPP-4 inhibitors in the high HGI group (-2.4, -1.4, -1.2 and -2.2% [-26.2, -15.3, -13.1 and -24.0 mmol/mol] for vildagliptin, linagliptin, saxagliptin and sitagliptin, respectively) but not in the low HGI group. Conclusions The HGI index derived from FPG and HbA1c may be able to identify who will have a better response to DPP-4 inhibitors. PMID:28182722

  1. Estimation of serum, salivary immunoglobulin G, immunoglobulin A levels and total protein, hemoglobin in smokeless tobacco chewers and oral submucous fibrosis patients

    PubMed Central

    Balakrishnan, Chandrakanth; Aswath, Nalini

    2015-01-01

    Background: Oral submucous fibrosis (OSMF) is a debilitating, potentially cancerous oral condition. Although areca nut is the most important causative agent, it is also considered that the disease is immunologically mediated. Aim of the Study: To establish that autoimmunity and nutritional deficiency play a role in the etiopathogenesis of OSMF. Objectives of the Study: To show that serum immunoglobulin markers (immunoglobulin-G [IgG], immunoglobulin-A [IgA]) and nutritional parameters such as total serum protein (TSP), Hemoglobin (Hb) play a role in causing OSMF and also to correlate serum, salivary IgG, IgA levels in OSMF patients. Settings and Design: A case-control study was done with 50 patients (25 patients who were provisionally diagnosed as OSMF - Group I, and 25 patients who were chronic smokeless tobacco chewers and who did not have any intraoral lesion - Group II). Materials and Methods: Five milliliters of blood and saliva were collected from both the groups. Quantitative analysis of serum, and salivary IgG, IgA was done by turbidometric immunoassay. TSP and Hemoglobin (Hb) were estimated by spectrophotometry. Statistical Analysis: Results were analyzed by independent samples t-test and one-way analysis of variance (ANOVA). Results: All patients of OSMF showed significant (P < 0.01) increase in serum IgG, IgA, and salivary IgG levels as compared to smokeless tobacco chewers. The salivary IgA levels showed a significant decrease in OSMF patients (P < 0.05). TSP and Hb levels showed significant (P < 0.01) decrease in OSMF patients as compared to smokeless tobacco chewers. Conclusion: The elevation of immunoglobulin levels supports the concept of autoimmunity. The decrease in TSP and Hb suggests that nutritional deficiency plays a defined role in the occurrence as well as a further progression of OSMF. PMID:26604567

  2. Side-necked turtle (Pleurodira, Chelonia, reptilia) hemoglobin: cDNA-derived primary structures and X-ray crystal structures of Hb A.

    PubMed

    Hasegawa, Tomokazu; Shishikura, Fumio; Kuwada, Takao

    2011-03-01

    Red blood cells of yellow-spotted river turtles (Podocnemis unifilis, Pleurodira, Chelonia, REPTILIA) have two hemoglobin (Hb) components, Hb A and Hb D. We purified the hemoglobin component homologous to amniote (reptiles, birds, and mammals) adult Hb A which comprises two identical α(A) -globin polypeptides and two identical β-globin polypeptides. To establish the crystal structure of Podocnemis Hb A, we first determined the globin primary structures using cDNA nucleotide sequencing with the assistance of protein sequencing. The purified Podocnemis Hb A produced a different form of crystal for each of the two different buffer systems used: form A, tetragonal crystals (space group, P4₁2₁2), produced under neutral pH (pH 7-8) conditions; and form B, hexagonal crystals (space group, P6₁22), produced under high alkaline pH (pH 11-13) conditions. Single crystals of the two forms were examined by Raman microscopy with an excitation of 532 nm, indicating their structural differences. The crystal structures of the two forms were constructed by X-ray crystallographic diffraction at a resolution of 2.20 Å for form A and 2.35 Å for form B. The differences of the tertiary and quaternary structures of the two forms were marginal; however, one clear difference was found in helix structure. When comparing Podocnemis Hb A with Hb A from specimens in other taxa, such as Anser indicus (birds) and Homo sapiens (mammals) by SHELXPRO, the root mean square deviation (RMSD) between the corresponding Cα atoms of the two globins does not exceed 2.0 Å. These low values indicate the crystal structures resemble each other. Our data on X-ray crystal structures and Raman spectra not only reveal the first findings on the two crystal forms of Podocnemis unifilis Hb A but also provide the first refined models for reptilian adult Hb A.

  3. Achieving comparability with IFCC reference method for the measurement of hemoglobin A1c by use of an improved isotope-dilution mass spectrometry method.

    PubMed

    Liu, Hong; Wong, Lingkai; Yong, Sharon; Liu, Qinde; Lee, Tong Kooi

    2015-10-01

    The development of reference measurement methods for hemoglobin A1c (HbA1c) is important for quality assurance in diabetes management. The IFCC reference method using purified proteins as calibration standards is the recommended accuracy-based reference method for the standardization of HbA1c measurement. We developed a highly precise and accurate liquid chromatography-isotope-dilution tandem mass spectrometry (LC-IDMS/MS) procedure, which can serve as an alternative accuracy-based method for HbA1c measurement. In this method, enzymatic proteolysis was applied to sample preparation, followed by LC-IDMS/MS measurement of hemoglobin A0 (HbA0) and HbA1c, using two "signature" hexapeptides for calibration. The concentrations of the signature hexapeptide calibration solutions were, in turn, determined using a hydrolysis method with HCl, followed by LC-IDMS/MS measurement using amino acid solutions as calibration standards. These solutions were gravimetrically prepared from pure amino acid certified reference materials (CRMs). The developed LC-IDMS/MS method was used in participation in an IFCC ring trial for reference laboratories (RELA 2013 and 2014) for HbA1c, where our results were compared with those using the IFCC reference method. The deviations were found to be 0.4-1.7 mmol mol(-1) [or 0.04-0.16% in National Glygohemoglobin Standardization Program (NGSP) units], revealing good comparability with the IFCC reference method. The relative expanded uncertainty of the LC-IDMS/MS was in the range of 2.6% to 2.8% (1.6% to 2.2% after converting to NGSP units). With excellent method precision, good comparability with the IFCC reference method, and a small measurement uncertainty, the developed LC-IDMS/MS method may be used as an alternative accuracy-based reference method for HbA1c measurement.

  4. 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.

  5. 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.

  6. 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

  7. Novel hemin binding domains in the Corynebacterium diphtheriae HtaA protein interact with hemoglobin and are critical for heme iron utilization by HtaA.

    PubMed

    Allen, Courtni E; Schmitt, Michael P

    2011-10-01

    The human pathogen Corynebacterium diphtheriae utilizes hemin and hemoglobin as iron sources for growth in iron-depleted environments. The use of hemin iron in C. diphtheriae involves the dtxR- and iron-regulated hmu hemin uptake locus, which encodes an ABC hemin transporter, and the surface-anchored hemin binding proteins HtaA and HtaB. Sequence analysis of HtaA and HtaB identified a conserved region (CR) of approximately 150 amino acids that is duplicated in HtaA and present in a single copy in HtaB. The two conserved regions in HtaA, designated CR1 and CR2, were used to construct glutathione S-transferase (GST) fusion proteins (GST-CR1 and GST-CR2) to assess hemin binding by UV-visual spectroscopy. These studies showed that both domains were able to bind hemin, suggesting that the conserved sequences are responsible for the hemin binding property previously ascribed to HtaA. HtaA and the CR2 domain were also shown to be able to bind hemoglobin (Hb) by the use of an enzyme-linked immunosorbent assay (ELISA) method in which Hb was immobilized on a microtiter plate. The CR1 domain exhibited a weak interaction with Hb in the ELISA system, while HtaB showed no significant binding to Hb. Competitive binding studies demonstrated that soluble hemin and Hb were able to inhibit the binding of HtaA and the CR domains to immobilized Hb. Moreover, HtaA was unable to bind to Hb from which the hemin had been chemically removed. Alignment of the amino acid sequences of CR domains from various Corynebacterium species revealed several conserved residues, including two highly conserved tyrosine (Y) residues and one histidine (H) residue. Site-directed mutagenesis studies showed that Y361 and H412 were critical for the binding to hemin and Hb by the CR2 domain. Biological assays showed that Y361 was essential for the hemin iron utilization function of HtaA. Hemin transfer experiments demonstrated that HtaA was able to acquire hemin from Hb and that hemin bound to HtaA could be

  8. A Voltammetric Biosensor Based on Glassy Carbon Electrodes Modified with Single-Walled Carbon Nanotubes/Hemoglobin for Detection of Acrylamide in Water Extracts from Potato Crisps.

    PubMed

    Krajewska, Agnieszka; Radecki, Jerzy; Radecka, Hanna

    2008-09-23

    The presence of toxic acrylamide in a wide range of food products such as potato crisps, French fries or bread has been confirmed by Swedish scientists from Stockholm University. The neurotoxicity, possible carcinogenicity of this compound and its metabolites compels us to control them by quantitative and qualitative assays. Acrylamide forms adduct with hemoglobin (Hb) as a result of the reaction the -NH2 group of the Nterminal valine with acrylamide. In this work we present the use of glassy carbon electrodes coated with single-walled carbon nanotubes (SWCNTs) and Hb for voltammetric detection of acrylamide in water solutions. The electrodes presented a very low detection limit (1.0×10(-9) M). The validation made in the matrix obtained by water extraction of potato crisps showed that the electrodes presented are suitable for the direct determination of acrylamide in food samples.

  9. Expression of heat shock protein and hemoglobin genes in Chironomus tentans (Diptera, chironomidae) larvae exposed to various environmental pollutants: a potential biomarker of freshwater monitoring.

    PubMed

    Lee, Soon-Mi; Lee, Se-Bum; Park, Chul-Hwi; Choi, Jinhee

    2006-11-01

    To identify a sensitive biomarker of freshwater monitoring, we evaluated pollutant-induced expression of heat shock proteins (HSPs) and hemoglobins (Hbs) genes in the larvae of the aquatic midge Chironomus tentans (Diptera, Chironomidae). As pollutants, we examined nonylphenol, bisphenol-A, 17alpha-ethynyl estradiol, bis(2-ethylhexyl) phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride. We also investigated larval growth as a physiological descriptor by measuring changes in the body fresh weight and dry weight after chemical exposure. The response of the HSPs gene expression by chemical exposure was rapid and sensitive to low chemical concentrations but it was not stressor specific. Interestingly, an increase in the expression of HSPs genes was observed not only in a stress inducible form (HSP70), but also in a constitutively (HSC70) expressed form. The expression of Hb genes showed chemical-specific responses: that is, alkyl phenolic compounds increased the expression of hemoglobin genes, whereas pesticides decreased the expression. As expected, molecular-level markers were more sensitive than physiological endpoints, suggesting that gene expression could be developed as an early warning biomarker in this animal. The overall results suggest that the expression of HSP and Hb genes in Chironomus could give useful information for diagnosing general health conditions in fresh water ecosystem. The expression of Hb genes, in particular, seems to be a promising biomarker, especially in view of the potential of Chironomus larvae as a biomonitoring species and of the physiological particularities of their respiratory pigments.

  10. Two new hemoglobin variants: Hb Brem-sur-Mer [beta9(A6)Ser-->Tyr] and Hb Passy [alpha81(F2)Ser-->Pro (alpha2)].

    PubMed

    Lacan, Philippe; Moreau, Mathieu; Becchi, Michel; Zanella-Cleon, Isabelle; Aubry, Martine; Louis, Jean-Jacques; Couprie, Nicole; Francina, Alain

    2005-01-01

    Two new hemoglobin (Hb) variants: Hb Brem-sur-Mer [codon 9 (TCT-->TAT); beta9(A6)Ser-->Tyr] on the first exon of the beta-globin gene and Hb Passy [codon 81 (TCC-->CCC); alpha81(F2)Ser-->Pro (alpha2)] on the second exon of the alpha2-globin gene, are described. The two variants were characterized by DNA sequencing and mass spectrometry (MS). Hematological abnormalities: microcytosis and hypochromia were found only in the carrier of Hb Passy. In the absence of an association with an alpha-thalassemic deletion or mutation, the mutation 81(F2)Pro could induce a possible alpha-thalassemia (thal).

  11. 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.

  12. Effects of resuscitation with polymerized porcine hemoglobin (pPolyHb) on hemodynamic stability and oxygen delivery in a rat model of hemorrhagic shock.

    PubMed

    Wang, Li; Liu, Fang; Yan, Kunping; Pan, Wencan; Xu, Lijuan; Liu, Huifang; Yan, Chengbin; Chen, Chao; Zhu, Hongli

    2017-02-01

    The objective of this study was to evaluate the effects of polymerized porcine hemoglobin (pPolyHb) on hemodynamic stability and oxygen delivery in a rat model of hemorrhagic shock. Rats underwent controlled hemorrhage, resulting in the loss of 65% of their blood volume in 90 minutes. The results showed that pPolyHb was superior to hetastarch and saline, and similar to whole blood, in restoring hemodynamic stability and reversing anaerobic metabolism caused by hemorrhage. Furthermore, pPolyHb improved oxygen supply and increased blood oxygen content. These data suggest that pPolyHb can be effective in improving tissue perfusion under conditions of severe hemorrhagic shock.

  13. 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.

  14. 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

  15. Absolute near-infrared oximetry for urology: a quantitative study of the tissue hemoglobin saturation before and after testicular torsion in a rabbit model

    NASA Astrophysics Data System (ADS)

    Hallacoglu, Bertan; Matulewicz, Richard S.; Paltiel, Harriet J.; Padua, Horacio; Gargollo, Patricio; Cannon, Glenn; Alomari, Ahmad; Sassaroli, Angelo; Fantini, Sergio

    2009-02-01

    We present an experimental study on four rabbits to demonstrate the feasibility of near-infrared spectroscopy in the noninvasive assessment of testicular torsion. We used a multi-distance frequency-domain method, based on a fixed detector position and a 9-mm linear scan of the illumination optical fibers, to measure absolute values of pre- and post-operative testicular oxygen saturation. Unilateral testicular torsions (by 0°, 540° or 720°) on experimental testes and contralateral sham surgeries (no torsion) on control testes were performed and studied. Our results showed (a) a consistent baseline absolute tissue oxygen saturation value of 78% +/- 5%; (b) a comparable absolute saturation of 77% +/- 6% on the control side (testes after sham surgery); and (c) a significantly lower tissue oxygen saturation of 36% +/- 2% on the experimental side (testes after 540° or 720° torsion surgery). These results demonstrate the capability of frequency domain nearinfrared spectroscopy in the assessment of absolute testicular hemoglobin desaturation caused by torsion, and show promise as a potential method to serve as a complement to conventional color and spectral Doppler ultrasonography.

  16. 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.

  17. Hemoglobin allostery: new views on old players.

    PubMed

    Miele, Adriana Erica; Bellelli, Andrea; Brunori, Maurizio

    2013-05-13

    Proteins are dynamic molecular machines whose structure and function are modulated by environmental perturbations and natural selection. Allosteric regulation, discovered in 1963 as a novel molecular mechanism of enzymatic adaptation [Monod, Changeux & Jacob (1963). J. Mol. Biol.6, 306-329], seems to be the leit motiv of enzymes and metabolic pathways, enabling fine and quick responses toward external perturbations. Hemoglobin (Hb), the oxygen transporter of all vertebrates, has been for decades the paradigmatic system to test the validity of the conformational selection mechanism, the conceptual innovation introduced by Monod, Wyman and Changeux. We present hereby the results of a comparative analysis of structure, function and thermodynamics of two extensively investigated hemoglobins: human HbA and trout HbI. They represent a unique and challenging comparison to test the general validity of the stereochemical model proposed by Perutz. Indeed both proteins are ideal for the purpose being very similar yet very different. In fact, T-HbI is a low-ligand-affinity cooperative tetrameric Hb, insensitive to all allosteric effectors. This remarkable feature, besides being physiologically sound, supports the stereochemical model, given that the six residues identified in HbA as responsible for the Bohr and the 2,3-di-phosphoglycerate effects are all mutated. Comparison of the three-dimensional structures of HbA and T-HbI allows unveiling the molecular mechanism whereby the latter has a lower O2 affinity. Moreover, the energetic balance sheet shows that the salt bridges breaking upon allosteric quaternary transition are important yet insufficient to account for the free energy of heme-heme interactions in both hemoglobins.

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

    SciTech Connect

    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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Hemoglobin

    MedlinePlus

    ... Failure of the right side of the heart ( cor pulmonale ) Severe chronic obstructive pulmonary disease (COPD) Scarring or ... chronic disease Aplastic anemia Bleeding CBC blood test Cor pulmonale Diabetes Drug-induced immune hemolytic anemia Erythropoietin test ...

  5. 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.

  6. A randomized comparison of hemoglobin content-based versus standard (unit-based) red blood cell transfusion policy.

    PubMed

    Atilla, Erden; Toprak, Selami Koçak; Civriz Bozdağ, Sinem; Topçuoğlu, Pervin; Arslan, Önder

    2015-02-20

    Amaç: Eritrosit süspansiyonu (ES) ünitelerinin hacimleri standart kriterlerle belirlenmişse de hemoglobin (Hb) içerikleri farklıdır. Halen klinik rutin transfüzyon uygulamaları, eritrosit süspansiyonlarının ünite sayısına dayanmaktadır. Biz bu çalışma ile iki yöntemin etkinliklerini karşılaştırmayı amaçladık. Materyal ve Metod: Ortanca yaşı 46 (19-75) olan 89 hastaya (55 erkek; 34 kadın) 178 transfüzyon epizodu; 92’ si çalışma, 86’ sı kontrol kolun olarak randomize edildi. 51 hasta 1, 38 hasta ≥2 epizotta değerlendirildi (ortanca 3; 1-7). Hesaplamalar kan bankalarımızda kullanılan, Hemosoft İşletim Sistemi’yle yapıldı. Çalışma kolunda alıcı; boy, güncel kilo, güncel ve hedef Hb verileri ile gerekli Hb miktarı hesaplandı. Uygun ünite bulunamayanlarda (başarısız) ve kontrol kolunda istenen sayıda ES ünitesi gönderildi. Bulgular: Çalışma kolunda 38 epizotta ES ünitesi isteme göre %19.8 olarak azaldı. Uygun Hb içeriğinde ünite bulma başarısı; düşük kilolu, kısa boylu hastalarda ve ES stok sayısı fazla olduğunda; daha yüksek bulundu. Hedeflenen Hb değerine ulaşma oranları; çalışma ve kontrol kolunda (p=0,1), başarılı ve başarısız gruplarda (p=0,3), kontrol kolu ve başarısız grupta (p= 0,4); istatistiksel olarak benzer bulundu. Ünite Hb içeriği ve hedef Hb’e ulaşma ilişkisinin, anlamlı olduğu gösterildi (p=0,01). Raf ömrü ve hedef Hb’e ulaşma ilişkisi anlamsızdı (p=0,7). Sonuç: Hb içeriğine dayalı ve ünite sayısına dayalı ES transfüzyonlarının, etkinliklerinin benzerdir ve Hb içeriğine dayalı transfüzyon ile ünite sayısı azaltılabilir.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. A1M Ameliorates Preeclampsia-Like Symptoms in Placenta and Kidney Induced by Cell-Free Fetal Hemoglobin in Rabbit

    PubMed Central

    Axelsson, Josefin; Larsson, Irene; Johansson, Martin; Wester-Rosenlöf, Lena; Mörgelin, Matthias; Casslén, Vera; Gram, Magnus; Åkerström, Bo; Hansson, Stefan R.

    2015-01-01

    Preeclampsia is one of the most serious pregnancy-related diseases and clinically manifests as hypertension and proteinuria after 20 gestational weeks. The worldwide prevalence is 3-8% of pregnancies, making it the most common cause of maternal and fetal morbidity and mortality. Preeclampsia lacks an effective therapy, and the only “cure” is delivery. We have previously shown that increased synthesis and accumulation of cell-free fetal hemoglobin (HbF) in the placenta is important in the pathophysiology of preeclampsia. Extracellular hemoglobin (Hb) and its metabolites induce oxidative stress, which may lead to acute renal failure and vascular dysfunction seen in preeclampsia. The human endogenous protein, α1-microglobulin (A1M), removes cell-free heme-groups and induces natural tissue repair mechanisms. Exogenously administered A1M has been shown to alleviate the effects of Hb-induced oxidative stress in rat kidneys. Here we attempted to establish an animal model mimicking the human symptoms at stage two of preeclampsia by administering species-specific cell-free HbF starting mid-gestation until term, and evaluated the therapeutic effect of A1M on the induced symptoms. Female pregnant rabbits received HbF infusions i.v. with or without A1M every second day from gestational day 20. The HbF-infused animals developed proteinuria and a significantly increased glomerular sieving coefficient in kidney that was ameliorated by co-administration of A1M. Transmission electron microscopy analysis of kidney and placenta showed both intracellular and extracellular tissue damages after HbF-treatment, while A1M co-administration resulted in a significant reduction of the structural and cellular changes. Neither of the HbF-treated animals displayed any changes in blood pressure during pregnancy. In conclusion, infusion of cell-free HbF in the pregnant rabbits induced tissue damage and organ failure similar to those seen in preeclampsia, and was restored by co

  14. A1M Ameliorates Preeclampsia-Like Symptoms in Placenta and Kidney Induced by Cell-Free Fetal Hemoglobin in Rabbit.

    PubMed

    Nääv, Åsa; Erlandsson, Lena; Axelsson, Josefin; Larsson, Irene; Johansson, Martin; Wester-Rosenlöf, Lena; Mörgelin, Matthias; Casslén, Vera; Gram, Magnus; Åkerström, Bo; Hansson, Stefan R

    2015-01-01

    Preeclampsia is one of the most serious pregnancy-related diseases and clinically manifests as hypertension and proteinuria after 20 gestational weeks. The worldwide prevalence is 3-8% of pregnancies, making it the most common cause of maternal and fetal morbidity and mortality. Preeclampsia lacks an effective therapy, and the only "cure" is delivery. We have previously shown that increased synthesis and accumulation of cell-free fetal hemoglobin (HbF) in the placenta is important in the pathophysiology of preeclampsia. Extracellular hemoglobin (Hb) and its metabolites induce oxidative stress, which may lead to acute renal failure and vascular dysfunction seen in preeclampsia. The human endogenous protein, α1-microglobulin (A1M), removes cell-free heme-groups and induces natural tissue repair mechanisms. Exogenously administered A1M has been shown to alleviate the effects of Hb-induced oxidative stress in rat kidneys. Here we attempted to establish an animal model mimicking the human symptoms at stage two of preeclampsia by administering species-specific cell-free HbF starting mid-gestation until term, and evaluated the therapeutic effect of A1M on the induced symptoms. Female pregnant rabbits received HbF infusions i.v. with or without A1M every second day from gestational day 20. The HbF-infused animals developed proteinuria and a significantly increased glomerular sieving coefficient in kidney that was ameliorated by co-administration of A1M. Transmission electron microscopy analysis of kidney and placenta showed both intracellular and extracellular tissue damages after HbF-treatment, while A1M co-administration resulted in a significant reduction of the structural and cellular changes. Neither of the HbF-treated animals displayed any changes in blood pressure during pregnancy. In conclusion, infusion of cell-free HbF in the pregnant rabbits induced tissue damage and organ failure similar to those seen in preeclampsia, and was restored by co-administration of A

  15. Combined use of fasting plasma glucose and glycated hemoglobin A1c in a stepwise fashion to detect undiagnosed diabetes mellitus.

    PubMed

    Nakagami, Tomoko; Tominaga, Makoto; Nishimura, Rimei; Daimon, Makoto; Oizumi, Toshihide; Yoshiike, Nobuo; Tajima, Naoko

    2007-09-01

    Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.

  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. 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.

  18. 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

  19. The “Coagulation Box” and a New Hemoglobin-Driven Algorithm for Bleeding Control in Patients with Severe Multiple Traumas

    PubMed Central

    Hilbert, Peter; Hofmann, Gunther Olaf; Teichmann, Jörg; Struck, Manuel F.; Stuttmann, Ralph

    2013-01-01

    Background Extensive hemorrhage is the leading cause of death in the first few hours following multiple traumas. Therefore, early and aggressive treatment of clotting disorders could reduce mortality. Unfortunately, the availability of results from commonly performed blood coagulation studies are often delayed whereas hemoglobin (Hb) levels are quickly available. Objectives In this study, we evaluated the use of initial hemoglobin (Hb) levels as a guide line for the initial treatment of clotting disorders in multiple trauma patients. Patients and Methods We have developed an Hb-driven algorithm to initiate the initial clotting therapy. The algorithm contains three different steps for aggressive clotting therapy depending on the first Hb value measured in the shock trauma room, (SR) and utilizes fibrinogen, prothrombin complex concentrate (PCC), factor VIIa, tranexamic acid and desmopressin. The above-mentioned drugs were stored in a special “coagulation box” in the hospital pharmacy, and this box could be immediately brought to the SR or operating room (OR) upon request. Despite the use of clotting factors, transfusions using red blood cells (RBC) and fresh frozen plasma (FFP) were performed at an RBC-to-FFP ratio of 2:1 to 1:1. Results Over a 12-month investigation period, 123 severe multiple trauma patients needing intensive care therapy were admitted to our trauma center (mean age 48 years, mean ISS (injury severity score) 30). Fourteen (11%) patients died; 25 (mean age 51.5 years, mean ISS 53) of the 123 patients were treated using the “coagulation box,” and 17 patients required massive transfusions. Patients treated with the “coagulation box” required an average dose of 16.3 RBC and 12.9 FFP, whereas 17 of the 25 patients required an average dose of 3.6 platelet packs. According to the algorithm, 25 patients received fibrinogen (average dose of 8.25 g), 24 (96%) received PCC (3000 IU.), 14 (56%) received desmopressin (36.6 µg), 13 (52%) received

  20. Coexpression of Human α- and Circularly Permuted β-Globins Yields a Hemoglobin with Normal R State but Modified T State Properties†

    PubMed Central

    Asmundson, Anna L.; Taber, Alexandria M.; van der Walde, Adella; Lin, Danielle H.; Olson, John S.; Anthony-Cahill, Spencer J.

    2009-01-01

    For the first time, a circularly permuted human β-globin (cpβ) has been coexpressed with human α-globin in bacterial cells and shown to associate to form α-cpβ hemoglobin in solution. Flash photolysis studies of α-cpβ show markedly biphasic CO and O2 kinetics with the amplitudes for the fast association phases being dominant due the presence of large amounts of high-affinity liganded hemoglobin dimers. Extensive dimerization of liganded but not deoxygenated α-cpβ was observed by gel chromatography. The rate constants for O2 and CO binding to the R state forms of α-cpβ are almost identical to those of native HbA (k′R(CO) ≈ 5.0 μM−1 s−1; k′R(O2) ≈ 50 μM−1 s−1), and the rate of O2 dissociation from fully oxygenated α-cpβ is also very similar to that observed for HbA (kR(O2) ≈ 21–28 s−1). When the equilibrium deoxyHb form of α-cpβ is reacted with CO in rapid mixing experiments, the observed time courses are monophasic and the observed bimolecular association rate constant is ∼1.0 μM−1 s−1, which is intermediate between the R state rate measured in partial photolysis experiments (∼5 μM−1 s−1) and that observed for T state deoxyHbA (k′T(CO) ≈ 0.1 to 0.2 μM−1 s−1). Thus the deoxygenated permutated β subunits generate an intermediate, higher affinity, deoxyHb quaternary state. This conclusion is supported by equilibrium oxygen binding measurements in which α-cpβ exhibits a P50 of ∼1.5 mmHg and a low n-value (∼1.3) at pH 7, 20 °C, compared to 8.5 mmHg and n ≈ 2.8 for native HbA under identical, dilute conditions. PMID:19397368

  1. 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

  2. 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.

  3. Correction of patient results for Beckman Coulter LX-20 assays affected by interference due to hemoglobin, bilirubin or lipids: a practical approach.

    PubMed

    Vermeer, Henricus J; Steen, Gerard; Naus, André J M; Goevaerts, Berrie; Agricola, Pauline T; Schoenmakers, Christian H H

    2007-01-01

    The influence of interference by hemolysis, icterus and lipemia on the results of routine chemistries may lead to wrong interpretations. On Synchron LX-20 instruments (Beckman Coulter) serum or plasma indices can be used as reliable semi-quantitative measures of the magnitude of such interference. In an article recently published in this journal, we presented the results of a multicenter study carried out in Dutch hospitals in which we determined cutoff indices for analytes above which analytically significant interference exists. Clinically significant interference cutoff indices were also derived for these analytes. In this article, we describe the handling of patient samples with clinically significant interference by hemolysis, icterus or lipemia. We investigated several possible approaches for correction of the result: dilution of the interference; mathematical correction in the case of hemolysis; treatment with ferrocyanide to destroy bilirubin; and removal of lipids in lipemic patient samples. We concluded, that mathematical correction of potassium or lactate dehydrogenase results in hemolytic samples can only be carried out if intravascular hemolysis is ruled out. Hemoglobin quantification in serial patient samples, combined with measurement of haptoglobin, represents a useful tool to rule out in vivo hemolysis. We derived an algorithm for this situation. We do not simply recommend mathematical correction, unless it is clinically acceptable. We present formulas for potassium and lactate dehydrogenase: corrected potassium=measured potassium-(hemolytic index increment x 0.14); corrected lactate dehydrogenase=measured lactate dehydrogenase-(hemolytic index increment x 75). The dilution studies indicated that dilution is only applicable for bilirubin, C-reactive protein and iron. The results of treatment with ferrocyanide were poor, and we do not recommend this method. Removal of lipids using high-speed centrifugation or LipoClear (StatSpin Inc.), a non

  4. 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.

  5. Comparison of 2-chlorobenzoic acid biodegradation in a membrane bioreactor by B. cepacia and B. cepacia bearing the bacterial hemoglobin gene.

    PubMed

    Urgun-Demirtas, Meltem; Stark, Benjamin C; Pagilla, K R

    2006-09-01

    Degradation of 2-chlorobenzoic acid (2-CBA), a model recalcitrant chlorinated organic compound, by pure cultures of Burkholderia cepacia strain DNT with (transformed B. cepacia) and without (untransformed B. cepacia) the bacterial hemoglobin (Vitreoscilla hemoglobin, VHb) gene, vgb, was investigated in parallel membrane bioreactors (MBRs). This was done aseptically to prevent contamination during the operation of the MBRs. The objective was to determine whether the degradation of 2-CBA by cometabolism, using acetate as a primary carbon source, under hypoxic conditions might be enhanced for vgb-bearing cells in MBRs. The 2-CBA removal efficiency of transformed B. cepacia (97-99%) was slightly higher than that of untransformed B. cepacia (95-99%) at all stages. The average amount of chloride released from 2-CBA by transformed cells was also higher than for untransformed cells, 92-96% compared to 64-84% of the maximum theoretical amount, the exact value depending on the operating conditions. These results indicate that 2-CBA degradation/transformation is not accompanied by the stoichiometric release of chloride for the untransformed strain. The difference between percentages of 2-CBA removal and chloride release by untransformed cells was attributed to persistence, under hypoxic conditions, of the 2-CBA chlorine atom in 2-CBA metabolites. Growth of transformed cells was also significantly enhanced under hypoxic conditions compared to untransformed cells. For varying media compositions, the transformed cells reached higher cell densities (3.2-5.4 g/L) relative to untransformed cells (2.8-4.7 g/L) at food to microorganism ratios ranging from 0.44-0.59 to 0.38-0.49 g COD/g biomass-d The observed yields thus ranged from 0.16-0.20 and 0.15-0.18 g TSS/g COD for untransformed and transformed cells, respectively. The value of the yield depended on medium composition. The MBR system using vgb-containing B. cepacia maintained a high biomass concentration without oxygen

  6. Comparability of Point-of-Care versus Central Laboratory Hemoglobin Determination in Emergency Patients at a Supra-Maximal Care Hospital

    PubMed Central

    Dolscheid-Pommerich, Ramona C.; Dolscheid, Sarah; Grigutsch, Daniel; Stoffel-Wagner, Birgit; Graeff, Ingo

    2016-01-01

    Fulfilling the requirements of point-of-care testing (POCT) training regarding proper execution of measurements and compliance with internal and external quality control specifications is a great challenge. Our aim was to compare the values of the highly critical parameter hemoglobin (Hb) determined with POCT devices and central laboratory analyzer in the highly vulnerable setting of an emergency department in a supra maximal care hospital to assess the quality of POCT performance. In 2548 patients, Hb measurements using POCT devices (POCT-Hb) were compared with Hb measurements performed at the central laboratory (Hb-ZL). Additionally, sub collectives (WHO anemia classification, patients with Hb <8 g/dl and suprageriatric patients (age >85y.) were analyzed. Overall, the correlation between POCT-Hb and Hb-ZL was highly significant (r = 0.96, p<0.001). Mean difference was -0.44g/dl. POCT-Hb values tended to be higher than Hb-ZL values (t(2547) = 36.1, p<0.001). Standard deviation of the differences was 0.62 g/dl. Only in 26 patients (1%), absolute differences >2.5g/dl occurred. McNemar´s test revealed significant differences regarding anemia diagnosis according to WHO definition for male, female and total patients (♂ p<0.001; ♀ p<0.001, total p<0.001). Hb-ZL resulted significantly more often in anemia diagnosis. In samples with Hb<8g/dl, McNemar´s test yielded no significant difference (p = 0.169). In suprageriatric patients, McNemar´s test revealed significant differences regarding anemia diagnosis according to WHO definition in male, female and total patients (♂ p<0.01; ♀ p = 0.002, total p<0.001). The difference between Hb-ZL and POCT-Hb with Hb<8g/dl was not statistically significant (<8g/dl, p = 1.000). Overall, we found a highly significant correlation between the analyzed hemoglobin concentration measurement methods, i.e. POCT devices and at the central laboratory. The results confirm the successful implementation of the presented POCT concept

  7. Comparability of Point-of-Care versus Central Laboratory Hemoglobin Determination in Emergency Patients at a Supra-Maximal Care Hospital.

    PubMed

    Dolscheid-Pommerich, Ramona C; Dolscheid, Sarah; Grigutsch, Daniel; Stoffel-Wagner, Birgit; Graeff, Ingo

    2016-01-01

    Fulfilling the requirements of point-of-care testing (POCT) training regarding proper execution of measurements and compliance with internal and external quality control specifications is a great challenge. Our aim was to compare the values of the highly critical parameter hemoglobin (Hb) determined with POCT devices and central laboratory analyzer in the highly vulnerable setting of an emergency department in a supra maximal care hospital to assess the quality of POCT performance. In 2548 patients, Hb measurements using POCT devices (POCT-Hb) were compared with Hb measurements performed at the central laboratory (Hb-ZL). Additionally, sub collectives (WHO anemia classification, patients with Hb <8 g/dl and suprageriatric patients (age >85y.) were analyzed. Overall, the correlation between POCT-Hb and Hb-ZL was highly significant (r = 0.96, p<0.001). Mean difference was -0.44g/dl. POCT-Hb values tended to be higher than Hb-ZL values (t(2547) = 36.1, p<0.001). Standard deviation of the differences was 0.62 g/dl. Only in 26 patients (1%), absolute differences >2.5g/dl occurred. McNemar´s test revealed significant differences regarding anemia diagnosis according to WHO definition for male, female and total patients (♂ p<0.001; ♀ p<0.001, total p<0.001). Hb-ZL resulted significantly more often in anemia diagnosis. In samples with Hb<8g/dl, McNemar´s test yielded no significant difference (p = 0.169). In suprageriatric patients, McNemar´s test revealed significant differences regarding anemia diagnosis according to WHO definition in male, female and total patients (♂ p<0.01; ♀ p = 0.002, total p<0.001). The difference between Hb-ZL and POCT-Hb with Hb<8g/dl was not statistically significant (<8g/dl, p = 1.000). Overall, we found a highly significant correlation between the analyzed hemoglobin concentration measurement methods, i.e. POCT devices and at the central laboratory. The results confirm the successful implementation of the presented POCT concept

  8. 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.

  9. Significance of borderline hemoglobin A2 values in an Italian population with a high prevalence of beta-thalassemia.

    PubMed

    Giambona, Antonino; Passarello, Cristina; Vinciguerra, Margherita; Li Muli, Rita; Teresi, Pietro; Anzà, Maurizio; Ruggeri, Gaetano; Renda, Disma; Maggio, Aurelio

    2008-09-01

    We report a retrospective analysis carried out on 23,485 subjects submitted to a screening program from 2000 to 2006. Of these subjects, 3,934 had borderline HbA(2) values from 3.1 to 3.9%; 410 samples, analyzed previously using PCR methods and sequencing because all of these were partners of a carrier of classical beta-thalassemia, were selected for statistical analysis. Of 410 subjects, 94 (22.9%) were positive for a molecular defect in the beta-, delta- or alpha-globin genes. The most prevalent molecular defects were beta IVS1 nt 6 (HBB c.92+6T C), co-inheritance of severe beta thalassemia and delta mutations, beta-promoter mutations and triplication of alpha genes were detected; alpha-thalassemia and Hb-variants were also evident. Borderline HbA(2) is not a rare event in a population with a high prevalence of beta-thalassemia carriers. These data support the necessity to investigate these cases at a molecular level, particularly if the partner is a carrier of beta-thalassemia.

  10. Elevated hemoglobin A1c Is Associated with Carotid Plaque Vulnerability: Novel Findings from Magnetic Resonance Imaging Study in Hypertensive Stroke Patients

    PubMed Central

    Sun, Beibei; Zhao, Huilin; Liu, Xiaosheng; Lu, Qing; Zhao, Xihai; Pu, Jun; Xu, Jianrong

    2016-01-01

    The association between hemoglobin A1c (HbA1c) level and carotid plaque vulnerability has been rarely studied by magnetic resonance imaging (MRI). The present study of MRI-identified carotid atherosclerotic lesions in hypertensive patients with acute stroke therefore sought to determine the associations between HbA1c level and plaque morphological and compositional characteristics and acute cerebral infarction (ACI) severity. Eighty hypertensive patients with acute stroke were enrolled; stratified into high (≥6.5%) and low (<6.5%) HbA1c groups; and underwent carotid and brain MRI to assess carotid plaque features and ACI volume in the region supplied by the internal carotid artery (ICA) in the symptomatic side. Plaque burden [percent wall volume (PWV), max wall thickness (max-WT)] and lipid-rich necrotic core (LRNC) were larger in the high as compared to the low HbA1c group. High HbA1c was an independent risk factor for the presence of plaque (odds ratio [OR] = 3.71) and LRNC plaque (OR = 7.08). HbA1c independently correlated with ACI severity among patients with ICA region cerebral infarction and carotid plaque. Our study suggested that an elevated HbA1c may have an adverse effect on carotid plaque vulnerability especially those with larger LRNC volumes in hypertensive stroke patients, which might exacerbate the severity of ACIs. PMID:27629481

  11. [Glycosylated hemoglobin A1c as a diagnostic test for diabetes mellitus in adolescents with overweight and obesity].

    PubMed

    Rivera-Hernández, Aleida; Zurita-Cruz, Jessie Nallely; Garrido-Magaña, Eulalia; Fiorentini-Fayad, Gigliola Margaretta; Nishimura-Meguro, Elisa

    2015-01-01

    Introducción: en 2009 se introdujo un criterio diagnóstico para la diabetes mellitus 2 (DM2) en población adulta, basado en los niveles de hemoglobina glucosilada (HbA1c) mayor o igual a 6.5 %; el punto de corte en población pediátrica podría ser menor. Se buscó determinar la utilidad de este criterio en adolescentes mexicanos con sobrepeso u obesidad. Métodos: se hizo somatometría completa, revisión del estadio de Tanner y presión arterial, glucemia, curva de tolerancia a la glucosa (CTOG) y HbA1c. Se calculó especificidad, sensibilidad, valores predictivos positivos y negativos y curva ROC para el diagnóstico de DM con HbA1c. Resultados: se estudiaron 109 pacientes entre 10 y 16 años referidos por obesidad o sobrepeso más comorbilidades, 58 % mujeres, edad 13 ± 1.74 años, IMC percentil 95.3 y HbA1c 5.73 ± 0.9 %. Se estableció el diagnóstico de DM en 9 casos (8.3 %), prediabetes en 8 (7.3 %) y tolerancia normal a la glucosa en 92 (84.4 %), el promedio de HbA1c fue de 5.6 ± 0.04, 5.7 ± 0.4 y 5.6 ± 0.73 %, respectivamente. La HbA1c mayor o igual a 6.5 % tuvo una sensibilidad de 12.5 %, especificidad de 89.8 %, VPP 10.65 y VPN 14.28. El mejor punto de corte para diagnosticar DM por curva ROC de HbA1c fue de 5.45 %, con sensibilidad de 62.5 % y especificidad de 57.1 %, VPP 2.53 y VPN 33.3. Conclusiones: el nivel de HbA1c mayor o igual a 6.5% tuvo baja sensibilidad y especificidad para diagnosticar DM. Un punto de corte menor es insuficiente para utilizar la HbA1c como criterio diagnóstico.

  12. Hb San Cataldo [β144(HC1)Lys→Thr; HBB: C.434A > C]: A New Hemoglobin Variant with Increased Affinity for Oxygen.

    PubMed

    Vinciguerra, Margherita; Passarello, Cristina; Cassarà, Filippo; Leto, Filippo; Cannata, Monica; Crivello, Anna; Di Salvo, Veronica; Maggio, Aurelio; Giambona, Antonino

    2016-08-01

    A 59-year-old Italian woman came to our center for revaluation of a previous diagnosis of polycythemia vera. The patient presented with a lifelong history of polycythemia, no increase in white blood cells (WBCs) and platelets, and a negative bone marrow biopsy. Analysis of hemoglobin (Hb) fractions showed an abnormal fast moving Hb component. We aimed to determine if this variant was the cause of polycythemia in this patient. A complete blood count (CBC) was performed by an automated cell counter and Hb fractions were determined by high performance liquid chromatography (HPLC). Standard stability tests and oxygen affinity evaluation were also performed. Genomic DNA was extracted from peripheral blood leukocytes using the phenol chloroform method and the entire β-globin gene was analyzed by direct sequencing. At the hematological level, no anemia or hemolysis was observed but an abnormal Hb fraction was detected using cation exchange HPLC. Molecular analysis of the β-globin gene showed heterozygosity for an AAG > ACG substitution at codon 144, resulting in a Lys→Thr amino acid replacement. We demonstrated that this is a new Hb variant with increased oxygen affinity. Its altered physiology is caused by the reduction of 2,3-diphosphoglycerate (2,3-DPG) effects, due to an amino acid substitution in the central pocket near the C-terminal of the β chain. We called this new variant Hb San Cataldo for the native city of proband.

  13. Association between Variants at BCL11A Erythroid-Specific Enhancer and Fetal Hemoglobin Levels among Sickle Cell Disease Patients in Cameroon: Implications for Future Therapeutic Interventions

    PubMed Central

    Pule, Gift Dineo; Ngo Bitoungui, Valentina Josiane; Chemegni, Bernard Chetcha; Kengne, Andre Pascal; Antonarakis, Stylianos

    2015-01-01

    Abstract Variants in BCL11A were previously associated with fetal hemoglobin (HbF) levels among Cameroonian sickle cell disease (SCD) patients, however explaining only ∼2% of the variance. In the same patients, we have investigated the relationship between HbF and two SNPs in a BCL11A erythroid-specific enhancer (N = 626). Minor allele frequencies in rs7606173 and rs1427407 were 0.42 and 0.24, respectively. Both variants were significantly associated with HbF levels (p = 3.11e-08 and p = 6.04e-06, respectively) and explained 8% and 6.2% variations, respectively. These data have confirmed a stronger effect on HbF of genomic variations at the BCL11A erythroid-specific enhancer among patients with SCD in Cameroon, the first report on a West African population. The relevance of these findings is of prime importance because the disruption of this enhancer would alter BCL11A expression in erythroid precursors and thus HbF expression, while sparing the induced functional challenges of any alterations on the expression of this transcription factor in non-erythroid lineages, thus providing an attractive approach for new treatment strategies of SCD. PMID:26393293

  14. 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

  15. 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