Structural alterations of faecal and mucosa-associated bacterial communities in irritable bowel syndrome.

PubMed

Durbán, Ana; Abellán, Juan J; Jiménez-Hernández, Nuria; Salgado, Patricia; Ponce, Marta; Ponce, Julio; Garrigues, Vicente; Latorre, Amparo; Moya, Andrés

2012-04-01

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder in western countries. Previous studies on IBS, mostly based on faecal samples, suggest alterations in the intestinal microbiota. However, no consensus has been reached regarding the association between specific bacteria and IBS. We explore the alterations of intestinal bacterial communities in IBS using massive sequencing of amplified 16S rRNA genes. Mucosal biopsies of the ascending and descending colon and faeces from 16 IBS patients and 9 healthy controls were analysed. Strong inter-individual variation was observed in the composition of the bacterial communities in both patients and controls. These communities showed less diversity in IBS cases. There were larger differences in the microbiota composition between biopsies and faeces than between patients and controls. We found a few over-represented and under-represented taxa in IBS cases with respect to controls. The detected alterations varied by site, with no changes being consistent across sample types. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

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

PubMed Central

Rieder, Ronald F.

1970-01-01

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

Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH.

PubMed

Zhang, Yuting; Shen, Hong; He, Xinhua; Thomas, Ben W; Lupwayi, Newton Z; Hao, Xiying; Thomas, Matthew C; Shi, Xiaojun

2017-01-01

Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007-2014) of applying chemical nitrogen, phosphorus and potassium (NPK) fertilizers, composted manure or their combination to acidic (pH 5.8), near-neutral (pH 6.8) or alkaline (pH 8.4) Eutric Regosol soil in a maize-vegetable rotation in southwest China. In alkaline soil, nutrient sources did not affect bacterial Operational Taxonomic Unit (OTU) richness or Shannon diversity index, despite higher available N, P, K, and soil organic carbon in fertilized than in unfertilized soil. In contrast, bacterial OTU richness and Shannon diversity index were significantly lower in acidic and near-neutral soils under NPK than under manure or their combination, which corresponded with changes in soil pH. Permutational multivariate analysis of variance showed that bacterial community structure was significantly affected across these three soils, but the PCoA ordination patterns indicated the effect was less distinct among nutrient sources in alkaline than in acidic and near-neural soils. Distance-based redundancy analysis showed that bacterial community structures were significantly altered by soil pH in acidic and near-neutral soils, but not by any soil chemical properties in alkaline soil. The relative abundance (%) of most bacterial phyla was higher in near-neutral than in acidic or alkaline soils. The most dominant phyla were Proteobacteria (24.6%), Actinobacteria (19.7%), Chloroflexi (15.3%) and Acidobacteria (12.6%); the medium dominant phyla were Bacterioidetes (5.3%), Planctomycetes (4.8%), Gemmatimonadetes (4.5%), Firmicutes (3.4%), Cyanobacteria (2.1%), Nitrospirae (1.8%), and candidate division TM7 (1

Reverse engineering the cooperative machinery of human hemoglobin.

PubMed

Ren, Zhong

2013-01-01

Hemoglobin transports molecular oxygen from the lungs to all human tissues for cellular respiration. Its α2β2 tetrameric assembly undergoes cooperative binding and releasing of oxygen for superior efficiency and responsiveness. Over past decades, hundreds of hemoglobin structures were determined under a wide range of conditions for investigation of molecular mechanism of cooperativity. Based on a joint analysis of hemoglobin structures in the Protein Data Bank (Ren, companion article), here I present a reverse engineering approach to elucidate how two subunits within each dimer reciprocate identical motions that achieves intradimer cooperativity, how ligand-induced structural signals from two subunits are integrated to drive quaternary rotation, and how the structural environment at the oxygen binding sites alter their binding affinity. This mechanical model reveals the intricate design that achieves the cooperative mechanism and has previously been masked by inconsistent structural fluctuations. A number of competing theories on hemoglobin cooperativity and broader protein allostery are reconciled and unified.

Canopy soil bacterial communities altered by severing host tree limbs

PubMed Central

Dangerfield, Cody R.; Nadkarni, Nalini M.

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities. PMID:28894646

Canopy soil bacterial communities altered by severing host tree limbs.

PubMed

Dangerfield, Cody R; Nadkarni, Nalini M; Brazelton, William J

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

The effect of abnormal hemoglobins on the membrane regulation of cell hydration.

PubMed

Clark, M R; Shohet, S B

Several hemoglobinopathies are associated with abnormalities in the permeability of the red cell membrane, in some cases leading to permanent alterations of the intracellular milieu. Homozygous sickle cell disease is the most thoroughly studied example. Deoxygenation of sickle cells causes a transient increase in the permeability to monovalent cations and Ca; prolonged deoxygenation can lead to a permanent accumulation of Ca and loss of total cations and water. Although the mechanisms for the permeability changes are not yet defined, mechanical stress on the membrane, with subsequent damages by excess Ca or membrane-associated hemoglobin have been suggested to play a role. Loss of cell water and increase in mean cell hemoglobin concentration causes massive reduction of cell deformability in the oxygenated state and makes the hemoglobin more likely to undergo sickling because of the strong concentration dependence of the sickling process. Limited evidence suggests the occurrence of permeability defects in other hemoglobinopathies and the thalassemias. The suggested alterations range from a slight increase in K permeability of incubated thalassemia cells to substantial dehydration of cells from patients with homozygous hemoglobin C disease. Oxidative damage to the membrane, involving an abnormal hemoglobin-membrane association, may underly the permeability changes in these cells.

Altered Functionality of Anti-Bacterial Antibodies in Patients with Chronic Hepatitis C Virus Infection

PubMed Central

Lamontagne, Anne; Long, Ronald E.; Comunale, Mary Ann; Hafner, Julie; Rodemich-Betesh, Lucy; Wang, Mengjun; Marrero, Jorge; Di Bisceglie, Adrian M.; Block, Timothy; Mehta, Anand

2013-01-01

Background Using comparative glycoproteomics, we have previously identified a glycoprotein that is altered in both amount and glycosylation as a function of liver cirrhosis. The altered glycoprotein is an agalactosylated (G0) immunoglobulin G molecule (IgG) that recognizes the heterophilic alpha-gal epitope. Since the alpha gal epitope is found on gut enterobacteria, it has been hypothesized that anti-gal antibodies are generated as a result of increased bacterial exposure in patients with liver disease. Methods The N-linked glycosylation of anti-gal IgG molecules from patients with fibrosis and cirrhosis was determined and the effector function of anti-bacterial antibodies from over 100 patients examined. In addition, markers of microbial exposure were determined. Results Surprisingly, the subset of agalactosylated anti-gal antibodies described here, was impaired in their ability to mediate complement mediated lysis and inhibited the complement-mediated destruction of common gut bacteria. In an analysis of serum from more than 100 patients with liver disease, we have shown that those with increased levels of this modified anti-gal antibody had increased levels of markers of bacterial exposure. Conclusions Anti-gal antibodies in patients with liver cirrhosis were reduced in their ability to mediate complement mediated lysis of target cells. As bacterial infection is a major complication in patients with cirrhosis and bacterial products such as LPS are thought to play a major role in the development and progression of liver fibrosis, this finding has many clinical implications in the etiology, prognosis and treatment of liver disease. PMID:23750224

Alteration textures in terrestrial volcanic glass and the associated bacterial community.

PubMed

Cockell, C S; Olsson-Francis, K; Herrera, A; Meunier, A

2009-01-01

Alteration textures were examined in subglacial (hyaloclastite) deposits at Valafell, Southern Iceland. Pitted and 'elongate' alteration features are observed in the glass similar to granular and tubular features reported previously in deep-ocean basaltic glasses, but elongate features generally did not have a length to width ratio greater than five. Elongate features were found in only 7% of surfaces. Crystalline basalt clasts, which are incorporated into the hyaloclastite, did not display elongate structures. Pitted alteration features were poorly defined in crystalline basalt, comprising only 4% of the surface compared to 47% in the case of basaltic glass. Examination of silica-rich glass (obsidian) and rhyolite similarly showed poorly defined pitted textures that comprised less than 15% of the surface and no elongate features were observed. These data highlight the differences in alteration textures between terrestrial basaltic glass and previously studied deep-ocean and subsurface basaltic glass, and the important role of mineralogy in controlling the type and abundance of alteration features. The hyaloclastite contains a diverse and abundant bacterial population, as determined by 16S rDNA analysis, which could be involved in weathering the glass. Despite the presence of phototrophs, we show that they were not involved in the production of most alteration textures in the basaltic glass materials we examined.

Long-Term Nitrogen Amendment Alters the Diversity and Assemblage of Soil Bacterial Communities in Tallgrass Prairie

PubMed Central

Todd, Timothy C.; Blair, John M.; Herman, Michael A.

2013-01-01

Anthropogenic changes are altering the environmental conditions and the biota of ecosystems worldwide. In many temperate grasslands, such as North American tallgrass prairie, these changes include alteration in historically important disturbance regimes (e.g., frequency of fires) and enhanced availability of potentially limiting nutrients, particularly nitrogen. Such anthropogenically-driven changes in the environment are known to elicit substantial changes in plant and consumer communities aboveground, but much less is known about their effects on soil microbial communities. Due to the high diversity of soil microbes and methodological challenges associated with assessing microbial community composition, relatively few studies have addressed specific taxonomic changes underlying microbial community-level responses to different fire regimes or nutrient amendments in tallgrass prairie. We used deep sequencing of the V3 region of the 16S rRNA gene to explore the effects of contrasting fire regimes and nutrient enrichment on soil bacterial communities in a long-term (20 yrs) experiment in native tallgrass prairie in the eastern Central Plains. We focused on responses to nutrient amendments coupled with two extreme fire regimes (annual prescribed spring burning and complete fire exclusion). The dominant bacterial phyla identified were Proteobacteria, Verrucomicrobia, Bacteriodetes, Acidobacteria, Firmicutes, and Actinobacteria and made up 80% of all taxa quantified. Chronic nitrogen enrichment significantly impacted bacterial community diversity and community structure varied according to nitrogen treatment, but not phosphorus enrichment or fire regime. We also found significant responses of individual bacterial groups including Nitrospira and Gammaproteobacteria to long-term nitrogen enrichment. Our results show that soil nitrogen enrichment can significantly alter bacterial community diversity, structure, and individual taxa abundance, which have important

Hemoglobin Rahere, a human hemoglobin variant with amino acid substitution at the 2,3-diphosphoglycerate binding site. Functional consequences of the alteration and effects of bezafibrate on the oxygen bindings.

PubMed

Sugihara, J; Imamura, T; Nagafuchi, S; Bonaventura, J; Bonaventura, C; Cashon, R

1985-09-01

We encountered an abnormal hemoglobin (Rahere), with a threonine residue replacing the beta 82 (EF6) lysine residue at the binding site of 2,3-diphosphoglycerate, which was responsible for overt erythrocytosis in two individuals of a Japanese family. Hemoglobin Rahere shows a lower oxygen affinity on the binding of 2,3-diphosphoglycerate or chloride ions than hemoglobin A. Although a decrease in the positive charge density at the binding sites of 2,3-diphosphoglycerate in hemoglobin Rahere apparently shifts the allosteric equilibrium toward the low affinity state, it greatly diminishes the cofactor effects by anions. The oxygen affinity of the patient's erythrocytes is substantially lowered by the presence of bezafibrate, which combines with sites different from those of 2,3-diphosphoglycerate in either hemoglobin Rahere or hemoglobin A.

Hemoglobin Rahere, a human hemoglobin variant with amino acid substitution at the 2,3-diphosphoglycerate binding site. Functional consequences of the alteration and effects of bezafibrate on the oxygen bindings.

PubMed Central

Sugihara, J; Imamura, T; Nagafuchi, S; Bonaventura, J; Bonaventura, C; Cashon, R

1985-01-01

We encountered an abnormal hemoglobin (Rahere), with a threonine residue replacing the beta 82 (EF6) lysine residue at the binding site of 2,3-diphosphoglycerate, which was responsible for overt erythrocytosis in two individuals of a Japanese family. Hemoglobin Rahere shows a lower oxygen affinity on the binding of 2,3-diphosphoglycerate or chloride ions than hemoglobin A. Although a decrease in the positive charge density at the binding sites of 2,3-diphosphoglycerate in hemoglobin Rahere apparently shifts the allosteric equilibrium toward the low affinity state, it greatly diminishes the cofactor effects by anions. The oxygen affinity of the patient's erythrocytes is substantially lowered by the presence of bezafibrate, which combines with sites different from those of 2,3-diphosphoglycerate in either hemoglobin Rahere or hemoglobin A. PMID:3930571

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.

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

DOEpatents

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

1988-01-01

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

Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.

PubMed

Hao, Yi; Ma, Chuanxin; Zhang, Zetian; Song, Youhong; Cao, Weidong; Guo, Jing; Zhou, Guopeng; Rui, Yukui; Liu, Liming; Xing, Baoshan

2018-01-01

The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C 60 ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C 60 , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.

ABSTRACT Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their totalmore » lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production.

PubMed

Lemmer, Kimberly C; Zhang, Weiping; Langer, Samantha J; Dohnalkova, Alice C; Hu, Dehong; Lemke, Rachelle A; Piotrowski, Jeff S; Orr, Galya; Noguera, Daniel R; Donohue, Timothy J

2017-05-23

Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation in Rhodobacter sphaeroides By screening an R. sphaeroides Tn 5 mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their total lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCE This paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these alterations can be

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE PAGES

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.; ...

2017-05-23

ABSTRACT Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their totalmore » lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these

Human gut bacterial communities are altered by addition of cruciferous vegetables to a controlled fruit- and vegetable-free diet.

PubMed

Li, Fei; Hullar, Meredith A J; Schwarz, Yvonne; Lampe, Johanna W

2009-09-01

In the human gut, commensal bacteria metabolize food components that typically serve as energy sources. These components have the potential to influence gut bacterial community composition. Cruciferous vegetables, such as broccoli and cabbage, contain distinctive compounds that can be utilized by gut bacteria. For example, glucosinolates can be hydrolyzed by certain bacteria, and dietary fibers can be fermented by a range of species. We hypothesized that cruciferous vegetable consumption would alter growth of certain bacteria, thereby altering bacterial community composition. We tested this hypothesis in a randomized, crossover, controlled feeding study. Fecal samples were collected from 17 participants at the end of 2 14-d intake periods: a low-phytochemical, low-fiber basal diet (i.e. refined grains without fruits or vegetables) and a high ("double") cruciferous vegetable diet [basal diet + 14 g cruciferous vegetables/(kg body weightd)]. Fecal bacterial composition was analyzed by the terminal restriction fragment length polymorphism (tRFLP) method using the bacterial 16S ribosomal RNA gene and nucleotide sequencing. Using blocked multi-response permutation procedures analysis, we found that overall bacterial community composition differed between the 2 consumption periods (delta = 0.603; P = 0.011). The bacterial community response to cruciferous vegetables was individual-specific, as revealed by nonmetric multidimensional scaling ordination analysis. Specific tRFLP fragments that characterized each of the diets were identified using indicator species analysis. Putative species corresponding to these fragments were identified through gene sequencing as Eubacterium hallii, Phascolarctobacterium faecium, Burkholderiales spp., Alistipes putredinis, and Eggerthella spp. In conclusion, human gut bacterial community composition was altered by cruciferous vegetable consumption, which could ultimately influence gut metabolism of bioactive food components and host

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 ... Americans. You are more likely to have hemoglobin C disease if someone in your family has had ...

Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

PubMed Central

2010-01-01

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

A Molecular Dynamic Modeling of Hemoglobin-Hemoglobin Interactions

NASA Astrophysics Data System (ADS)

Wu, Tao; Yang, Ye; Sheldon Wang, X.; Cohen, Barry; Ge, Hongya

2010-05-01

In this paper, we present a study of hemoglobin-hemoglobin interaction with model reduction methods. We begin with a simple spring-mass system with given parameters (mass and stiffness). With this known system, we compare the mode superposition method with Singular Value Decomposition (SVD) based Principal Component Analysis (PCA). Through PCA we are able to recover the principal direction of this system, namely the model direction. This model direction will be matched with the eigenvector derived from mode superposition analysis. The same technique will be implemented in a much more complicated hemoglobin-hemoglobin molecule interaction model, in which thousands of atoms in hemoglobin molecules are coupled with tens of thousands of T3 water molecule models. In this model, complex inter-atomic and inter-molecular potentials are replaced by nonlinear springs. We employ the same method to get the most significant modes and their frequencies of this complex dynamical system. More complex physical phenomena can then be further studied by these coarse grained models.

Bioturbating shrimp alter the structure and diversity of bacterial communities in coastal marine sediments.

PubMed

Laverock, Bonnie; Smith, Cindy J; Tait, Karen; Osborn, A Mark; Widdicombe, Steve; Gilbert, Jack A

2010-12-01

bacterial diversity in surface sediments and resulting in distinct bacterial communities even at depth within the burrow. In an area of high macrofaunal abundance, this could lead to alterations in the microbial transformations of important nutrients at the sediment-water interface.

Bacterial chitinolytic communities respond to chitin and pH alteration in soil.

PubMed

Kielak, Anna M; Cretoiu, Mariana Silvia; Semenov, Alexander V; Sørensen, Søren J; van Elsas, Jan Dirk

2013-01-01

Chitin amendment is a promising soil management strategy that may enhance the suppressiveness of soil toward plant pathogens. However, we understand very little of the effects of added chitin, including the putative successions that take place in the degradative process. We performed an experiment in moderately acid soil in which the level of chitin, next to the pH, was altered. Examination of chitinase activities revealed fast responses to the added crude chitin, with peaks of enzymatic activity occurring on day 7. PCR-denaturing gradient gel electrophoresis (DGGE)-based analyses of 16S rRNA and chiA genes showed structural changes of the phylogenetically and functionally based bacterial communities following chitin addition and pH alteration. Pyrosequencing analysis indicated (i) that the diversity of chiA gene types in soil is enormous and (i) that different chiA gene types are selected by the addition of chitin at different prevailing soil pH values. Interestingly, a major role of Gram-negative bacteria versus a minor one of Actinobacteria in the immediate response to the added chitin (based on 16S rRNA gene abundance and chiA gene types) was indicated. The results of this study enhance our understanding of the response of the soil bacterial communities to chitin and are of use for both the understanding of soil suppressiveness and the possible mining of soil for novel enzymes.

A Bactericidal Guanidinomethyl Biaryl That Alters the Dynamics of Bacterial FtsZ Polymerization

PubMed Central

Kaul, Malvika; Parhi, Ajit K.; Zhang, Yongzheng; LaVoie, Edmond J.; Tuske, Steve; Arnold, Eddy; Kerrigan, John E.; Pilch, Daniel S.

2014-01-01

The prevalence of multidrug resistance among clinically significant bacterial pathogens underscores a critical need for the development of new classes of antibiotics with novel mechanisms of action. Here we describe the synthesis and evaluation of a guanidinomethyl biaryl compound {1-((4′-(tert-butyl)-[1,1′-biphenyl]-3-yl)methyl)guanidine} that targets the bacterial cell division protein FtsZ. In vitro studies with various bacterial FtsZ proteins reveal that the compound alters the dynamics of FtsZ self-polymerization via a stimulatory mechanism, while minimally impacting the polymerization of tubulin, the closest mammalian homologue of FtsZ. The FtsZ binding site of the compound is identified through a combination of computational and mutational approaches. The compound exhibits a broad spectrum of bactericidal activity, including activity against the multidrug-resistant pathogens methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), while also exhibiting a minimal potential to induce resistance. Taken together, our results highlight the compound as a promising new FtsZ-targeting bactericidal agent. PMID:23050700

Vizantin inhibits bacterial adhesion without affecting bacterial growth and causes Streptococcus mutans biofilm to detach by altering its internal architecture.

PubMed

Takenaka, Shoji; Oda, Masataka; Domon, Hisanori; Ohsumi, Tatsuya; Suzuki, Yuki; Ohshima, Hayato; Yamamoto, Hirofumi; Terao, Yutaka; Noiri, Yuichiro

2016-11-11

An ideal antibiofilm strategy is to control both in the quality and quantity of biofilm while maintaining the benefits derived from resident microflora. Vizantin, a recently developed immunostimulating compound, has also been found to have antibiofilm property. This study evaluated the influence on biofilm formation of Streptococcus mutans in the presence of sulfated vizantin and biofilm development following bacterial adhesion on a hydroxyapatite disc coated with sulfated vizantin. Supplementation with sulfated vizantin up to 50 μM did not affect either bacterial growth or biofilm formation, whereas 50 μM sulfated vizantin caused the biofilm to readily detach from the surface. Sulfated vizantin at the concentration of 50 μM upregulated the expression of the gtfB and gtfC genes, but downregulated the expression of the gtfD gene, suggesting altered architecture in the biofilm. Biofilm development on the surface coated with sulfated vizantin was inhibited depending on the concentration, suggesting prevention from bacterial adhesion. Among eight genes related to bacterial adherence in S. mutans, expression of gtfB and gtfC was significantly upregulated, whereas the expression of gtfD, GbpA and GbpC was downregulated according to the concentration of vizantin, especially with 50 μM vizantin by 0.8-, 0.4-, and 0.4-fold, respectively. These findings suggest that sulfated vizantin may cause structural degradation as a result of changing gene regulation related to bacterial adhesion and glucan production of S. mutans. Copyright © 2016 Elsevier Inc. All rights reserved.

Impervious Surfaces Alter Soil Bacterial Communities in Urban Areas: A Case Study in Beijing, China

PubMed Central

Hu, Yinhong; Dou, Xiaolin; Li, Juanyong; Li, Feng

2018-01-01

The rapid expansion of urbanization has caused land cover change, especially the increasing area of impervious surfaces. Such alterations have significant effects on the soil ecosystem by impeding the exchange of gasses, water, and materials between soil and the atmosphere. It is unclear whether impervious surfaces have any effects on soil bacterial diversity and community composition. In the present study, we conducted an investigation of bacterial communities across five typical land cover types, including impervious surfaces (concrete), permeable pavement (bricks with round holes), shrub coverage (Buxus megistophylla Levl.), lawns (Festuca elata Keng ex E. Alexeev), and roadside trees (Sophora japonica Linn.) in Beijing, to explore the response of bacteria to impervious surfaces. The soil bacterial communities were addressed by high-throughput sequencing of the bacterial 16S rRNA gene. We found that Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, and Firmicutes were the predominant phyla in urban soils. Soil from impervious surfaces presented a lower bacterial diversity, and differed greatly from other types of land cover. Soil bacterial diversity was predominantly affected by Zn, dissolved organic carbon (DOC), and soil moisture content (SMC). The composition of the bacterial community was similar under shrub coverage, roadside trees, and lawns, but different from beneath impervious surfaces and permeable pavement. Variance partitioning analysis showed that edaphic properties contributed to 12% of the bacterial community variation, heavy metal pollution explained 3.6% of the variation, and interaction between the two explained 33% of the variance. Together, our data indicate that impervious surfaces induced changes in bacterial community composition and decrease of bacterial diversity. Interactions between edaphic properties and heavy metals were here found to change the composition of the bacterial community and diversity across

Structure and stability of human hemoglobin microparticles prepared with a double emulsion technique.

PubMed

Cedrati, N; Bonneaux, F; Labrude, P; Maincent, P

1997-09-01

Hemoglobin solutions can be used as blood substitutes but they present some disadvantages often due to their rapid removal from the bloodstream after injection. A possible way of overcoming this problem is to trap hemoglobin inside particles. This study deals with the preparation, structure and stability of poly(lactic acid) and ethylcellulose microparticles containing human hemoglobin obtained with a double emulsion technique. We investigated the manufacturing process of these particles in order to increase the encapsulation ratio of hemoglobin. For this purpose, some parameters involved in the procedure were optimized, such as hemoglobin concentration and duration of stirring: hemoglobin loading increases with its concentration in the preparation and well-defined stirring time avoids a leakage of hemoglobin. Hemoglobin concentration, surfactant concentration i.e. poly(vinylic alcohol), amounts of polymer and solvent (methylene chloride), duration and speed of stirring. The microparticles were prepared with satisfactory yields (60 to 73%). They were spherical and their mean size was lower than 200 microns. The functional properties of entrapped hemoglobin were studied. The encapsulation did not alter hemoglobin and the oxygen affinity of the hemoglobin remained unmodified (P50 about 13.9 mm Hg in a Bis-Tris buffer pH 7.4 at 37 degrees C). Moreover, only low levels of methemoglobin could be detected (less than 3%). Besides, about 90% of encapsulated hemoglobin could be released from microparticles, with a speed related to the internal structure of the particles. The prepared microparticles were stored during one month at +4 degrees C. No degradation of the particle structure occurred and the functional properties of hemoglobin were preserved. These particles could provide a potential source of oxygen in the field of biotechnologies but any application for a transfusional purpose would first require a drastic reduction in particle size.

Attenuation of Streptococcus suis virulence by the alteration of bacterial surface architecture

PubMed Central

Feng, Youjun; Cao, Min; Shi, Jie; Zhang, Huimin; Hu, Dan; Zhu, Jing; Zhang, Xianyun; Geng, Meiling; Zheng, Feng; Pan, Xiuzhen; Li, Xianfu; Hu, Fuquan; Tang, Jiaqi; Wang, Changjun

2012-01-01

NeuB, a sialic acid synthase catalyzes the last committed step of the de novo biosynthetic pathway of sialic acid, a major element of bacterial surface structure. Here we report a functional NeuB homologue of Streptococcus suis, a zoonotic agent, and systematically address its molecular and immunological role in bacterial virulence. Disruption of neuB led to thinner capsules and more susceptibility to pH, and cps2B inactivation resulted in complete absence of capsular polysaccharides. These two mutants both exhibited increased adhesion and invasion to Hep-2 cells and improved sensibility to phagocytosis. Not only do they retain the capability of inducing the release of host pro-inflammatory cytokines, but also result in the faster secretion of IL-8. Easier cleaning up of the mutant strains in whole blood is consistent with virulence attenuation seen with experimental infections of both mice and SPF-piglets. Therefore we concluded that altered architecture of S. suis surface attenuates its virulence. PMID:23050094

Hemoglobin

DTIC Science & Technology

1993-03-08

affinity, which is less at low levels of hemoglobin saturation, increases markedly as fractional saturation increases. Thus, high affinity for 02 at... diphosphoglycerate (2,3-DPG), and carbon dioxide (Co 2). Since they are linked to 02 binding, they are called oxygen-linked effectors. The oxygen...hemoglobin molecule because of the negative charge of the ions. 2,3- Diphosphoglycerate is a molecule formed during the breakdown of sugar in normal human

Hemoglobin J-Korat in Thais.

PubMed

Blackwell, R Q; Blackwell, B N; Huang, J T; Chien, L C; Samaharn, A; Thephusdin, C; Borvornsin, C

1965-12-17

Hemoglobin J(Korat), a "fast" hemoglobin with an anomaly in its beta chain different from the anomalies previously reported, was the major hemoglobin component in the blood of nine subjects among 1923 Thais from northeastern Thailand. After hemoglobin E, J(Korat) is the second most frequent of the anomalous hemoglobins among Thais.

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

PubMed Central

2011-01-01

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

Intraspecific Polymorphism, Interspecific Divergence, and the Origins of Function-Altering Mutations in Deer Mouse Hemoglobin

PubMed Central

Natarajan, Chandrasekhar; Hoffmann, Federico G.; Lanier, Hayley C.; Wolf, Cole J.; Cheviron, Zachary A.; Spangler, Matthew L.; Weber, Roy E.; Fago, Angela; Storz, Jay F.

2015-01-01

Major challenges for illuminating the genetic basis of phenotypic evolution are to identify causative mutations, to quantify their functional effects, to trace their origins as new or preexisting variants, and to assess the manner in which segregating variation is transduced into species differences. Here, we report an experimental analysis of genetic variation in hemoglobin (Hb) function within and among species of Peromyscus mice that are native to different elevations. A multilocus survey of sequence variation in the duplicated HBA and HBB genes in Peromyscus maniculatus revealed that function-altering amino acid variants are widely shared among geographically disparate populations from different elevations, and numerous amino acid polymorphisms are also shared with closely related species. Variation in Hb-O2 affinity within and among populations of P. maniculatus is attributable to numerous amino acid mutations that have individually small effects. One especially surprising feature of the Hb polymorphism in P. maniculatus is that an appreciable fraction of functional standing variation in the two transcriptionally active HBA paralogs is attributable to recurrent gene conversion from a tandemly linked HBA pseudogene. Moreover, transpecific polymorphism in the duplicated HBA genes is not solely attributable to incomplete lineage sorting or introgressive hybridization; instead, it is mainly attributable to recurrent interparalog gene conversion that has occurred independently in different species. Partly as a result of concerted evolution between tandemly duplicated globin genes, the same amino acid changes that contribute to variation in Hb function within P. maniculatus also contribute to divergence in Hb function among different species of Peromyscus. In the case of function-altering Hb mutations in Peromyscus, there is no qualitative or quantitative distinction between segregating variants within species and fixed differences between species. PMID:25556236

Bioaugmentation of Hydrogenispora ethanolica LX-B affects hydrogen production through altering indigenous bacterial community structure.

PubMed

Yang, Zhiman; Guo, Rongbo; Shi, Xiaoshuang; He, Shuai; Wang, Lin; Dai, Meng; Qiu, Yanling; Dang, Xiaoxiao

2016-07-01

Bioaugmentation can facilitate hydrogen production from complex organic substrates, but it still is unknown how indigenous microbial communities respond to the added bacteria. Here, using a Hydrogenispora ethanolica LX-B (named as LX-B) bioaugmentation experiments, the distribution of metabolites and the responses of indigenous bacterial communities were investigated via batch cultivation (BC) and repeated batch cultivation (RBC). In BC the LX-B/sludge ratio of 0.12 achieved substantial high hydrogen yield, which was over twice that of control. In RBC one-time bioaugmentation and repeated batch bioaugmentation of LX-B resulted in the hydrogen yield that was average 1.2-fold and 0.8-fold higher than that in control, respectively. This improved hydrogen production performance mainly benefited from a shift in composition of the indigenous bacterial community caused by LX-B bioaugmentation. The findings represented an important step in understanding the relationship between bioaugmentation, a shift in bacterial communities, and altered bioreactor performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Copper and the oxidation of hemoglobin: a comparison of horse and human hemoglobins.

PubMed

Rifkind, J M; Lauer, L D; Chiang, S C; Li, N C

1976-11-30

Oxidation studies of hemoglobin by Cu(II) indicate that for horse hemoglobin, up to a Cu(II)/heme molar ratio of 0.5, all of the Cu(II) added is used to rapidly oxidize the heme. On the other hand, most of the Cu(II) added to human hemoglobin at low Cu(II)/heme molar ratios is unable to oxidize the heme. Only at Cu(II)/heme molar ratios greater than 0.5 does the amount of oxidation per added Cu(II) approach that of horse hemoglobin. At the same time, binding studies indicate that human hemoglobin has an additional binding site involving one copper for every two hemes, which has a higher copper affinity than the single horse hemoglobin binding site. The Cu(II) oxidation of human hemoglobin is explained utilizing this additional binding site by a mechanism where a transfer of electrons cannot occur between the heme and the Cu(II) bound to the high affinity human binding site. The electron transfer must involve the Cu(II) bound to the lower affinity human hemoglobin binding site, which is similar to the only horse hemoglobin site. The involvement of beta-2 histidine in the binding of this additional copper is indicated by a comparison of the amino acid sequences of various hemoglobins which possess the additional site, with the amino acid sequences of hemoglobins which do not possess the additional site. Zn(II), Hg(II), and N-ethylmaleimide (NEM) are found to decrease the Cu(II) oxidation of hemoglobin. The sulfhydryl reagents, Hg(II) and NEM, produce a very dramatic decrease in the rate of oxidation, which can only be explained by an effect on the rate for the actual transfer of electrons between the Cu(II) and the Fe(II). The effect of Zn(II) is much smaller and can, for the most part, be explained by the increased oxygen affinity, which affects the ligand dissociation process that must precede the electron transfer process.

Inhaled nitric oxide augments nitric oxide transport on sickle cell hemoglobin without affecting oxygen affinity.

PubMed

Gladwin, M T; Schechter, A N; Shelhamer, J H; Pannell, L K; Conway, D A; Hrinczenko, B W; Nichols, J S; Pease-Fye, M E; Noguchi, C T; Rodgers, G P; Ognibene, F P

1999-10-01

Nitric oxide (NO) inhalation has been reported to increase the oxygen affinity of sickle cell erythrocytes. Also, proposed allosteric mechanisms for hemoglobin, based on S-nitrosation of beta-chain cysteine 93, raise the possibility of altering the pathophysiology of sickle cell disease by inhibiting polymerization or by increasing NO delivery to the tissue. We studied the effects of a 2-hour treatment, using varying concentrations of inhaled NO. Oxygen affinity, as measured by P(50), did not respond to inhaled NO, either in controls or in individuals with sickle cell disease. At baseline, the arterial and venous levels of nitrosylated hemoglobin were not significantly different, but NO inhalation led to a dose-dependent increase in mean nitrosylated hemoglobin, and at the highest dosage, a significant arterial-venous difference emerged. The levels of nitrosylated hemoglobin are too low to affect overall hemoglobin oxygen affinity, but augmented NO transport to the microvasculature seems a promising strategy for improving microvascular perfusion.

Soluble metals in residual oil fly ash alter innate and adaptive pulmonary immune responses to bacterial infection in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Jenny R.; Young, Shih-Houng; Castranova, Vincent

2007-06-15

The soluble metals of the pollutant, residual oil fly ash (ROFA), have been shown to alter pulmonary bacterial clearance in rats. The goal of this study was to determine the potential effects on both the innate and adaptive lung immune responses after bacterial infection in rats pre-exposed to the soluble metals in ROFA. Sprague-Dawley rats were intratracheally dosed (i.t.) at day 0 with ROFA (R-Total) (1.0 mg/100 g body weight), the soluble fraction of ROFA (R-Soluble), the soluble sample subject to a chelator (R-Chelex), or phosphate-buffered saline (Saline). On day 3, rats were administered an i.t. dose of 5 xmore » 10{sup 4} Listeria monocytogenes. On days 6, 8, and 10, bacterial pulmonary clearance was monitored and bronchoalveolar lavage (BAL) was performed on days 3 (pre-infection), 6, 8, and 10. A concentrated first fraction of lavage fluid was retained for analysis of lactate dehydrogenase and albumin to assess lung injury. BAL cell number, phenotype, and production of reactive oxygen (ROS) and nitrogen species (RNS) were assessed, and a variety of cytokines were measured in the BAL fluid. Rats pre-treated with R-Soluble showed elevated lung injury/cytotoxicity and increased cellular influx into the lungs. R-Soluble-treatment also altered ROS, RNS, and cytokine levels, and caused a degree of macrophage and T cell inhibition. These effects of R-Soluble result in increased pulmonary bacterial burden after infection. The results suggest that soluble metals in ROFA increase lung injury and inflammation, and alter both innate and adaptive pulmonary immune responses.« less

Serum free hemoglobin test

MedlinePlus

... the red blood cells. Most of the hemoglobin is found inside the red blood cells, not in the serum. Hemoglobin carries oxygen ... Hemoglobin (Hb) is the main component of red blood cells. It is a ... oxygen. This test is done to diagnose or monitor how severe ...

Energetic Differences at The Subunit Interfaces of Normal Human Hemoglobins Correlate with Their Developmental Profile†

PubMed Central

Manning, Lois R.; Russell, J. Eric; Popowicz, Anthony M.; Manning, Robert S.; Padovan, Julio C.; Manning, James M.

2013-01-01

A previously unrecognized function of normal human hemoglobins occurring during protein assembly is described - - self-regulation of subunit pairings and their durations arising from the variable strengths of their subunit interactions. Although it is known that many mutant human hemoglobins have altered subunit interface strengths, those of the normal embryonic, fetal, and adult human hemoglobins have not been considered to differ significantly. However, in a comprehensive study of both types of subunit interfaces of seven of the eight normal oxy human hemoglobins, we found that the strength, i.e. the free energies of the tetramer-dimer interfaces, contrary to previous reports, differ by 3-orders of magnitude and display an undulating profile similar to the transitions (“switches”) of various globin subunit types over time. The dimer interface strengths are also variable and correlate linearly with their developmental profile; embryonic hemoglobins are the weakest, fetal hemoglobin is of intermediate strength, and adult hemoglobins are the strongest. The pattern also correlates generally with their different O2 affinities and responses to allosteric regulatory molecules. Acetylation of fetal hemoglobin weakens its unusually strong subunit interactions and occurs progressively as its expression diminishes and adult hemoglobin A formations begins; a causal relationship is suggested. The relative contributions of globin gene order and competition among subunits due to differences in their interface strengths were found to be complementary and establish a connection between genetics, thermodynamics, and development. PMID:19583196

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

PubMed

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

2013-01-01

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

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

PubMed Central

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

2014-01-01

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

Diffusion coefficients of oxygen and hemoglobin measured by facilitated oxygen diffusion through hemoglobin solutions.

PubMed

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

1997-03-07

Diffusion coefficients of oxygen (DO2) and hemoglobin (DHb) were obtained from measuring the oxygen flux through thin layers of hemoglobin solutions at 20 degrees C. The liquid layers were supported by a membrane and not soaked in any filter material. Oxygen fluxes were measured from the changes in oxygen partial pressure in the gas phases at both sides of the layer. A mathematical treatment is presented for correct evaluation of the measurements. Measurements were done for bovine and for human hemoglobin. Hemoglobin concentrations (CHb) were between 11 and 42 g/dl, which covers the concentrations in the erythrocyte. Both DO2 and DHb could be fitted to the empirical equation D = D0(1-CHb/C1)10-CHb/C2. The following parameters were obtained: DO = 1.80 x 10(-9) m2/s, C1 = 100 g/dl, C2 = 119 g/dl, for oxygen and D0 = 7.00 x 10(-11) m2/s, C1 = 46 g/dl, C2 = 128 g/dl, for hemoglobin. No difference between the diffusion coefficients of bovine or human hemoglobin was found. The diffusion coefficients of hemoglobin were higher than most values reported in the literature, probably because in this study the mobility of hemoglobin was not hindered by surrounding filter material.

Effects of Iron Supplementation and Activity on Serum Iron Depletion and Hemoglobin Levels in Female Athletes

ERIC Educational Resources Information Center

Cooter, G. Rankin; Mowbray, Kathy W.

1978-01-01

Research revealed that a four-month basketball training program did not significantly alter serum iron, total iron binding capacity, hemoglobin, and percent saturation levels in female basketball athletes. (JD)

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. © 2017 by the Association of Clinical Scientists, Inc.

The Hemoglobin E Thalassemias

PubMed Central

Fucharoen, Suthat; Weatherall, David J.

2012-01-01

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

Asymptomatic Child Heterozygous for Hemoglobin S and Hemoglobin Pôrto Alegre

PubMed Central

Lojo, Liliana; Santiago-Borrero, Pedro; Rivera, Enid; Renta, Jessicca; Cadilla, Carmen L

2013-01-01

Hemoglobin Pôrto Alegre (PA) is a rare hemoglobin resulting from a mutation in β9(A6)Ser→Cys. We describe an asymptomatic Puerto Rican female with combined heterozygosity for Hb PA and Hb S. Since birth, she has maintained normal hemoglobin, bilirubin, LDH levels, and reticulocyte count. Peripheral smear evaluation has revealed normal erythrocyte morphology with no changes suggestive of hemolysis. We conclude that the presence of Hb PA does not increase the risk of red blood cell sickling in patients who carry the Hb S mutation. PMID:21225927

Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

PubMed

Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

2018-01-15

To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

Asymptomatic child heterozygous for hemoglobin S and hemoglobin Pôrto Alegre.

PubMed

Lojo, Liliana; Santiago-Borrero, Pedro; Rivera, Enid; Renta, Jessicca; Cadilla, Carmen L

2011-03-01

Hemoglobin Pôrto Alegre (PA) is a rare hemoglobin resulting from a mutation in β9(A6)Ser → Cys. We describe an asymptomatic Puerto Rican female with combined heterozygosity for Hb PA and Hb S. Since birth, she has maintained normal hemoglobin, bilirubin, LDH levels, and reticulocyte count. Peripheral smear evaluation has revealed normal erythrocyte morphology with no changes suggestive of hemolysis. We conclude that the presence of Hb PA does not increase the risk of red blood cell sickling in patients who carry the Hb S mutation. Copyright © 2010 Wiley-Liss, Inc.

Deoxygenation alters bacterial diversity and community composition in the ocean's largest oxygen minimum zone.

PubMed

Beman, J Michael; Carolan, Molly T

2013-01-01

Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans' largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

Subunit dissociation in fish hemoglobins.

PubMed

Edelstein, S J; McEwen, B; Gibson, Q H

1976-12-10

The tetramer-dimer dissociation equilibria (K 4,2) of several fish hemoglobins have been examined by sedimentation velocity measurements with a scanner-computer system for the ultracentrifuge and by flash photolysis measurements using rapid kinetic methods. Samples studied in detail included hemoglobins from a marine teleost, Brevoortia tyrannus (common name, menhaden); a fresh water teleost, Cyprinus carpio, (common name, carp); and an elasmobranch Prionace glauca (common name, blue shark). For all three species in the CO form at pH 7, in 0.1 M phosphate buffer, sedimentation coefficients of 4.3 S (typical of tetrameric hemoglobin) are observed in the micromolar concentration range. In contrast, mammalian hemoglobins dissociate appreciably to dimers under these conditions. The inability to detect dissociation in three fish hemoglobins at the lowest concentrations examined indicates that K 4,2 must have a value of 10(-8) M or less. In flash photolysis experiments on very dilute solutions in long path length cells, two kinetic components were detected with their proportions varying as expected for an equilibrium between tetramers (the slower component) and dimers (the faster component); values of K 4,2 for the three fish hemoglobins in the range 10(-9) to 10(-8) M were calculated from these data. Thus, the values of K 4,2 for liganded forms of the fish hemoglobins appear to be midway between the value for liganded human hemoglobin (K 4,2 approximately 10(-6) M) and unliganded human hemoglobin (K 4,2 approximately 10(-12) M). This conclusion is supported by measurements on solutions containing guanidine hydrochloride to enhance the degree of dissociation. All three fish hemoglobins are appreciably dissociated at guanidine concentrations of about 0.8 M, which is roughly midway between the guanidine concentrations needed to cause comparable dissociation of liganded human hemoglobin (about 0.4 M) and unliganded human hemoglobin (about 1.6 M). Kinetic measurements on

Hemoglobin C, S-C, and E Diseases

MedlinePlus

... quickly than others, resulting in chronic anemia. Hemoglobin C disease Hemoglobin C disease occurs mostly in blacks. ... a common complication of hemoglobin C disease. Hemoglobin S-C disease Hemoglobin S-C disease occurs in people who ...

Low NO Concentration Dependence of Reductive Nitrosylation Reaction of Hemoglobin*

PubMed Central

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

2012-01-01

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

Gel Filtration Of Dilute Human Embryonic Hemoglobins Reveals Basis For Their Increased Oxygen Binding

PubMed Central

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

2016-01-01

This report establishes a correlation between two known properties of the human embryonic hemoglobins-- their weak subunit assemblies as demonstrated here by gel filtration at very dilute protein concentrations and their high oxygen affinities and reduced cooperativities reported previously by others but without a mechanistic basis. We demonstrate here that their high oxygen affinities are a consequence of their weak assemblies. Weak vs strong hemoglobin tetramers represent a regulatory mechanism to modulate oxygen binding capacity by altering the equilibrium between the various steps in the assembly process that can be described as an inverse allosteric effect. PMID:27965062

Pseudosickling of hemoglobin Setif.

PubMed

Charache, S; Raik, E; Holtzclaw, D; Hathaway, P J; Powell, E; Fleming, P

1987-07-01

Hemoglobin Setif produces pseudosickling of red cells in vitro; the nature of the process and the conditions that "trigger" it are unknown. Studies of red cells, hemolysates, purified hemoglobin solutions, and artificial mixtures of Hb A and Setif suggest that pseudosickling is produced by intracellular crystallization of insoluble hemoglobin. Increased tonicity of the suspending medium accentuates the process, probably by causing a rise in intracellular hemoglobin concentration. If precipitates from A/Setif mixtures are analyzed, they always contain Hb A, suggesting an unusual mechanism for the process. Despite the fact that osmolality in the renal medulla is similar to that which produces pseudosickling in vitro, carriers do not have renal dysfunction of the type found in patients with sickle cell disease.

Increasing the Size of the Microbial Biomass Altered Bacterial Community Structure which Enhances Plant Phosphorus Uptake

PubMed Central

Shen, Pu; Murphy, Daniel Vaughan; George, Suman J.; Lapis-Gaza, Hazel; Xu, Minggang

2016-01-01

Agricultural production can be limited by low phosphorus (P) availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C) and nitrogen (N) availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i) the addition of readily-available organic substrates would increase the size of the microbial biomass thus exhausting the pool of easily-available P and (ii) this would cause the microbial biomass to access P from more recalcitrant pools. In this model it is hypothesised that the size of the microbial population is regulating access to less available P rather than the diversity of organisms contained within this biomass. To test this hypothesis we added mixtures of simple organic compounds that reflect typical root exudates at different C:N ratios to a soil microcosm experiment and assessed changes in soil P pools, microbial biomass and bacterial diversity measures. We report that low C:N ratio (C:N = 12.5:1) artificial root exudates increased the size of the microbial biomass while high C:N ratio (C:N = 50:1) artificial root exudates did not result in a similar increase in microbial biomass. Interestingly, addition of the root exudates did not alter bacterial diversity (measured via univariate diversity indices) but did alter bacterial community structure. Where C, N and P supply was sufficient to support plant growth the increase observed in microbial biomass occurred with a concurrent increase in plant yield. PMID:27893833

I. RENAL THRESHOLDS FOR HEMOGLOBIN IN DOGS

PubMed Central

Lichty, John A.; Havill, William H.; Whipple, George H.

1932-01-01

We use the term "renal threshold for hemoglobin" to indicate the smallest amount of hemoglobin which given intravenously will effect the appearance of recognizable hemoglobin in the urine. The initial renal threshold level for dog hemoglobin is established by the methods employed at an average value of 155 mg. hemoglobin per kilo body weight with maximal values of 210 and minimal of 124. Repeated daily injections of hemoglobin will depress this initial renal threshold level on the average 46 per cent with maximal values of 110 and minimal values of 60 mg. hemoglobin per kilo body weight. This minimal or depression threshold is relatively constant if the injections are continued. Rest periods without injections cause a return of the renal threshold for hemoglobin toward the initial threshold levels—recovery threshold level. Injections of hemoglobin below the initial threshold level but above the minimal or depression threshold will eventually reduce the renal threshold for hemoglobin to its depression threshold level. We believe the depression threshold or minimal renal threshold level due to repeated hemoglobin injections is a little above the glomerular threshold which we assume is the base line threshold for hemoglobin. Our reasons for this belief in the glomerular threshold are given above and in the other papers of this series. PMID:19870016

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

PubMed

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

2008-01-01

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

Solid phase pegylation of hemoglobin.

PubMed

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

2009-01-01

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

Hemoglobin Test: MedlinePlus Lab Test Information

MedlinePlus

... page: https://medlineplus.gov/labtests/hemoglobintest.html Hemoglobin Test To use the sharing features on this page, please enable JavaScript. What is a Hemoglobin Test? A hemoglobin test measures the levels of hemoglobin ...

Gel filtration of dilute human embryonic hemoglobins reveals basis for their increased oxygen binding.

PubMed

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

2017-02-15

This report establishes a correlation between two known properties of the human embryonic hemoglobins-- their weak subunit assemblies as demonstrated here by gel filtration at very dilute protein concentrations and their high oxygen affinities and reduced cooperativities reported previously by others but without a mechanistic basis. We demonstrate here that their high oxygen affinities are a consequence of their weak assemblies. Weak vs strong hemoglobin tetramers represent a regulatory mechanism to modulate oxygen binding capacity by altering the equilibrium between the various steps in the assembly process that can be described as an inverse allosteric effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Deoxygenation alters bacterial diversity and community composition in the ocean’s largest oxygen minimum zone

NASA Astrophysics Data System (ADS)

Beman, J. Michael; Carolan, Molly T.

2013-10-01

Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans’ largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

Multispectroscopic and calorimetric studies on the binding of the food colorant tartrazine with human hemoglobin.

PubMed

Basu, Anirban; Suresh Kumar, Gopinatha

2016-11-15

Interaction of the food colorant tartrazine with human hemoglobin was studied using multispectroscopic and microcalorimetric techniques to gain insights into the binding mechanism and thereby the toxicity aspects. Hemoglobin spectrum showed hypochromic changes in the presence of tartrazine. Quenching of the fluorescence of hemoglobin occurred and the quenching mechanism was through a static mode as revealed from temperature dependent and time-resolved fluorescence studies. According to the FRET theory the distance between β-Trp37 of hemoglobin and bound tartrazine was evaluated to be 3.44nm. Synchronous fluorescence studies showed that tartrazine binding led to alteration of the microenvironment around the tryptophans more in comparison to tyrosines. 3D fluorescence and FTIR data provided evidence for conformational changes in the protein on binding. Circular dichroism studies revealed that the binding led to significant loss in the helicity of hemoglobin. The esterase activity assay further complemented the circular dichroism data. Microcalorimetric study using isothermal titration calorimetry revealed the binding to be exothermic and driven largely by positive entropic contribution. Dissection of the Gibbs energy change proposed the protein-dye complexation to be dominated by non-polyelectrolytic forces. Negative heat capacity change also corroborated the involvement of hydrophobic forces in the binding process. Copyright © 2016 Elsevier B.V. All rights reserved.

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. Copyright © 2015 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

21 CFR 864.5620 - Automated hemoglobin system.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

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). [45 FR 60601, Sept...

The Oxygen Equilibrium of Mammalian Hemoglobin

PubMed Central

Roughton, F. J. W.

1965-01-01

The three chief physicochemical theories of the oxygen-hemoglobin equilibrium in vogue 40 years ago still influence current thought on the problem. Although the Hill theory lost its fundamental basis some 40 years ago, the famous empiric equation to which it gave rise is still much used, as a useful phenomenological expression, only involving two disposable constants. The Haldane theory, of which a difference in aggregation of oxygenated and deoxygenated hemoglobin was a fundamental feature, lay for many years dormant but has recently had an astonishing reawakening through the work on lamprey hemoglobin, which clearly reveals such differences in aggregation. Lamprey hemoglobin might thus be called a "Haldane type" hemoglobin. Adair's four-stage intermediate compound theory still seems applicable in the case of hemoglobins such as those of sheep, whose tetramer molecules do not tend to dissociate into dimers, and which might therefore be called "Adair type" hemoglobins. Horse and human hemoglobins appear to reveal both "Haldane" and "Adair" behaviour. The effects of pH, temperature, and protein concentration on the oxygen-equilibrium of sheep hemoglobin are summarised, and it is shown that, although the equilibrium curves are often isomorphous over their middle range, intensive work at the top and bottom of the curves reveals considerable differences in the relative effects of these factors on the several equilibrium constants of Adair's four intermediate equations. In the last section an account is given of preliminary experimental attempts to interpret the oxygen- and carbon monoxide—equilibrium curves of whole human blood, under physiological conditions in terms of the Adair intermediate compound hypothesis. PMID:5859923

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). [45 FR 60618, Sept. 12, 1980] ...

21 CFR 864.7415 - Abnormal hemoglobin assay.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

Experimental sulfate amendment alters peatland bacterial community structure.

PubMed

Strickman, R J S; Fulthorpe, R R; Coleman Wasik, J K; Engstrom, D R; Mitchell, C P J

2016-10-01

As part of a long-term, peatland-scale sulfate addition experiment, the impact of varying sulfate deposition on bacterial community responses was assessed using 16S tag encoded pyrosequencing. In three separate areas of the peatland, sulfate manipulations included an eight year quadrupling of atmospheric sulfate deposition (experimental), a 3-year recovery to background deposition following 5years of elevated deposition (recovery), and a control area. Peat concentrations of methylmercury (MeHg), a bioaccumulative neurotoxin, were measured, the production of which is attributable to a growing list of microorganisms, including many sulfate-reducing Deltaproteobacteria. The total bacterial and Deltaproteobacterial community structures in the experimental treatment differed significantly from those in the control and recovery treatments that were either indistinguishable or very similar to one another. Notably, the relatively rapid return (within three years) of bacterial community structure in the recovery treatment to a state similar to the control, demonstrates significant resilience of the peatland bacterial community to changes in atmospheric sulfate deposition. Changes in MeHg accumulation between sulfate treatments correlated with changes in the Deltaproteobacterial community, suggesting that sulfate may affect MeHg production through changes in the community structure of this group. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

21 CFR 864.7470 - Glycosylated hemoglobin assay.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Glycosylated hemoglobin assay. 864.7470 Section... Glycosylated hemoglobin assay. (a) Identification. A glycosylated hemoglobin assay is a device used to measure the glycosylated hemoglobins (A1a, A1b, and A1c) in a patient's blood by a column chromatographic...

Bacterial endophytes enhance competition by invasive plants.

PubMed

Rout, Marnie E; Chrzanowski, Thomas H; Westlie, Tara K; DeLuca, Thomas H; Callaway, Ragan M; Holben, William E

2013-09-01

Invasive plants can alter soil microbial communities and profoundly alter ecosystem processes. In the invasive grass Sorghum halepense, these disruptions are consequences of rhizome-associated bacterial endophytes. We describe the effects of N2-fixing bacterial strains from S. halepense (Rout and Chrzanowski, 2009) on plant growth and show that bacteria interact with the plant to alter soil nutrient cycles, enabling persistence of the invasive. • We assessed fluxes in soil nutrients for ∼4 yr across a site invaded by S. halepense. We assayed the N2-fixing bacteria in vitro for phosphate solubilization, iron chelation, and production of the plant-growth hormone indole-3-acetic acid (IAA). We assessed the plant's ability to recruit bacterial partners from substrates and vertically transmit endophytes to seeds and used an antibiotic approach to inhibit bacterial activity in planta and assess microbial contributions to plant growth. • We found persistent alterations to eight biogeochemical cycles (including nitrogen, phosphorus, and iron) in soils invaded by S. halepense. In this context, three bacterial isolates solubilized phosphate, and all produced iron siderophores and IAA in vitro. In growth chamber experiments, bacteria were transmitted vertically, and molecular analysis of bacterial community fingerprints from rhizomes indicated that endophytes are also horizontally recruited. Inhibiting bacterial activity with antibiotics resulted in significant declines in plant growth rate and biomass, with pronounced rhizome reductions. • This work suggests a major role of endophytes on growth and resource allocation of an invasive plant. Indeed, bacterial isolate physiology is correlated with invader effects on biogeochemical cycles of nitrogen, phosphate, and iron.

Nonlinear photoacoustic spectroscopy of hemoglobin.

PubMed

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.

[Hemoglobin oxygen transport capacity in surgical endotoxicosis ].

PubMed

Poryadin, G V; Vlasov, A P; Trofimov, V A; Vlasova, T I; Kamkina, O V; Grigoryev, A G; Vlasov, P A

2016-01-01

In surgical endointoxication hemoglobin oxygen transport capacity of red blood cells (hemoglobin affinity ligands: the ability to bind and release ligands) is reduced and is associated with the severity of endogenous intoxication. Violation of oxygen transport function of hemoglobin at endogenous intoxication is associated with conformational changes of a biomolecule, and its possible influence on reactive oxygen species, which confirmed in experiments in vitro: under the influence of oxygen-iron ascorbate ability of hemoglobin deteriorates. Largely similar structural and functional changes in hemoglobin occur in patients with surgical endotoxicosis.

HEMOGLOBIN AND PLASMA PROTEIN PRODUCTION

PubMed Central

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

1946-01-01

Given healthy dogs, fed abundant iron and protein-free or low protein diets, with sustained anemia and hypoproteinemia due to bleeding, we can study the capacity of these animals to produce simultaneousiy new hemoglobin and plasma protein. The reserve stores of blood protein-producing materials in this way are largely depleted, and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for considerable periods of time. These dogs are very susceptible to infection and to injury by many poisons. Dogs tire of these diets and loss of appetite terminates many experiments. These incomplete experiments are not recorded in the present paper but give supporting evidence in harmony with those tabulated. Under these conditions (double depletion) the dogs use effectively the proteins listed above—egg, lactalbumin, meat, beef plasma, and digests of various food proteins and hemoglobin. Egg protein at times seems to favor slightly the production of plasma protein when compared with the average response (Tables 1 and 2). Various digests and concentrates compare favorably with good food proteins in the production of new hemoglobin and plasma protein in these doubly depleted dogs. Whole beef plasma by mouth is well utilized and the production of new hemoglobin is, if anything, above the average—certainly plasma protein production is not especially favored. "Modified" beef plasma by vein causes fatal anaphylaxis (Table 4). Hemoglobin digests are well used by mouth to form both hemoglobin and plasma protein. Supplementation by amino acids is recorded. Methionine in one experiment may have been responsible for a better protein output and digest utilization (Table 7). PMID:19871543

High affinity hemoglobin and Parkinson's disease.

PubMed

Graham, Jeffrey; Hobson, Douglas; Ponnampalam, Arjuna

2014-12-01

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra (SN) region of the midbrain. Oxidative damage in this region has been shown to play an important role in the pathogenesis of this disease. Human neurons have been discovered to contain hemoglobin, with an increased concentration seen in the neurons of the SN. High affinity hemoglobin is a clinical entity resulting from mutations that create a functional increase in the binding of hemoglobin to oxygen and an inability to efficiently unload it to tissues. This can result in a number of metabolic compensatory changes, including an elevation in circulating hemoglobin and an increase in the molecule 2,3-diphosphoglycerate (2,3-DPG). Population based studies have revealed that patients with PD have elevated hemoglobin as well as 2,3-DPG levels. Based on these observations, we hypothesize that the oxidative damage seen in PD is related to an underlying high affinity hemoglobin subtype. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nonlinear photoacoustic spectroscopy of hemoglobin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.

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,more » 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.« less

Nonlinear photoacoustic spectroscopy of hemoglobin

PubMed Central

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

2015-01-01

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. PMID:26045627

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

Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu

Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, andmore » chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.« less

Preparation of Hemoglobin-Containing Microcapsules.

DTIC Science & Technology

1982-04-01

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

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

Oxygen Measurements in Liposome Encapsulated Hemoglobin

NASA Astrophysics Data System (ADS)

Phiri, Joshua Benjamin

Liposome encapsulated hemoglobins (LEH's) are of current interest as blood substitutes. An analytical methodology for rapid non-invasive measurements of oxygen in artificial oxygen carriers is examined. High resolution optical absorption spectra are calculated by means of a one dimensional diffusion approximation. The encapsulated hemoglobin is prepared from fresh defibrinated bovine blood. Liposomes are prepared from hydrogenated soy phosphatidylcholine (HSPC), cholesterol and dicetylphosphate using a bath sonication method. An integrating sphere spectrophotometer is employed for diffuse optics measurements. Data is collected using an automated data acquisition system employing lock-in -amplifiers. The concentrations of hemoglobin derivatives are evaluated from the corresponding extinction coefficients using a numerical technique of singular value decomposition, and verification of the results is done using Monte Carlo simulations. In situ measurements are required for the determination of hemoglobin derivatives because most encapsulation methods invariably lead to the formation of methemoglobin, a nonfunctional form of hemoglobin. The methods employed in this work lead to high resolution absorption spectra of oxyhemoglobin and other derivatives in red blood cells and liposome encapsulated hemoglobin (LEH). The analysis using singular value decomposition method offers a quantitative means of calculating the fractions of oxyhemoglobin and other hemoglobin derivatives in LEH samples. The analytical methods developed in this work will become even more useful when production of LEH as a blood substitute is scaled up to large volumes.

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

PubMed

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

2017-06-01

IR spectra of heme and different O 2 -content hemoglobin were studied by the quantum computation method at the molecule level. IR spectra of heme and different O 2 -content hemoglobin were quantificationally characterized from 0 to 100 THz. The IR spectra of oxy-heme and de-oxy-heme are obviously different at the frequency regions of 9.08-9.48, 38.38-39.78, 50.46-50.82, and 89.04-91.00 THz. At 24.72 THz, there exists the absorption peak for oxy-heme, whereas there is not the absorption peak for de-oxy-heme. Whether the heme contains Fe-O-O bond or not has the great influence on its IR spectra and vibration intensities of functional groups in the mid-infrared area. The IR adsorption peak shape changes hardly for different O 2 -content hemoglobin. However, there exist three frequency regions corresponding to the large change of IR adsorption intensities for containing-O 2 hemoglobin in comparison with de-oxy-hemoglobin, which are 11.08-15.93, 44.70-50.22, and 88.00-96.68 THz regions, respectively. The most differential values with IR intensity of different O 2 -content hemoglobin all exceed 1.0 × 10 4  L mol -1  cm -1 . With the increase of oxygen content, the absorption peak appears in the high-frequency region for the containing-O 2 hemoglobin in comparison with de-oxy-hemoglobin. The more the O 2 -content is, the greater the absorption peak is at the high-frequency region. The IR spectra of different O 2 -content hemoglobin are so obviously different in the mid-infrared region that it is very easy to distinguish the hemoglobin variant by means of IR spectra detector. IR spectra of hemoglobin from quantum computation can provide scientific basis and specific identification of hemoglobin variant resulting from different O 2 contents in medical diagnosis.

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

PubMed Central

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. PMID:26380265

Preferential silent survival of intracellular bacteria in hemoglobin-primed macrophages.

PubMed

Subramanian, Karthik; Winarsih, Imelda; Keerthani, Chandrakumaran; Ho, Bow; Ding, Jeak Ling

2014-01-01

Hemolysis releases hemoglobin (Hb), a prooxidant, into circulation. While the heme iron is a nutrient for the invading pathogens, it releases ROS, which is both microbicidal and cytotoxic, making it a double-edged sword. Previously, we found a two-pass detoxification mechanism involving the endocytosis of Hb into monocytes in collaboration with vascular endothelial cells to overcome oxidative damage. This prompted us to examine the effect of Hb priming on host cell viability and intracellular bacterial clearance during a hemolytic infection. Here, we demonstrate that Hb-primed macrophages harbor a higher intracellular bacterial load but with suppressed apoptosis. p-ERK and p-p38 MAPK were significantly downregulated, with concomitant impairment of Bax and downstream caspases. The Hb-primed cells harboring intracellular bacteria upregulated anti-inflammatory IL-10 and downregulated proinflammatory TNF-α, which further enhanced the infectivity of the neighboring cells. Our findings suggest that opportunistic intracellular pathogens exploit the Hb-scavenging machinery of the host to silently persist within the circulating phagocytes by suppressing apoptosis while escaping immune surveillance. © 2014 S. Karger AG, Basel.

High-grain diets altered rumen fermentation and epithelial bacterial community and resulted in rumen epithelial injuries of goats.

PubMed

Zhang, Ruiyang; Ye, Huimin; Liu, Junhua; Mao, Shengyong

2017-09-01

This study evaluated the effects of high-grain diets on the rumen fermentation, epithelial bacterial community, morphology of rumen epithelium, and local inflammation of goats during high-grain feeding. Twelve 8-month-old goats were randomly assigned to two different diets, a hay diet or a high-grain diet (65% grain, HG). At the end of 7 weeks of treatment, samples of rumen content and rumen epithelium were collected. Rumen pH was lower (P < 0.05), but the levels of volatile fatty acids and lipopolysaccharides were higher (P < 0.05) in the HG group than those in the hay group. The principal coordinate analysis indicated that HG diets altered the rumen epithelial bacterial community, with an increase in the proportion of genus Prevotella and a decrease in the relative abundance of the genera Shuttleworthia and Fibrobacteres. PICRUSt analysis suggested that the HG-fed group had a higher (P < 0.05) relative abundance of gene families related to energy metabolism; folding, sorting, and degradation; translation; metabolic diseases; and immune system. Furthermore, HG feeding resulted in the rumen epithelial injury and upregulated (P < 0.05) the gene expressions of IL-1β and IL-6, and the upregulations were closely related to the rumen pH, LPS level, and rumen epithelial bacteria abundance. In conclusion, our results indicated that the alterations in the rumen environment and epithelial bacterial community which were induced by HG feeding may result in the damage and local inflammation in the rumen epithelium, warranting further study of rumen microbial-host interactions in the HG feeding model.

A review of variant hemoglobins interfering with hemoglobin A1c measurement.

PubMed

Little, Randie R; Roberts, William L

2009-05-01

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

Purification and spectroscopic characterization of Ctb, a group III truncated hemoglobin implicated in oxygen metabolism in the food-borne pathogen Campylobacter jejuni†

PubMed Central

Wainwright, Laura M.; Wang, Yinghua; Park, Simon F.; Yeh, Syun-Ru; Poole, Robert K.

2008-01-01

Campylobacter jejuni is a foodborne bacterial pathogen that possesses two distinct hemoglobins, encoded by the ctb and cgb genes. The former codes for a truncated hemoglobin (Ctb) in group III, an assemblage of uncharacterized globins in diverse clinically- and technologically-significant bacteria. Here, we show that Ctb purifies as a monomeric, predominantly oxygenated species. Optical spectra of ferric, ferrous, O2- and CO-bound forms resemble those of other hemoglobins. However, resonance Raman analysis shows Ctb to have an atypical νFe-CO stretching mode at 514 cm-1, compared to the other truncated hemoglobins that have been characterized so far. This implies unique roles in ligand stabilisation for TyrB10, HisE7 and TrpG8, residues highly conserved within group III truncated hemoglobins. Since C. jejuni is a microaerophile, and a ctb mutant exhibits O2-dependent growth defects, one of the hypothesised roles of Ctb is in the detoxification, sequestration or transfer of O2 The midpoint potential (Eh) of Ctb was found to be −33 mV, but no evidence was obtained in vitro to support the hypothesis that Ctb is reducible by NADH or NADPH. This truncated hemoglobin may function in the facilitation of O2 transfer to one of the terminal oxidases of C. jejuni or instead facilitate O2 transfer to Cgb for NO detoxification. PMID:16681372

Hemoglobin (image)

MedlinePlus

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

21 CFR 864.7500 - Whole blood hemoglobin assays.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

21 CFR 864.7500 - Whole blood hemoglobin assays.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

21 CFR 864.7500 - Whole blood hemoglobin assays.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

21 CFR 864.7500 - Whole blood hemoglobin assays.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 864.7500 - Whole blood hemoglobin assays.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

Bacterial meningitis.

PubMed

Heckenberg, Sebastiaan G B; Brouwer, Matthijs C; van de Beek, Diederik

2014-01-01

Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained, preceding any imaging studies. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, and an altered level of consciousness but signs may be scarce in children, in the elderly, and in meningococcal disease. Host genetic factors are major determinants of susceptibility to meningococcal and pneumococcal disease. Dexamethasone therapy has been implemented as adjunctive treatment of adults with pneumococcal meningitis. Adequate and prompt treatment of bacterial meningitis is critical to outcome. In this chapter we review the epidemiology, pathophysiology, and management of bacterial meningitis. © 2014 Elsevier B.V. All rights reserved.

Pharmaceuticals suppress algal growth and microbial respiration and alter bacterial communities in stream biofilms.

PubMed

Rosi-Marshall, Emma J; Kincaid, Dustin W; Bechtold, Heather A; Royer, Todd V; Rojas, Miguel; Kelly, John J

2013-04-01

Pharmaceutical and personal care products are ubiquitous in surface waters but their effects on aquatic biofilms and associated ecosystem properties are not well understood. We measured in situ responses of stream biofilms to six common pharmaceutical compounds (caffeine, cimetidine, ciprofloxacin, diphenhydramine, metformin, ranitidine, and a mixture of each) by deploying pharmaceutical-diffusing substrates in streams in Indiana, Maryland, and New York. Results were consistent across seasons and geographic locations. On average, algal biomass was suppressed by 22%, 4%, 22%, and 18% relative to controls by caffeine, ciprofloxacin, diphenhydramine, and the mixed treatment, respectively. Biofilm respiration was significantly suppressed by caffeine (53%), cimetidine (51%), ciprofloxacin (91%), diphenhydramine (63%), and the mixed treatment (40%). In autumn in New York, photosynthesis was also significantly suppressed by diphenhydramine (99%) and the mixed treatment (88%). Pyrosequencing of 16S rRNA genes was used to examine the effects of caffeine and diphenhydramine on biofilm bacterial community composition at the three sites. Relative to the controls, diphenhydramine exposure significantly altered bacterial community composition and resulted in significant relative increases in Pseudomonas sp. and decreases in Flavobacterium sp. in all three streams. These ubiquitous pharmaceuticals, alone or in combination, influenced stream biofilms, which could have consequences for higher trophic levels and important ecosystem processes.

21 CFR 864.7400 - Hemoglobin A2 assay.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 864.7400 - Hemoglobin A2 assay.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

High-grain feeding alters caecal bacterial microbiota composition and fermentation and results in caecal mucosal injury in goats.

PubMed

Liu, Junhua; Xu, Tingting; Zhu, Weiyun; Mao, Shengyong

2014-08-14

The effect of high-grain (HG) feeding on caecal bacterial microbiota composition and fermentation and mucosa health is largely unknown. In the present study, ten male goats were randomly assigned to either a group fed a hay diet (0 % grain; n 5) or a group fed a HG diet (65 % grain; n 5) to characterise the changes in the composition of the bacterial community and mucosal morphology in the caecum. After 7 weeks of feeding, the HG diet decreased the caecal pH (P< 0·001) and increased (P< 0·001 to P< 0·004) the caecal digesta concentrations of total volatile fatty acids and lipopolysaccharide (LPS). Pyrosequencing of the 16S ribosomal RNA gene revealed that HG feeding increased (P= 0·001 to P= 0·009) the abundance of predominant genera Turicibacter and Clostridium in the caecal lumen and in the caecal mucosa and decreased (P< 0·001 to P< 0·009) the proportion of Bacteroides in the lumen and Mucispirillum in the mucosa compared with the hay diet. Furthermore, the HG diet-fed goats exhibited intense epithelial damage and up-regulation (P< 0·001 to P< 0·025) of the relative mRNA expression of IL-1β, IL-6, IL-12 and interferon-γ (IFN-γ) in the caecal mucosa. The correlation analysis revealed that alterations in caecal pH, LPS concentration and mucosa-associated microbiota abundance during HG feeding might partly contribute to local inflammation. Collectively, these results provide insight into the adaptive response of caecal bacterial populations to HG feeding in goats and reveal that the fermentable substrates that flow into the caecum may cause dramatic alterations in microbial compositions and play a significant role in caecal dysfunction.

Non-invasive vibrational SFG spectroscopy reveals that bacterial adhesion can alter the conformation of grafted "brush" chains on SAM.

PubMed

Bulard, Emilie; Guo, Ziang; Zheng, Wanquan; Dubost, Henri; Fontaine-Aupart, Marie-Pierre; Bellon-Fontaine, Marie-Noëlle; Herry, Jean-Marie; Briandet, Romain; Bourguignon, Bernard

2011-04-19

Understanding bacterial adhesion on a surface is a crucial step to design new materials with improved properties or to control biofilm formation and eradication. Sum Frequency Generation (SFG) vibrational spectroscopy has been employed to study in situ the conformational response of a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film to the adhesion of hydrophilic and hydrophobic ovococcoid model bacteria. The present work highlights vibrational SFG spectroscopy as a powerful and unique non-invasive biophysical technique to probe and control bacteria interaction with ordered surfaces. Indeed, the SFG vibrational spectral changes reveal different ODT SAM conformations in air and upon exposure to aqueous solution or bacterial adhesion. Furthermore, this effect depends on the bacterial cell surface properties. The SFG spectral modeling demonstrates that hydrophobic bacteria flatten the ODT SAM alkyl chain terminal part, whereas the hydrophilic ones raise this ODT SAM terminal part. Microorganism-induced alteration of grafted chains can thus affect the desired interfacial functionality, a result that should be considered for the design of new reactive materials. © 2011 American Chemical Society

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.

21 CFR 864.7455 - Fetal hemoglobin assay.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 864.7455 - Fetal hemoglobin assay.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

Convergent evolution of hemoglobin switching in jawed and jawless vertebrates.

PubMed

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

2016-02-01

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

The hemoglobin system of the primitive fish, Amia calva: isolation and functional characterization of the individual hemoglobin components.

PubMed

Weber, R E; Sullivan, B; Bonaventura, J; Bonaventura, C

1976-05-20

Blood from the primitive holostean fish, the bowfin, Amia calva, contains 2 mo of ATP per mol of hemoglobin. The hemolysates contain at least five tetrameric hemoglobin components which differ in their oxygen affinities and their response to cofactors such as ATP. The binding of oxygen by each chromatographically isolated component, including a cathodal component, is influenced by pH and organic phosphates; there is no significant differentiation of function or structure as seen in trout and certain other fish hemolysates. Kinetic analyses of ligand binding indicate that the Bohr and Root effects of Amia calva hemoglobins are best explained by changes in both the "on" and "off" constants. At low pH, the increase in the "off" constant is smaller than for most other Root hemoglobins. The hemoglobin system of Amina calva is functionally undifferentiated and may be representative of the ancestral condition in teleosts.

Bacterial pathogen manipulation of host membrane trafficking.

PubMed

Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

2014-01-01

Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell.

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 ...

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

NASA Astrophysics Data System (ADS)

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

2011-02-01

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

Validation of a predictive model for identifying febrile young infants with altered urinalysis at low risk of invasive bacterial infection.

PubMed

Velasco, R; Gómez, B; Hernández-Bou, S; Olaciregui, I; de la Torre, M; González, A; Rivas, A; Durán, I; Rubio, A

2017-02-01

In 2015, a predictive model for invasive bacterial infection (IBI) in febrile young infants with altered urine dipstick was published. The aim of this study was to externally validate a previously published set of low risk criteria for invasive bacterial infection in febrile young infants with altered urine dipstick. Retrospective multicenter study including nine Spanish hospitals. Febrile infants ≤90 days old with altered urinalysis (presence of leukocyturia and/or nitrituria) were included. According to our predictive model, an infant is classified as low-risk for IBI when meeting all the following: appearing well at arrival to the emergency department, being >21 days old, having a procalcitonin value <0.5 ng/mL and a C-reactive protein value <20 mg/L. IBI was considered as secondary to urinary tract infection if the same pathogen was isolated in the urine culture and in the blood or cerebrospinal fluid culture. A total of 391 patients with altered urine dipstick were included. Thirty (7.7 %) of them developed an IBI, with 26 (86.7 %) of them secondary to UTI. Prevalence of IBI was 2/104 (1.9 %; CI 95% 0.5-6.7) among low-risk patients vs 28/287 (9.7 %; CI 95% 6.8-13.7) among high-risk patients (p < 0.05). Sensitivity of the model was 93.3 % (CI 95% 78.7-98.2) and negative predictive value was 98.1 % (93.3-99.4). Although our predictive model was shown to be less accurate in the validation cohort, it still showed a good discriminatory ability to detect IBI. Larger prospective external validation studies, taking into account fever duration as well as the role of ED observation, should be undertaken before its implementation into clinical practice.

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 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin...

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 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin...

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 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin...

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 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin...

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 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7440 Electrophoretic hemoglobin analysis system. (a) Identification. An electrophoretic hemoglobin...

Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.

PubMed

Poosakkannu, Anbu; Nissinen, Riitta; Kytöviita, Minna-Maarit

2017-11-01

The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculation did not affect microbial species richness or diversity indices in leaves or roots, but the AM fungus inoculation significantly affected bacterial community composition in leaves. A total of three OTUs in leaves belonging to the phylum Firmicutes positively responded to the presence of the AM fungus in roots. Another six OTUs belonging to the Proteobacteria (Alpha, Beta, and Gamma) and Bacteroidetes were significantly more abundant in NM plants when compared to AM fungus-inoculated plants. Further, there was a significant correlation between plant dry weight and leaf microbial community compositional shift. Also, there was a significant correlation between leaf bacterial community compositional shift and foliar nitrogen content changes due to AM fungus inoculation. The results suggest that AM fungus colonization in roots has a profound effect on plant physiology that is reflected in leaf bacterial community composition.

Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition.

PubMed

Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

2009-09-01

We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A+PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems.

Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition†

PubMed Central

Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

2010-01-01

We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A + PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems. PMID:19707620

21 CFR 866.5470 - Hemoglobin immunological test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5470 Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hemoglobin immunological test system. 866.5470...

21 CFR 866.5470 - Hemoglobin immunological test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... blood cells), and leukemia (cancer of the blood-forming organs). (b) Classification. Class II...

21 CFR 866.5470 - Hemoglobin immunological test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... blood cells), and leukemia (cancer of the blood-forming organs). (b) Classification. Class II...

21 CFR 866.5470 - Hemoglobin immunological test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... blood cells), and leukemia (cancer of the blood-forming organs). (b) Classification. Class II...

21 CFR 866.5470 - Hemoglobin immunological test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... hemoglobin (the oxygen-carrying pigment in red blood cells) in blood, urine, plasma, or other body fluids... Hemoglobin immunological test system. (a) Indentification. A hemoglobin immunological test system is a device... blood cells), and leukemia (cancer of the blood-forming organs). (b) Classification. Class II...

Effect of hemoglobin polymerization on oxygen transport in hemoglobin solutions.

PubMed

Budhiraja, Vikas; Hellums, J David

2002-09-01

The effect of hemoglobin (Hb) polymerization on facilitated transport of oxygen in a bovine hemoglobin-based oxygen carrier was studied using a diffusion cell. In high oxygen tension gradient experiments (HOTG) at 37 degrees C the diffusion of dissolved oxygen in polymerized Hb samples was similar to that in unpolymerized Hb solutions during oxygen uptake. However, in the oxygen release experiments, the transport by diffusion of dissolved oxygen was augmented by diffusion of oxyhemoglobin over a range of oxygen saturations. The augmentation was up to 30% in the case of polymerized Hb and up to 100% in the case of unpolymerized Hb solution. In experiments performed at constant, low oxygen tension gradients in the range of physiological significance, the augmentation effect was less than that in the HOTG experiments. Oxygen transport in polymerized Hb samples was approximately the same as that in unpolymerized samples over a wide range of oxygen tensions. However, at oxygen tensions lower than 30 mm Hg, there were more significant augmentation effects in unpolymerized bovine Hb samples than in polymerized Hb. The results presented here are the first accurate, quantitative measurements of effective diffusion coefficients for oxygen transport in hemoglobin-based oxygen carriers of the type being evaluated to replace red cells in transfusions. In all cases the oxygen carrier was found to have higher effective oxygen diffusion coefficients than blood.

Blood Test: Hemoglobin A1C

MedlinePlus

... levels can be high if diabetes is not well controlled. Why Are Hemoglobin A1c Tests Done? When a child has diabetes, hemoglobin A1c levels are followed to see how well medicines are working. If a child with diabetes ...

Hemoglobin level in older persons and incident Alzheimer disease

PubMed Central

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

2011-01-01

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

Nanobiotechnology for hemoglobin-based blood substitutes.

PubMed

Chang, T M S

2009-04-01

Nanobiotechnology is the assembling of biological molecules into nanodimension complexes. This has been used for the preparation of polyhemoglobin formed by the assembling of hemoglobin molecules into a soluble nanodimension complex. New generations of this approach include the nanobiotechnological assembly of hemoglobin, catalase, and superoxide dismutase into a soluble nanodimension complex. This acts as an oxygen carrier and an antioxidant for those conditions with potential for ischemiareperfusion injuries. Another recent novel approach is the assembling of hemoglobin and fibrinogen into a soluble nanodimension polyhemoglobin-fibrinogen complex that acts as an oxygen carrier with platelet-like activity. This is potentially useful in cases of extensive blood loss requiring massive replacement using blood substitutes, resulting in the need for the replacement of platelets and clotting factors. A further step is the preparation of nanodimension artificial red blood cells that contain hemoglobin and all the enzymes present in red blood cells.

A Mouse β-Globin Mutant That Is an Exact Model of Hemoglobin Rainier in Man

PubMed Central

Peters, J.; Andrews, S. J.; Loutit, J. F.; Clegg, J. B.

1985-01-01

A mutation induced by ethylnitrosourea in a spermatogonial stem cell of a 101/H mouse has resulted in a structurally altered β-diffuse major globin in one of his offspring. The mutant hemoglobin is associated with polycythemia, rubor, increased oxygen affinity and decreased hem-hem interaction. The mutant haplotype has been designated Hbb d4, polycythemia. Amino acid analysis of the mutant globin has shown that a single substitution β145 Tyr → Cys has occurred, and it is proposed that ethylnitrosourea induced an A → G transition in the tyrosine codon (TAC → TGC). This murine polycythemia is homologous with hemoglobin Rainier in man, in which the amino acid substitution is also β145 Tyr → Cys and which is associated with similar physiological consequences. PMID:3839762

Electron Paramagnetic Resonance Studies of Spin-Labeled Hemoglobins and Their Implications to the Nature of Cooperative Oxygen Binding to Hemoglobin*

PubMed Central

Ho, Chien; Baldassare, Joseph J.; Charache, Samuel

1970-01-01

The spin label technique has been used to study human hemoglobins A, F, Zürich, and Chesapeake as a function of carbon monoxide saturation. The experimental results suggest that the changes in the electron paramagnetic resonance spectra of hemoglobin labeled with N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide depend on the state of ligation of more than one heme group. For those hemoglobins with full or large cooperative ligand binding (such as A, F, and Zürich), there is a lack of isosbestic points in the spectra as a function of CO saturation. However, for those hemoglobins with little or no cooperative ligand binding (such as Chesapeake and methemoglobins), there is a sharp set of isosbestic points. These findings confirm and extend the early work of McConnell and co-workers. The absence of a set of isosbestic points in those hemoglobins with full cooperative ligand binding is consistent with the sequential model of Koshland, Némethy, and Filmer for cooperative oxygen binding to hemoglobin. The present results, with hemoglobin variants having known amino acid substitutions, also focus on the importance of the interactions among the amino acid residues located at α1-β2 or α2-β1 subunit contacts for the functioning of hemoglobin as an oxygen carrier. In addition, the resonance spectra of the spin label are very sensitive to small structural variations around the heme groups in the β- or γ-chains where the labels are attached. The results of the spin label experiment are discussed in relation to recent findings on the mechanism of oxygenation of hemoglobin from the nuclear magnetic resonance studies of this laboratory and the x-ray crystallographic analysis of Perutz and co-workers. PMID:4316679

Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

PubMed Central

Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

2014-01-01

Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

Spectrophotometric Properties of Hemoglobin: Classroom Applications.

ERIC Educational Resources Information Center

Frary, Roger

1997-01-01

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

Interaction of Human Hemoglobin with Methotrexate

NASA Astrophysics Data System (ADS)

Zaharia, M.; Gradinaru, R.

2015-05-01

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

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

Code of Federal Regulations, 2011 CFR

2011-04-01

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

The use of hemoglobin solutions in kidney perfusions.

PubMed

Daniels, F H; McCabe, R E; Leonard, E F

1984-01-01

Solutions of hemoglobin have often been considered for both hypothermic and normothermic perfusion of isolated kidneys. This paper considers basic issues, preparative techniques, and the viscosity of hemoglobin solutions, as well as the demands made by the kidney on a perfusate. The natural system of oxygen transport in higher animals is complex, and its perturbation to produce convenient hemoglobin-based renal perfusates produces numerous problems. The desirable effect of 2,3-diphosphoglycerate is not easily maintained in a perfusate, but its inclusion can be avoided by appropriate choice of species donating hemoglobin. Hemoglobin tetramer in free solution may dissociate and be lost by glomerular filtration. Ferric hemoglobin, the dominant form at redox equilibrium, is useless for oxygen transport; the ferrous form is maintained in the erythrocyte by reducing metabolites and, under normothermic conditions, the ferrous to ferric conversion is slow but significant. Methods for lysis of erythrocytes and removal of their stroma are discussed; reduction of ferric hemoglobin by chemical agents and electrolysis are considered in detail; and means for adjusting concentration and solute background are presented. The need for carbonic anhydrase in hemoglobin solutions used as perfusates is shown and methods for its provision are discussed. A review of viscometric data for hemoglobin solutions is provided to which original data are added. Hemoglobin solutions show a temperature-independent intrinsic viscosity, according to Einstein's theory for a molecule of 23 A radius. The O2 and CO2 transport requirements of renal perfusates are analyzed comprehensively. The normothermic kidney has an unusual respiration pattern, requiring an amount of oxygen that is not fixed but, rather, proportional to the total blood flow rate. In canines the average arterio-venous O2 content difference found by many investigators is 2.14 vol%; the corresponding CO2 value is 2.47 vol%; and the

Soil bacterial community composition altered by increased nutrient availability in Arctic tundra soils

PubMed Central

Koyama, Akihiro; Wallenstein, Matthew D.; Simpson, Rodney T.; Moore, John C.

2014-01-01

The pool of soil organic carbon (SOC) in the Arctic is disproportionally large compared to those in other biomes. This large quantity of SOC accumulated over millennia due to slow rates of decomposition relative to net primary productivity. Decomposition is constrained by low temperatures and nutrient concentrations, which limit soil microbial activity. We investigated how nutrients limit bacterial and fungal biomass and community composition in organic and mineral soils within moist acidic tussock tundra ecosystems. We sampled two experimental arrays of moist acidic tussock tundra that included fertilized and non-fertilized control plots. One array included plots that had been fertilized annually since 1989 and the other since 2006. Fertilization significantly altered overall bacterial community composition and reduced evenness, to a greater degree in organic than mineral soils, and in the 1989 compared to the 2006 site. The relative abundance of copiotrophic α-Proteobacteria and β-Proteobacteria was higher in fertilized than control soils, and oligotrophic Acidobacteria were less abundant in fertilized than control soils at the 1989 site. Fungal community composition was less sensitive to increased nutrient availability, and fungal responses to fertilization were not consistent between soil horizons and sites. We detected two ectomycorrhizal genera, Russula and Cortinarius spp., associated with shrubs. Their relative abundance was not affected by fertilization despite increased dominance of their host plants in the fertilized plots. Our results indicate that fertilization, which has been commonly used to simulate warming in Arctic tundra, has limited applicability for investigating fungal dynamics under warming. PMID:25324836

Direct Measurement of Equilibrium Constants for High-Affinity Hemoglobins

PubMed Central

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

2003-01-01

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 (KD ≪ 1 μM) 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 ∼100 μM−1 respectively, indicate that they are not capable of facilitating oxygen transport. PMID:12770899

Crystal structure analysis of Great Cormorant (Phalacrocorax carbo) Hemoglobin.

PubMed

Ganapathy, Jagadeesan; Palayam, Malathy; Pennathur, Gautam; Sanmargam, Aravindhan; Krishnasamy, Gunasekaran

2018-06-20

Rfree to 23% and 27% respectively. The structure has been deposited in Protein Data Bank with PDB code: 3WR1. The Great cormorant hemoglobin consists of 287 amino acids, two heme and one water molecule located in alpha heme site. The structure has been crystallized in a tetragonal system having half a molecule in the assymetric unit. In order to characterize the tertiary and quaternary structural differences, the structure of cormorant hemoglobin is compared with GLG, BHG and human Hb. The larger variation observed between GCT and human Hb indicates that GCT Hb differs remarkably from human. The α1β1 interface of Great cormorant Hb is similar to bar-headed goose Hb with few amino acid substitutions. It has been found that the interaction which is common among avian hemoglobins (α119 Pro- β55Leu) is altered by Ala 119 in GCT. This intra-dimer contact (α119 Pro - β 55 Leu) disruption leads to high oxygen affinity in BGH Hb. In cormorant, GLG and human the proline is unchanged but interestingly, in cormorant Hb, the β55 position was found to be Thr instead of Leu. Similar kind of substitutions (β 55 Leu - Ser) observed in Andean goose Hb structure leads to elevated oxygen affinity between Hb-O2. To our surprise, such type of substitution at β 55 (Thr) in cormorant Hb confirms that it is comparable with Andean goose Hb structure. Thus the sequence, structural differences at alpha, beta heme pocket and interface contacts confirms that GCT adopts high oxygen affinity conformation. The three dimensional structure of Great cormorant hemoglobin has been investigated to understand its unique structural features to adopt during hypoxia condition. The comparative studies of GCT's α, β heme pockets and the subunit interface with other Hbs reveal its similarities with goose Hbs. Also the loss of α119 - β55 contact in GCT and its unique mutation (Leu β55 Thr ) as in goose Hbs may play an important role in oxygen affinity. Thus by comparing the sequence and overall

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

Transcriptional Mechanisms Underlying Hemoglobin Synthesis

PubMed Central

Katsumura, Koichi R.; DeVilbiss, Andrew W.; Pope, Nathaniel J.; Johnson, Kirby D.; Bresnick, Emery H.

2013-01-01

The physiological switch in expression of the embryonic, fetal, and adult β-like globin genes has garnered enormous attention from investigators interested in transcriptional mechanisms and the molecular basis of hemoglobinopathies. These efforts have led to the discovery of cell type-specific transcription factors, unprecedented mechanisms of transcriptional coregulator function, genome biology principles, unique contributions of nuclear organization to transcription and cell function, and promising therapeutic targets. Given the vast literature accrued on this topic, this article will focus on the master regulator of erythroid cell development and function GATA-1, its associated proteins, and its frontline role in controlling hemoglobin synthesis. GATA-1 is a crucial regulator of genes encoding hemoglobin subunits and heme biosynthetic enzymes. GATA-1-dependent mechanisms constitute an essential regulatory core that nucleates additional mechanisms to achieve the physiological control of hemoglobin synthesis. PMID:23838521

Bohr effect of hemoglobins: Accounting for differences in magnitude.

PubMed

Okonjo, Kehinde O

2015-09-07

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

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

PubMed

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

2015-01-01

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

The interaction of 2,3-diphosphoglycerate with various human hemoglobins

PubMed Central

Bunn, H. Franklin; Briehl, Robin W.

1970-01-01

Oxygen equilibria were measured on a number of human hemoglobins, which had been “stripped” of organic phosphates and isolated by column chromatography. In the presence of 2 × 10-4 M 2,3-diphosphoglycerate (2,3-DPG), the P50 of hemoglobins A, A2, S, and C increased about twofold, signifying a substantial and equal decrease in oxygen affinity. Furthermore, hemoglobins Chesapeake and MMilwaukee-1 which have intrinsically high and low oxygen affinities, respectively, also showed a twofold increase in P50 in the presence of 2 × 10-4 M 2,3-DPG. In comparison to these, hemoglobins AIC and F were less reactive with 2,3-DPG while hemoglobin FI showed virtually no reactivity. The N-terminal amino of each β-chain of hemoglobin AIC is linked to a hexose. In hemoglobin FI the N-terminal amino of each γ-chain is acetylated. These results suggest that the N-terminal amino groups of the non-α-chains are involved in the binding of 2,3-DPG to hemoglobin. PMID:5422014

Porphyromonas endodontalis binds, reduces and grows on human hemoglobin.

PubMed

Zerr, M; Drake, D; Johnson, W; Cox, C D

2001-08-01

Porphyromonas endodontalis is a black-pigmented, obligate anaerobic rod-shaped bacterium implicated as playing a major role in endodontic infections. We have previously shown that P. endodontalis requires the porphyrin nucleus, preferably supplied as hemoglobin, as a growth supplement. The bacteria also actively transport free iron, although this activity does not support growth in the absence of a porphyrin source. The purpose of this study was to further investigate the binding and subsequent utilization of human hemoglobin by P. endodontalis. P. endodontalis binds hemoglobin and reduces the Fe(III) porphyrin, resulting in a steady accumulation of ferrous hemoglobin. Reduction of methemoglobin was similar to the extracellular reduction of nitrobluetetrazolium in the presence of oxidizable substrate. Turbidimetric and viable cell determinations showed that P. endodontalis grew when supplied only hemoglobin. Therefore, we conclude that hemoglobin appears to serve as a sole carbon and nitrogen source, and that these bacteria reduce extracellular compounds at the expense of oxidized substrates.

A Functional Element Necessary for Fetal Hemoglobin Silencing

PubMed Central

Sankaran, Vijay G.; Xu, Jian; Byron, Rachel; Greisman, Harvey A.; Fisher, Chris; Weatherall, David J.; Sabath, Daniel E.; Groudine, Mark; Orkin, Stuart H.; Premawardhena, Anuja; Bender, M.A.

2011-01-01

BACKGROUND An improved understanding of the regulation of the fetal hemoglobin genes holds promise for the development of targeted therapeutic approaches for fetal hemoglobin induction in the β-hemoglobinopathies. Although recent studies have uncovered trans-acting factors necessary for this regulation, limited insight has been gained into the cis-regulatory elements involved. METHODS We identified three families with unusual patterns of hemoglobin expression, suggestive of deletions in the locus of the β-globin gene (β-globin locus). We performed array comparative genomic hybridization to map these deletions and confirmed breakpoints by means of polymerase-chain-reaction assays and DNA sequencing. We compared these deletions, along with previously mapped deletions, and studied the trans-acting factors binding to these sites in the β-globin locus by using chromatin immunoprecipitation. RESULTS We found a new (δβ)0-thalassemia deletion and a rare hereditary persistence of fetal hemoglobin deletion with identical downstream breakpoints. Comparison of the two deletions resulted in the identification of a small intergenic region required for γ-globin (fetal hemoglobin) gene silencing. We mapped a Kurdish β0-thalassemia deletion, which retains the required intergenic region, deletes other surrounding sequences, and maintains fetal hemoglobin silencing. By comparing these deletions and other previously mapped deletions, we elucidated a 3.5-kb intergenic region near the 5′ end of the δ-globin gene that is necessary for γ-globin silencing. We found that a critical fetal hemoglobin silencing factor, BCL11A, and its partners bind within this region in the chromatin of adult erythroid cells. CONCLUSIONS By studying three families with unusual deletions in the β-globin locus, we identified an intergenic region near the δ-globin gene that is necessary for fetal hemoglobin silencing. (Funded by the National Institutes of Health and others.) PMID:21879898

Modulation of hemoglobin dynamics by an allosteric effector

DOE PAGES

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

2016-12-15

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

The high affinity of small-molecule antioxidants for hemoglobin.

PubMed

Puscas, Cristina; Radu, Luana; Carrascoza, Francisco; Mot, Augustin C; Amariei, Diana; Lungu, Oana; Scurtu, Florina; Podea, Paula; Septelean, Raluca; Matei, Alina; Mic, Mihaela; Attia, Amr A; Silaghi-Dumitrescu, Radu

2018-06-18

Hemoglobin has previously been shown to display ascorbate peroxidase and urate peroxidase activity, with measurable Michaelis-Menten parameters that reveal a particularly low Km for ascorbate as well as for urate - lower than the respective in vivo concentrations of these antioxidants in blood. Also, direct detection of a hemoglobin-ascorbate interaction was possible by monitoring the 1H-NMR spectrum of ascorbate in the presence of hemoglobin. The relative difference in structures between ascorbate and urate may raise the question as to exactly what the defining structural features would be, for a substrate that binds to hemoglobin with high affinity. Reported here are Michaelis-Menten parameters for hemoglobin acting as peroxidase against a number of other substrates of varying structures - gallate, caffeate, rutin, 3-hydroxyflavone, 3,6-dihydroxyflavone, quercetin, epicatechin, luteolin - all with high affinities (some higher than those of physiologically-relevant redox partners of Hb - ascorbate and urate). Moreover, this high affinity appears general to animal hemoglobins. 1 H-NMR and 13 C-NMR spectra reveal a general pattern wherein small hydrophilic antioxidants appear to all have their signals affected, presumably due to binding to hemoglobin. Fluorescence and calorimetry measurements confirm these conclusions. Docking calculations confirm the existence of binding sites on hemoglobin and on myoglobin for ascorbate as well as for other antioxidants. Support is found for involvement of Tyr42 in binding of three out of the four substrates investigated in the case of hemoglobin (including ascorbate and urate, as blood-contained relevant substrates), but also for Tyr145 (with urate and caffeate) and Tyr35 (with gallate). Copyright © 2018 Elsevier Inc. All rights reserved.

Microbiome and bacterial translocation in cirrhosis.

PubMed

Gómez-Hurtado, Isabel; Such, José; Francés, Rubén

2016-12-01

Qualitative and quantitative changes in gut microbiota play a very important role in cirrhosis. Humans harbour around 100 quintillion gut bacteria, thus representing around 10 times more microbial cells than eukaryotic ones. The gastrointestinal tract is the largest surface area in the body and it is subject to constant exposure to these living microorganisms. The existing symbiosis, proven by the lack of proinflammatory response against commensal bacteria, implies the presence of clearly defined communication lines that contribute to the maintenance of homeostasis of the host. Therefore, alterations of gut flora seem to play a role in the pathogenesis and progress of multiple liver and gastrointestinal diseases. This has made its selective modification into an area of high therapeutic interest. Bacterial translocation is defined as the migration of bacteria or bacterial products from the intestines to the mesenteric lymph nodes. It follows that alteration in gut microbiota have shown importance, at least to some extent, in the pathogenesis of several complications arising from terminal liver disease, such as hepatic encephalopathy, portal hypertension and spontaneous bacterial peritonitis. This review sums up, firstly, how liver disease can alter the common composition of gut microbiota, and secondly, how this alteration contributes to the development of complications in cirrhosis. Copyright © 2015 Elsevier España, S.L.U., AEEH y AEG. All rights reserved.

The role of facilitated diffusion in oxygen transport by cell-free hemoglobins: implications for the design of hemoglobin-based oxygen carriers.

PubMed

McCarthy, M R; Vandegriff, K D; Winslow, R M

2001-08-30

We compared rates of oxygen transport in an in vitro capillary system using red blood cells (RBCs) and cell-free hemoglobins. The axial PO(2) drop down the capillary was calculated using finite-element analysis. RBCs, unmodified hemoglobin (HbA(0)), cross-linked hemoglobin (alpha alpha-Hb) and hemoglobin conjugated to polyethylene-glycol (PEG-Hb) were evaluated. According to their fractional saturation curves, PEG-Hb showed the least desaturation down the capillary, which most closely matched the RBCs; HbA(0) and alpha alpha-Hb showed much greater desaturation. A lumped diffusion parameter, K*, was calculated based on the Fick diffusion equation with a term for facilitated diffusion. The overall rates of oxygen transfer are consistent with hemoglobin diffusion rates according to the Stokes-Einstein Law and with previously measured blood pressure responses in rats. This study provides a conceptual framework for the design of a 'blood substitute' based on mimicking O(2) transport by RBCs to prevent autoregulatory changes in blood flow and pressure.

Blood transfusion-acquired hemoglobin C.

PubMed

Suarez, A A; Polski, J M; Grossman, B J; Johnston, M F

1999-07-01

Unexpected and confusing laboratory test results can occur if a blood sample is inadvertently collected following a blood transfusion. A potential for transfusion-acquired hemoglobinopathy exists because heterozygous individuals show no significant abnormalities during the blood donor screening process. Such spurious results are infrequently reported in the medical literature. We report a case of hemoglobin C passively transferred during a red blood cell transfusion. The proper interpretation in our case was assisted by calculations comparing expected hemoglobin C concentration with the measured value. A review of the literature on transfusion-related preanalytic errors is provided.

21 CFR 864.7455 - Fetal hemoglobin assay.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin...

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin...

21 CFR 864.7455 - Fetal hemoglobin assay.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fetal hemoglobin assay. 864.7455 Section 864.7455 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7455 Fetal hemoglobin...

Hemoglobin phase of oxygenation and deoxygenation in early brain development measured using fNIRS

PubMed Central

Watanabe, Hama; Shitara, Yoshihiko; Aoki, Yoshinori; Inoue, Takanobu; Tsuchida, Shinya; Takahashi, Naoto; Taga, Gentaro

2017-01-01

A crucial issue in neonatal medicine is the impact of preterm birth on the developmental trajectory of the brain. Although a growing number of studies have shown alterations in the structure and function of the brain in preterm-born infants, we propose a method to detect subtle differences in neurovascular and metabolic functions in neonates and infants. Functional near-infrared spectroscopy (fNIRS) was used to obtain time-averaged phase differences between spontaneous low-frequency (less than 0.1 Hz) oscillatory changes in oxygenated hemoglobin (oxy-Hb) and those in deoxygenated hemoglobin (deoxy-Hb). This phase difference was referred to as hemoglobin phase of oxygenation and deoxygenation (hPod) in the cerebral tissue of sleeping neonates and infants. We examined hPod in term, late preterm, and early preterm infants with no evidence of clinical issues and found that all groups of infants showed developmental changes in the values of hPod from an in-phase to an antiphase pattern. Comparison of hPod among the groups revealed that developmental changes in hPod in early preterm infants precede those in late preterm and term infants at term equivalent age but then, progress at a slower pace. This study suggests that hPod measured using fNIRS is sensitive to the developmental stage of the integration of circular, neurovascular, and metabolic functions in the brains of neonates and infants. PMID:28196885

Nanobiotechnological modification of hemoglobin and enzymes from this laboratory

PubMed Central

Chang, Thomas Ming Swi

2012-01-01

Polyhemoglobin is formed by the nanobiotechnological assembling of hemoglobin molecules into soluble nanodimension complex. A further step involves the nanobiotechnological assembly of hemoglobin, catalase and superoxide dismutase into a soluble nanodimension complex. This acts both as oxygen carrier and antioxidant to prevent the oxidative effects of hemoglobin. A further step is the preparation of nanodimension artificial red blood cells that contain hemoglobin and all the enzymes present in red blood cells. Other approaches include a polyhemoglobin–fibrinogen that acts as an oxygen carrier with platelet-like activity, and a polyhemoglobin–tyrosinase to retard the growth of a fatal skin cancer, melanoma. PMID:18565337

Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

PubMed

Jonsson, Ing-Marie; Juuti, Jarmo T; François, Patrice; AlMajidi, Rana; Pietiäinen, Milla; Girard, Myriam; Lindholm, Catharina; Saller, Manfred J; Driessen, Arnold J M; Kuusela, Pentti; Bokarewa, Maria; Schrenzel, Jacques; Kontinen, Vesa P

2010-12-02

Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown. In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine. Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

[Hemolytic anemia due to hemoglobin Evans in an Argentinean family].

PubMed

Zanotto, María I; Calvo, Karina; Schvartzman, Gabriel; Deana, Alejandra; Noguera, Nélida; Bragós, Irma; Milani, Angela

2010-12-01

Unstable hemoglobins are structural variants of the hemoglobin molecule, mostly originated by single amino-acid replacement in some globin chains. These changes affect molecule stability, leading to loss of solubility, precipitation, and cellular lysis. Patients carrying these unstable hemoglobins may present mild to severe chronic hemolytic anemia. Hemoglobin Evans is an unstable variant originated by replacement of valine with methionine at position 62 of the α-globin chain. We have identified this variant in a girl with an acute hemolytic crisis associated to pharyngitis, as well as in two of her family members. This is the third case of hemolytic anemia due to hemoglobin Evans reported in the literature.

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.

Gadd34 Requirement for Normal Hemoglobin Synthesis

PubMed Central

Patterson, Andrew D.; Hollander, M. Christine; Miller, Georgina F.; Fornace, Albert J.

2006-01-01

The protein encoded by growth arrest and DNA damage-inducible transcript 34 (Gadd34) is associated with translation initiation regulation following certain stress responses. Through interaction with the protein phosphatase 1 catalytic subunit (PP1c), Gadd34 recruits PP1c for the removal of an inhibitory phosphate group on the α subunit of elongation initiation factor 2, thereby reversing the shutoff of protein synthesis initiated by stress-inducible kinases. In the absence of stress, the physiologic consequences of Gadd34 function are not known. Initial analysis of Gadd34-null mice revealed several significant findings, including hypersplenism, decreased erythrocyte volume, increased numbers of circulating erythrocytes, and decreased hemoglobin content, resembling some thalassemia syndromes. Biochemical analysis of the hemoglobin-producing reticulocyte (an erythrocyte precursor) revealed that the decreased hemoglobin content in the Gadd34-null erythrocyte is due to the reduced initiation of the globin translation machinery. We propose that an equilibrium state exists between Gadd34/PP1c and the opposing heme-regulated inhibitor kinase during hemoglobin synthesis in the reticulocyte. PMID:16478986

Soil bacterial community and functional shifts in response to altered snowpack in moist acidic tundra of northern Alaska

NASA Astrophysics Data System (ADS)

Ricketts, Michael P.; Poretsky, Rachel S.; Welker, Jeffrey M.; Gonzalez-Meler, Miquel A.

2016-09-01

. Bacterial functional potential was inferred using ancestral state reconstruction to approximate functional gene abundance, revealing a decreased abundance of genes required for soil organic matter (SOM) decomposition in the organic layers of the deep snow accumulation zones. These results suggest that predicted climate change scenarios may result in altered soil bacterial community structure and function, and indicate a reduction in decomposition potential, alleviated temperature limitations on extracellular enzymatic efficiency, or both. The fate of stored C in Arctic soils ultimately depends on the balance between these mechanisms.

21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a hemoglobin derivative and that is used to set instruments intended to measure hemoglobin, the hematocrit, or both. It is a material whose characteristics have been precisely and accurately determined. (b...

21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a hemoglobin derivative and that is used to set instruments intended to measure hemoglobin, the hematocrit, or both. It is a material whose characteristics have been precisely and accurately determined. (b...

21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a hemoglobin derivative and that is used to set instruments intended to measure hemoglobin, the hematocrit, or both. It is a material whose characteristics have been precisely and accurately determined. (b...

21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a hemoglobin derivative and that is used to set instruments intended to measure hemoglobin, the hematocrit, or both. It is a material whose characteristics have been precisely and accurately determined. (b...

21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a hemoglobin derivative and that is used to set instruments intended to measure hemoglobin, the hematocrit, or both. It is a material whose characteristics have been precisely and accurately determined. (b...

Molecular basis of thermal stability in truncated (2/2) hemoglobins.

PubMed

Bustamante, Juan P; Bonamore, Alessandra; Nadra, Alejandro D; Sciamanna, Natascia; Boffi, Alberto; Estrin, Darío A; Boechi, Leonardo

2014-07-01

Understanding the molecular mechanism through which proteins are functional at extreme high and low temperatures is one of the key issues in structural biology. To investigate this phenomenon, we have focused on two instructive truncated hemoglobins from Thermobifida fusca (Tf-trHbO) and Mycobacterium tuberculosis (Mt-trHbO); although the two proteins are structurally nearly identical, only the former is stable at high temperatures. We used molecular dynamics simulations at different temperatures as well as thermal melting profile measurements of both wild type proteins and two mutants designed to interchange the amino acid residue, either Pro or Gly, at E3 position. The results show that the presence of a Pro at the E3 position is able to increase (by 8°) or decrease (by 4°) the melting temperature of Mt-trHbO and Tf-trHbO, respectively. We observed that the ProE3 alters the structure of the CD loop, making it more flexible. This gain in flexibility allows the protein to concentrate its fluctuations in this single loop and avoid unfolding. The alternate conformations of the CD loop also favor the formation of more salt-bridge interactions, together augmenting the protein's thermostability. These results indicate a clear structural and dynamical role of a key residue for thermal stability in truncated hemoglobins. Copyright © 2014 Elsevier B.V. All rights reserved.

WAXS studies of the structural diversity of hemoglobin in solution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makowski, L.; Bardhan, J.; Gore, D.

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 hemoglobinmore » 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.« less

Imaging the effect of hemoglobin on properties of RBCs using common-path digital holographic microscope

NASA Astrophysics Data System (ADS)

Joglekar, M.; Shah, H.; Trivedi, V.; Mahajan, S.; Chhaniwal, V.; Leitgeb, R.; Javidi, B.; Anand, A.

2017-07-01

Adequate supply of oxygen to the body is the most essential requirement. In vertebrate species this function is performed by Hemoglobin contained in red blood cells. The mass concentration of the Hb determines the oxygen carrying capacity of the blood. Thus it becomes necessary to determine its concentration in the blood, which helps in monitoring the health of a person. If the amount of Hb crosses certain range, then it is considered critical. As the Hb constitutes upto 96% of red blood cells dry content, it would be interesting to examine various physical and mechanical parameters of RBCs which depends upon its concentration. Various diseases bring about significant variation in the amount of hemoglobin which may alter certain parameters of the RBC such as surface area, volume, membrane fluctuation etc. The study of the variations of these parameters may be helpful in determining Hb content which will reflect the state of health of a human body leading to disease diagnosis. Any increase or decrease in the amount of Hb will change the density and hence the optical thickness of the RBCs, which affects the cell membrane and thereby changing its mechanical and physical properties. Here we describe the use of lateral shearing digital holographic microscope for quantifying the cell parameters for studying the change in biophysical properties of cells due to variation in hemoglobin concentration.

Hemoglobin in Frankia, a Nitrogen-Fixing Actinomycete†

PubMed Central

Tjepkema, John D.; Cashon, Robert E.; Beckwith, Jason; Schwintzer, Christa R.

2002-01-01

Frankia strain CcI3 grown in culture produced a hemoglobin which had optical absorption bands typical of a hemoglobin and a molecular mass of 14.1 kDa. Its equilibrium oxygen binding constant was 274 nM, the oxygen dissociation rate constant was 56 s−1, and the oxygen association rate constant was 206 μM−1 s−1. PMID:11976149

Capillary-scale direct measurement of hemoglobin concentration of erythrocytes using photothermal angular light scattering.

PubMed

Kim, Uihan; Song, Jaewoo; Lee, Donghak; Ryu, Suho; Kim, Soocheol; Hwang, Jaehyun; Joo, Chulmin

2015-12-15

We present a direct, rapid and chemical-free detection method for hemoglobin concentration ([Hb]), based on photothermal angular light scattering. The iron oxides contained in hemoglobin molecules exhibit high absorption of 532-nm light and generate heat under the illumination of 532-nm light, which subsequently alters the refractive index of blood. We measured this photothermal change in refractive index by employing angular light scattering spectroscopy with the goal of quantifying [Hb] in blood samples. Highly sensitive [Hb] measurement of blood samples was performed by monitoring the shifts in angularly dispersed scattering patterns from the blood-loaded microcapillary tubes. Our system measured [Hb] over the range of 0.35-17.9 g/dL with a detection limit of ~0.12 g/dL. Our sensor was characterized by excellent correlation with a reference hematology analyzer (r>0.96), and yielded a precision of 0.63 g/dL for a blood sample of 9.0 g/dL. Copyright © 2015 Elsevier B.V. All rights reserved.

INTRINSIC REGULATION OF HEMOGLOBIN EXPRESSION BY VARIABLE SUBUNIT INTERFACE STRENGTHS

PubMed Central

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

2012-01-01

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

Preparation and characterization of hemoglobin-silver composites as biocompatible antiseptics.

PubMed

Li, Peiyuan; Tong, Zhangfa; Jia, Zhiruo; Su, Wei

2016-11-01

Microbial contamination has been a major challenge in a wide variety of fields such as biomedical and biomaterial applications. The development of biomaterials that possess excellent antibacterial ability and biocompatibility is of great importance to enhance the service life of biomaterials. In this study, the main protein component of red blood cells, hemoglobin (Hb), was employed to prepare Ag-Hb nanocomposites as novel biocompatible antiseptics. The formation of Ag-Hb nanocomposites on the titanium substrate are confirmed by field-emission scanning electron microscopy, Fourier transformed infrared spectroscopic, contact angles, and inductively coupled plasma atomic emission spectrometry analysis. The Ag-Hb titanium shows potent antibacterial ability against planktonic bacteria in the suspension and ability to prevent bacterial adhesion. Moreover, the Ag-Hb titanium shows excellent biocompatibility, which supports healthy osteoblast cellular activity and osteoblast differentiation. The results indicate that the Ag-Hb nanocomposites can be potentially useful for the fabrication of biomaterials for long-term applications. © The Author(s) 2016.

Oxygen transport by hemoglobin.

PubMed

Mairbäurl, Heimo; Weber, Roy E

2012-04-01

Hemoglobin (Hb) constitutes a vital link between ambient O2 availability and aerobic metabolism by transporting oxygen (O2) from the respiratory surfaces of the lungs or gills to the O2-consuming tissues. The amount of O2 available to tissues depends on the blood-perfusion rate, as well as the arterio-venous difference in blood O2 contents, which is determined by the respective loading and unloading O2 tensions and Hb-O2-affinity. Short-term adjustments in tissue oxygen delivery in response to decreased O2 supply or increased O2 demand (under exercise, hypoxia at high altitude, cardiovascular disease, and ischemia) are mediated by metabolically induced changes in the red cell levels of allosteric effectors such as protons (H(+)), carbon dioxide (CO2), organic phosphates, and chloride (Cl(-)) that modulate Hb-O2 affinity. The long-term, genetically coded adaptations in oxygen transport encountered in animals that permanently are subjected to low environmental O2 tensions commonly result from changes in the molecular structure of Hb, notably amino acid exchanges that alter Hb's intrinsic O2 affinity or its sensitivity to allosteric effectors. Structure-function studies of animal Hbs and human Hb mutants illustrate the different strategies for adjusting Hb-O2 affinity and optimizing tissue oxygen supply. © 2012 American Physiological Society. Compr Physiol 2:1491-1539, 2012.

Hemoglobin level in older persons and incident Alzheimer disease: prospective cohort analysis.

PubMed

Shah, R C; Buchman, A S; Wilson, R S; Leurgans, S E; Bennett, D A

2011-07-19

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

[Role of hemoglobin affinity to oxygen in adaptation to hypoxemia].

PubMed

Kwasiborski, Przemysław Jerzy; Kowalczyk, Paweł; Zieliński, Jakub; Przybylski, Jacek; Cwetsch, Andrzej

2010-04-01

One of the basic mechanisms of adapting to hypoxemia is a decrease in the affinity of hemoglobin for oxygen. This process occurs mainly due to the increased synthesis of 2,3-diphosphoglycerate (2,3-DPG) in the erythrocytes, as well as through the Bohr effect. Hemoglobin with decreased affinity for oxygen increases the oxygenation of tissues, because it gives up oxygen more easily during microcirculation. In foetal circulation, however, at a partial oxygen pressure (pO2) of 25 mmHg in the umbilical vein, the oxygen carrier is type F hemoglobin which has a high oxygen affinity. The commonly accepted role for hemoglobin F is limited to facilitating diffusion through the placenta. Is fetal life the only moment when haemoglobin F is useful? THE AIM OF STUDY was to create a mathematical model, which would answer the question at what conditions an increase, rather than a decrease, in haemoglobin oxygen affinity is of benefit to the body. Using the kinetics of dissociation of oxygen from hemoglobin described by the Hill equation as the basis for further discussion, we created a mathematical model describing the pO2 value in the microcirculatory system and its dependence on arterial blood pO2. The calculations were performed for hemoglobin with low oxygen affinity (adult type) and high-affinity hemoglobin (fetal type). The modelling took into account both physiological and pathological ranges of acid-base equilibrium and tissue oxygen extraction parameters. It was shown that for the physiological range of acid-base equilibrium and the resting level of tissue oxygen extraction parameters, with an arterial blood pO2 of 26.8 mmHg, the higher-affinity hemoglobin becomes the more effective oxygen carrier. It was also demonstrated that the arterial blood pO2, below which the high-affinity hemoglobin becomes the more effective carrier, is dependent on blood pH and the difference between the arterial and venous oxygen saturation levels. Simulations performed for the pathological

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

PubMed

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

2001-02-16

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

Modulation of post-antibiotic bacterial community reassembly and host response by Candida albicans.

PubMed

Erb Downward, John R; Falkowski, Nicole R; Mason, Katie L; Muraglia, Ryan; Huffnagle, Gary B

2013-01-01

The introduction of Candida albicans into cefoperazone-treated mice results in changes in bacterial community reassembly. Our objective was to use high-throughput sequencing to characterize at much greater depth the specific changes in the bacterial microbiome. The colonization of C. albicans significantly altered bacterial community reassembly that was evident at multiple taxonomic levels of resolution. There were marked changes in the levels of Bacteriodetes and Lactobacillaceae. Lachnospiraceae and Ruminococcaceae, the two most abundant bacterial families, did not change in relative proportions after antibiotics, but there were marked genera-level shifts within these two bacterial families. The microbiome shifts occurred in the absence of overt intestinal inflammation. Overall, these experiments demonstrate that the introduction of a single new microbe in numerically inferior numbers into the bacterial microbiome during a broad community disturbance has the potential to significantly alter the subsequent reassembly of the bacterial community as it recovers from that disturbance.

Alteration of Blood Parameters and Histoarchitecture of Liver and Kidney of Silver Barb after Chronic Exposure to Quinalphos

PubMed Central

Mohammod Mostakim, Golam; Zahangir, Md. Mahiuddin; Monir Mishu, Mahbuba; Rahman, Md. Khalilur; Islam, M. Sadiqul

2015-01-01

Quinalphos (QP) is commonly used for pest control in the agricultural fields surrounding freshwater reservoirs. This study was conducted to evaluate the chronic toxicity of this pesticide on blood parameters and some organs of silver barb, Barbonymus gonionotus. Fish were exposed to two sublethal concentrations, 0.47 ppm and 0.94 ppm, of QP for a period of 28 days. All the blood parameters (red blood cell, hematocrit, and hemoglobin) and blood glucose except for white blood cells decreased with increasing concentration of toxicant and become significantly lower (p < 0.05) at higher concentration when compared with control. The derived hematological indices of mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration were equally altered compared to control. Histoarchitectural changes of liver and kidney were observed after exposure to the QP. Hypertrophy of hepatocytes, mild to severe necrosis, ruptured central vein, and vacuolation were observed in the liver of treated groups. Highly degenerated kidney tubules and hematopoietic tissue, degeneration of renal corpuscle, vacuolization, and necrosis were evident in the kidney of treated groups. In conclusion, chronic exposure to QP at sublethal concentrations induced hematological and histological alterations in silver barb and offers a simple tool to evaluate toxicity derived alterations. PMID:26635877

Bacterial Cell Mechanics.

PubMed

Auer, George K; Weibel, Douglas B

2017-07-25

Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

Rice (Oryza) hemoglobins

USDA-ARS?s Scientific Manuscript database

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

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.

Relationship of hemoglobin A1c to mortality in nonsmoking insurance applicants.

PubMed

Stout, Robert L; Fulks, Michael; Dolan, Vera F; Magee, Mark E; Suarez, Luis

2007-01-01

Determine the relationship between hemoglobin A1c value and 5-year, all-cause mortality in nonsmoking life insurance applicants. By use of the Social Security Master Death Index, mortality was examined in 286,443 non-smoking insurance applicants aged 40 and up for whom blood samples for hemoglobin A1c were submitted to the Clinical Reference Laboratory. Results were stratified by hemoglobin A1c value, gender and age bands 40 to 59, 60 to 69 and 70 and up. Increased mortality is apparent at hemoglobin A1c values of 6% and above, is linear, and on a percentage basis decreases with age. Hemoglobin A1c values less than 5% also are associated with increased mortality. Absolute mortality rates for females with elevated hemoglobin A1c are generally lower than rates for males, although mortality relative to the gender-specific reference group with hemoglobin A1c of 5% to 5.9% is generally the same for both. The importance of even small elevations of hemoglobin A1c above 5.9% is apparent. For screening, it is the degree of blood sugar elevation as measured by hemoglobin A1c rather than any diagnostic label that is critical in risk assessment.

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) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A 2...

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) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2...

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) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A 2...

Prevalence of common hemoglobin variants in an afro-descendent Ecuadorian population

PubMed Central

2013-01-01

Background Hemoglobinopathies are among the most studied and frequent pathologies. These genetic disorders are considered a very important health care threat in many tropical countries. Ecuador is a tropical Latin-American country with an important presence of afro-descendants (7.2%). Afro-descendants are among the ethnic groups with higher frequency of hemoglobinopathies reported. Ambuqui is a region within the Imbabura province with an important presence of afro-descendants (>50%). The present study analyzed the frequency of the most common hemoglobin variants in an asymptomatic afro-descendent population using capillary electrophoresis. Findings From 114 individuals, 25 (22%) reported a hemoglobin variant. All individuals that presented hemoglobin variants were heterozygotes (asymptomatic). Hemoglobin S (sickle cell trait) was the most frequent variant found (14%), followed by hemoglobin E (4.4%), Fetal (2.6%) and C (1%). Conclusion Prevalence of hemoglobin S was consistent with populations from other countries, but it was lower than other Ecuadorian afro-descendent populations. Frequency of hemoglobin C was lower than other afro-descendent populations. This data suggests the possibility of gene flow from Native American individuals to the Ambuqui population there by lowering the frequency of their hemoglobin variants compared with other afro-descendant populations. Evaluating the frequency of hemoglobinopathies in Ecuadorian populations is essential. Despite the high frequency of these disorders, very few health care facilities implement hemoglobinopathies tests as a routine practice. PMID:23557107

Low Diagnostic Utility of Rechecking Hemoglobins Within 24 Hours in Hospitalized Patients.

PubMed

Rajkomar, Alvin; McCulloch, Charles E; Fang, Margaret C

2016-11-01

Clinicians often repeat hemoglobin tests within a 24 hour period to detect or monitor anemia. We sought to determine the percentage of hemoglobin tests repeated within a single hospital day that were at least 1.0 g/dL lower than the first test. We performed a retrospective cross-sectional analysis of hospitalized adults on medical or surgical services over 1 year at a single academic hospital. Using patient and laboratory data in the electronic health record, we analyzed the proportion of repeated hemoglobin test results that were at least 1 g/dL less than the initial hemoglobin value of that day, excluding days when transfusions were administered. A total of 88,722 hemoglobin tests were obtained from 12,877 unique patients, who contributed a total of 86,859 hospitalization days. In 12,230 (14.1%) of those days, 2 or more hemoglobin tests were obtained within a single day. In the 6969 days with 2 hemoglobin tests obtained and no transfusions given, 949 (13.5%) were ≥1 g/dL lower than the initial hemoglobin value of that day, and 260 (3.7%) were ≥2 g/dL lower. Repeated tests did not often reach transfusion thresholds: 482 (6.9%) of repeat hemoglobin values were <8 g/dL, and 64 (0.9%) were <7 g/dL. Hemoglobin tests were repeated in 14% of hospital days. For patients who had 2 hemoglobin tests obtained on the same day, 13.5% demonstrated a clinically significant drop. This information may be helpful to clinicians when considering whether repeat testing is appropriate. Copyright © 2016 Elsevier Inc. All rights reserved.

The biosynthesis of human hemoglobin A1c. Slow glycosylation of hemoglobin in vivo.

PubMed Central

Bunn, H F; Haney, D N; Kamin, S; Gabbay, K H; Gallop, P M

1976-01-01

Hemoglobin A1c, the most abundant minor hemoglobin component in human erythrocytes, is formed by the condensation of glucose with the N-terminal amino groups of the beta-chains of Hb A. The biosynthesis of this glycosylated hemoglobin was studied in vitro by incubating suspensions of reticulocytes and bone marrow cells with [3H]leucine or 59Fe-bound transferrin. In all experiments, the specific activity of Hb A1c was significantly lower than that of Hb A, suggesting that the formation of Hb A1c is a posttranslational modification. The formation of Hb A1c in vivo was determined in two individuals who were given an infusion of 59Fe-labeled transferrin. As expected, the specific activity of Hb A rose promptly to a maximum during the 1st week and remained nearly constant thereafter. In contrast, the specific activity of Hb A1c and also of Hbs A1a and A1b rose slowly, reaching that of Hb A by about day 60. These results indicate that Hb A1c is slowly formed during the 120-day life-span of the erythrocyte, probably by a nonenzymatic process. Patients with shortened erythrocyte life-span due to hemolysis had markedly decreased levels of Hb A1c. PMID:932199

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

PubMed Central

Wilber, Andrew; Nienhuis, Arthur W.

2011-01-01

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

The Greenland shark Somniosus microcephalus-Hemoglobins and ligand-binding properties.

PubMed

Russo, Roberta; Giordano, Daniela; Paredi, Gianluca; Marchesani, Francesco; Milazzo, Lisa; Altomonte, Giovanna; Del Canale, Pietro; Abbruzzetti, Stefania; Ascenzi, Paolo; di Prisco, Guido; Viappiani, Cristiano; Fago, Angela; Bruno, Stefano; Smulevich, Giulietta; Verde, Cinzia

2017-01-01

A large amount of data is currently available on the adaptive mechanisms of polar bony fish hemoglobins, but structural information on those of cartilaginous species is scarce. This study presents the first characterisation of the hemoglobin system of one of the longest-living vertebrate species (392 ± 120 years), the Arctic shark Somniosus microcephalus. Three major hemoglobins are found in its red blood cells and are made of two copies of the same α globin combined with two copies of three very similar β subunits. The three hemoglobins show very similar oxygenation and carbonylation properties, which are unaffected by urea, a very important compound in marine elasmobranch physiology. They display identical electronic absorption and resonance Raman spectra, indicating that their heme-pocket structures are identical or highly similar. The quaternary transition equilibrium between the relaxed (R) and the tense (T) states is more dependent on physiological allosteric effectors than in human hemoglobin, as also demonstrated in polar teleost hemoglobins. Similar to other cartilaginous fishes, we found no evidence for functional differentiation among the three isoforms. The very similar ligand-binding properties suggest that regulatory control of O2 transport may be at the cellular level and that it may involve changes in the cellular concentrations of allosteric effectors and/or variations of other systemic factors. The hemoglobins of this polar shark have evolved adaptive decreases in O2 affinity in comparison to temperate sharks.

The Greenland shark Somniosus microcephalus—Hemoglobins and ligand-binding properties

PubMed Central

Paredi, Gianluca; Marchesani, Francesco; Milazzo, Lisa; Altomonte, Giovanna; Del Canale, Pietro; Abbruzzetti, Stefania; Ascenzi, Paolo; di Prisco, Guido; Viappiani, Cristiano; Fago, Angela; Bruno, Stefano; Smulevich, Giulietta

2017-01-01

A large amount of data is currently available on the adaptive mechanisms of polar bony fish hemoglobins, but structural information on those of cartilaginous species is scarce. This study presents the first characterisation of the hemoglobin system of one of the longest-living vertebrate species (392 ± 120 years), the Arctic shark Somniosus microcephalus. Three major hemoglobins are found in its red blood cells and are made of two copies of the same α globin combined with two copies of three very similar β subunits. The three hemoglobins show very similar oxygenation and carbonylation properties, which are unaffected by urea, a very important compound in marine elasmobranch physiology. They display identical electronic absorption and resonance Raman spectra, indicating that their heme-pocket structures are identical or highly similar. The quaternary transition equilibrium between the relaxed (R) and the tense (T) states is more dependent on physiological allosteric effectors than in human hemoglobin, as also demonstrated in polar teleost hemoglobins. Similar to other cartilaginous fishes, we found no evidence for functional differentiation among the three isoforms. The very similar ligand-binding properties suggest that regulatory control of O2 transport may be at the cellular level and that it may involve changes in the cellular concentrations of allosteric effectors and/or variations of other systemic factors. The hemoglobins of this polar shark have evolved adaptive decreases in O2 affinity in comparison to temperate sharks. PMID:29023598

Using the MWC model to describe heterotropic interactions in hemoglobin

PubMed Central

Rapp, Olga

2017-01-01

Hemoglobin is a classical model allosteric protein. Research on hemoglobin parallels the development of key cooperativity and allostery concepts, such as the ‘all-or-none’ Hill formalism, the stepwise Adair binding formulation and the concerted Monod-Wymann-Changuex (MWC) allosteric model. While it is clear that the MWC model adequately describes the cooperative binding of oxygen to hemoglobin, rationalizing the effects of H+, CO2 or organophosphate ligands on hemoglobin-oxygen saturation using the same model remains controversial. According to the MWC model, allosteric ligands exert their effect on protein function by modulating the quaternary conformational transition of the protein. However, data fitting analysis of hemoglobin oxygen saturation curves in the presence or absence of inhibitory ligands persistently revealed effects on both relative oxygen affinity (c) and conformational changes (L), elementary MWC parameters. The recent realization that data fitting analysis using the traditional MWC model equation may not provide reliable estimates for L and c thus calls for a re-examination of previous data using alternative fitting strategies. In the current manuscript, we present two simple strategies for obtaining reliable estimates for MWC mechanistic parameters of hemoglobin steady-state saturation curves in cases of both evolutionary and physiological variations. Our results suggest that the simple MWC model provides a reasonable description that can also account for heterotropic interactions in hemoglobin. The results, moreover, offer a general roadmap for successful data fitting analysis using the MWC model. PMID:28793329

Relationship of hemoglobin to occupational exposure to motor vehicle exhaust.

PubMed

Potula, V; Hu, H

1996-01-01

To study the relationship of hemoglobin to exposure to motor vehicle exhaust. Survey. Traffic police, bus drivers, and auto-shop workers (all exposed to auto exhaust in Madras, India) and unexposed office workers. We measured levels of blood lead (by graphite furnace atomic absorption spectrophotometry), and hemoglobin. Information also was collected on age, employment duration, smoking status, alcohol ingestion, and diet type (vegetarian or nonvegetarian). Increasing exposure to motor vehicle exhaust, as reflected by job category, was significantly associated with lower levels of hemoglobin (p < 0.01). A final multivariate regression model was constructed that began with indicator variables for each job (with office workers as the reference category) and included age, duration of employment, blood lead level, alcohol ingestion, dietary type, and smoking status. After a backward-elimination procedure, employment duration as an auto-shop worker or bus driver remained as significant correlates of lower hemoglobin level and current smoking and long employment duration as significant correlates of higher hemoglobin level. Occupational exposure to automobile exhaust may be a risk factor for decreased hemoglobin level in Madras. This effect appears to be independent of blood lead level and may represent hematopoietic suppression incurred by benzene or accumulated lead burden (which is not well reflected by blood lead levels). Smoking probably increased hemoglobin level through the chronic effects of exposure to carbon monoxide. In this study, a long employment duration may have served as a proxy for better socioeconomic, and therefore, better nutritional status.

The role of respiratory viruses in the etiology of bacterial pneumonia

PubMed Central

Lee, Kyu Han; Gordon, Aubree; Foxman, Betsy

2016-01-01

Pneumonia is the leading cause of death among children less than 5 years old worldwide. A wide range of viral, bacterial and fungal agents can cause pneumonia: although viruses are the most common etiologic agent, the severity of clinical symptoms associated with bacterial pneumonia and increasing antibiotic resistance makes bacterial pneumonia a major public health concern. Bacterial pneumonia can follow upper respiratory viral infection and complicate lower respiratory viral infection. Secondary bacterial pneumonia is a major cause of influenza-related deaths. In this review, we evaluate the following hypotheses: (i) respiratory viruses influence the etiology of pneumonia by altering bacterial community structure in the upper respiratory tract (URT) and (ii) respiratory viruses promote or inhibit colonization of the lower respiratory tract (LRT) by certain bacterial species residing in the URT. We conducted a systematic review of the literature to examine temporal associations between respiratory viruses and bacteria and a targeted review to identify potential mechanisms of interactions. We conclude that viruses both alter the bacterial community in the URT and promote bacterial colonization of the LRT. However, it is uncertain whether changes in the URT bacterial community play a substantial role in pneumonia etiology. The exception is Streptococcus pneumoniae where a strong link between viral co-infection, increased carriage and pneumococcal pneumonia has been established. PMID:26884414

Altered peripheral profile of blood cells in Alzheimer disease

PubMed Central

Chen, Si-Han; Bu, Xian-Le; Jin, Wang-Sheng; Shen, Lin-Lin; Wang, Jun; Zhuang, Zheng-Qian; Zhang, Tao; Zeng, Fan; Yao, Xiu-Qing; Zhou, Hua-Dong; Wang, Yan-Jiang

2017-01-01

Abstract Alzheimer disease (AD) has been made a global priority for its multifactorial pathogenesis and lack of disease-modifying therapies. We sought to investigate the changes of profile of blood routine in AD and its correlation with the disease severity. In all, 92 AD patients and 84 age and sex-matched normal controls were enrolled and their profiles of blood routine were evaluated. Alzheimer disease patients had increased levels of mean corpuscular hemoglobin, mean corpuscular volume, red cell distribution width-standard deviation, mean platelet volume,and decreased levels of platelet distribution width, red blood cell, hematocrit, hemoglobin, lymphocyte, and basophil compared with normal controls. Alterations in quantity and quality of blood cells may be involved in the pathogenesis of AD and contribute to the disease progression. PMID:28538375

A nanocluster-based fluorescent sensor for sensitive hemoglobin detection.

PubMed

Yang, Dongqin; Meng, Huijie; Tu, Yifeng; Yan, Jilin

2017-08-01

In this report, a fluorescence sensor for sensitive detection of hemoglobin was developed. Gold nanoclusters were first synthesized with bovine serum albumin. It was found that both hydrogen peroxide and hemoglobin could weakly quench the fluorescence from the gold nanoclusters, but when these two were applied onto the nanolcusters simultaneously, a much improved quenching was resulted. This enhancing effect was proved to come from the catalytic generation of hydroxyl radical by hemoglobin. Under an optimized condition, the quenching linearly related to the concentration of hemoglobin in the range of 1-250nM, and a limit of detection as low as 0.36nM could be obtained. This provided a sensitive means for the quantification of Hb. The sensor was then successfully applied for blood analyses with simple sample pretreatment. Copyright © 2017 Elsevier B.V. All rights reserved.

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)

IV. HEMOGLOBIN INJECTIONS AND CONSERVATION OF PIGMENT BY KIDNEY, LIVER AND SPLEEN

PubMed Central

Newman, William V.; Whipple, George H.

1932-01-01

When the minimal renal threshold for blood hemoglobin is exceeded there is observed a deposit of iron staining pigment in the epithelium of the renal convoluted tubules. At a certain point this epithelium cannot take up more hemoglobin and this coincides with the minimal renal threshold level. When the injections of blood hemoglobin are kept below the minimal renal threshold level we note a complete absence of iron staining pigment in the renal tubular epithelium. Given a deposit of iron staining pigment in the tubular epithelium, it will slowly disappear during rest periods with no hemoglobin injections. Anemia due to bleeding will accelerate this removal of pigment from the renal epithelium and this indicates a conservation of material by the kidney for use in construction of new hemoglobin. Pigment giving a positive stain for iron will be found in the liver and spleen when hemoglobin injections are given, regardless of the renal threshold. Removal of this pigment is accelerated by anemia due to bleeding and as a rule an anemia period of 2 months at a level of 1/3 normal (40 to 50 per cent hemoglobin) will render the spleen, liver and kidney free from iron staining pigment. Pigment giving a positive iron stain is frequently observed in the mesenteric and lower retroperitoneal lymph glands. This is merely a drainage of pigment and phagocytes including pigment from some organ in which the pigment deposit was primary. In stock dogs in this laboratory the hemoglobin level is quite high when the animals are in a perfectly normal state. The blood hemoglobin averages 120 to 150 per cent hemoglobin. In such dogs iron staining pigment in the spleen is a common finding and on occasion is observed in the liver. To establish an accurate base line for the study of iron and iron staining pigment storage due to diet intake one must submit these dogs to a preliminary anemia period of at least 2 months. Muscle hemoglobin has a very low renal threshold and escapes freely into the

Activity of Brazilian propolis against Aeromonas hydrophila and its effect on Nile tilapia growth, hematological and non-specific immune response under bacterial infection.

PubMed

Orsi, Ricardo O; Santos, Vivian G Dos; Pezzato, Luiz E; Carvalho, Pedro L P F DE; Teixeira, Caroline P; Freitas, Jakeline M A; Padovani, Carlos R; Sartori, Maria M P; Barros, Margarida M

2017-01-01

The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish-1). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H2O2) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.

Simple Model of Sickle Hemoglobin

NASA Astrophysics Data System (ADS)

Shiryayev, Andrey; Li, Xiaofei; Gunton, James

2006-03-01

A microscopic model is proposed for the interactions between sickle hemoglobin molecules based on information from the protein data bank. A Monte Carlo simulation of a simplified two patch model is carried out, with the goal of understanding fiber formation. A gradual transition from monomers to one dimensional chains is observed as one varies the density of molecules at fixed temperature, somewhat similar to the transition from monomers to polymer fibers in sickle hemoglobin molecules in solution. An observed competition between chain formation and crystallization for the model is also discussed. The results of the simulation of the equation of state are shown to be in excellent agreement with a theory for a model of globular proteins, for the case of two interacting sites.

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

Viral-bacterial coinfection affects the presentation and alters the prognosis of severe community-acquired pneumonia.

PubMed

Voiriot, Guillaume; Visseaux, Benoit; Cohen, Johana; Nguyen, Liem Binh Luong; Neuville, Mathilde; Morbieu, Caroline; Burdet, Charles; Radjou, Aguila; Lescure, François-Xavier; Smonig, Roland; Armand-Lefèvre, Laurence; Mourvillier, Bruno; Yazdanpanah, Yazdan; Soubirou, Jean-Francois; Ruckly, Stephane; Houhou-Fidouh, Nadhira; Timsit, Jean-François

2016-10-25

Multiplex polymerase chain reaction (mPCR) enables recovery of viruses from airways of patients with community-acquired pneumonia (CAP), although their clinical impact remains uncertain. Among consecutive adult patients who had undergone a mPCR within 72 hours following their admission to one intensive care unit (ICU), we retrospectively included those with a final diagnosis of CAP. Four etiology groups were clustered: bacterial, viral, mixed (viral-bacterial) and no etiology. A composite criterion of complicated course (hospital death or mechanical ventilation > 7 days) was used. A subgroup analysis compared patients with bacterial and viral-bacterial CAP matched on the bacterial pathogens. Among 174 patients (132 men [76 %], age 63 [53-75] years, SAPSII 38 [27;55], median PSI score 106 [78;130]), bacterial, viral, mixed and no etiology groups gathered 46 (26 %), 53 (31 %), 45 (26 %) and 30 (17 %) patients, respectively. Virus-infected patients displayed a high creatine kinase serum level, a low platelet count, and a trend toward more frequent alveolar-interstitial infiltrates. A complicated course was more frequent in the mixed group (31/45, 69 %), as compared to bacterial (18/46, 39 %), viral (15/53, 28 %) and no etiology (12/30, 40 %) groups (p < 0.01). In multivariate analysis, the mixed (viral-bacterial) infection was independently associated with complicated course (reference: bacterial pneumonia; OR, 3.58; CI 95 %, 1.16-11; p = 0.03). The subgroup analysis of bacteria-matched patients confirmed these findings. Viral-bacterial coinfection during severe CAP in adults is associated with an impaired presentation and a complicated course.

[Hemoglobins, XXXII. Analysis of the primary structure of the monomeric hemoglobin CTT VIIA (erythrocruorin) or Chironomus thummi thummi, Diptera (author's transl)].

PubMed

Kleinschmidt, T; Braunitzer, G

1980-01-01

The dimeric hemoglobin CTT VIIA (erythrocruorin) was isolated from the hemolymph of the larva from Chironomus thummi thummi and purified by preparative polyacrylamide gel electrophoresis. Peptides obtained by limited tryptical digestion were sequenced by automatic Edman degradation. For the elucidation of the sequence in the C-terminal region of the chain, additional cleavages with proteinase of Staphylococcus aureus and chymotrypsin were necessary. CTT VIIA is compared with human beta-chains and other hemoglobins of Chironomus. The amino acid residues in the pocket are especially discussed. Most of them are invariant in all Chironomus hemoglobins, independent of the size of the heme pocket, which is normal in some components and enlarged in others.

Cloned Hemoglobin Genes Enhance Growth Of Cells

NASA Technical Reports Server (NTRS)

Khosla, Chaitan; Bailey, James E.

1991-01-01

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

Hemoglobin Concentration and Risk of Incident Stroke in Community-Living Adults.

PubMed

Panwar, Bhupesh; Judd, Suzanne E; Warnock, David G; McClellan, William M; Booth, John N; Muntner, Paul; Gutiérrez, Orlando M

2016-08-01

In previous observational studies, hemoglobin concentrations have been associated with an increased risk of stroke. However, these studies were limited by a relatively low number of stroke events, making it difficult to determine whether the association of hemoglobin and stroke differed by demographic or clinical factors. Using Cox proportional hazards analysis and Kaplan-Meier plots, we examined the association of baseline hemoglobin concentrations with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a cohort of black and white adults aged ≥45 years. A total of 518 participants developed stroke over a mean 7±2 years of follow-up. There was a statistically significant interaction between hemoglobin and sex (P=0.05) on the risk of incident stroke. In Cox regression models adjusted for demographic and clinical variables, there was no association of baseline hemoglobin concentration with incident stroke in men, whereas in women, the lowest (<12.4 g/dL) and highest (>14.0 g/dL) quartiles of hemoglobin were associated with higher risk of stroke when compared with the second quartile (12.4-13.2 g/dL; quartile 1: hazard ratio, 1.59; 95% confidence interval, 1.09-2.31; quartile 2: referent; quartile 3: hazard ratio, 0.91; 95% confidence interval, 0.59-1.38; quartile 4: hazard ratio, 1.59; 95% confidence interval, 1.08-2.35). Similar results were observed in models stratified by hemoglobin and sex and when hemoglobin was modeled as a continuous variable using restricted quadratic spline regression. Lower and higher hemoglobin concentrations were associated with a higher risk of incident stroke in women. No such associations were found in men. © 2016 American Heart Association, Inc.

Quantifying risk of penile prosthesis infection with elevated glycosylated hemoglobin.

PubMed

Wilson, S K; Carson, C C; Cleves, M A; Delk, J R

1998-05-01

Elevation of glycosylated hemoglobin above levels of 11.5 mg.% has been considered a contraindication to penile prosthesis implantation in diabetic patients. We determine the predictive value of glycosylated hemoglobin A1C in penile prosthesis infections in diabetic and nondiabetic patients to confirm or deny this prevalent opinion. We conducted a 2-year prospective study of 389 patients, including 114 diabetics, who underwent 3-piece penile prosthesis implantation. All patients had similar preoperative preparation without regard to diabetic status, control or glycosylated hemoglobin A1C level. Risk of infection was statistically analyzed for diabetics versus nondiabetics, glycosylated hemoglobin A1C values above and below 11.5 mg.%, insulin dependent versus oral medication diabetics, and fasting blood sugars above and below 180 mg.%. Prosthesis infections developed in 10 diabetics (8.7%) and 11 nondiabetics (4.0%). No increased infection rate was observed in diabetics with high fasting sugars or diabetics on insulin. There was no statistically significant increased infection risk with increased levels of glycosylated hemoglobin A1C among all patients or among only the diabetics. In fact, there was no meaningful difference in the median or mean level of glycosylated hemoglobin A1C in the infected and noninfected patients regardless of diabetes. Use of glycosylated hemoglobin A1C values to identify and exclude surgical candidates with increased risk of infections is not proved by this study. Elevation of fasting sugar or insulin dependence also does not increase risk of infection in diabetics undergoing prosthesis implantation.

A spectroscopic study on the interaction between gold nanoparticles and hemoglobin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabagiu, Sorina, E-mail: sgarabagiu@itim-cj.ro

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 longermore » 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.« less

High oxygen affinity hemoglobins.

PubMed

Mangin, O

2017-02-01

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

Altered gut microbiota in Rett syndrome.

PubMed

Strati, Francesco; Cavalieri, Duccio; Albanese, Davide; De Felice, Claudio; Donati, Claudio; Hayek, Joussef; Jousson, Olivier; Leoncini, Silvia; Pindo, Massimo; Renzi, Daniela; Rizzetto, Lisa; Stefanini, Irene; Calabrò, Antonio; De Filippo, Carlotta

2016-07-30

The human gut microbiota directly affects human health, and its alteration can lead to gastrointestinal abnormalities and inflammation. Rett syndrome (RTT), a progressive neurological disorder mainly caused by mutations in MeCP2 gene, is commonly associated with gastrointestinal dysfunctions and constipation, suggesting a link between RTT's gastrointestinal abnormalities and the gut microbiota. The aim of this study was to evaluate the bacterial and fungal gut microbiota in a cohort of RTT subjects integrating clinical, metabolomics and metagenomics data to understand if changes in the gut microbiota of RTT subjects could be associated with gastrointestinal abnormalities and inflammatory status. Our findings revealed the occurrence of an intestinal sub-inflammatory status in RTT subjects as measured by the elevated values of faecal calprotectin and erythrocyte sedimentation rate. We showed that, overall, RTT subjects harbour bacterial and fungal microbiota altered in terms of relative abundances from those of healthy controls, with a reduced microbial richness and dominated by microbial taxa belonging to Bifidobacterium, several Clostridia (among which Anaerostipes, Clostridium XIVa, Clostridium XIVb) as well as Erysipelotrichaceae, Actinomyces, Lactobacillus, Enterococcus, Eggerthella, Escherichia/Shigella and the fungal genus Candida. We further observed that alterations of the gut microbiota do not depend on the constipation status of RTT subjects and that this dysbiotic microbiota produced altered short chain fatty acids profiles. We demonstrated for the first time that RTT is associated with a dysbiosis of both the bacterial and fungal component of the gut microbiota, suggesting that impairments of MeCP2 functioning favour the establishment of a microbial community adapted to the costive gastrointestinal niche of RTT subjects. The altered production of short chain fatty acids associated with this microbiota might reinforce the constipation status of RTT

The hemoglobin system of the serpent eel Ophisurus serpens: structural and functional characterization.

PubMed

Manconi, Barbara; Pellegrini, Mariagiuseppina; Messana, Irene; Sanna, Maria Teresa; Castagnola, Massimo; Iavarone, Federica; Coluccia, Elisabetta; Giardina, Bruno; Olianas, Alessandra

2013-10-01

The hemoglobin system of the serpent eel Ophisurus serpens was structurally and functionally characterized with the aim of comparing it to the hemoglobin system of other fish species, as oxygen loading under the severe habitat conditions experienced by O. serpens could have necessitated specific adaptation mechanisms during evolution. The hemoglobin system of O. serpens includes one cathodic and four anodic components. The molecular mass of the α and β chains of the cathodic component as well as the 2 α and 4 β of the anodic components were determined. Analysis of the intact α and β chains from cathodic hemoglobin and their proteolytic digestion products by high-resolution MS and MS/MS experiments resulted in 92 and 95 % sequence coverage of the α and β globins, respectively. The oxygen binding properties of both hemoglobin components were analyzed with respect to their interactions with their physiological effectors. Stripped cathodic hemoglobin displayed the highest oxygen affinity among Anguilliformes with no significant effect of pH on O2-affinity. In the presence of both chloride and organic phosphates, O2-affinity was strongly reduced, and cooperativity was enhanced; moreover, cathodic hemoglobin contains two indistinguishable GTP-binding sites. Stripped anodic hemoglobins exhibited both low O2-affinity and low cooperativity and a larger Bohr effect than cathodic hemoglobin. The cathodic hemoglobin of O. serpens and the corresponding component of Conger conger share the greatest structural and functional similarity among hemoglobin systems of Anguilliformes studied to date, consistent with their phylogenetic relationship.

Evidence by chromatography and mass spectrometry that inorganic nitrite induces S-glutathionylation of hemoglobin in human red blood cells.

PubMed

Böhmer, Anke; Pich, Andreas; Schmidt, Mario; Haghikia, Arash; Tsikas, Dimitrios

2016-04-15

Previously we found by HPLC with fluorescence detection that inorganic nitrite induces oxidation of glutathione (GSH) to its disulfide (GSSG) in intact and more abundantly in lyzed red blood cells (RBCs) from healthy humans. In the present work, we performed MS-based protein analysis and observed that nitrite (range, 0-20mM) induces formation of S-glutathionyl hemoglobin (HbSSG) at cysteine (Cys) β93 and β112 of oxyhemoglobin (HbO2) in lyzed human RBCs (range, 6-8mM HbO2). Hemoglobin species were isolated from incubation mixtures of nitrite in lyzed RBCs by ultrafiltration or affinity chromatography and analyzed by HPLC and LC-MS/MS. The mechanism likely involves inhibition of catalase activity by nitrite (IC50, 9 μM), which allows H2O2 to accumulate and oxidize Cys moieties of oxyhemoglobin and erythrocytic GSH to form HbSSG in addition to GSSG. In freshly prepared hemolysate samples, nitrite induced release of superoxide and molecular oxygen. In the presence of paracetamol and nitrite in hemolysate samples, 3-nitro-paracetamol was detected. Nitrite also induced S-nitroso hemoglobin (HbSNO) formation in low yield (i.e., 0.1%). Synthetic cysteine (Cys), glutathione (GSH), N-acetylcysteine (NAC) and N-acetylcysteine ethyl ester (NACET) inhibited nitrite-induced modifications of oxyhemoglobin including methemoglobin, HbSSG (CysSH > NACET > GSH ≈ NAC; thiol concentration, 50 μM) and HbSNO. Nitrite-induced oxidative modifications may alter physiological hemoglobin functions and may require alternative treatments for conditions associated with oxidized hemoglobin like in nitrite-induced methemoglobinemia. Accumulation of soluble Cys in RBCs via oral administration of NACET could be a new promising strategy to prevent nitrite-induced methemoglobinemia by nitrite and other oxidants. Copyright © 2016 Elsevier B.V. All rights reserved.

Hemoglobin Levels Across the Pediatric Critical Care Spectrum: A Point Prevalence Study.

PubMed

Hassan, Nabil E; Reischman, Diann E; Fitzgerald, Robert K; Faustino, Edward Vincent S

2018-05-01

To determine the prevailing hemoglobin levels in PICU patients, and any potential correlates. Post hoc analysis of prospective multicenter observational data. Fifty-nine PICUs in seven countries. PICU patients on four specific days in 2012. None. Patients' hemoglobin and other clinical and institutional data. Two thousand three hundred eighty-nine patients with median age of 1.9 years (interquartile range, 0.3-9.8 yr), weight 11.5 kg (interquartile range, 5.4-29.6 kg), and preceding PICU stay of 4.0 days (interquartile range, 1.0-13.0 d). Their median hemoglobin was 11.0 g/dL (interquartile range, 9.6-12.5 g/dL). The prevalence of transfusion in the 24 hours preceding data collection was 14.2%. Neonates had the highest hemoglobin at 13.1 g/dL (interquartile range, 11.2-15.0 g/dL) compared with other age groups (p < 0.001). The percentage of 31.3 of the patients had hemoglobin of greater than or equal to 12 g/dL, and 1.1% had hemoglobin of less than 7 g/dL. Blacks had lower median hemoglobin (10.5; interquartile range, 9.3-12.1 g/dL) compared with whites (median, 11.1; interquartile range, 9.0-12.6; p < 0.001). Patients in Spain and Portugal had the highest median hemoglobin (11.4; interquartile range, 10.0-12.6) compared with other regions outside of the United States (p < 0.001), and the highest proportion (31.3%) of transfused patients compared with all regions (p < 0.001). Patients in cardiac PICUs had higher median hemoglobin than those in mixed PICUs or noncardiac PICUs (12.3, 11.0, and 10.6 g/dL, respectively; p < 0.001). Cyanotic heart disease patients had the highest median hemoglobin (12.6 g/dL; interquartile range, 11.1-14.5). Multivariable regression analysis within diagnosis groups revealed that hemoglobin levels were significantly associated with the geographic location and history of complex cardiac disease in most of the models. In children with cancer, none of the variables tested correlated with patients' hemoglobin levels

Different Types of Dietary Fibers Trigger Specific Alterations in Composition and Predicted Functions of Colonic Bacterial Communities in BALB/c Mice

PubMed Central

Luo, Yuheng; Zhang, Ling; Li, Hua; Smidt, Hauke; Wright, André-Denis G.; Zhang, Keying; Ding, Xuemei; Zeng, Qiufeng; Bai, Shiping; Wang, Jianping; Li, Jian; Zheng, Ping; Tian, Gang; Cai, Jingyi; Chen, Daiwen

2017-01-01

altered bacterial community in the colon of mice with the two dietary fibers probably resulted in a more efficient degradation of dietary polysaccharides. Our result suggests that the influence of dietary β-glucan (SDF) on colonic bacterial community of mice was more extensively than MCC (IDF). Co-supplementation of the two fibers may help to increase the bacterial diversity and reduce the conditional pathogens in the colon of mice. PMID:28611761

Different Types of Dietary Fibers Trigger Specific Alterations in Composition and Predicted Functions of Colonic Bacterial Communities in BALB/c Mice.

PubMed

Luo, Yuheng; Zhang, Ling; Li, Hua; Smidt, Hauke; Wright, André-Denis G; Zhang, Keying; Ding, Xuemei; Zeng, Qiufeng; Bai, Shiping; Wang, Jianping; Li, Jian; Zheng, Ping; Tian, Gang; Cai, Jingyi; Chen, Daiwen

2017-01-01

that the altered bacterial community in the colon of mice with the two dietary fibers probably resulted in a more efficient degradation of dietary polysaccharides. Our result suggests that the influence of dietary β-glucan (SDF) on colonic bacterial community of mice was more extensively than MCC (IDF). Co-supplementation of the two fibers may help to increase the bacterial diversity and reduce the conditional pathogens in the colon of mice.

Computation Of Facilitated Transport of O2 In Hemoglobin

NASA Technical Reports Server (NTRS)

Davis, Sanford

1991-01-01

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

Point-of-care hemoglobin testing for postmortem diagnosis of anemia.

PubMed

Na, Joo-Young; Park, Ji Hye; Choi, Byung Ha; Kim, Hyung-Seok; Park, Jong-Tae

2018-03-01

An autopsy involves examination of a body using invasive methods such as dissection, and includes various tests using samples procured during dissection. During medicolegal autopsies, the blood carboxyhemoglobin concentration is commonly measured using the AVOXimeter® 4000 as a point-of-care test. When evaluating the body following hypovolemic shock, characteristics such as reduced livor mortis or an anemic appearance of the viscera can be identified, but these observations arequite subjective. Thus, a more objective test is required for the postmortem diagnosis of anemia. In the present study, the AVOXimeter® 4000 was used to investigate the utility of point-of-care hemoglobin testing. Hemoglobin tests were performed in 93 autopsy cases. The AVOXimeter® 4000 and the BC-2800 Auto Hematology Analyzer were used to test identical samples in 29 of these cases. The results of hemoglobin tests performed with these two devices were statistically similar (r = 0.969). The results of hemoglobin tests using postmortem blood were compared with antemortem test results from medical records from 31 cases, and these results were similar. In 13 of 17 cases of death from internal hemorrhage, hemoglobin levels were lower in the cardiac blood than in blood from the affected body cavity, likely due to compensatory changes induced by antemortem hemorrhage. It is concluded that blood hemoglobin testing may be useful as a point-of-care test for diagnosing postmortem anemia.

A proposal to standardize reporting units for fecal immunochemical tests for hemoglobin.

PubMed

Fraser, Callum G; Allison, James E; Halloran, Stephen P; Young, Graeme P

2012-06-06

Fecal immunochemical tests for hemoglobin are replacing traditional guaiac fecal occult blood tests in population screening programs for many reasons. However, the many available fecal immunochemical test devices use a range of sampling methods, differ with regard to hemoglobin stability, and report hemoglobin concentrations in different ways. The methods for sampling, the mass of feces collected, and the volume and characteristics of the buffer used in the sampling device also vary among fecal immunochemical tests, making comparisons of test performance characteristics difficult. Fecal immunochemical test results may be expressed as the hemoglobin concentration in the sampling device buffer and, sometimes, albeit rarely, as the hemoglobin concentration per mass of feces. The current lack of consistency in units for reporting hemoglobin concentration is particularly problematic because apparently similar hemoglobin concentrations obtained with different devices can lead to very different clinical interpretations. Consistent adoption of an internationally accepted method for reporting results would facilitate comparisons of outcomes from these tests. We propose a simple strategy for reporting fecal hemoglobin concentration that will facilitate the comparison of results between fecal immunochemical test devices and across clinical studies. Such reporting is readily achieved by defining the mass of feces sampled and the volume of sample buffer (with confidence intervals) and expressing results as micrograms of hemoglobin per gram of feces. We propose that manufacturers of fecal immunochemical tests provide this information and that the authors of research articles, guidelines, and policy articles, as well as pathology services and regulatory bodies, adopt this metric when reporting fecal immunochemical test results.

Rapid recovery of soil bacterial communities after wildfire in a Chinese boreal forest

PubMed Central

Xiang, Xingjia; Shi, Yu; Yang, Jian; Kong, Jianjian; Lin, Xiangui; Zhang, Huayong; Zeng, Jun; Chu, Haiyan

2014-01-01

Fires affect hundreds of millions of hectares annually. Above-ground community composition and diversity after fire have been studied extensively, but effects of fire on soil bacterial communities remain largely unexamined despite the central role of bacteria in ecosystem recovery and functioning. We investigated responses of bacterial community to forest fire in the Greater Khingan Mountains, China, using tagged pyrosequencing. Fire altered soil bacterial community composition substantially and high-intensity fire significantly decreased bacterial diversity 1-year-after-burn site. Bacterial community composition and diversity returned to similar levels as observed in controls (no fire) after 11 years. The understory vegetation community typically takes 20–100 years to reach pre-fire states in boreal forest, so our results suggest that soil bacteria could recover much faster than plant communities. Finally, soil bacterial community composition significantly co-varied with soil pH, moisture content, NH4+ content and carbon/nitrogen ratio (P < 0.05 in all cases) in wildfire-perturbed soils, suggesting that fire could indirectly affect bacterial communities by altering soil edaphic properties. PMID:24452061

Structural and functional properties of hemoglobins from unicellular organisms as revealed by resonance Raman spectroscopy.

PubMed

Egawa, Tsuyoshi; Yeh, Syun-Ru

2005-01-01

Hemoglobins have been discovered in organisms from virtually all kingdoms. Their presence in unicellular organisms suggests that the gene for hemoglobin is very ancient and that the hemoglobins must have functions other than oxygen transport, in view of the fact that O2 delivery is a diffusion-controlled process in these organisms. Based on sequence alignment, three groups of hemoglobins have been characterized in unicellular organisms. The group-one hemoglobins, termed truncated hemoglobins, consist of proteins with 110-140 amino acid residues and a novel two-over-two alpha-helical sandwich motif. The group-two hemoglobins, termed flavohemoglobins, consist of a hemoglobin domain, with a classical three-over-three alpha-helical sandwich motif, and a flavin-containing reductase domain that is covalently attached to it. The group-three hemoglobins consist of myoglobin-like proteins that have high sequence homology and structural similarity to the hemoglobin domain of flavohemoglobins. In this review, recent resonance Raman studies of each group of these proteins are presented. Their implications are discussed in the context of the structural and functional properties of these novel hemoglobins.

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%.

Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder

PubMed Central

Carrick, Hunter J.; Cavaletto, Joann; Chiang, Edna; Johengen, Thomas H.; Vanderploeg, Henry A.

2017-01-01

ABSTRACT One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptible to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions. IMPORTANCE Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a

Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder.

PubMed

Denef, Vincent J; Carrick, Hunter J; Cavaletto, Joann; Chiang, Edna; Johengen, Thomas H; Vanderploeg, Henry A

2017-01-01

One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptible to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions. IMPORTANCE Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of

Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denef, Vincent J.; Carrick, Hunter J.; Cavaletto, Joann

One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptiblemore » to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions.Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of

Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder

DOE PAGES

Denef, Vincent J.; Carrick, Hunter J.; Cavaletto, Joann; ...

2017-05-31

One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptiblemore » to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions.Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of

Identification of Hemoglobin Levels Based on Anthropometric Indices in Elderly Koreans

PubMed Central

Kim, Jong Yeol

2016-01-01

Objectives Anemia is independently and strongly associated with an increased risk of mortality in older people and is also strongly associated with obesity. The objectives of the present study were to examine the associations between the hemoglobin level and various anthropometric indices, to predict low and normal hemoglobin levels using combined anthropometric indices, and to assess differences in the hemoglobin level and anthropometric indices between Korean men and women. Methods A total of 7,156 individuals ranging in age from 53–90 years participated in this retrospective cross-sectional study. Binary logistic regression (LR) and naïve Bayes (NB) models were used to identify significant differences in the anthropometric indices between subjects with low and normal hemoglobin levels and to assess the predictive power of these indices for the hemoglobin level. Results Among all of the variables, age displayed the strongest association with the hemoglobin level in both men (p < 0.0001, odds ratio [OR] = 0.487, area under the receiver operating characteristic curve based on the LR [LR-AUC] = 0.702, NB-AUC = 0.701) and women (p < 0.0001, OR = 0.636, LR-AUC = 0.625, NB-AUC = 0.624). Among the anthropometric indices, weight and body mass index (BMI) were the best predictors of the hemoglobin level. The predictive powers of all of the variables were higher in men than in women. The AUC values for the NB-Wrapper and LR-Wrapper predictive models generated using combined anthropometric indices were 0.734 and 0.723, respectively, for men and 0.649 and 0.652, respectively, for women. The use of combined anthropometric indices may improve the predictive power for the hemoglobin level. Discussion Among the various anthropometric indices, with the exception of age, we did not identify any indices that were better predictors than weight and BMI for low and normal hemoglobin levels. In addition, none of the ratios between pairs of indices were good indicators of the

Hemoglobin diffusion and the dynamics of oxygen capture by red blood cells.

PubMed

Longeville, Stéphane; Stingaciu, Laura-Roxana

2017-09-05

Translational diffusion of macromolecules in cell is generally assumed to be anomalous due high macromolecular crowding of the milieu. Red blood cells are a special case of cells filled quasi exclusively (95% of the dry weight of the cell) with an almost spherical protein: hemoglobin. Hemoglobin diffusion has since a long time been recognized as facilitating the rate of oxygen diffusion through a solution. We address in this paper the question on how hemoglobin diffusion in the red blood cells can help the oxygen capture at the cell level and hence to improve oxygen transport. We report a measurement by neutron spin echo spectroscopy of the diffusion of hemoglobin in solutions with increasing protein concentration. We show that hemoglobin diffusion in solution can be described as Brownian motion up to physiological concentration and that hemoglobin diffusion in the red blood cells and in solutions at similar concentration are the same. Finally, using a simple model and the concentration dependence of the diffusion of the protein reported here, we show that hemoglobin concentration observed in human red blood cells ([Formula: see text]330 g.L -1 ) corresponds to an optimum for oxygen transport for individuals under strong activity.

Molecularly imprinted composite cryogels for hemoglobin depletion from human blood.

PubMed

Baydemir, Gözde; Andaç, Müge; Perçin, Işιk; Derazshamshir, Ali; Denizli, Adil

2014-09-01

A molecularly imprinted composite cryogel (MICC) was prepared for depletion of hemoglobin from human blood prior to use in proteome applications. Poly(hydroxyethyl methacrylate) based MICC was prepared with high gel fraction yields up to 90%, and characterized by Fourier transform infrared spectrophotometer, scanning electron microscopy, swelling studies, flow dynamics and surface area measurements. MICC exhibited a high binding capacity and selectivity for hemoglobin in the presence of immunoglobulin G, albumin and myoglobin. MICC column was successfully applied in fast protein liquid chromatography system for selective depletion of hemoglobin for human blood. The depletion ratio was highly increased by embedding microspheres into the cryogel (93.2%). Finally, MICC can be reused many times with no apparent decrease in hemoglobin adsorption capacity. Copyright © 2014 John Wiley & Sons, Ltd.

Specific inflammatory response of Anemonia sulcata (Cnidaria) after bacterial injection causes tissue reaction and enzymatic activity alteration.

PubMed

Trapani, M R; Parisi, M G; Parrinello, D; Sanfratello, M A; Benenati, G; Palla, F; Cammarata, M

2016-03-01

The evolution of multicellular organisms was marked by adaptations to protect against pathogens. The mechanisms for discriminating the ''self'' from ''non-self" have evolved into a long history of cellular and molecular strategies, from damage repair to the co-evolution of host-pathogen interactions. We investigated the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of substances that varied in type and dimension, and observed clear, strong and specific reactions, especially after injection of Escherichia coli and Vibrio alginolyticus. Moreover, we analyzed enzymatic activity of protease, phosphatase and esterase, showing how the injection of different bacterial strains alters the expression of these enzymes and suggesting a correlation between the appearance of the inflammatory reaction and the modification of enzymatic activities. Our study shows for the first time, a specific reaction and enzymatic responses following injection of bacteria in a cnidarian. Copyright © 2016 Elsevier Inc. All rights reserved.

Simultaneous estimation of transcutaneous bilirubin, hemoglobin, and melanin based on diffuse reflectance spectroscopy

NASA Astrophysics Data System (ADS)

Nishidate, Izumi; Abdul, Wares MD.; Ohtsu, Mizuki; Nakano, Kazuya; Haneishi, Hideaki

2018-02-01

We propose a method to estimate transcutaneous bilirubin, hemoglobin, and melanin based on the diffuse reflectance spectroscopy. In the proposed method, the Monte Carlo simulation-based multiple regression analysis for an absorbance spectrum in the visible wavelength region (460-590 nm) is used to specify the concentrations of bilirubin (Cbil), oxygenated hemoglobin (Coh), deoxygenated hemoglobin (Cdh), and melanin (Cm). Using the absorbance spectrum calculated from the measured diffuse reflectance spectrum as a response variable and the extinction coefficients of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Total hemoglobin concentration (Cth) and tissue oxygen saturation (StO2) are simply calculated from the oxygenated hemoglobin and deoxygenated hemoglobin. In vivo animal experiments with bile duct ligation in rats demonstrated that the estimated Cbil is increased after ligation of bile duct and reaches to around 20 mg/dl at 72 h after the onset of the ligation, which corresponds to the reference value of Cbil measured by a commercially available transcutaneous bilirubin meter. We also performed in vivo experiments with rats while varying the fraction of inspired oxygen (FiO2). Coh and Cdh decreased and increased, respectively, as FiO2 decreased. Consequently, StO2 was dramatically decreased. The results in this study indicate potential of the method for simultaneous evaluation of multiple chromophores in skin tissue.

The narrow therapeutic window of glycated hemoglobin and assay variability.

PubMed

Hosseini, S S; Bibler, I; Charles, M A

1999-12-01

Glycated hemoglobin is measured by a variety of assays, each of which has a unique normal level. Our purpose is to show that among the different assays available in the United States, using the same patient's blood sample, assay results may vary widely and may more or less easily achieve a glycated hemoglobin value within the normal range. The following assays were compared using the same patient's blood sample for each pair of assays: glycohemoglobin affinity assay (GHB Reader; Isolab, Akron, OH) versus gel electrophoresis assay (n = 76); Isolab versus ion capture assay (IMX; Abbott Laboratories, Irving, TX) (n = 57); monoclonal antibody assay (DCA2000; Bayer Diagnostics, Pittsburgh, PA) versus IMX (n = 100); and high-performance liquid chromatography (HPLC) assay (Bio-Rad Variant A1c; Bio-Rad Laboratories, Richmond, CA) versus IMX assay (n = 55). Our analyses indicate that a relative ranking can be established for the ease of achieving a normal glycated hemoglobin level. The ranking indicates that the most stringent or difficult assays for achieving a normal level are the Isolab and DCA2000 assays. The intermediate assays are the IMX and Bio-Rad Variant, and the easiest method for achieving a normal value is the gel electrophoresis assay. Our results indicate that various glycated hemoglobin assays vary widely and are associated with more or less difficulty for an individual patient to achieve a glycated hemoglobin level within the normal range. These results are especially significant with respect to (1) the clinically narrow therapeutic window of glycated hemoglobin values in type 1 diabetes to avoid rapidly advancing severe hypoglycemia rates and chronic microvascular complication rates, and (2) the glycated hemoglobin threshold for rapidly advancing macrovascular disease in both type 1 and type 2 patients.

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.

Bacterial-like PPP protein phosphatases: novel sequence alterations in pathogenic eukaryotes and peculiar features of bacterial sequence similarity.

PubMed

Kerk, David; Uhrig, R Glen; Moorhead, Greg B

2013-01-01

Reversible phosphorylation is a widespread modification affecting the great majority of eukaryotic cellular proteins, and whose effects influence nearly every cellular function. Protein phosphatases are increasingly recognized as exquisitely regulated contributors to these changes. The PPP (phosphoprotein phosphatase) family comprises enzymes, which catalyze dephosphorylation at serine and threonine residues. Nearly a decade ago, "bacterial-like" enzymes were recognized with similarity to proteins from various bacterial sources: SLPs (Shewanella-like phosphatases), RLPHs (Rhizobiales-like phosphatases), and ALPHs (ApaH-like phosphatases). A recent article from our laboratory appearing in Plant Physiology characterizes their extensive organismal distribution, abundance in plant species, predicted subcellular localization, motif organization, and sequence evolution. One salient observation is the distinct evolutionary trajectory followed by SLP genes and proteins in photosynthetic eukaryotes vs. animal and plant pathogens derived from photosynthetic ancestors. We present here a closer look at sequence data that emphasizes the distinctiveness of pathogen SLP proteins and that suggests that they might represent novel drug targets. A second observation in our original report was the high degree of similarity between the bacterial-like PPPs of eukaryotes and closely related proteins of the "eukaryotic-like" phyla Myxococcales and Planctomycetes. We here reflect on the possible implications of these observations and their importance for future research.

Protein relaxation without a geminate phase in nanosecond photodissociated CO carp hemoglobin

NASA Astrophysics Data System (ADS)

Loupiac, Camille; Kruk, Nicolay; Valat, Pierre; Alpert, Bernard

1999-03-01

Transient heme-protein interactions upon passing from ligated to deligated carp hemoglobin were observed through time-resolved optical spectra following nanosecond CO photodissociation. The spectral evolution of the heme, in the nanosecond and microsecond time ranges, shows a protein conformational relaxation and the absence of a geminate CO recombination in carp hemoglobin. The comparison of the phenomena in carp and human hemoglobin implies that the physical basis of the geminate rebinding in human hemoglobin should involve an out-of-equilibrium protein conformation, close to a dissipative structure defined by the thermodynamics of Prigogine.

Hemoglobin spectra affect measurement of tissue oxygen saturation

NASA Astrophysics Data System (ADS)

Ostojic, Daniel; Kleiser, Stefan; Nasseri, Nassim; Isler, Helene; Scholkmann, Felix; Karen, Tanja; Wolf, Martin

2018-02-01

Tissue oxygen saturation (StO2) is a valuable clinical parameter e.g. for intensive care applications or monitoring during surgery. Studies showed that near-infrared spectroscopy (NIRS) based tissue oximeters of different brands give systematically different readings of StO2. Usually these readings are linearly correlated and therefore StO2 readings from one instrument can easily be converted to those of another instrument. However, it is interesting to understand why there is this difference. One reason may be that different brands employ different spectra of hemoglobin. The aim here was to investigate how these different absorption spectra of hemoglobin affect the StO2 readings. Therefore, we performed changes in StO2 in a phantom experiment with real human hemoglobin at three different concentrations (26.5, 45 and 70 μM): desaturation by yeast consuming the oxygen and re-saturation by bubbling oxygen gas. The partial pressure of O2 in the liquid changed from at least 10 kPa to 0 kPa and ISS OxiplexTS, a frequency-domain NIRS instrument, was used to monitor changes of StO2. When we employed two different absorption spectra for hemoglobin, StO2 values were comparable in the normal physiological range. However, particularly at high and low StO2 values, a difference of >6% between these two spectra were noticed. Such a difference of >6% is substantial and relevant for medical applications. This may partly explain why different brands of NIRS instruments provide different StO2 readings. The hemoglobin spectra are therefore a factor to be considered for future developments and applications of NIRS oximeters.

Purification of diverse hemoglobins by metal salt precipitation.

PubMed

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

2016-09-01

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

Hemoglobin diffusion and the dynamics of oxygen capture by red blood cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Longeville, Stéphane; Stingaciu, Laura-Roxana

Translational diffusion of macromolecules in cell is generally assumed to be anomalous due high macromolecular crowding of the milieu. Red blood cells are a special case of cells filled quasi exclusively (95% of the dry weight of the cell) with an almost spherical protein: hemoglobin. Hemoglobin diffusion has since a long time been recognized as facilitating the rate of oxygen diffusion through a solution. We address in this paper the question on how hemoglobin diffusion in the red blood cells can help the oxygen capture at the cell level and hence to improve oxygen transport. We report a measurement bymore » neutron spin echo spectroscopy of the diffusion of hemoglobin in solutions with increasing protein concentration. We show that hemoglobin diffusion in solution can be described as Brownian motion up to physiological concentration and that hemoglobin diffusion in the red blood cells and in solutions at similar concentration are the same. Finally, using a simple model and the concentration dependence of the diffusion of the protein reported here, we show that hemoglobin concentration observed in human red blood cells (≃330 g.L -1) corresponds to an optimum for oxygen transport for individuals under strong activity.« less

Hemoglobin diffusion and the dynamics of oxygen capture by red blood cells

DOE PAGES

Longeville, Stéphane; Stingaciu, Laura-Roxana

2017-09-05

Translational diffusion of macromolecules in cell is generally assumed to be anomalous due high macromolecular crowding of the milieu. Red blood cells are a special case of cells filled quasi exclusively (95% of the dry weight of the cell) with an almost spherical protein: hemoglobin. Hemoglobin diffusion has since a long time been recognized as facilitating the rate of oxygen diffusion through a solution. We address in this paper the question on how hemoglobin diffusion in the red blood cells can help the oxygen capture at the cell level and hence to improve oxygen transport. We report a measurement bymore » neutron spin echo spectroscopy of the diffusion of hemoglobin in solutions with increasing protein concentration. We show that hemoglobin diffusion in solution can be described as Brownian motion up to physiological concentration and that hemoglobin diffusion in the red blood cells and in solutions at similar concentration are the same. Finally, using a simple model and the concentration dependence of the diffusion of the protein reported here, we show that hemoglobin concentration observed in human red blood cells (≃330 g.L -1) corresponds to an optimum for oxygen transport for individuals under strong activity.« less

Bacterial strategies of resistance to antimicrobial peptides.

PubMed

Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

2016-05-26

Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

Bacterial symbionts and natural products

PubMed Central

Crawford, Jason M.; Clardy, Jon

2011-01-01

The study of bacterial symbionts of eukaryotic hosts has become a powerful discovery engine for chemistry. This highlight looks at four case studies that exemplify the range of chemistry and biology involved in these symbioses: a bacterial symbiont of a fungus and a marine invertebrate that produce compounds with significant anticancer activity, and bacterial symbionts of insects and nematodes that produce compounds that regulate multilateral symbioses. In the last ten years, a series of shocking revelations – the molecular equivalents of a reality TV show’s uncovering the true parents of a well known individual or a deeply hidden family secret – altered the study of genetically encoded small molecules, natural products for short. These revelations all involved natural products produced by bacterial symbionts, and while details differed, two main plot lines emerged: parentage, in which the real producers of well known natural products with medical potential were not the organisms from which they were originally discovered, and hidden relationships, in which bacterially produced small molecules turned out to be the unsuspected regulators of complex interactions. For chemists, these studies led to new molecules, new biosynthetic pathways, and an understanding of the biological functions these molecules fulfill. PMID:21594283

Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

PubMed

Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

2014-05-01

Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Modeling the integration of bacterial rRNA fragments into the human cancer genome.

PubMed

Sieber, Karsten B; Gajer, Pawel; Dunning Hotopp, Julie C

2016-03-21

Cancer is a disease driven by the accumulation of genomic alterations, including the integration of exogenous DNA into the human somatic genome. We previously identified in silico evidence of DNA fragments from a Pseudomonas-like bacteria integrating into the 5'-UTR of four proto-oncogenes in stomach cancer sequencing data. The functional and biological consequences of these bacterial DNA integrations remain unknown. Modeling of these integrations suggests that the previously identified sequences cover most of the sequence flanking the junction between the bacterial and human DNA. Further examination of these reads reveals that these integrations are rich in guanine nucleotides and the integrated bacterial DNA may have complex transcript secondary structures. The models presented here lay the foundation for future experiments to test if bacterial DNA integrations alter the transcription of the human genes.

Influence of hemoglobin on non-invasive optical bilirubin sensing

NASA Astrophysics Data System (ADS)

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

2012-03-01

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

Oxygen transport of hemoglobin in high-altitude animals (Camelidae).

PubMed

Reynafarje, C; Faura, J; Villavicencio, D; Curaca, A; Reynafarje, B; Oyola, L; Contreras, L; Vallenas, E; Faura, A

1975-05-01

To clarify the mechanisms by which high-altitude Camelidae can adapt to hypoxia, the study of some blood characteristics were carried out in apacas and llamas. The results show that there is a peculiar dissociation curve of hemoglobin in alpacas which permits great affinity of hemoglobin for oxygen at lung level and the release of oxygen at the tissue level with a facility similar to that in man. Fetal hemoglobin was found high in adult alpacas (55 percent). Electrophoretic studies of hemoglobin showed that this pigment has two components, both of which have a very low mobility. Lactic dehydrogenase was found six times higher than in humans. RBC glucose-6-phosphate dehydrogenase was two times higher than in man living at the same altitude. Myoglobin was found to be higher than in man living at altitude. Alpacas have erythrocytes in which the amount of 2,3-DPG is approximately the same as in man. RBC are more resistent to hypotonic solutions than humans. The amount of lactic dehydrogenase, myoglobin, and glucose-6-phosphate dehydrogenase dimishes when alpacas are bought down to sea level.

A Hemoglobin Variant Associated with Neonatal Cyanosis and Anemia

PubMed Central

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

2013-01-01

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

Ethnically Tibetan women in Nepal with low hemoglobin concentration have better reproductive outcomes

PubMed Central

Cho, Jang Ik; Basnyat, Buddha; Jeong, Choongwon; Di Rienzo, Anna; Childs, Geoff; Craig, Sienna R.; Sun, Jiayang

2017-01-01

Abstract Background and objectives: Tibetans have distinctively low hemoglobin concentrations at high altitudes compared with visitors and Andean highlanders. This study hypothesized that natural selection favors an unelevated hemoglobin concentration among Tibetans. It considered nonheritable sociocultural factors affecting reproductive success and tested the hypotheses that a higher percent of oxygen saturation of hemoglobin (indicating less stress) or lower hemoglobin concentration (indicating dampened response) associated with higher lifetime reproductive success. Methodology: We sampled 1006 post-reproductive ethnically Tibetan women residing at 3000–4100 m in Nepal. We collected reproductive histories by interviews in native dialects and noninvasive physiological measurements. Regression analyses selected influential covariates of measures of reproductive success: the numbers of pregnancies, live births and children surviving to age 15. Results: Taking factors such as marriage status, age of first birth and access to health care into account, we found a higher percent of oxygen saturation associated weakly and an unelevated hemoglobin concentration associated strongly with better reproductive success. Women who lost all their pregnancies or all their live births had hemoglobin concentrations significantly higher than the sample mean. Elevated hemoglobin concentration associated with a lower probability a pregnancy progressed to a live birth. Conclusions and implications: These findings are consistent with the hypothesis that unelevated hemoglobin concentration is an adaptation shaped by natural selection resulting in the relatively low hemoglobin concentration of Tibetans compared with visitors and Andean highlanders. PMID:28567284

Blood replacement with nanobiotechnologically engineered hemoglobin and hemoglobin nanocapsules

PubMed Central

Chang, Thomas Ming Swi

2012-01-01

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

Method for construction of bacterial strains with increased succinic acid production

DOEpatents

Donnelly, Mark I.; Sanville-Millard, Cynthia; Chatterjee, Ranjini

2000-01-01

A fermentation process for producing succinic acid is provided comprising selecting a bacterial strain that does not produce succinic acid in high yield, disrupting the normal regulation of sugar metabolism of said bacterial strain, and combining the mutant bacterial strain and selected sugar in anaerobic conditions to facilitate production of succinic acid. Also provided is a method for changing low yield succinic acid producing bacteria to high yield succinic acid producing bacteria comprising selecting a bacterial strain having a phosphotransferase system and altering the phosphotransferase system so as to allow the bacterial strain to simultaneously metabolize different sugars.

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.

Optical wavelength selection for portable hemoglobin determination by near-infrared spectroscopy method

NASA Astrophysics Data System (ADS)

Tian, Han; Li, Ming; Wang, Yue; Sheng, Dinggao; Liu, Jun; Zhang, Linna

2017-11-01

Hemoglobin concentration is commonly used in clinical medicine to diagnose anemia, identify bleeding, and manage red blood cell transfusions. The golden standard method for determining hemoglobin concentration in blood requires reagent. Spectral methods were advantageous at fast and non-reagent measurement. However, model calibration with full spectrum is time-consuming. Moreover, it is necessary to use a few variables considering size and cost of instrumentation, especially for a portable biomedical instrument. This study presents different wavelength selection methods for optical wavelengths for total hemoglobin concentration determination in whole blood. The results showed that modelling using only two wavelengths combination (1143 nm, 1298 nm) can keep on the fine predictability with full spectrum. It appears that the proper selection of optical wavelengths can be more effective than using the whole spectra for determination hemoglobin in whole blood. We also discussed the influence of water absorptivity on the wavelength selection. This research provides valuable references for designing portable NIR instruments determining hemoglobin concentration, and may provide some experience for noninvasive hemoglobin measurement by NIR methods.

Bacterial vaginosis and preterm birth.

PubMed

Manns-James, Laura

2011-01-01

Although it has been clear for more than 2 decades that bacterial vaginosis increases the risk for preterm birth in some women, it is not yet fully understood why this association exists or how best to modify the risk. Incomplete understanding of this polymicrobial condition and difficulties in classification contribute to the challenge. The relationship between altered vaginal microflora and preterm birth is likely mediated by host immune responses. Because treatment of bacterial vaginosis during pregnancy does not improve preterm birth rates, and may in fact increase them, screening and treatment of asymptomatic pregnant women is discouraged. Symptomatic women should be treated for symptom relief. This article reviews the pathophysiology of bacterial vaginosis and controversy surrounding management during pregnancy. Agents currently recommended for treatment of this condition are reviewed. © 2011 by the American College of Nurse-Midwives.

PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION

PubMed Central

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

1947-01-01

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

Nitric Oxide in Plants: The Roles of Ascorbate and Hemoglobin

PubMed Central

Wang, Xiaoguang; Hargrove, Mark S.

2013-01-01

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

Subunit assembly of hemoglobin: an important determinant of hematologic phenotype.

PubMed

Bunn, H F

1987-01-01

Hemoglobin's physiologic properties depend on the orderly assembly of its subunits in erythropoietic cells. The biosynthesis of alpha- and beta-globin polypeptide chains is normally balanced. Heme rapidly binds to the globin subunit, either during translation or shortly thereafter. The formation of the alpha beta-dimer is facilitated by electrostatic attraction of a positively charged alpha-subunit to a negatively charged beta-subunit. The alpha beta-dimer dissociates extremely slowly. The difference between the rate of dissociation of alpha beta- and alpha gamma-dimers with increasing pH explains the well-known alkaline resistance of Hb F. Two dimers combine to form the functioning alpha 2 beta 2-tetramer. This model of hemoglobin assembly explains the different levels of positively charged and negatively charged mutant hemoglobins that are encountered in heterozygotes and the effect of alpha-thalassemia and heme deficiency states in modifying the level of the variant hemoglobin as well as Hb A2. Electrostatic interactions also affect the binding of hemoglobin to the cytoplasmic surface of the red cell membrane and may underlie the formation of target cells. Enhanced binding of positively charged variants such as S and C trigger a normally dormant pathway for potassium and water loss. Thus, the positive charge on beta c is responsible for the two major contributors to the pathogenesis of Hb SC disease: increased proportion of Hb S and increased intracellular hemoglobin concentration. It is likely that electrostatic interactions play an important role in the assembly of a number of other multisubunit macromolecules, including membrane receptors, cytoskeletal proteins, and DNA binding proteins.

Manipulation of host membranes by bacterial effectors.

PubMed

Ham, Hyeilin; Sreelatha, Anju; Orth, Kim

2011-07-18

Bacterial pathogens interact with host membranes to trigger a wide range of cellular processes during the course of infection. These processes include alterations to the dynamics between the plasma membrane and the actin cytoskeleton, and subversion of the membrane-associated pathways involved in vesicle trafficking. Such changes facilitate the entry and replication of the pathogen, and prevent its phagocytosis and degradation. In this Review, we describe the manipulation of host membranes by numerous bacterial effectors that target phosphoinositide metabolism, GTPase signalling and autophagy.

Theoretical model for optical oximetry at the capillary level: exploring hemoglobin oxygen saturation through backscattering of single red blood cells

NASA Astrophysics Data System (ADS)

Liu, Rongrong; Spicer, Graham; Chen, Siyu; Zhang, Hao F.; Yi, Ji; Backman, Vadim

2017-02-01

Oxygen saturation (sO2) of red blood cells (RBCs) in capillaries can indirectly assess local tissue oxygenation and metabolic function. For example, the altered retinal oxygenation in diabetic retinopathy and local hypoxia during tumor development in cancer are reflected by abnormal sO2 of local capillary networks. However, it is far from clear whether accurate label-free optical oximetry (i.e., measuring hemoglobin sO2) is feasible from dispersed RBCs at the single capillary level. The sO2-dependent hemoglobin absorption contrast present in optical scattering signal is complicated by geometry-dependent scattering from RBCs. We present a numerical study of backscattering spectra from single RBCs based on the first-order Born approximation, considering practical factors: RBC orientations, size variation, and deformations. We show that the oscillatory spectral behavior of RBC geometries is smoothed by variations in cell size and orientation, resulting in clear sO2-dependent spectral contrast. In addition, this spectral contrast persists with different mean cellular hemoglobin content and different deformations of RBCs. This study shows for the first time the feasibility of, and provides a theoretical model for, label-free optical oximetry at the single capillary level using backscattering-based imaging modalities, challenging the popular view that such measurements are impossible at the single capillary level.

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

Role of Reversible Histidine Coordination in Hydroxylamine Reduction by Plant Hemoglobins (Phytoglobins).

PubMed

Athwal, Navjot Singh; Alagurajan, Jagannathan; Andreotti, Amy H; Hargrove, Mark S

2016-10-18

Reduction of hydroxylamine to ammonium by phytoglobin, a plant hexacoordinate hemoglobin, is much faster than that of other hexacoordinate hemoglobins or pentacoordinate hemoglobins such as myoglobin, leghemoglobin, and red blood cell hemoglobin. The reason for differences in reactivity is not known but could be intermolecular electron transfer between protein molecules in support of the required two-electron reduction, hydroxylamine binding, or active site architecture favoring the reaction. Experiments were conducted with phytoglobins from rice, tomato, and soybean along with human neuroglobin and soybean leghemoglobin that reveal hydroxylamine binding as the rate-limiting step. For hexacoordinate hemoglobins, binding is limited by the dissociation rate constant for the distal histidine, while leghemoglobin is limited by an intrinsically low affinity for hydroxylamine. When the distal histidine is removed from rice phytoglobin, a hydroxylamine-bound intermediate is formed and the reaction rate is diminished, indicating that the distal histidine imidazole side chain is critical for the reaction, albeit not for electron transfer but rather for direct interaction with the substrate. Together, these results demonstrate that phytoglobins are superior at hydroxylamine reduction because they have distal histidine coordination affinity constants near 1, and facile rate constants for binding and dissociation of the histidine side chain. Hexacoordinate hemoglobins such as neuroglobin are limited by tighter histidine coordination that blocks hydroxylamine binding, and pentacoordinate hemoglobins have intrinsically lower hydroxylamine affinities.

The refractive index of human hemoglobin in the visible range.

PubMed

Zhernovaya, O; Sydoruk, O; Tuchin, V; Douplik, A

2011-07-07

Because the refractive index of hemoglobin in the visible range is sensitive to the hemoglobin concentration, optical investigations of hemoglobin are important for medical diagnostics and treatment. Direct measurements of the refractive index are, however, challenging; few such measurements have previously been reported, especially in a wide wavelength range. We directly measured the refractive index of human deoxygenated and oxygenated hemoglobin for nine wavelengths between 400 and 700 nm for the hemoglobin concentrations up to 140 g l(-1). This paper analyzes the results and suggests a set of model functions to calculate the refractive index depending on the concentration. At all wavelengths, the measured values of the refractive index depended on the concentration linearly. Analyzing the slope of the lines, we determined the specific refraction increments, derived a set of model functions for the refractive index depending on the concentration, and compared our results with those available in the literature. Based on the model functions, we further calculated the refractive index at the physiological concentration within the erythrocytes of 320 g l(-1). The results can be used to calculate the refractive index in the visible range for arbitrary concentrations provided that the refractive indices depend on the concentration linearly.

Nitroreduction and formation of hemoglobin adducts in rats with a human intestinal microflora

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scheepers, P.T.J.; Straetemans, M.M.E.; Koopman, J.P.

1994-10-01

In the covalent binding of nitroarenes to macromolecules, nitroreduction is an important step. The intestinal microflora represents an enormous potential of bacterial nitroreductase activity. As a consequence, the in vivo nitroreduction of orally administerednitroarenes is primarily located in the intestine. In this study, we have investigated the nitroreduction of 2-nitrofluorene (2-NF) by a human microflora in female Wistar rats. Germ-free (FG) rats were equipped with a bacterial flora derived from human feces. Nontreated GF rats and GF animals equipped with a conventional rat flora were used as controls. The composition of the human and the conventional microflora isolated from themore » rats were consistent with the microflora of the administered feces. In the rats receiving only sunflower seed oil, no adducts were detected. The animals equipped with a human or rat microflora that received 2-aminofluorene (2-AF) formed 2-AF hemoglobin (Hb)-adducts at average levels mean {+-} 0.003 and 0.043 {+-} 0.010 {mu}mole/g Hb, respectively. In the FG rats, an adduct level of 0.57 {+-} 0.09 was determined after 2-AF administration and non adducts were detected after 2-NF administration. The results show that nitroreduction by an acquired human intestinal microflora and subsequent adduct formation can be studied in the rate in vivo. 21 refs., 3 tabs.« less

Structurally altered capsular polysaccharides produced by mutant bacteria

NASA Technical Reports Server (NTRS)

Petersen, Gene R. (Inventor); Kern, Roger G. (Inventor); Richards, Gil F. (Inventor)

1995-01-01

Structurally altered capsular polysaccharides are produced by mutant bacteria. These polysaccharides are isolated by selecting a wild type bacterial strain and a phage producing degradative enzymes that have substrate specificity for the capsular polysaccharides produced by the wild type bacteria. Phage-resistant mutants producing capsular polysaccharides are selected and the structurally altered capsular polysaccharide is isolated therefrom.

Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

PubMed Central

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

2011-01-01

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

Genetic resistance to malaria, oxidative stress and hemoglobin oxidation.

PubMed

Destro Bisol, G

1999-09-01

I describe a model which posits the molecular basis of some malaria-resistance genes in the interaction between oxidized hemoglobin and membrane components. The model is supported by a considerable body of evidence which indicates that erythrocytes of genetically protected individuals (carriers of sickle cell trait, alpha- and beta-thalassemia, and G6PD deficiency) are susceptible to the increase of oxidation of hemoglobin following H2O2 release in the host cell by Plasmodium falciparum. I suggest that the irreversible interaction between oxidized hemoglobin and the red cell membrane could trigger mechanisms that: (i) reduce invasion of erythrocytes by the falciparum parasite; (ii) impair parasite survival and development within the cell; (iii) accelerate infected erythrocyte clearance by phagocytosis.

Genetic and developmental variation of hemoglobin in the deermouse, Peromyscus maniculatus.

PubMed

Maybank, K M; Dawson, W D

1976-04-01

A genetic investigation of electrophoretic hemoglobin variants of the deermouse, Peromyscus maniculatus, shows three alleles, Hblf, Hblr, and Hblo, at a duplicated site controlling the six adult phenotypes. The Hblf allele has not been described previously. The hemoglobin locus is not closely linked to the albino locus. Fetal hemoglobin is distinct from any of the adult components and has a slower electrophoretic mobility. The fetal phenotype changes to the adult type between the days 15 and 18 of prenatal life.

Mapping of hemoglobin in erythrocytes and erythrocyte ghosts using two photon excitation fluorescence microscopy

NASA Astrophysics Data System (ADS)

Bukara, Katarina; Jovanić, Svetlana; Drvenica, Ivana T.; Stančić, Ana; Ilić, Vesna; Rabasović, Mihailo D.; Pantelić, Dejan; Jelenković, Branislav; Bugarski, Branko; Krmpot, Aleksandar J.

2017-02-01

The present study describes utilization of two photon excitation fluorescence (2PE) microscopy for visualization of the hemoglobin in human and porcine erythrocytes and their empty membranes (i.e., ghosts). High-quality, label- and fixation-free visualization of hemoglobin was achieved at excitation wavelength 730 nm by detecting visible autofluorescence. Localization in the suspension and spatial distribution (i.e., mapping) of residual hemoglobin in erythrocyte ghosts has been resolved by 2PE. Prior to the 2PE mapping, the presence of residual hemoglobin in the bulk suspension of erythrocyte ghosts was confirmed by cyanmethemoglobin assay. 2PE analysis revealed that the distribution of hemoglobin in intact erythrocytes follows the cells' shape. Two types of erythrocytes, human and porcine, characterized with discocyte and echinocyte morphology, respectively, showed significant differences in hemoglobin distribution. The 2PE images have revealed that despite an extensive washing out procedure after gradual hypotonic hemolysis, a certain amount of hemoglobin localized on the intracellular side always remains bound to the membrane and cannot be eliminated. The obtained results open the possibility to use 2PE microscopy to examine hemoglobin distribution in erythrocytes and estimate the purity level of erythrocyte ghosts in biotechnological processes.

Persistent bacterial infections, antibiotic tolerance, and the oxidative stress response

PubMed Central

Grant, Sarah Schmidt; Hung, Deborah T.

2013-01-01

Certain bacterial pathogens are able to evade the host immune system and persist within the human host. The consequences of persistent bacterial infections potentially include increased morbidity and mortality from the infection itself as well as an increased risk of dissemination of disease. Eradication of persistent infections is difficult, often requiring prolonged or repeated courses of antibiotics. During persistent infections, a population or subpopulation of bacteria exists that is refractory to traditional antibiotics, possibly in a non-replicating or metabolically altered state. This review highlights the clinical significance of persistent infections and discusses different in vitro models used to investigate the altered physiology of bacteria during persistent infections. We specifically focus on recent work establishing increased protection against oxidative stress as a key element of the altered physiologic state across different in vitro models and pathogens. PMID:23563389

Deer mouse hemoglobin exhibits a lowered oxygen affinity owing to mobility of the E helix.

PubMed

Inoguchi, Noriko; Oshlo, Jake R; Natarajan, Chandrasekhar; Weber, Roy E; Fago, Angela; Storz, Jay F; Moriyama, Hideaki

2013-04-01

The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hanging-drop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the hydrogen bond between α1Trp14 in the A helix and α1Thr67 in the E helix owing to the Thr67Ala substitution. In addition, deer mouse hemoglobin has a unique hydrogen bond at the α1β1 interface between residues α1Cys34 and β1Ser128.

Deer mouse hemoglobin exhibits a lowered oxygen affinity owing to mobility of the E helix

PubMed Central

Inoguchi, Noriko; Oshlo, Jake R.; Natarajan, Chandrasekhar; Weber, Roy E.; Fago, Angela; Storz, Jay F.; Moriyama, Hideaki

2013-01-01

The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hanging-drop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the hydrogen bond between α1Trp14 in the A helix and α1Thr67 in the E helix owing to the Thr67Ala substitution. In addition, deer mouse hemoglobin has a unique hydrogen bond at the α1β1 interface between residues α1Cys34 and β1Ser128. PMID:23545644

Hemoglobin genetics: recent contributions of GWAS and gene editing

PubMed Central

Smith, Elenoe C.; Orkin, Stuart H.

2016-01-01

The β-hemoglobinopathies are inherited disorders resulting from altered coding potential or expression of the adult β-globin gene. Impaired expression of β-globin reduces adult hemoglobin (α2β2) production, the hallmark of β-thalassemia. A single-base mutation at codon 6 leads to formation of HbS (α2βS2) and sickle cell disease. While the basis of these diseases is known, therapy remains largely supportive. Bone marrow transplantation is the only curative therapy. Patients with elevated levels of fetal hemoglobin (HbF, α2γ2) as adults exhibit reduced symptoms and enhanced survival. The β-globin gene locus is a paradigm of cell- and developmental stage-specific regulation. Although the principal erythroid cell transcription factors are known, mechanisms responsible for silencing of the γ-globin gene were obscure until application of genome-wide association studies (GWAS). Here, we review findings in the field. GWAS identified BCL11A as a candidate negative regulator of γ-globin expression. Subsequent studies have established BCL11A as a quantitative repressor. GWAS-related single-nucleotide polymorphisms lie within an essential erythroid enhancer of the BCL11A gene. Disruption of a discrete region within the enhancer reduces BCL11A expression and induces HbF expression, providing the basis for gene therapy using gene editing tools. A recently identified, second silencing factor, leukemia/lymphoma-related factor/Pokemon, shares features with BCL11A, including interaction with the nucleosome remodeling deacetylase repressive complex. These findings suggest involvement of a common pathway for HbF silencing. In addition, we discuss other factors that may be involved in γ-globin gene silencing and their potential manipulation for therapeutic benefit in treating the β-hemoglobinopathies. PMID:27340226

A microfluidic approach for hemoglobin detection in whole blood

NASA Astrophysics Data System (ADS)

Taparia, Nikita; Platten, Kimsey C.; Anderson, Kristin B.; Sniadecki, Nathan J.

2017-10-01

Diagnosis of anemia relies on the detection of hemoglobin levels in a blood sample. Conventional blood analyzers are not readily available in most low-resource regions where anemia is prevalent, so detection methods that are low-cost and point-of-care are needed. Here, we present a microfluidic approach to measure hemoglobin concentration in a sample of whole blood. Unlike conventional approaches, our microfluidic approach does not require hemolysis. We detect the level of hemoglobin in a blood sample optically by illuminating the blood in a microfluidic channel at a peak wavelength of 540 nm and measuring its absorbance using a CMOS sensor coupled with a lens to magnify the image onto the detector. We compare measurements in microchannels with channel heights of 50 and 115 μm and found the channel with the 50 μm height provided a better range of detection. Since we use whole blood and not lysed blood, we fit our data to an absorption model that includes optical scattering in order to obtain a calibration curve for our system. Based on this calibration curve and data collected, we can measure hemoglobin concentration within 1 g/dL for severe cases of anemia. In addition, we measured optical density for blood flowing at a shear rate of 500 s-1 and observed it did not affect the nonlinear model. With this method, we provide an approach that uses microfluidic detection of hemoglobin levels that can be integrated with other microfluidic approaches for blood analysis.

Concurrent measurement of cellular turbidity and hemoglobin to evaluate the antioxidant activity of plants.

PubMed

Bellik, Yuva; Iguer-Ouada, Mokrane

2016-01-01

In past decades, a multitude of analytical methods for measuring antioxidant activity of plant extracts has been developed. However, when using methods to determine hemoglobin released from human erythrocytes treated with ginger extracts, we found hemoglobin concentrations were significantly higher than in untreated control samples. This suggests in the presence of antioxidants that measuring hemoglobin alone is not sufficient to determine hemolysis. We show concurrent measurement of erythrocyte concentration and hemoglobin is essential in such assays, and describe a new protocol based on simultaneous measurement of cellular turbidity and hemoglobin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Drought consistently alters the composition of soil fungal and bacterial communities in grasslands from two continents.

PubMed

Ochoa-Hueso, Raúl; Collins, Scott L; Delgado-Baquerizo, Manuel; Hamonts, Kelly; Pockman, William T; Sinsabaugh, Robert L; Smith, Melinda D; Knapp, Alan K; Power, Sally A

2018-03-05

The effects of short-term drought on soil microbial communities remain largely unexplored, particularly at large scales and under field conditions. We used seven experimental sites from two continents (North America and Australia) to evaluate the impacts of imposed extreme drought on the abundance, community composition, richness, and function of soil bacterial and fungal communities. The sites encompassed different grassland ecosystems spanning a wide range of climatic and soil properties. Drought significantly altered the community composition of soil bacteria and, to a lesser extent, fungi in grasslands from two continents. The magnitude of the fungal community change was directly proportional to the precipitation gradient. This greater fungal sensitivity to drought at more mesic sites contrasts with the generally observed pattern of greater drought sensitivity of plant communities in more arid grasslands, suggesting that plant and microbial communities may respond differently along precipitation gradients. Actinobateria, and Chloroflexi, bacterial phyla typically dominant in dry environments, increased their relative abundance in response to drought, whereas Glomeromycetes, a fungal class regarded as widely symbiotic, decreased in relative abundance. The response of Chlamydiae and Tenericutes, two phyla of mostly pathogenic species, decreased and increased along the precipitation gradient, respectively. Soil enzyme activity consistently increased under drought, a response that was attributed to drought-induced changes in microbial community structure rather than to changes in abundance and diversity. Our results provide evidence that drought has a widespread effect on the assembly of microbial communities, one of the major drivers of soil function in terrestrial ecosystems. Such responses may have important implications for the provision of key ecosystem services, including nutrient cycling, and may result in the weakening of plant-microbial interactions and a

Longitudinal Discriminant Analysis of Hemoglobin Level for Predicting Preeclampsia

PubMed Central

Nasiri, Malihe; Faghihzadeh, Soghrat; Alavi Majd, Hamid; Zayeri, Farid; Kariman, Noorosadat; Safavi Ardebili, Nastaran

2015-01-01

Background: Preeclampsia is one of the most serious complications during pregnancy with important effects on health of mother and fetus that causes maternal and fetal morbidity and mortality. This study was performed to evaluate whether high levels of hemoglobin may increase the risk of preeclampsia. Objectives: The present study aimed to predict preeclampsia by the hemoglobin profiles through longitudinal discriminant analysis and comparing the error rate of discrimination in longitudinal and cross sectional data. Patients and Methods: In a prospective cohort study from October 2010 to July 2011, 650 pregnant women referred to the prenatal clinic of Milad Hospital in Tehran were evaluated in 3 stages. The hemoglobin level of each woman was measured in the first, second, and third trimester of pregnancy by an expert technician. The subjects were followed up to delivery and preeclampsia was the main outcome under study. The covariance pattern and linear-mixed effects models are common methods that were applied for discriminant analysis of longitudinal data. Also Student t, Mann-Whitney U, and chi-square tests were used for comparing the demographic and clinical characteristics between two groups. Statistical analyses were performed using the SAS software version 9.1. Results: The prevalence rate of preeclampsia was 7.2% (47 women). The women with preeclampsia had a higher mean of hemoglobin values and the difference was 0.46 g/dL (P = 0.003). Also the mean of hemoglobin in the first trimester was higher than that of the second trimester, and was lower than that of the third trimester and the differences were significant (P = 0.015 and P < 0.001, respectively). The sensitivity for longitudinal data and cross-sectional data in three trimesters was 90%, 67%, 72%, and 54% and the specificity was 88%, 55%, 63%, and 50%, respectively. Conclusions: The levels of hemoglobin can be used to predict preeclampsia and monitoring the pregnant women and its regular measure in 3

NITRITE REDUCTASE ACTIVITY OF NON-SYMBIOTIC HEMOGLOBINS FROM ARABIDOPSIS THALIANA†

PubMed Central

Tiso, Mauro; Tejero, Jesús; Kenney, Claire; Frizzell, Sheila; Gladwin, Mark T.

2013-01-01

Plant non-symbiotic hemoglobins possess hexa-coordinate heme geometry similar to the heme protein neuroglobin. We recently discovered that deoxygenated neuroglobin converts nitrite to nitric oxide (NO), an important signaling molecule involved in many processes in plants. We sought to determine whether Arabidopsis thaliana non-symbiotic hemoglobins class 1 and 2 (AHb1 and AHb2) might function as nitrite reductases. We found that the reaction of nitrite with deoxygenated AHb1 and AHb2 generates NO gas and iron-nitrosyl-hemoglobin species. The bimolecular rate constants for nitrite reduction to NO are 19.8 ± 3.2 and 4.9 ± 0.2 M−1s−1, at pH = 7.4 and 25°C, respectively. We determined the pH dependence of these bimolecular rate constants and found a linear correlation with the concentration of protons, indicating the requirement for one proton in the reaction. Release of free NO gas during reaction in anoxic and hypoxic (2% oxygen) conditions was confirmed by chemiluminescence detection. These results demonstrate that deoxygenated AHb1 and AHb2 reduce nitrite to form NO via a mechanism analogous to that observed for hemoglobin, myoglobin and neuroglobin. Our findings suggest that during severe hypoxia and in the anaerobic plant roots, especially in water submerged species, non-symbiotic hemoglobins provide a viable pathway for NO generation via nitrite reduction. PMID:22620259

Effect of the N-terminal residues on the quaternary dynamics of human adult hemoglobin

NASA Astrophysics Data System (ADS)

Chang, Shanyan; Mizuno, Misao; Ishikawa, Haruto; Mizutani, Yasuhisa

2016-05-01

The protein dynamics of human hemoglobin following ligand photolysis was studied by time-resolved resonance Raman spectroscopy. The time-resolved spectra of two kinds of recombinant hemoglobin expressed in Escherichia coli, normal recombinant hemoglobin and the α(V1M)/β(V1M) double mutant, were compared with those of human adult hemoglobin (HbA) purified from blood. A frequency shift of the iron-histidine stretching [ν(Fe-His)] band was observed in the time-resolved spectra of all three hemoglobin samples, indicative of tertiary and quaternary changes in the protein following photolysis. The spectral changes of the α(V1M)/β(V1M) double mutant were distinct from those of HbA in the tens of microseconds region, whereas the spectral changes of normal recombinant hemoglobin were similar to those of HbA isolated from blood. These results demonstrated that a structural change in the N-termini is involved in the second step of the quaternary structure change of hemoglobin. We discuss the implications of these results for understanding the allosteric pathway of HbA.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueser, Timothy C., E-mail: timothy.mueser@utoledo.edu; Griffith, Wendell P.; Kovalevsky, Andrey Y.

2010-11-01

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

Insensitivity of cerebral oxygen transport to oxygen affinity of hemoglobin-based oxygen carriers

PubMed Central

Koehler, Raymond C.; Fronticelli, Clara; Bucci, Enrico

2008-01-01

The cerebrovascular effects of exchange transfusion of various cell-free hemoglobins that possess different oxygen affinities are reviewed. Reducing hematocrit by transfusion of a non-oxygen-carrying solution dilates pial arterioles on the brain surface and increases cerebral blood flow to maintain a constant bulk oxygen transport to the brain. In contrast, transfusion of hemoglobins with P50 of 4–34 Torr causes constriction of pial arterioles that offsets the decrease in blood viscosity to maintain cerebral blood flow and oxygen transport. The autoregulatory constriction is dependent on synthesis of 20-HETE from arachidonic acid. This oxygen-dependent reaction is apparently enhanced by facilitated oxygen diffusion from the red cell to the endothelium arising from increased plasma oxygen solubility in the presence of low or high-affinity hemoglobin. Exchange transfusion of recombinant hemoglobin polymers with P50 of 3 and 18 Torr reduces infarct volume from experimental stroke. Cell-free hemoglobins do not require a P50 as high as red blood cell hemoglobin to facilitate oxygen delivery. PMID:18230370

Insensitivity of cerebral oxygen transport to oxygen affinity of hemoglobin-based oxygen carriers.

PubMed

Koehler, Raymond C; Fronticelli, Clara; Bucci, Enrico

2008-10-01

The cerebrovascular effects of exchange transfusion of various cell-free hemoglobins that possess different oxygen affinities are reviewed. Reducing hematocrit by transfusion of a non-oxygen-carrying solution dilates pial arterioles on the brain surface and increases cerebral blood flow to maintain a constant bulk oxygen transport to the brain. In contrast, transfusion of hemoglobins with P50 of 4-34 Torr causes constriction of pial arterioles that offsets the decrease in blood viscosity to maintain cerebral blood flow and oxygen transport. The autoregulatory constriction is dependent on synthesis of 20-HETE from arachidonic acid. This oxygen-dependent reaction is apparently enhanced by facilitated oxygen diffusion from the red cell to the endothelium arising from increased plasma oxygen solubility in the presence of low or high-affinity hemoglobin. Exchange transfusion of recombinant hemoglobin polymers with P50 of 3 and 18 Torr reduces infarct volume from experimental stroke. Cell-free hemoglobins do not require a P50 as high as red blood cell hemoglobin to facilitate oxygen delivery.

Artemisinin activity against Plasmodium falciparum requires hemoglobin uptake and digestion

PubMed Central

Klonis, Nectarios; Crespo-Ortiz, Maria P.; Bottova, Iveta; Abu-Bakar, Nurhidanatasha; Kenny, Shannon; Rosenthal, Philip J.; Tilley, Leann

2011-01-01

Combination regimens that include artemisinin derivatives are recommended as first line antimalarials in most countries where malaria is endemic. However, the mechanism of action of artemisinin is not fully understood and the usefulness of this drug class is threatened by reports of decreased parasite sensitivity. We treated Plasmodium falciparum for periods of a few hours to mimic clinical exposure to the short half-life artemisinins. We found that drug treatment retards parasite growth and inhibits uptake of hemoglobin, even at sublethal concentrations. We show that potent artemisinin activity is dependent on hemoglobin digestion by the parasite. Inhibition of hemoglobinase activity with cysteine protease inhibitors, knockout of the cysteine protease falcipain-2 by gene deletion, or direct deprivation of host cell lysate, significantly decreases artemisinin sensitivity. Hemoglobin digestion is also required for artemisinin-induced exacerbation of oxidative stress in the parasite cytoplasm. Arrest of hemoglobin digestion by early stage parasites provides a mechanism for surviving short-term artemisinin exposure. These insights will help in the design of new drugs and new treatment strategies to circumvent drug resistance. PMID:21709259

Structural characterization of hemoglobins from Monilifera and Frenulata tubeworms (Siboglinids): first discovery of giant hexagonal-bilayer hemoglobin in the former "Pogonophora" group.

PubMed

Meunier, Cédric; Andersen, Ann C; Bruneaux, Matthieu; Le Guen, Dominique; Terrier, Peran; Leize-Wagner, Emmanuelle; Zal, Franck

2010-01-01

Siboglinids are symbiotic polychete annelids having hemoglobins as essential oxygen- and sulfide-carriers for their endosymbiotic bacteria. We analyzed the structure of the hemoglobins from two species of siboglinids: the monilifera Sclerolinum contortum and the frenulata Oligobrachia webbi (i.e. haakonmosbiensis) from Norwegian cold seeps. Measured by Multi-Angle Laser Light Scattering (MALLS), Sclerolinum shows a 3190+/-50 kDa hexagonal bilayer hemoglobin (HBL-Hb) and a 461+/-46 kDa ring-Hb, just as vestimentifera, whereas Oligobrachia has a 409+/-3.7 kDa ring-Hb only. Electrospray Ionization-Mass Spectrometry (ESI-MS) showed Sclerolinum HBL-Hb composed of seven monomeric globins (15-16 kDa), three disulfide-bonded globin heterodimers and three linkers. The heterodimers always contain globin-b (15814.4+/-1.5 Da). Sclerolinum ring-Hb is composed of globins and dimers with identical masses as its HBL-Hb, but lacks linkers. Oligobrachia ring-Hb has three globin monomers (14-15 kDa) only, with no disulfide-bonded dimers. Comparison of Sclerolinum hemoglobins between Storegga and Haakon Mosby Mud Volcano, using the normalized height of deconvoluted ESI-MS peaks, shows differences in globin monomers abundances that could reflect genetic differences or differential gene expression between distinct seep populations. The discovery of HBL-Hb in Sclerolinum is a new element supporting the hypothesis of monilifera being phylogenetically more closely related to vestimentifera, than to frenulata.

The Differential Effects of Anesthetics on Bacterial Behaviors

PubMed Central

Chamberlain, Matthew; Koutsogiannaki, Sophia; Schaefers, Matthew; Babazada, Hasan; Liu, Renyu; Yuki, Koichi

2017-01-01

Volatile anesthetics have been in clinical use for a long period of time and are considered to be promiscuous by presumably interacting with several ion channels in the central nervous system to produce anesthesia. Because ion channels and their existing evolutionary analogues, ion transporters, are very important in various organisms, it is possible that volatile anesthetics may affect some bacteria. In this study, we hypothesized that volatile anesthetics could affect bacterial behaviors. We evaluated the impact of anesthetics on bacterial growth, motility (swimming and gliding) and biofilm formation of four common bacterial pathogens in vitro. We found that commonly used volatile anesthetics isoflurane and sevoflurane affected bacterial motility and biofilm formation without any effect on growth of the common bacterial pathogens studied here. Using available Escherichia coli gene deletion mutants of ion transporters and in silico molecular docking, we suggested that these altered behaviors might be at least partly via the interaction of volatile anesthetics with ion transporters. PMID:28099463

Measurement of refractive index of hemoglobin in the visible/NIR spectral range

NASA Astrophysics Data System (ADS)

Lazareva, Ekaterina N.; Tuchin, Valery V.

2018-03-01

This study is focused on the measurements of the refractive index of hemoglobin solutions in the visible/near-infrared (NIR) spectral range at room temperature for characteristic laser wavelengths: 480, 486, 546, 589, 644, 656, 680, 930, 1100, 1300, and 1550 nm. Measurements were performed using the multiwavelength Abbe refractometer. Aqua hemoglobin solutions of different concentrations obtained from human whole blood were investigated. The specific increment of refractive index on hemoglobin concentration and the Sellmeier coefficients were calculated.

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.

Hemoglobin Aggregation in Single Red Blood Cells of Sickle Cell Anemia

NASA Astrophysics Data System (ADS)

Nishio, Izumi; Tanaka, Toyoichi; Sun, Shao-Tang; Imanishi, Yuri; Tsuyoshi Ohnishi, S.

1983-06-01

A laser light scattering technique was used to observe the extent of hemoglobin aggregation in solitary red blood cells of sickle cell anemia. Hemoglobin aggregation was confirmed in deoxygenated cells. The light scattering technique can also be applied to cytoplasmic studies of any biological cell.

The role of hemoglobin oxygen affinity in oxygen transport at high altitude.

PubMed

Winslow, Robert M

2007-09-30

Hemoglobin is involved in the regulation of O(2) transport in two ways: a long-term adjustment in red cell mass is mediated by erythropoietin (EPO), a response to renal oxgyenation. Short-term, rapid-response adjustments are mediated by ventilation, cardiac output, hemoglobin oxygen affinity (P50), barriers to O(2) diffusion, and the control of local microvascular tissue perfusion. The distribution of O(2) between dissolved (PO2) and hemoglobin-bound (saturation) is the familiar oxygen equilibrium curve, whose position is noted as P50. Human hemoglobin is not genetically adapted for function at high altitude. However, more specialized species native to high altitudes (guinea pig and bar-headed goose, for example) seem to have a lower P50 than their sea level counterparts, an adaptation that presumably promotes O(2) uptake from a hypoxic environment. Humans, native to very high altitude either in the Andes or Himalayan mountains, also can increase O(2) affinity, not because of a fundamental difference in hemoglobin structure or function, but because of extreme hyperventilation and alkalosis.

Interaction of toxic azo dyes with heme protein: biophysical insights into the binding aspect of the food additive amaranth with human hemoglobin.

PubMed

Basu, Anirban; Kumar, Gopinatha Suresh

2015-05-30

A biophysical study on the interaction of the food colorant amaranth with hemoglobin was undertaken. Spectrophotometric and spectrofluorimetric studies proposed for an intimate binding interaction between the dye and the protein. The dye quenched the fluorescence of the protein remarkably and the mechanism of quenching was found to be static in nature. Synchronous fluorescence studies suggested that the polarity around the tryptophan residues was altered in the presence of amaranth whereas the polarity around tyrosine residues remained largely unaltered. 3D fluorescence, FTIR and circular dichroism results suggested that the binding reaction caused conformational changes in hemoglobin. The negative far-UV CD bands exhibited a significantly large decrease in magnitude in the presence of amaranth. From calorimetry studies it was established that the binding was driven by a large positive entropic contribution and a small but favorable enthalpy change. Copyright © 2015 Elsevier B.V. All rights reserved.

Smoking cessation alters subgingival microbial recolonization.

PubMed

Fullmer, S C; Preshaw, P M; Heasman, P A; Kumar, P S

2009-06-01

Smoking cessation improves the clinical manifestations of periodontitis; however, its effect on the subgingival biofilm, the primary etiological agent of periodontitis, is unclear. The purpose of this study was to investigate, longitudinally, if smoking cessation altered the composition of the subgingival microbial community, by means of a quantitative, cultivation-independent assay for bacterial profiling. Subgingival plaque was collected at baseline, and 3, 6, and 12 months post-treatment from smokers who received root planing and smoking cessation counseling. The plaque was analyzed by terminal restriction fragment length polymorphism (t-RFLP). Microbial profiles differed significantly between smokers and quitters at 6 and 12 months following smoking cessation. The microbial community in smokers was similar to baseline, while quitters demonstrated significantly divergent profiles. Changes in bacterial levels contributed to this shift. These findings reveal a critical role for smoking cessation in altering the subgingival biofilm and suggest a mechanism for improved periodontal health associated with smoking cessation.

Alteration of intracellular protein expressions as a key mechanism of the deterioration of bacterial denitrification caused by copper oxide nanoparticles.

PubMed

Su, Yinglong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun

2015-10-28

The increasing production and utilization of copper oxide nanoparticles (CuO NPs) result in the releases into the environment. However, the influence of CuO NPs on bacterial denitrification, one of the most important pathways to transform nitrate to dinitrogen in environment, has seldom been studied. Here we reported that CuO NPs caused a significant alteration of key protein expressions of a model denitrifier, Paracoccus denitrificans, leading to severe inhibition to denitrification. Total nitrogen removal efficiency was decreased from 98.3% to 62.1% with the increase of CuO NPs from 0.05 to 0.25 mg/L. Cellular morphology and integrity studies indicated that nanoparticles entered the cells. The proteomic bioinformatics analysis showed that CuO NPs caused regulation of proteins involved in nitrogen metabolism, electron transfer and substance transport. The down-regulation of GtsB protein (responsible for glucose transport) decreased the production of NADH (electron donor for denitrification). Also, the expressions of key electron-transfer proteins (including NADH dehydrogenase and cytochrome) were suppressed by CuO NPs, which adversely affected electrons transfer for denitrification. Further investigation revealed that CuO NPs significantly inhibited the expressions and catalytic activities of nitrate reductase and nitrite reductase. These results provided a fundamental understanding of the negative influences of CuO NPs on bacterial denitrification.

Alteration of intracellular protein expressions as a key mechanism of the deterioration of bacterial denitrification caused by copper oxide nanoparticles

PubMed Central

Su, Yinglong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun

2015-01-01

The increasing production and utilization of copper oxide nanoparticles (CuO NPs) result in the releases into the environment. However, the influence of CuO NPs on bacterial denitrification, one of the most important pathways to transform nitrate to dinitrogen in environment, has seldom been studied. Here we reported that CuO NPs caused a significant alteration of key protein expressions of a model denitrifier, Paracoccus denitrificans, leading to severe inhibition to denitrification. Total nitrogen removal efficiency was decreased from 98.3% to 62.1% with the increase of CuO NPs from 0.05 to 0.25 mg/L. Cellular morphology and integrity studies indicated that nanoparticles entered the cells. The proteomic bioinformatics analysis showed that CuO NPs caused regulation of proteins involved in nitrogen metabolism, electron transfer and substance transport. The down-regulation of GtsB protein (responsible for glucose transport) decreased the production of NADH (electron donor for denitrification). Also, the expressions of key electron-transfer proteins (including NADH dehydrogenase and cytochrome) were suppressed by CuO NPs, which adversely affected electrons transfer for denitrification. Further investigation revealed that CuO NPs significantly inhibited the expressions and catalytic activities of nitrate reductase and nitrite reductase. These results provided a fundamental understanding of the negative influences of CuO NPs on bacterial denitrification. PMID:26508362

Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

PubMed

Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

2016-06-01

Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

The role of respiratory viruses in the etiology of bacterial pneumonia: An ecological perspective.

PubMed

Lee, Kyu Han; Gordon, Aubree; Foxman, Betsy

2016-02-15

Pneumonia is the leading cause of death among children less than 5 years old worldwide. A wide range of viral, bacterial and fungal agents can cause pneumonia: although viruses are the most common etiologic agent, the severity of clinical symptoms associated with bacterial pneumonia and increasing antibiotic resistance makes bacterial pneumonia a major public health concern. Bacterial pneumonia can follow upper respiratory viral infection and complicate lower respiratory viral infection. Secondary bacterial pneumonia is a major cause of influenza-related deaths. In this review, we evaluate the following hypotheses: (i) respiratory viruses influence the etiology of pneumonia by altering bacterial community structure in the upper respiratory tract (URT) and (ii) respiratory viruses promote or inhibit colonization of the lower respiratory tract (LRT) by certain bacterial species residing in the URT. We conducted a systematic review of the literature to examine temporal associations between respiratory viruses and bacteria and a targeted review to identify potential mechanisms of interactions. We conclude that viruses both alter the bacterial community in the URT and promote bacterial colonization of the LRT. However, it is uncertain whether changes in the URT bacterial community play a substantial role in pneumonia etiology. The exception is Streptococcus pneumoniae where a strong link between viral co-infection, increased carriage and pneumococcal pneumonia has been established. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

Metabolism links bacterial biofilms and colon carcinogenesis

PubMed Central

Johnson, Caroline H.; Dejea, Christine M.; Edler, David; Hoang, Linh T.; Santidrian, Antonio F.; Felding, Brunhilde H.; Cho, Kevin; Wick, Elizabeth C.; Hechenbleikner, Elizabeth M.; Uritboonthai, Winnie; Goetz, Laura; Casero, Robert A.; Pardoll, Drew M.; White, James R.; Patti, Gary J.; Sears, Cynthia L.; Siuzdak, Gary

2015-01-01

SUMMARY Bacterial biofilms in the colon alter the host tissue microenvironment. A role for biofilms in colon cancer metabolism has been suggested but to date has not been evaluated. Using metabolomics, we investigated the metabolic influence that microbial biofilms have on colon tissues and the related occurrence of cancer. Patient-matched colon cancers and histologically normal tissues, with or without biofilms, were examined. We show the upregulation of polyamine metabolites in tissues from cancer hosts with significant enhancement of N1, N12-diacetylspermine in both biofilm positive cancer and normal tissues. Antibiotic treatment, which cleared biofilms, decreased N1, N12-diacetylspermine levels to those seen in biofilm negative tissues, indicating that host cancer and bacterial biofilm structures contribute to the polyamine metabolite pool. These results show that colonic mucosal biofilms alter the cancer metabolome, to produce a regulator of cellular proliferation and colon cancer growth potentially affecting cancer development and progression. PMID:25959674

Metabolism links bacterial biofilms and colon carcinogenesis.

PubMed

Johnson, Caroline H; Dejea, Christine M; Edler, David; Hoang, Linh T; Santidrian, Antonio F; Felding, Brunhilde H; Ivanisevic, Julijana; Cho, Kevin; Wick, Elizabeth C; Hechenbleikner, Elizabeth M; Uritboonthai, Winnie; Goetz, Laura; Casero, Robert A; Pardoll, Drew M; White, James R; Patti, Gary J; Sears, Cynthia L; Siuzdak, Gary

2015-06-02

Bacterial biofilms in the colon alter the host tissue microenvironment. A role for biofilms in colon cancer metabolism has been suggested but to date has not been evaluated. Using metabolomics, we investigated the metabolic influence that microbial biofilms have on colon tissues and the related occurrence of cancer. Patient-matched colon cancers and histologically normal tissues, with or without biofilms, were examined. We show the upregulation of polyamine metabolites in tissues from cancer hosts with significant enhancement of N(1), N(12)-diacetylspermine in both biofilm-positive cancer and normal tissues. Antibiotic treatment, which cleared biofilms, decreased N(1), N(12)-diacetylspermine levels to those seen in biofilm-negative tissues, indicating that host cancer and bacterial biofilm structures contribute to the polyamine metabolite pool. These results show that colonic mucosal biofilms alter the cancer metabolome to produce a regulator of cellular proliferation and colon cancer growth potentially affecting cancer development and progression. Copyright © 2015 Elsevier Inc. All rights reserved.

Prognostic Factors Affecting Locally Recurrent Rectal Cancer and Clinical Significance of Hemoglobin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rades, Dirk; Kuhn, Hildegard; Schultze, Juergen

2008-03-15

Purpose: To investigate potential prognostic factors, including hemoglobin levels before and during radiotherapy, for associations with survival and local control in patients with unirradiated locally recurrent rectal cancer. Patients and Methods: Ten potential prognostic factors were investigated in 94 patients receiving radiotherapy for recurrent rectal cancer: age ({<=}68 vs. {>=}69 years), gender, Eastern Cooperative Oncology Group performance status (0-1 vs. 2-3), American Joint Committee on Cancer (AJCC) stage ({<=}II vs. III vs. IV), grading (G1-2 vs. G3), surgery, administration of chemotherapy, radiation dose (equivalent dose in 2-Gy fractions: {<=}50 vs. >50 Gy), and hemoglobin levels before (<12 vs. {>=}12 g/dL)more » and during (majority of levels: <12 vs. {>=}12 g/dL) radiotherapy. Multivariate analyses were performed, including hemoglobin levels, either before or during radiotherapy (not both) because these are confounding variables. Results: Improved survival was associated with better performance status (p < 0.001), lower AJCC stage (p = 0.023), surgery (p = 0.011), chemotherapy (p = 0.003), and hemoglobin levels {>=}12 g/dL both before (p = 0.031) and during (p < 0.001) radiotherapy. On multivariate analyses, performance status, AJCC stage, and hemoglobin levels during radiotherapy maintained significance. Improved local control was associated with better performance status (p = 0.040), lower AJCC stage (p = 0.010), lower grading (p = 0.012), surgery (p < 0.001), chemotherapy (p < 0.001), and hemoglobin levels {>=}12 g/dL before (p < 0.001) and during (p < 0.001) radiotherapy. On multivariate analyses, chemotherapy, grading, and hemoglobin levels before and during radiotherapy remained significant. Subgroup analyses of the patients having surgery demonstrated the extent of resection to be significantly associated with local control (p = 0.011) but not with survival (p = 0.45). Conclusion: Predictors for outcome in patients who received

Photochemical alteration of dissolved organic matter and the subsequent effects on bacterial carbon cycling and diversity.

PubMed

Lønborg, Christian; Nieto-Cid, Mar; Hernando-Morales, Victor; Hernández-Ruiz, Marta; Teira, Eva; Álvarez-Salgado, Xosé Antón

2016-05-01

The impact of solar radiation on dissolved organic matter (DOM) derived from 3 different sources (seawater, eelgrass leaves and river water) and the effect on the bacterial carbon cycling and diversity were investigated. Seawater with DOM from the sources was first either kept in the dark or exposed to sunlight (4 days), after which a bacterial inoculum was added and incubated for 4 additional days. Sunlight exposure reduced the coloured DOM and carbon signals, which was followed by a production of inorganic nutrients. Bacterial carbon cycling was higher in the dark compared with the light treatment in seawater and river samples, while higher levels were found in the sunlight-exposed eelgrass experiment. Sunlight pre-exposure stimulated the bacterial growth efficiency in the seawater experiments, while no impact was found in the other experiments. We suggest that these responses are connected to differences in substrate composition and the production of free radicals. The bacterial community that developed in the dark and sunlight pre-treated samples differed in the seawater and river experiments. Our findings suggest that impact of sunlight exposure on the bacterial carbon transfer and diversity depends on the DOM source and on the sunlight-induced production of inorganic nutrients. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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...

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...

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...

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...

Dietary supplementation with rice bran or navy bean alters gut bacterial metabolism in colorectal cancer survivors.

PubMed

Sheflin, Amy M; Borresen, Erica C; Kirkwood, Jay S; Boot, Claudia M; Whitney, Alyssa K; Lu, Shen; Brown, Regina J; Broeckling, Corey D; Ryan, Elizabeth P; Weir, Tiffany L

2017-01-01

Heat-stabilized rice bran (SRB) and cooked navy bean powder (NBP) contain a variety of phytochemicals that are fermented by colonic microbiota and may influence intestinal health. Dietary interventions with these foods should be explored for modulating colorectal cancer risk. A randomized-controlled pilot clinical trial investigated the effects of eating SRB (30 g/day) or cooked navy bean powder (35 g/day) on gut microbiota and metabolites (NCT01929122). Twenty-nine overweight/obese volunteers with a prior history of colorectal cancer consumed a study-provided meal and snack daily for 28 days. Volunteers receiving SRB or NBP showed increased gut bacterial diversity and altered gut microbial composition at 28 days compared to baseline. Supplementation with SRB or NBP increased total dietary fiber intake similarly, yet only rice bran intake led to a decreased Firmicutes:Bacteroidetes ratio and increased SCFA (propionate and acetate) in stool after 14 days but not at 28 days. These findings support modulation of gut microbiota and fermentation byproducts by SRB and suggest that foods with similar ability to increase dietary fiber intake may not have equal effects on gut microbiota and microbial metabolism. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High temperature unfolding of a truncated hemoglobin by molecular dynamics simulation.

PubMed

Sharma, Ravi Datta; Kanwal, Rajnee; Lynn, Andrew M; Singh, Prerna; Pasha, Syed Tazeen; Fatma, Tasneem; Jawaid, Safdar

2013-09-01

Heme containing proteins are associated with peroxidase activity. The proteins like hemoglobin, myoglobins, cytochrome c and micro-peroxidase other than peroxidases have been shown to exhibit weak peroxidase-like activity. This weak peroxidase-like activity in hemoglobin-like molecules is due to heme moiety. We conducted molecular dynamics (MD) studies to decipher the unfolding path of Ba-Glb (a truncated hemoglobin from Bacillus anthracis) and the role of heme moiety to its unfolding path. The similar unfolding path is also observed in vitro by UV/VIS spectroscopy. The data confirmed that the unfolding of Ba-Glb follows a three state process with a meta-stable (intermediate) state between the native and unfolded conformations. The present study is supported by several unfolding parameters like root-mean-square-deviation (RMSD), dictionary of protein secondary structure (DSSP), and free energy landscape. Understanding the structure of hemoglobin like proteins in unicellular dreaded pathogens like B. anthracis will pave way for newer drug discovery targets and in the disease management of anthrax.

Hemoglobin Kinetics and Long-term Prognosis in Heart Failure.

PubMed

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

2016-09-01

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

Candida albicans and bacterial microbiota interactions in the cecum during recolonization following broad-spectrum antibiotic therapy.

PubMed

Mason, Katie L; Erb Downward, John R; Mason, Kelly D; Falkowski, Nicole R; Eaton, Kathryn A; Kao, John Y; Young, Vincent B; Huffnagle, Gary B

2012-10-01

Candida albicans is a normal member of the gastrointestinal (GI) tract microbiota of healthy humans, but during host immunosuppression or alterations in the bacterial microbiota, C. albicans can disseminate and cause life-threatening illness. The bacterial microbiome of the GI tract, including lactic acid bacteria (LAB), plays a vital role in preventing fungal invasion. However, little is known about the role of C. albicans in shaping the bacterial microbiota during antibiotic recovery. We investigated the fungal burdens in the GI tracts of germfree mice and mice with a disturbed microbiome to demonstrate the role of the microbiota in preventing C. albicans colonization. Histological analysis demonstrated that colonization with C. albicans during antibiotic treatment does not trigger overt inflammation in the murine cecum. Bacterial diversity is reduced long term following cefoperazone treatment, but the presence of C. albicans during antibiotic recovery promoted the recovery of bacterial diversity. Cefoperazone diminishes Bacteroidetes populations long term in the ceca of mice, but the presence of C. albicans during cefoperazone recovery promoted Bacteroidetes population recovery. However, the presence of C. albicans resulted in a long-term reduction in Lactobacillus spp. and promoted Enterococcus faecalis populations. Previous studies have focused on the ability of bacteria to alter C. albicans; this study addresses the ability of C. albicans to alter the bacterial microbiota during nonpathogenic colonization.

Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

PubMed

Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G

2012-11-01

Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

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…

Association of Hemoglobin Concentration With Total and Cause-Specific Mortality in a Cohort of Postmenopausal Women.

PubMed

Kabat, Geoffrey C; Kim, Mimi Y; Verma, Amit K; Manson, JoAnn E; Lessin, Lawrence S; Kamensky, Victor; Lin, Juan; Wassertheil-Smoller, Sylvia; Rohan, Thomas E

2016-05-15

Anemia and low and high levels of hemoglobin have been associated with increased mortality and morbidity. However, most studies have measured hemoglobin at only 1 time point, and few studies have considered possible reverse causation. We used data from the Women's Health Initiative, in which baseline hemoglobin was measured in 160,081 postmenopausal women and year 3 hemoglobin was measured in 75,658 participants, to examine the associations of hemoglobin concentration with total mortality, coronary heart disease mortality, and cancer mortality. Women were enrolled from 1993 to 1998 and followed for a median of 16 years. Cox proportional hazards models were used to estimate the relative mortality hazards associated with deciles of baseline hemoglobin and the mean of baseline + year 3 hemoglobin. Both low and high deciles of baseline hemoglobin were positively associated with all 3 outcomes in the total cohort. In analyses restricted to women with 2 measurements, a low mean hemoglobin level was robustly and positively associated with all 3 outcomes, after exclusion of the early years of follow-up. High mean hemoglobin was also associated with increased risk of total mortality, whereas associations with heart disease mortality and cancer mortality were weaker and inconsistent. Our results provide evidence that low and high levels of hemoglobin are associated with increased risk of mortality in otherwise healthy women. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Body Temperature-Related Structural Transitions of Monotremal and Human Hemoglobin

PubMed Central

Digel, I.; Maggakis-Kelemen, Ch.; Zerlin, K. F.; Linder, Pt.; Kasischke, N.; Kayser, P.; Porst, D.; Temiz Artmann, A.; Artmann, G. M.

2006-01-01

In this study, temperature-related structural changes were investigated in human, duck-billed platypus (Ornithorhynchus anatinus, body temperature Tb = 31–33°C), and echidna (Tachyglossus aculeatus, body temperature Tb = 32–33°C) hemoglobin using circular dichroism spectroscopy and dynamic light scattering. The average hydrodynamic radius (Rh) and fractional (normalized) change in the ellipticity (Fobs) at 222 ± 2 nm of hemoglobin were measured. The temperature was varied stepwise from 25°C to 45°C. The existence of a structural transition of human hemoglobin at the critical temperature Tc between 36–37°C was previously shown by micropipette aspiration experiments, viscosimetry, and circular dichroism spectroscopy. Based on light-scattering measurements, this study proves the onset of molecular aggregation at Tc. In two different monotremal hemoglobins (echidna and platypus), the critical transition temperatures were found between 32–33°C, which are close to the species' body temperature Tb. The data suggest that the correlation of the structural transition's critical temperature Tc and the species' body temperature Tb is not mere coincidence but, instead, is a more widespread structural phenomenon possibly including many other proteins. PMID:16844747

Body temperature-related structural transitions of monotremal and human hemoglobin.

PubMed

Digel, I; Maggakis-Kelemen, Ch; Zerlin, K F; Linder, Pt; Kasischke, N; Kayser, P; Porst, D; Temiz Artmann, A; Artmann, G M

2006-10-15

In this study, temperature-related structural changes were investigated in human, duck-billed platypus (Ornithorhynchus anatinus, body temperature T(b) = 31-33 degrees C), and echidna (Tachyglossus aculeatus, body temperature T(b) = 32-33 degrees C) hemoglobin using circular dichroism spectroscopy and dynamic light scattering. The average hydrodynamic radius (R(h)) and fractional (normalized) change in the ellipticity (F(obs)) at 222 +/- 2 nm of hemoglobin were measured. The temperature was varied stepwise from 25 degrees C to 45 degrees C. The existence of a structural transition of human hemoglobin at the critical temperature T(c) between 36-37 degrees C was previously shown by micropipette aspiration experiments, viscosimetry, and circular dichroism spectroscopy. Based on light-scattering measurements, this study proves the onset of molecular aggregation at T(c). In two different monotremal hemoglobins (echidna and platypus), the critical transition temperatures were found between 32-33 degrees C, which are close to the species' body temperature T(b). The data suggest that the correlation of the structural transition's critical temperature T(c) and the species' body temperature T(b) is not mere coincidence but, instead, is a more widespread structural phenomenon possibly including many other proteins.

Effect of Some High Consumption Spices on Hemoglobin Glycation

PubMed Central

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

2014-01-01

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

Effect of some high consumption spices on hemoglobin glycation.

PubMed

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

2014-01-01

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

Adult, embryonic and fetal hemoglobin are expressed in human glioblastoma cells.

PubMed

Emara, Marwan; Turner, A Robert; Allalunis-Turner, Joan

2014-02-01

Hemoglobin is a hemoprotein, produced mainly in erythrocytes circulating in the blood. However, non-erythroid hemoglobins have been previously reported in other cell types including human and rodent neurons of embryonic and adult brain, but not astrocytes and oligodendrocytes. Human glioblastoma multiforme (GBM) is the most aggressive tumor among gliomas. However, despite extensive basic and clinical research studies on GBM cells, little is known about glial defence mechanisms that allow these cells to survive and resist various types of treatment. We have shown previously that the newest members of vertebrate globin family, neuroglobin (Ngb) and cytoglobin (Cygb), are expressed in human GBM cells. In this study, we sought to determine whether hemoglobin is also expressed in GBM cells. Conventional RT-PCR, DNA sequencing, western blot analysis, mass spectrometry and fluorescence microscopy were used to investigate globin expression in GBM cell lines (M006x, M059J, M059K, M010b, U87R and U87T) that have unique characteristics in terms of tumor invasion and response to radiotherapy and hypoxia. The data showed that α, β, γ, δ, ζ and ε globins are expressed in all tested GBM cell lines. To our knowledge, we are the first to report expression of fetal, embryonic and adult hemoglobin in GBM cells under normal physiological conditions that may suggest an undefined function of those expressed hemoglobins. Together with our previous reports on globins (Ngb and Cygb) expression in GBM cells, the expression of different hemoglobins may constitute a part of series of active defence mechanisms supporting these cells to resist various types of treatments including chemotherapy and radiotherapy.

Comparison of the gold standard of hemoglobin measurement with the clinical standard (BGA) and noninvasive hemoglobin measurement (SpHb) in small children: a prospective diagnostic observational study.

PubMed

Wittenmeier, Eva; Bellosevich, Sophia; Mauff, Susanne; Schmidtmann, Irene; Eli, Michael; Pestel, Gunther; Noppens, Ruediger R

2015-10-01

Collecting a blood sample is usually necessary to measure hemoglobin levels in children. Especially in small children, noninvasively measuring the hemoglobin level could be extraordinarily helpful, but its precision and accuracy in the clinical environment remain unclear. In this study, noninvasive hemoglobin measurement and blood gas analysis were compared to hemoglobin measurement in a clinical laboratory. In 60 healthy preoperative children (0.2-7.6 years old), hemoglobin was measured using a noninvasive method (SpHb; Radical-7 Pulse Co-Oximeter), a blood gas analyzer (clinical standard, BGAHb; ABL 800 Flex), and a laboratory hematology analyzer (reference method, labHb; Siemens Advia). Agreement between the results was assessed by Bland-Altman analysis and by determining the percentage of outliers. Sixty SpHb measurements, 60 labHb measurements, and 59 BGAHb measurements were evaluated. In 38% of the children, the location of the SpHb sensor had to be changed more than twice for the signal quality to be sufficient. The bias/limits of agreement between SpHb and labHb were -0.65/-3.4 to 2.1 g·dl(-1) . Forty-four percent of the SpHb values differed from the reference value by more than 1 g·dl(-1) . Age, difficulty of measurement, and the perfusion index (PI) had no influence on the accuracy of SpHb. The bias/limits of agreement between BGAHb and labHb were 1.14/-1.6 to 3.9 g·dl(-1) . Furthermore, 66% of the BGAHb values differed from the reference values by more than 1 g·dl(-1) . The absolute mean difference between SpHb and labHb (1.1 g·dl(-1) ) was smaller than the absolute mean difference between BGAHb and labHb (1.5 g·dl(-1) /P = 0.024). Noninvasive measurement of hemoglobin agrees more with the reference method than the measurement of hemoglobin using a blood gas analyzer. However, both methods can show clinically relevant differences from the reference method (ClinicalTrials.gov: NCT01693016). © 2015 John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

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

2012-02-01

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

Predictors of improvement in hemoglobin concentration among toddlers enrolled in the Massachusetts WIC Program.

PubMed

Altucher, Kristine; Rasmussen, Kathleen M; Barden, Elizabeth M; Habicht, Jean-Pierre

2005-05-01

Nutrition supplementation programs are generally targeted to those members of the population who are thought to be at risk of an undesirable outcome, but not all who participate in such programs respond to them. We sought to identify determinants of improvement in hemoglobin concentration among young children in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). We conducted an observational study using data from 9,930 children who were enrolled in the Massachusetts WIC program and had data available on their hemoglobin values at both 1 and 2 years of age. Predictors of change in hemoglobin concentration between these ages were studied using multivariate statistical modeling. Overall, hemoglobin concentrations increased from age 1 to 2 years in those who had been breastfed 25 or more weeks (P < .0001) and were female (P < .01), and decreased with increasing weight at 1 year of age (P < .001). The determinants of change in hemoglobin concentration differed from the determinants of hemoglobin concentration at age 1 year. The analytical approach used here could be extended to identify subgroups of WIC participants likely to improve in other outcomes. If current efforts to increase the duration of breastfeeding among WIC participants are successful, the importance of WIC in improving hemoglobin concentration among young children also will increase.

Molecular cloning and characterization of adult Sparus aurata hemoglobin genes.

PubMed

Campo, Salvatore; Nastasi, Giancarlo; Fedeli, Donatella; D'Ascola, Angela; Campo, Giuseppe M; Avenoso, Angela; Ferlazzo, Alida; Calatroni, Alberto; Falcioni, Giancarlo

2010-04-01

Among Teleosts, Sparus aurata occupies a prominent place in the gastronomic and economic fields of the Mediterranean basin and other geographic districts. The knowledge of its molecular structures and functional features, such as hemoglobin, may be helpful to understand the adaptive biochemical mechanisms that allow this fish to live under extreme conditions, including fish farming. In Sparus aurata red blood cells two different alpha and one beta hemoglobin genes have been identified. The alpha1 gene codifies a putative protein of 144 amino acids, the alpha2 gene produces a protein of 143 amino acids, and the beta gene encodes a chain of 148 amino acids. Comparative analysis of various hemoglobins indicates that allosteric regulation can be modified by the substitution of one or a few key residues. The comparison of the percentage sequence differences for alpha and beta chains in fishes indicates that evolutionary relationships between different species may be helpful to understand the mechanisms of their differentiation from other vertebrates. Hemoglobin alpha and beta chains of about 50 teleostean temperate and Antarctic fishes were analyzed to build phylogenetic trees using different algorithms: the neighbor-joining method, the maximum likelihood approach, and the Bayesian inference computation. Sparus aurata alpha chains are positioned in a paraphyletic cluster, which includes the same subunit of Chrysophrys auratus and Seriola quinqueradiata, whereas the beta chain is on an homophyletic branch with that of Chrysophrys auratus. Therefore, the phylogenetic approach suggests that both Sparus aurata hemoglobin alpha genes are paralogues and may have derived from a duplication event.

Mapping Polymerization and Allostery of Hemoglobin S Using Point Mutations

PubMed Central

Weinkam, Patrick; Sali, Andrej

2014-01-01

Hemoglobin is a complex system that undergoes conformational changes in response to oxygen, allosteric effectors, mutations, and environmental changes. Here, we study allostery and polymerization of hemoglobin and its variants by application of two previously described methods: (i) AllosMod for simulating allostery dynamics given two allosterically related input structures and (ii) a machine-learning method for dynamics- and structure-based prediction of the mutation impact on allostery (Weinkam et al. J. Mol. Biol. 2013), now applicable to systems with multiple coupled binding sites such as hemoglobin. First, we predict the relative stabilities of substates and microstates of hemoglobin, which are determined primarily by entropy within our model. Next, we predict the impact of 866 annotated mutations on hemoglobin’s oxygen binding equilibrium. We then discuss a subset of 30 mutations that occur in the presence of the sickle cell mutation and whose effects on polymerization have been measured. Seven of these HbS mutations occur in three predicted druggable binding pockets that might be exploited to directly inhibit polymerization; one of these binding pockets is not apparent in the crystal structure but only in structures generated by AllosMod. For the 30 mutations, we predict that mutation-induced conformational changes within a single tetramer tend not to significantly impact polymerization; instead, these mutations more likely impact polymerization by directly perturbing a polymerization interface. Finally, our analysis of allostery allows us to hypothesize why hemoglobin evolved to have multiple subunits and a persistent low frequency sickle cell mutation. PMID:23957820

An Iron-Regulated Autolysin Remodels the Cell Wall To Facilitate Heme Acquisition in Staphylococcus lugdunensis

PubMed Central

Farrand, Allison J.; Haley, Kathryn P.; Lareau, Nichole M.; Heilbronner, Simon; McLean, John A.; Foster, Timothy

2015-01-01

Bacteria alter their cell surface in response to changing environments, including those encountered upon invasion of a host during infection. One alteration that occurs in several Gram-positive pathogens is the presentation of cell wall-anchored components of the iron-regulated surface determinant (Isd) system, which extracts heme from host hemoglobin to fulfill the bacterial requirement for iron. Staphylococcus lugdunensis, an opportunistic pathogen that causes infective endocarditis, encodes an Isd system. Unique among the known Isd systems, S. lugdunensis contains a gene encoding a putative autolysin located adjacent to the Isd operon. To elucidate the function of this putative autolysin, here named IsdP, we investigated its contribution to Isd protein localization and hemoglobin-dependent iron acquisition. S. lugdunensis IsdP was found to be iron regulated and cotranscribed with the Isd operon. IsdP is a specialized peptidoglycan hydrolase that cleaves the stem peptide and pentaglycine crossbridge of the cell wall and alters processing and anchoring of a major Isd system component, IsdC. Perturbation of IsdC localization due to isdP inactivation results in a hemoglobin utilization growth defect. These studies establish IsdP as an autolysin that functions in heme acquisition and describe a role for IsdP in cell wall reorganization to accommodate nutrient uptake systems during infection. PMID:26123800

Accuracy of a continuous noninvasive hemoglobin monitor in intensive care unit patients.

PubMed

Frasca, Denis; Dahyot-Fizelier, Claire; Catherine, Karen; Levrat, Quentin; Debaene, Bertrand; Mimoz, Olivier

2011-10-01

To determine whether noninvasive hemoglobin measurement by Pulse CO-Oximetry could provide clinically acceptable absolute and trend accuracy in critically ill patients, compared to other invasive methods of hemoglobin assessment available at bedside and the gold standard, the laboratory analyzer. Prospective study. Surgical intensive care unit of a university teaching hospital. Sixty-two patients continuously monitored with Pulse CO-Oximetry (Masimo Radical-7). None. Four hundred seventy-one blood samples were analyzed by a point-of-care device (HemoCue 301), a satellite lab CO-Oximeter (Siemens RapidPoint 405), and a laboratory hematology analyzer (Sysmex XT-2000i), which was considered the reference device. Hemoglobin values reported from the invasive methods were compared to the values reported by the Pulse CO-Oximeter at the time of blood draw. When the case-to-case variation was assessed, the bias and limits of agreement were 0.0±1.0 g/dL for the Pulse CO-Oximeter, 0.3±1.3g/dL for the point-of-care device, and 0.9±0.6 g/dL for the satellite lab CO-Oximeter compared to the reference method. Pulse CO-Oximetry showed similar trend accuracy as satellite lab CO-Oximetry, whereas the point-of-care device did not appear to follow the trend of the laboratory analyzer as well as the other test devices. When compared to laboratory reference values, hemoglobin measurement with Pulse CO-Oximetry has absolute accuracy and trending accuracy similar to widely used, invasive methods of hemoglobin measurement at bedside. Hemoglobin measurement with pulse CO-Oximetry has the additional advantages of providing continuous measurements, noninvasively, which may facilitate hemoglobin monitoring in the intensive care unit.

Hemoglobin A1c (HbA1c) Test: MedlinePlus Lab Test Information

MedlinePlus

... medlineplus.gov/labtests/hemoglobina1chba1ctest.html Hemoglobin A1c (HbA1c) Test To use the sharing features on this page, ... enable JavaScript. What is a hemoglobin A1c (HbA1c) test? A hemoglobin A1c (HbA1c) test measures the amount ...

Hemoglobin concentration does not impact 3-month outcome following acute ischemic stroke.

PubMed

Sharma, Kartavya; Johnson, Daniel J; Johnson, Brenda; Frank, Steven M; Stevens, Robert D

2018-06-02

There is uncertainty regarding the effect of anemia and red blood cell transfusion on functional outcome following acute ischemic stroke. We studied the relationship of hemoglobin parameters and red cell transfusion with post stroke functional outcome after adjustment for neurological severity and medical comorbidities. Retrospective cohort study of 536 patients discharged with a diagnosis of ischemic stroke from a tertiary care hospital between January 2012 and April 2015. Hemoglobin level at hospital admission, lowest recorded value during hospitalization (nadir), delta hemoglobin (admission minus nadir), red cell transfusion during hospitalization were noted. Charlson Comorbidity Index (CCI) was computed as a summary measure of medical comorbidities. A multivariable logistic regression model was used to determine risk-adjusted odds of unfavorable outcome, defined as a modified Rankin Score of > 2. Anemia was present on hospital admission in 31% of patients. Forty five percent of patients had unfavorable outcome. In the univariable analysis increasing age, admission National Institutes of Health Stroke Scale (NIHSS), CCI, nadir hemoglobin, delta hemoglobin and blood transfusion were associated with unfavorable outcome. In the multivariable model, only increasing age, CCI and NIHSS remained associated with unfavorable outcome. No quadratic association was found on repeating the model to identify a possible U-shaped relationship of hemoglobin with outcome. Our findings contradict prior observational studies and highlight an area of clinical equipoise regarding the optimal management of anemia in patients hospitalized for ischemic stroke. This uncertainty could be addressed with appropriately designed clinical trials.

Nutrition education and knowledge, attitude and hemoglobin status of Malaysian adolescents.

PubMed

Yusoff, Hafzan; Daud, Wan Nudri Wan; Ahmad, Zulkifli

2012-01-01

A higher occurrence of iron deficiency anemia is present in rural Malaysia than urban Malaysia due to a lower socio-economic status of rural residents. This study was conducted in Tanah Merah, a rural district of Kelantan, Malaysia. Our objective was to investigate the impact of nutrition education alone, daily iron, folate and vitamin C supplementation or both on knowledge, attitudes and hemoglobin status of adolescent students. Two hundred eighty fourth year secondary students were each assigned by school to 1 of 4 different treatment groups. Each intervention was carried out for 3 months followed by 3 months without treatment. A validated self-reported knowledge and attitude questionnaire was administered; hemoglobin levels were measured before and after intervention. At baseline, no significant difference in hemoglobin was noted among the 4 groups (p = 0.06). The changes in hemoglobin levels at 3 months were 11, 4.6, 3.9 and -3.7% for the supplementation, nutrition education, combination and control groups, respectively. The changes at 6 months were 1.0, 6.8, 3.7 and -14.8%, respectively. Significant improvements in knowledge and attitude were evidenced in both the nutritional education and combination groups. The supplementation and control groups had no improvement in knowledge or attitudes. This study suggests nutritional education increases knowledge, attitudes and hemoglobin levels among Malaysian secondary school adolescents.

The Steady-State Transport of Oxygen through Hemoglobin Solutions

PubMed Central

Keller, K. H.; Friedlander, S. K.

1966-01-01

The steady-state transport of oxygen through hemoglobin solutions was studied to identify the mechanism of the diffusion augmentation observed at low oxygen tensions. A novel technique employing a platinum-silver oxygen electrode was developed to measure the effective diffusion coefficient of oxygen in steady-state transport. The measurements were made over a wider range of hemoglobin and oxygen concentrations than previously reported. Values of the Brownian motion diffusion coefficient of oxygen in hemoglobin solution were obtained as well as measurements of facilitated transport at low oxygen tensions. Transport rates up to ten times greater than ordinary diffusion rates were found. Predictions of oxygen flux were made assuming that the oxyhemoglobin transport coefficient was equal to the Brownian motion diffusivity which was measured in a separate set of experiments. The close correlation between prediction and experiment indicates that the diffusion of oxyhemoglobin is the mechanism by which steady-state oxygen transport is facilitated. PMID:5943608

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

Fluorescent analysis of interaction of flavonols with hemoglobin and bovine serum albumin

NASA Astrophysics Data System (ADS)

Sentchouk, V. V.; Bondaryuk, E. V.

2007-09-01

We have studied the fluorescent properties of flavonols (quercetin, fisetin, morin, rutin) with the aim of studying possible interaction with hemoglobin and bovine serum albumin (BSA). We observed an increase in the intensity of intrinsic fluorescence for all the flavonols except rutin in the presence of BSA. From the changes in the fluorescence spectra, we concluded that tautomeric forms are formed on interaction with hemoglobin. We determined the interconnection between the structure of related flavonols and their fluorescent properties on interaction with proteins, and we determined the binding constants for binding with BSA and hemoglobin.

Measurement of refractive index of hemoglobin in the visible/NIR spectral range.

PubMed

Lazareva, Ekaterina N; Tuchin, Valery V

2018-03-01

This study is focused on the measurements of the refractive index of hemoglobin solutions in the visible/near-infrared (NIR) spectral range at room temperature for characteristic laser wavelengths: 480, 486, 546, 589, 644, 656, 680, 930, 1100, 1300, and 1550 nm. Measurements were performed using the multiwavelength Abbe refractometer. Aqua hemoglobin solutions of different concentrations obtained from human whole blood were investigated. The specific increment of refractive index on hemoglobin concentration and the Sellmeier coefficients were calculated. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Hemoglobins of the opossum (Didelphis marsupialis). II. Polymorphism; electrophoretic and chromatographic observations.

PubMed

Bethlenfalvay, N C; Brown, G L; Waterman, M R

1976-12-01

Eighty-five adult opossums (Didelphis marsupialis) were examined for variation of hemaglobin by means of electrophoresis and column chromatography. A single hemoglobin was found in 83 animals while two hemoglobins were observed in two animals. The results of the chromatography studies suggested that the polymorphism was due to primary sequence differences in the alpha chain. Attempts to confirm this result by hybridization with human or canine hemoglobins were unsuccessful. The polymorphism was found not to be due to size differences and further investigation into its genetic basis was suggested.

Antibiotic-induced dysbiosis alters host-bacterial interactions and leads to colonic sensory and motor changes in mice

PubMed Central

Aguilera, M; Cerdà-Cuéllar, M; Martínez, V

2015-01-01

Alterations in the composition of the commensal microbiota (dysbiosis) seem to be a pathogenic component of functional gastrointestinal disorders, mainly irritable bowel syndrome (IBS), and might participate in the secretomotor and sensory alterations observed in these patients.We determined if a state antibiotics-induced intestinal dysbiosis is able to modify colonic pain-related and motor responses and characterized the neuro-immune mechanisms implicated in mice. A 2-week antibiotics treatment induced a colonic dysbiosis (increments in Bacteroides spp, Clostridium coccoides and Lactobacillus spp and reduction in Bifidobacterium spp). Bacterial adherence was not affected. Dysbiosis was associated with increased levels of secretory-IgA, up-regulation of the antimicrobial lectin RegIIIγ, and toll-like receptors (TLR) 4 and 7 and down-regulation of the antimicrobial-peptide Resistin-Like Molecule-β and TLR5. Dysbiotic mice showed less goblet cells, without changes in the thickness of the mucus layer. Neither macroscopical nor microscopical signs of inflammation were observed. In dysbiotic mice, expression of the cannabinoid receptor 2 was up-regulated, while the cannabinoid 1 and the mu-opioid receptors were down-regulated. In antibiotic-treated mice, visceral pain-related responses elicited by intraperitoneal acetic acid or intracolonic capsaicin were significantly attenuated. Colonic contractility was enhanced during dysbiosis. Intestinal dysbiosis induce changes in the innate intestinal immune system and modulate the expression of pain-related sensory systems, an effect associated with a reduction in visceral pain-related responses. Commensal microbiota modulates gut neuro-immune sensory systems, leading to functional changes, at least as it relates to viscerosensitivity. Similar mechanisms might explain the beneficial effects of antibiotics or certain probiotics in the treatment of IBS. PMID:25531553

Immunization with the Haemophilus ducreyi hemoglobin receptor HgbA protects against infection in the swine model of chancroid.

PubMed

Afonina, Galyna; Leduc, Isabelle; Nepluev, Igor; Jeter, Chrystina; Routh, Patty; Almond, Glen; Orndorff, Paul E; Hobbs, Marcia; Elkins, Christopher

2006-04-01

The etiologic agent of chancroid is Haemophilus ducreyi. To fulfill its obligate requirement for heme, H. ducreyi uses two TonB-dependent receptors: the hemoglobin receptor (HgbA) and a receptor for free heme (TdhA). Expression of HgbA is necessary for H. ducreyi to survive and initiate disease in a human model of chancroid. In this study, we used a swine model of H. ducreyi infection to demonstrate that an experimental HgbA vaccine efficiently prevents chancroid, as determined by several parameters. Histological sections of immunized animals lacked typical microscopic features of chancroid. All inoculated sites from mock-immunized pigs yielded viable H. ducreyi cells, whereas no viable H. ducreyi cells were recovered from inoculated sites of HgbA-immunized pigs. Antibodies from sera of HgbA-immunized animals bound to and initiated antibody-dependent bactericidal activity against homologous H. ducreyi strain 35000HP and heterologous strain CIP542 ATCC; however, an isogenic hgbA mutant of 35000HP was not killed, proving specificity. Anti-HgbA immunoglobulin G blocked hemoglobin binding to the HgbA receptor, suggesting a novel mechanism of protection through the limitation of heme/iron acquisition by H. ducreyi. Such a vaccine strategy might be applied to other bacterial pathogens with strict heme/iron requirements. Taken together, these data suggest continuing the development of an HgbA subunit vaccine to prevent chancroid.

Immunization with the Haemophilus ducreyi Hemoglobin Receptor HgbA Protects against Infection in the Swine Model of Chancroid

PubMed Central

Afonina, Galyna; Leduc, Isabelle; Nepluev, Igor; Jeter, Chrystina; Routh, Patty; Almond, Glen; Orndorff, Paul E.; Hobbs, Marcia; Elkins, Christopher

2006-01-01

The etiologic agent of chancroid is Haemophilus ducreyi. To fulfill its obligate requirement for heme, H. ducreyi uses two TonB-dependent receptors: the hemoglobin receptor (HgbA) and a receptor for free heme (TdhA). Expression of HgbA is necessary for H. ducreyi to survive and initiate disease in a human model of chancroid. In this study, we used a swine model of H. ducreyi infection to demonstrate that an experimental HgbA vaccine efficiently prevents chancroid, as determined by several parameters. Histological sections of immunized animals lacked typical microscopic features of chancroid. All inoculated sites from mock-immunized pigs yielded viable H. ducreyi cells, whereas no viable H. ducreyi cells were recovered from inoculated sites of HgbA-immunized pigs. Antibodies from sera of HgbA-immunized animals bound to and initiated antibody-dependent bactericidal activity against homologous H. ducreyi strain 35000HP and heterologous strain CIP542 ATCC; however, an isogenic hgbA mutant of 35000HP was not killed, proving specificity. Anti-HgbA immunoglobulin G blocked hemoglobin binding to the HgbA receptor, suggesting a novel mechanism of protection through the limitation of heme/iron acquisition by H. ducreyi. Such a vaccine strategy might be applied to other bacterial pathogens with strict heme/iron requirements. Taken together, these data suggest continuing the development of an HgbA subunit vaccine to prevent chancroid. PMID:16552053

Novel Mechanism of Hemin Capture by Hbp2, the Hemoglobin-binding Hemophore from Listeria monocytogenes*

PubMed Central

Malmirchegini, G. Reza; Sjodt, Megan; Shnitkind, Sergey; Sawaya, Michael R.; Rosinski, Justin; Newton, Salete M.; Klebba, Phillip E.; Clubb, Robert T.

2014-01-01

Iron is an essential nutrient that is required for the growth of the bacterial pathogen Listeria monocytogenes. In cell cultures, this microbe secretes hemin/hemoglobin-binding protein 2 (Hbp2; Lmo2185) protein, which has been proposed to function as a hemophore that scavenges heme from the environment. Based on its primary sequence, Hbp2 contains three NEAr transporter (NEAT) domains of unknown function. Here we show that each of these domains mediates high affinity binding to ferric heme (hemin) and that its N- and C-terminal domains interact with hemoglobin (Hb). The results of hemin transfer experiments are consistent with Hbp2 functioning as an Hb-binding hemophore that delivers hemin to other Hbp2 proteins that are attached to the cell wall. Surprisingly, our work reveals that the central NEAT domain in Hbp2 binds hemin even though its primary sequence lacks a highly conserved YXXXY motif that is used by all other previously characterized NEAT domains to coordinate iron in the hemin molecule. To elucidate the mechanism of hemin binding by Hbp2, we determined crystal structures of its central NEAT domain (Hbp2N2; residues 183–303) in its free and hemin-bound states. The structures reveal an unprecedented mechanism of hemin binding in which Hbp2N2 undergoes a major conformational rearrangement that facilitates metal coordination by a non-canonical tyrosine residue. These studies highlight previously unrecognized plasticity in the hemin binding mechanism of NEAT domains and provide insight into how L. monocytogenes captures heme iron. PMID:25315777

Serum-free Erythroid Differentiation for Efficient Genetic Modification and High-Level Adult Hemoglobin Production.

PubMed

Uchida, Naoya; Demirci, Selami; Haro-Mora, Juan J; Fujita, Atsushi; Raines, Lydia N; Hsieh, Matthew M; Tisdale, John F

2018-06-15

In vitro erythroid differentiation from primary human cells is valuable to develop genetic strategies for hemoglobin disorders. However, current erythroid differentiation methods are encumbered by modest transduction rates and high baseline fetal hemoglobin production. In this study, we sought to improve both genetic modification and hemoglobin production among human erythroid cells in vitro . To model therapeutic strategies, we transduced human CD34 + cells and peripheral blood mononuclear cells (PBMCs) with lentiviral vectors and compared erythropoietin-based erythroid differentiation using fetal-bovine-serum-containing media and serum-free media. We observed more efficient transduction (85%-93%) in serum-free media than serum-containing media (20%-69%), whereas the addition of knockout serum replacement (KSR) was required for serum-free media to promote efficient erythroid differentiation (96%). High-level adult hemoglobin production detectable by electrophoresis was achieved using serum-free media similar to serum-containing media. Importantly, low fetal hemoglobin production was observed in the optimized serum-free media. Using KSR-containing, serum-free erythroid differentiation media, therapeutic adult hemoglobin production was detected at protein levels with β-globin lentiviral transduction in both CD34 + cells and PBMCs from sickle cell disease subjects. Our in vitro erythroid differentiation system provides a practical evaluation platform for adult hemoglobin production among human erythroid cells following genetic manipulation.

Using the Cascade Model to Improve Antenatal Screening for the Hemoglobin Disorders

ERIC Educational Resources Information Center

Gould, Dinah; Papadopoulos, Irena; Kelly, Daniel

2012-01-01

Introduction: The inherited hemoglobin disorders constitute a major public health problem. Facilitators (experienced hemoglobin counselors) were trained to deliver knowledge and skills to "frontline" practitioners to enable them to support parents during antenatal screening via a cascade (train-the-trainer) model. Objectives of…

Patterns of glycemic control using glycosylated hemoglobin in diabetics.

PubMed

Kahlon, Arunpreet Singh; Pathak, Rambha

2011-07-01

Till now estimation of blood glucose is the highly effective method for diagnosing diabetes mellitus but it provides a short-term picture of control. More evidence is required to prove that plasma glucose and glycosylated hemoglobin levels together gives a better estimate of glycemic control and compliance with treatment. Indian diabetes risk score (IDRS) is a simplified screening tool for identifying undiagnosed diabetic subjects, requires minimum time, and effort and can help to considerably reduce the costs of screening. To study patterns of glycemic control using glycosylated hemoglobin in diabetic patients. To find out correlation between levels of plasma glucose and glycosylated hemoglobin in diabetics and to calculate IDRS of the study population. A cross sectional study was conducted among 300 known diabetic patients attending outpatient department of a rural medical college in Haryana, India. Following standard procedures and protocols FPG and glycosylated hemoglobin were measured to find out a pattern of glycemic control in them after taking their written and informed consent. A correlation between the levels of glycosylated hemoglobin and fasting blood glucose was also calculated. These patients were made to fill a performa and their demographic and clinical risk factors were noted and based on this, their IDRS was calculated. This was done to validate the IDRS in Indian rural population. Fifty-two percent of the population had fasting plasma glucose level between 125-150 mg/dl, 21% had this level between 151-175 mg/dl. Thirteen percent of the study subjects had HbA1C between 6.5-7.5, more than half (57.3%) had this value between 7.5-8.5, 12% and 18% had values between 8.5-9.5 and 9.5-10.5, respectively. Twelve percent of the participants had HbA1C level higher than 10.5. Correlation of fasting plasma glucose level and HbA1C was also studied and found that correlation coefficient came out to be .311. This correlation was found to be statistically

Evaluation of four rapid methods for hemoglobin screening of whole blood donors in mobile collection settings.

PubMed

Gómez-Simón, Antonia; Navarro-Núñez, Leyre; Pérez-Ceballos, Elena; Lozano, María L; Candela, María J; Cascales, Almudena; Martínez, Constantino; Corral, Javier; Vicente, Vicente; Rivera, José

2007-06-01

Predonation hemoglobin measurement is a problematic requirement in mobile donation settings, where accurate determination of venous hemoglobin by hematology analyzers is not available. We have evaluated hemoglobin screening in prospective donors by the semiquantitative copper sulphate test and by capillary blood samples analyzed by three portable photometers, HemoCue, STAT-Site MHgb, and the CompoLab HB system. Capillary blood samples were obtained from 380 donors and tested by the copper sulphate test and by at least one of the named portable photometers. Predonation venous hemoglobin was also determined in all donors using a Coulter Max-M analyzer. The three photometers provided acceptable reproducibility (CV below 5%), and displayed a significant correlation between the capillary blood samples and the venous hemoglobin (R2 0.5-0.8). HemoCue showed the best agreement with venous hemoglobin determination, followed by STAT-Site MHgb, and the CompoLab HB system. The copper sulphate test provided the highest rate of donors acceptance (83%) despite unacceptable hemoglobin levels, and the lowest rate for donor deferral (1%) despite acceptable hemoglobin levels. The percentage of donors correctly categorized for blood donation by the portable hemoglobinometers was 85%, 82%, and 76% for CompoLab HB system, HemoCue and STAT-Site, respectively. Our data suggest that hemoglobin determination remains a conflictive issue in donor selection in the mobile setting. Without appropriate performance control, capillary hemoglobin screening by either the copper sulphate method or by the novel portable hemoglobinometers could be inaccurate, thus potentially affecting both donor safety and the blood supply.

Ligand migration in the truncated hemoglobin of Mycobacterium tuberculosis.

PubMed

Heroux, Maxime S; Mohan, Anne D; Olsen, Kenneth W

2011-03-01

The truncated hemoglobin of Mycobacterium tuberculosis (Mt-trHbO) is a small heme protein belonging to the hemoglobin superfamily. Truncated hemoglobins (trHbs) are believed to have functional roles such as terminal oxidases and oxygen sensors involved in the response to oxidative and nitrosative stress, nitric oxide (NO) detoxification, O₂/NO chemistry, O₂ delivery under hypoxic conditions, and long-term ligand storage. Based on sequence similarities, they are classified into three groups. Experimental studies revealed that all trHbs display a 2-on-2 α-helical sandwich fold rather than the 3-on-3 α-helical sandwich fold of the classical hemoglobin fold. Using locally enhanced sampling (LESMD) molecular dynamics, the ligand-binding escape pathways from the distal heme binding cavity of Mt-trHbO were determined to better understand how this protein functions. The importance of specific residues, such as the group II and III invariant W(G8) residue, can be seen in terms of ligand diffusion pathways and ligand dynamics. LESMD simulations show that the wild-type Mt-trHbO has three diffusion pathways while the W(G8)F Mt-trHbO mutant has only two. The W(G8) residue plays a critical role in ligand binding and stabilization and helps regulate the rate of ligand escape from the distal heme pocket. Thus, this invariant residue is important in creating ligand diffusion pathways and possibly in the enzymatic functions of this protein. Copyright © 2011 Wiley Periodicals, Inc.

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

PubMed

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

2017-01-01

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

Correlation of Oxygenated Hemoglobin Concentration and Psychophysical Amount on Speech Recognition

NASA Astrophysics Data System (ADS)

Nozawa, Akio; Ide, Hideto

The subjective understanding on oral language understanding task is quantitatively evaluated by the fluctuation of oxygenated hemoglobin concentration measured by the near-infrared spectroscopy. The English listening comprehension test wihch consists of two difficulty level was executed by 4 subjects during the measurement. A significant correlation was found between the subjective understanding and the fluctuation of oxygenated hemoglobin concentration.

Hemoglobin promotes somatic embryogenesis in peanut cultures.

PubMed

Jayabalan, N; Anthony, P; Davey, M R; Power, J B; Lowe, K C

2004-02-01

Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).

HbA1c levels in individuals heterozygous for hemoglobin variants.

PubMed

Tavares, Ricardo Silva; Souza, Fábio Oliveira de; Francescantonio, Isabel Cristina Carvalho Medeiros; Soares, Weslley Carvalho; Mesquita, Mauro Meira

2017-04-01

To evaluate the levels of glycated hemoglobin (HbA1c) in patients heterozygous for hemoglobin variants and compare the results of this test with those of a control group. This was an experimental study based on the comparison of HbA1c tests in two different populations, with a test group represented by individuals heterozygous for hemoglobin variants (AS and AC) and a control group consisting of people with electrophoretic profile AA. The two populations were required to meet the following inclusion criteria: Normal levels of fasting glucose, hemoglobin, urea and triglycerides, bilirubin > 20 mg/dL and non-use of acetylsalicylic acid. 50 heterozygous subjects and 50 controls were evaluated between August 2013 and May 2014. The comparison of HbA1c levels between heterozygous individuals and control subjects was performed based on standard deviation, mean and G-Test. The study assessed a test group and a control group, both with 39 adults and 11 children. The mean among heterozygous adults for HbA1c was 5.0%, while the control group showed a rate of 5.74%. Heterozygous children presented mean HbA1c at 5.11%, while the controls were at 5.78%. G-Test yielded p=0.93 for children and p=0.89 for adults. Our study evaluated HbA1c using ion exchange chromatography resins, and the patients heterozygous for hemoglobin variants showed no significant difference from the control group.

Effects of Short-Term Warming and Altered Precipitation on Soil Microbial Communities in Alpine Grassland of the Tibetan Plateau

PubMed Central

Zhang, Kaoping; Shi, Yu; Jing, Xin; He, Jin-Sheng; Sun, Ruibo; Yang, Yunfeng; Shade, Ashley; Chu, Haiyan

2016-01-01

Soil microbial communities are influenced by climate change drivers such as warming and altered precipitation. These changes create abiotic stresses, including desiccation and nutrient limitation, which act on microbes. However, our understanding of the responses of microbial communities to co-occurring climate change drivers is limited. We surveyed soil bacterial and fungal diversity and composition after a 1-year warming and altered precipitation manipulation in the Tibetan plateau alpine grassland. In isolation, warming and decreased precipitation treatments each had no significant effects on soil bacterial community structure; however, in combination of both treatments altered bacterial community structure (p = 0.03). The main effect of altered precipitation specifically impacted the relative abundances of Bacteroidetes and Gammaproteobacteria compared to the control, while the main effect of warming impacted the relative abundance of Betaproteobacteria. In contrast, the fungal community had no significant response to the treatments after 1-year. Using structural equation modeling (SEM), we found bacterial community composition was positively related to soil moisture. Our results indicate that short-term climate change could cause changes in soil bacterial community through taxonomic shifts. Our work provides new insights into immediate soil microbial responses to short-term stressors acting on an ecosystem that is particularly sensitive to global climate change. PMID:27446064

Effects of Short-Term Warming and Altered Precipitation on Soil Microbial Communities in Alpine Grassland of the Tibetan Plateau.

PubMed

Zhang, Kaoping; Shi, Yu; Jing, Xin; He, Jin-Sheng; Sun, Ruibo; Yang, Yunfeng; Shade, Ashley; Chu, Haiyan

2016-01-01

Soil microbial communities are influenced by climate change drivers such as warming and altered precipitation. These changes create abiotic stresses, including desiccation and nutrient limitation, which act on microbes. However, our understanding of the responses of microbial communities to co-occurring climate change drivers is limited. We surveyed soil bacterial and fungal diversity and composition after a 1-year warming and altered precipitation manipulation in the Tibetan plateau alpine grassland. In isolation, warming and decreased precipitation treatments each had no significant effects on soil bacterial community structure; however, in combination of both treatments altered bacterial community structure (p = 0.03). The main effect of altered precipitation specifically impacted the relative abundances of Bacteroidetes and Gammaproteobacteria compared to the control, while the main effect of warming impacted the relative abundance of Betaproteobacteria. In contrast, the fungal community had no significant response to the treatments after 1-year. Using structural equation modeling (SEM), we found bacterial community composition was positively related to soil moisture. Our results indicate that short-term climate change could cause changes in soil bacterial community through taxonomic shifts. Our work provides new insights into immediate soil microbial responses to short-term stressors acting on an ecosystem that is particularly sensitive to global climate change.

Hemoglobin drop after anesthesia in craniosynstosis: Dilemma of operate or not to operate

PubMed Central

El-Ghandour, Nihal; Kassem, Salah; Al Sabbagh, Abdelrahman J.; Al-Banyan, Ayman; Shubbak, Firas A.; Hassib, Ahmad; Zaki, Hazem

2011-01-01

An infant with craniosynostosis for craniectomy and cranial-vault remodelling was detected to have very low hemoglobin (6.8 gm%) after induction of anesthesia. This posed a dilemma whether to proceed with or abandon the surgical procedure. The case was postponed and was rescheduled for surgery one week later with hope that his hemoglobin would rise during this period. However, even before second anesthesia his hemoglobin level was found to be unchanged. Meticulous anesthesia management resulted in uneventful surgical procedure. PMID:25885398

Quantitative, single-step dual measurement of hemoglobin A1c and total hemoglobin in human whole blood using a gold sandwich immunochromatographic assay for personalized medicine.

PubMed

Ang, Shu Hwang; Rambeli, Musalman; Thevarajah, T Malathi; Alias, Yatimah Binti; Khor, Sook Mei

2016-04-15

We describe a gold nanoparticle-based sandwich immunoassay for the dual detection and measurement of hemoglobin A1c (HbA1c) and total hemoglobin in the whole blood (without pretreatment) in a single step for personalized medicine. The optimized antibody-functionalized gold nanoparticles immunoreact simultaneously with HbA1c and total hemoglobin to form a sandwich at distinctive test lines to transduce visible signals. The applicability of this method as a personal management tool was demonstrated by establishing a calibration curve to relate % HbA1c, a useful value for type 2 diabetes management, to the signal ratio of captured HbA1c to all other forms of hemoglobin. The platform showed excellent selectivity (100%) toward HbA1c at distinctive test lines when challenged with HbA0, glycated HbA0 and HbA2. The reproducibility of the measurement was good (6.02%) owing to the dual measurement of HbA1c and total hemoglobin. A blood sample stability test revealed that the quantitative measurement of % HbA1c was consistent and no false-positive results were detected. Also, this method distinguished the blood sample with elevated HbF from the normal samples and the variants. The findings of this study highlight the potential of a lateral flow immunosensor as a simple, inexpensive, consistent, and convenient strategy for the dual measurement of HbA1c and total Hb to provide useful % HbA1c values for better on-site diabetes care. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effect of a Low Fluoride Delivery System on Bacterial Metabolism.

DTIC Science & Technology

1980-09-01

Fluorides, an4 -Ique mechanisms, slow release delivery, temporary restora- tions, bacterial attachment, Streptococcus mutans , bacterial metabo’ilsm...concentrations of NaF, SnF 4 , Na2SnF6 , TiF 4 , and SnCI2 on altering plaque formation by Streptococcus mutans NCTC 10449. Specific tests were...preparation. Microorganisms, Growth Media, and Growth A streptomycin resistant mutant of Streptococcus mutans NCTC 10449 (Bratthall serotype c) has been

Bacterial Flora Changes in Conjunctiva of Rats with Streptozotocin-Induced Type I Diabetes.

PubMed

Yang, Chao; Fei, Yuda; Qin, Yali; Luo, Dan; Yang, Shufei; Kou, Xinyun; Zi, Yingxin; Deng, Tingting; Jin, Ming

2015-01-01

The microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ)-induced type I diabetes. A high dose of STZ (60 mg/kg, i.p.) was injected into Sprague-Dawley (SD) rats to induce type I diabetes mellitus (T1DM). The diabetic rats were raised in the animal laboratory and at 8 months post-injection of STZ swab samples were taken from the bulbar conjunctiva for cultivation of aerobic bacteria. The bacterial isolates were identified by Gram staining and biochemical features. The identified bacteria from both diabetic and healthy rats were then compared. The diabetic and healthy rats had different bacterial flora present in their bulbar conjunctiva. In total, 10 and 8 bacterial species were found in the STZ and control groups, respectively, with only three species (Enterococcus faecium, Enterococcus gallinarum and Escherichia coli) shared between the two groups. Gram-positive bacteria were common in both groups and the most abundant was Enterococcus faecium. However, after the development of T1DM, the bacterial flora in the rat bulbar conjunctiva changed considerably, with a reduced complexity evident. STZ-induced diabetes caused alterations of bacterial flora in the bulbar conjunctiva in rats, with some bacterial species disappearing and others emerging. Our results indicate that the conjunctival bacterial flora in diabetic humans should be surveyed for potential diagnostic markers or countermeasures to prevent eye infections in T1DM patients.

Bacterial Flora Changes in Conjunctiva of Rats with Streptozotocin-Induced Type I Diabetes

PubMed Central

Qin, Yali; Luo, Dan; Yang, Shufei; Kou, Xinyun; Zi, Yingxin; Deng, Tingting; Jin, Ming

2015-01-01

Background The microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ)-induced type I diabetes. Methods A high dose of STZ (60 mg/kg, i.p.) was injected into Sprague-Dawley (SD) rats to induce type I diabetes mellitus (T1DM). The diabetic rats were raised in the animal laboratory and at 8 months post-injection of STZ swab samples were taken from the bulbar conjunctiva for cultivation of aerobic bacteria. The bacterial isolates were identified by Gram staining and biochemical features. The identified bacteria from both diabetic and healthy rats were then compared. Results The diabetic and healthy rats had different bacterial flora present in their bulbar conjunctiva. In total, 10 and 8 bacterial species were found in the STZ and control groups, respectively, with only three species (Enterococcus faecium, Enterococcus gallinarum and Escherichia coli) shared between the two groups. Gram-positive bacteria were common in both groups and the most abundant was Enterococcus faecium. However, after the development of T1DM, the bacterial flora in the rat bulbar conjunctiva changed considerably, with a reduced complexity evident. Conclusions STZ-induced diabetes caused alterations of bacterial flora in the bulbar conjunctiva in rats, with some bacterial species disappearing and others emerging. Our results indicate that the conjunctival bacterial flora in diabetic humans should be surveyed for potential diagnostic markers or countermeasures to prevent eye infections in T1DM patients. PMID:26176548

Dietary Supplementation with Rice Bran or Navy Bean Alters Gut Bacterial Metabolism in Colorectal Cancer Survivors

PubMed Central

Sheflin, Amy M.; Borresen, Erica C.; Kirkwood, Jay S.; Boot, Claudia M.; Whitney, Alyssa K.; Lu, Shen; Brown, Regina J.; Broeckling, Corey D.; Ryan, Elizabeth P.; Weir, Tiffany L.

2016-01-01

Scope Heat-stabilized rice bran and cooked navy bean powder contain a variety of phytochemicals that are fermented by colonic microbiota and may influence intestinal health. Dietary interventions with these foods should be explored for modulating colorectal cancer risk. Methods and results A randomized-controlled pilot clinical trial investigated the effects of eating heat-stabilized rice bran (30g/day) or cooked navy bean powder (35g/day) on gut microbiota and metabolites (NCT01929122). Twenty-nine overweight/obese volunteers with a prior history of colorectal cancer consumed a study-provided meal and snack daily for 28 days. Volunteers receiving rice bran or bean powder showed increased gut bacterial diversity and altered gut microbial composition at 28 days compared to baseline. Supplementation with rice bran or bean powder increased total dietary fiber intake similarly, yet only rice bran intake led to a decreased Firmicutes:Bacteroidetes ratio and increased short chain fatty acids (propionate and acetate) in stool after 14 days but not at 28 days. Conclusion These findings support modulation of gut microbiota and fermentation by-products by heat-stabilized rice bran and suggest that foods with similar ability to increase dietary fiber intake may not have equal effects on gut microbiota and microbial metabolism. PMID:27461523

Pitfalls in the biological diagnosis of common hemoglobin disorders.

PubMed

Wajcman, Henri; Moradkhani, Kamran

2015-01-01

In West-European countries, hemoglobin disorders are no more rare diseases. Programs for diagnosis of heterozygous carriers have been established to prevent cases with major sickle cell disease or thalassemias. These studies have been done essentially by high performance liquid chromatography on cation-exchange columns and electrophoresis (mostly capillary electrophoresis). They have been done through systematic population studies or premarital diagnosis. We describe in this work the frequent or rare pitfalls encountered, which led to false negative or positive diagnosis both in the field of sickle cell disease and thalassemias. In the absence of a well identified hemoglobin disorder in the proband's family, it is a rule that the use of a single test is insufficient to identify formally HbS. The presence of HbS could also be masked by another hemoglobin abnormality. The sole measurement of HbA2 level is insufficient to characterize a thalassemic trait: this level needs always to be interpreted considering RBC parameters and iron metabolic status. In difficult cases, the definitive answer may require a family study and/or a molecular genetic characterization.

Identification of hemoglobin variants by top-down mass spectrometry using selected diagnostic product ions.

PubMed

Coelho Graça, Didia; Hartmer, Ralf; Jabs, Wolfgang; Beris, Photis; Clerici, Lorella; Stoermer, Carsten; Samii, Kaveh; Hochstrasser, Denis; Tsybin, Yury O; Scherl, Alexander; Lescuyer, Pierre

2015-04-01

Hemoglobin disorder diagnosis is a complex procedure combining several analytical steps. Due to the lack of specificity of the currently used protein analysis methods, the identification of uncommon hemoglobin variants (proteoforms) can become a hard task to accomplish. The aim of this work was to develop a mass spectrometry-based approach to quickly identify mutated protein sequences within globin chain variants. To reach this goal, a top-down electron transfer dissociation mass spectrometry method was developed for hemoglobin β chain analysis. A diagnostic product ion list was established with a color code strategy allowing to quickly and specifically localize a mutation in the hemoglobin β chain sequence. The method was applied to the analysis of rare hemoglobin β chain variants and an (A)γ-β fusion protein. The results showed that the developed data analysis process allows fast and reliable interpretation of top-down electron transfer dissociation mass spectra by nonexpert users in the clinical area.

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

Shared and distinct mechanisms of iron acquisition by bacterial and fungal pathogens of humans

PubMed Central

Caza, Mélissa; Kronstad, James W.

2013-01-01

Iron is the most abundant transition metal in the human body and its bioavailability is stringently controlled. In particular, iron is tightly bound to host proteins such as transferrin to maintain homeostasis, to limit potential damage caused by iron toxicity under physiological conditions and to restrict access by pathogens. Therefore, iron acquisition during infection of a human host is a challenge that must be surmounted by every successful pathogenic microorganism. Iron is essential for bacterial and fungal physiological processes such as DNA replication, transcription, metabolism, and energy generation via respiration. Hence, pathogenic bacteria and fungi have developed sophisticated strategies to gain access to iron from host sources. Indeed, siderophore production and transport, iron acquisition from heme and host iron-containing proteins such as hemoglobin and transferrin, and reduction of ferric to ferrous iron with subsequent transport are all strategies found in bacterial and fungal pathogens of humans. This review focuses on a comparison of these strategies between bacterial and fungal pathogens in the context of virulence and the iron limitation that occurs in the human body as a mechanism of innate nutritional defense. PMID:24312900

Surface-enhanced Raman spectra of hemoglobin for esophageal cancer diagnosis

NASA Astrophysics Data System (ADS)

Zhou, Xue; Diao, Zhenqi; Fan, Chunzhen; Guo, Huiqiang; Xiong, Yang; Tang, Weiyue

2014-03-01

Surface-enhanced Raman scattering (SERS) spectra of hemoglobin from 30 esophageal cancer patients and 30 healthy persons have been detected and analyzed. The results indicate that, there are more iron ions in low spin state and less in high for the hemoglobin of esophageal cancer patients than normal persons, which is consistent with the fact that it is easier to hemolyze for the blood of cancer patients. By using principal component analysis (PCA) and discriminate analysis, we can get a three-dimensional scatter plot of PC scores from the SERS spectra of healthy persons and cancer patients, from which the two groups can be discriminated. The total accuracy of this method is 90%, while the diagnostic specificity is 93.3% and sensitivity is 86.7%. Thus SERS spectra of hemoglobin analysis combined with PCA may be a new technique for the early diagnose of esophageal cancer.

Assessing the relative stabilities of engineered hemoglobins using electrospray mass spectrometry.

PubMed

Apostol, I

1999-07-15

An ion trap mass spectrometer equipped with an electrospray source was used to examine the relative thermodynamic stabilities of various hemoglobins with respect to both tetramer dissociation and hemin dissociation. The results demonstrated that the stability of hemoglobin molecules can be differentiated by the amount of applied collision-induced dissociation (CID) energy necessary to break up the intact tetramer into its constituent globins. The stability of the intact tetramer was affected by single mutations in the beta-globins. The stabilities of the constituent hologlobins were assessed via trap CID of selected ions. The results demonstrated the importance of the contributions of the hologlobin components to the stability of the intact tetramer. Genetic fusion of two alpha-globins, through the introduction of a single glycine residue between the C-terminus of one alpha-chain and the N-terminus of the second, significantly increased the stability of the hemoglobin pseudo-tetramer. Chemical crosslinking of the beta-globins in addition to genetic fusion of alpha-globins further stabilized the hemoglobin molecule. A dihemoglobin molecule produced by the genetic fusion of two di-alpha-globins with a flexible linker demonstrated a decreased stability relative to the corresponding monohemoglobin. Copyright 1999 Academic Press.

Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination.

PubMed

Jia, Shuyu; Shi, Peng; Hu, Qing; Li, Bing; Zhang, Tong; Zhang, Xu-Xiang

2015-10-20

For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.

The mechanism of formation, structure and physiological relevance of covalent hemoglobin attachment to the erythrocyte membrane.

PubMed

Welbourn, Elizabeth M; Wilson, Michael T; Yusof, Ashril; Metodiev, Metodi V; Cooper, Chris E

2017-02-01

Covalent hemoglobin binding to membranes leads to band 3 (AE1) clustering and the removal of erythrocytes from the circulation; it is also implicated in blood storage lesions. Damaged hemoglobin, with the heme being in a redox and oxygen-binding inactive hemichrome form, has been implicated as the binding species. However, previous studies used strong non-physiological oxidants. In vivo hemoglobin is constantly being oxidised to methemoglobin (ferric), with around 1% of hemoglobin being in this form at any one time. In this study we tested the ability of the natural oxidised form of hemoglobin (methemoglobin) in the presence or absence of the physiological oxidant hydrogen peroxide to initiate membrane binding. The higher the oxidation state of hemoglobin (from Fe(III) to Fe(V)) the more binding was observed, with approximately 50% of this binding requiring reactive sulphydryl groups. The hemoglobin bound was in a high molecular weight complex containing spectrin, ankyrin and band 4.2, which are common to one of the cytoskeletal nodes. Unusually, we showed that hemoglobin bound in this way was redox active and capable of ligand binding. It can initiate lipid peroxidation showing the potential to cause cell damage. In vivo oxidative stress studies using extreme endurance exercise challenges showed an increase in hemoglobin membrane binding, especially in older cells with lower levels of antioxidant enzymes. These are then targeted for destruction. We propose a model where mild oxidative stress initiates the binding of redox active hemoglobin to the membrane. The maximum lifetime of the erythrocyte is thus governed by the redox activity of the cell; from the moment of its release into the circulation the timer is set. Copyright © 2016. Published by Elsevier Inc.

Temperature transition of human hemoglobin at body temperature: effects of calcium.

PubMed Central

Kelemen, C; Chien, S; Artmann, G M

2001-01-01

We studied the effects of calcium ion concentration on the temperature dependence of rheological behavior of human red blood cells (RBCs) and concentrated hemoglobin solutions. Our previous study (G. M. Artmann, C. Kelemen, D. Porst, G. Büldt, and S. Chien, 1998, Biophys. J., 75:3179-3183) showed a critical temperature (Tc) of 36.4 +/- 0.3 degrees C at which the RBCs underwent a transition from non-passage to passage through 1.3 microm micropipettes in response to an aspiration pressure of -2.3 kPa. An increase in intracellular Ca2+ concentration by using the ionophore A23187 reduced the passability of intact RBCs through small micropipettes above T(c); the micropipette diameter needed for >90% passage increased to 1.7 microm. Viscometry of concentrated hemoglobin solutions (45 and 50 g/dl) showed a sudden viscosity transition at 36 +/- 1 degrees C (Tc(eta)) at all calcium concentrations investigated. Below Tc(eta), the viscosity value of the concentrated hemoglobin solution at 1.8 mM Ca(2+) was higher than that at other concentrations (0.2 microM, 9 mM, and 18 mM). Above Tc(eta), the viscosity was almost Ca2+ independent. At 1.8 mM Ca2+ and 36 +/- 1 degrees C, the activation energy calculated from the viscometry data showed a strong dependence on the hemoglobin concentration. We propose that the transition of rheological behavior is attributable to a high-to-low viscosity transition mediated by a partial release of the hemoglobin-bound water. PMID:11371439

Microscopic diffusion and hydrodynamic interactions of hemoglobin in red blood cells.

PubMed

Doster, Wolfgang; Longeville, Stéphane

2007-08-15

The cytoplasm of red blood cells is congested with the oxygen storage protein hemoglobin occupying a quarter of the cell volume. The high protein concentration leads to a reduced mobility; the self-diffusion coefficient of hemoglobin in blood cells is six times lower than in dilute solution. This effect is generally assigned to excluded volume effects in crowded media. However, the collective or gradient diffusion coefficient of hemoglobin is only weakly dependent on concentration, suggesting the compensation of osmotic and friction forces. This would exclude hydrodynamic interactions, which are of dynamic origin and do not contribute to the osmotic pressure. Hydrodynamic coupling between protein molecules is dominant at short time- and length scales before direct interactions are fully established. Employing neutron spin-echo-spectroscopy, we study hemoglobin diffusion on a nanosecond timescale and protein displacements on the scale of a few nanometers. A time- and wave-vector dependent diffusion coefficient is found, suggesting the crossover of self- and collective diffusion. Moreover, a wave-vector dependent friction function is derived, which is a characteristic feature of hydrodynamic interactions. The wave-vector and concentration dependence of the long-time self-diffusion coefficient of hemoglobin agree qualitatively with theoretical results on hydrodynamics in hard spheres suspensions. Quantitative agreement requires us to adjust the volume fraction by including part of the hydration shell: Proteins exhibit a larger surface/volume ratio compared to standard colloids of much larger size. It is concluded that hydrodynamic and not direct interactions dominate long-range molecular transport at high concentration.

Introduction of a new regulatory mechanism into human hemoglobin.

PubMed

Fronticelli, Clara; Bobofchak, Kevin M; Karavitis, Michael; Sanna, Maria Teresa; Brinigar, William S

2002-07-10

Previous studies on bovine hemoglobin (HbBv) have suggested amino acid substitutions, which might introduce into human hemoglobin (HbA) functional characteristics of HbBv, namely a low intrinsic oxygen affinity regulated by Cl(-). Accordingly, we have constructed and characterized a multiple mutant, PB5, [beta(V1M + H2 Delta + T4I + P5A + A76K)] replacing four amino acid residues of HbA with those present at structurally analogous positions in HbBv, plus an additional substitution, beta T4I, which does not occur in either HbBv or HbA. This 'pseudobovine' hemoglobin has oxygen binding properties very similar to those of HbBv: the P(50) of HbA, PB5 and HbBv in the absence of Cl(-) are 1.6, 4.6 and 4.8 torr, respectively, and in 100 mM Cl(-) are 3.7, 10.5 and 12 torr, respectively. Moreover, PB5 has 3-fold slower autoxidation rate compared to HbA and HbBv. These are desirable characteristics for a human hemoglobin to be considered for use as a clinical artificial oxygen carrier. Although the functional properties of PB5 and HbBv are similar, van't Hoff plots indicate that the two hemoglobins interact differently with water, suggesting that factors regulating the R to T equilibrium are not the same in the two proteins. A further indication that PB5 is not a functional mimic of HbBv derives from PB5(control), a human hemoglobin with the same substitutions as PB5, except the beta T4I replacement. PB5(control) has a high oxygen affinity (P(50)=2.3 torr) in the absence of Cl(-), but retains the Cl(-) effect of PB5. The Cl(-) regulation of oxygen affinity in PB5 involves lysine residues at beta 8 and beta 76. PB4, which has the same substitutions as PB5 except beta A76K, and PB6, which has all the substitutions of PB5 plus beta K8Q, both have a low intrinsic oxygen affinity, like HbBv and PB5, but exhibit a decreased sensitivity to Cl(-). Since HbBv has lysine residues at both beta 8 and beta 76, these results imply that Cl(-) regulation in HbBv likewise involves these two

Hemoglobin Threshold for Blood Transfusion in a Pediatric Intensive Care Unit.

PubMed

Chegondi, Madhuradhar; Sasaki, Jun; Raszynski, André; Totapally, Balagangadhar R

2016-07-01

To evaluate the hemoglobin threshold for red cell transfusion in children admitted to a pediatric intensive care unit (PICU). Retrospective chart review study. Tertiary care PICU. Critically ill pediatric patients requiring blood transfusion. No intervention. We analyzed the charts of all children between 1 month and 21 years of age who received packed red blood cell (PRBC) transfusions during a 2-year period. The target patients were identified from our blood bank database. For analysis, the patients were subdivided into four groups: acute blood loss (postsurgically, trauma, or acute gastrointestinal bleeding from other causes), hematologic (hematologic malignancies, bone marrow suppression, hemolytic anemia, or sickle cell disease), unstable (FiO 2 > 0.6 and/or on inotropic support), and stable groups. We also compared the pre-transfusion hemoglobin threshold in all unstable patients with that of all stable patients. A total of 571 transfusion episodes in 284 patients were analyzed. 28% (n = 160) of transfusions were administered to patients in the acute blood loss group, 36% (n = 206) to hematologic patients, 17% (n = 99) to unstable patients, and 18% (n = 106) to stable patients. The mean pre-transfusion hemoglobin (± SD) in all children as well as in the acute blood loss, hematologic, unstable and stable groups was 7.3 ± 1.20, 7.83 ± 1.32, 6.97 ± 1.31, 7.96 ± 1.37, 7.31 ± 1.09 g/dl, respectively. The transfusion threshold for acute blood loss and unstable groups was higher compared to hematologic and stable groups (p < 0.001; ANOVA with multiple comparisons). The mean pre-transfusion hemoglobin threshold for stable and unstable patients among all groups was 7.3 ± 1.3 and 7.9 ± 1.3 (p < 0.0001), respectively. The observed mortality rate was higher among children who received transfusion compared to other children admitted to PICU. The hemoglobin threshold for transfusion varied according to clinical conditions. Overall, the hemoglobin threshold for

Methylation of hemoglobin to enhance flocculant performance

USDA-ARS?s Scientific Manuscript database

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

[Susceptibility of induced sickle in samples of heterozygous hemoglobin S patients (sickle cell trait) suffering diabetes mellitus type 2].

PubMed

Díaz-Piedra, Pablo; Cervantes-Villagrana, Alberto Rafael; Ramos-Jiménez, Raúl; Presno-Bernal, José Miguel; Cervantes-Villagrana, Rodolfo Daniel

2015-01-01

Hemoglobin S is an abnormal protein that induces morphological changes in erythrocyte in low-oxygen conditions. In Mexico, it is reported that up to 13.7% of the population with mutation in one allele are considered asymptomatic (sickle cell trait). The sickle cell trait and diabetes mellitus are conditions that occur together in more than one million patients worldwide. Both diseases possibly produce microvascular changes in retinopathy and acute chest syndrome. The aim of this study was to evaluate the induction of sickle cells in samples of diabetic patients with sickle cell trait to identify altered red cell parameters. We obtained samples of diabetic patients to determine hemoglobin A1c and S; furthermore, red blood cell biometrics data were analyzed. We found that older men with diabetes were susceptible to generate sickle cells and this correlated with reduced red blood cell count and an increase in media cell volume. In samples of women diabetes, there were no differences. We conclude that samples from patients with sickle cell trait and diabetes can cause sickle cells with high frequency in men, with lower red blood cells count and increased mean corpuscular volume as susceptibility parameters.

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

USDA-ARS?s Scientific Manuscript database

Maize is an important staple crop in many parts of the world but has low iron bioavailability, in part due to its high phytate content. Hemoglobin is a form of iron that is highly bioavailable and its bioavailability is not inhibited by phytate. We hypothesize that maize hemoglobin is a highly bioav...

NO Dioxygenase Activity in Hemoglobins Is Ubiquitous In Vitro, but Limited by Reduction In Vivo

PubMed Central

Smagghe, Benoit J.; Trent, James T.; Hargrove, Mark S.

2008-01-01

Genomics has produced hundreds of new hemoglobin sequences with examples in nearly every living organism. Structural and biochemical characterizations of many recombinant proteins reveal reactions, like oxygen binding and NO dioxygenation, that appear general to the hemoglobin superfamily regardless of whether they are related to physiological function. Despite considerable attention to “hexacoordinate” hemoglobins, which are found in nearly every plant and animal, no clear physiological role(s) has been assigned to them in any species. One popular and relevant hypothesis for their function is protection against NO. Here we have tested a comprehensive representation of hexacoordinate hemoglobins from plants (rice hemoglobin), animals (neuroglobin and cytoglobin), and bacteria (Synechocystis hemoglobin) for their abilities to scavenge NO compared to myoglobin. Our experiments include in vitro comparisons of NO dioxygenation, ferric NO binding, NO-induced reduction, NO scavenging with an artificial reduction system, and the ability to substitute for a known NO scavenger (flavohemoglobin) in E. coli. We conclude that none of these tests reveal any distinguishing predisposition toward a role in NO scavenging for the hxHbs, but that any hemoglobin could likely serve this role in the presence of a mechanism for heme iron re-reduction. Hence, future research to test the role of Hbs in NO scavenging would benefit more from the identification of cognate reductases than from in vitro analysis of NO and O2 binding. PMID:18446211

Long term repeated fire disturbance alters soil bacterial diversity but not the abundance in an Australian wet sclerophyll forest.

PubMed

Shen, Ju-pei; Chen, C R; Lewis, Tom

2016-01-20

Effects of fire on biogeochemical cycling in terrestrial ecosystem are widely acknowledged, while few studies have focused on the bacterial community under the disturbance of long-term frequent prescribed fire. In this study, three treatments (burning every two years (B2), burning every four years (B4) and no burning (B0)) were applied for 38 years in an Australian wet sclerophyll forest. Results showed that bacterial alpha diversity (i.e. bacterial OTU) in the top soil (0-10 cm) was significantly higher in the B2 treatment compared with the B0 and B4 treatments. Non-metric multidimensional analysis (NMDS) of bacterial community showed clear separation of the soil bacterial community structure among different fire frequency regimes and between the depths. Different frequency fire did not have a substantial effect on bacterial composition at phylum level or bacterial 16S rRNA gene abundance. Soil pH and C:N ratio were the major drivers for bacterial community structure in the most frequent fire treatment (B2), while other factors (EC, DOC, DON, MBC, NH4(+), TC and TN) were significant in the less frequent burning and no burning treatments (B4 and B0). This study suggested that burning had a dramatic impact on bacterial diversity but not abundance with more frequent fire.

Long term repeated fire disturbance alters soil bacterial diversity but not the abundance in an Australian wet sclerophyll forest

PubMed Central

Shen, Ju-pei; Chen, C. R.; Lewis, Tom

2016-01-01

Effects of fire on biogeochemical cycling in terrestrial ecosystem are widely acknowledged, while few studies have focused on the bacterial community under the disturbance of long-term frequent prescribed fire. In this study, three treatments (burning every two years (B2), burning every four years (B4) and no burning (B0)) were applied for 38 years in an Australian wet sclerophyll forest. Results showed that bacterial alpha diversity (i.e. bacterial OTU) in the top soil (0–10 cm) was significantly higher in the B2 treatment compared with the B0 and B4 treatments. Non-metric multidimensional analysis (NMDS) of bacterial community showed clear separation of the soil bacterial community structure among different fire frequency regimes and between the depths. Different frequency fire did not have a substantial effect on bacterial composition at phylum level or bacterial 16S rRNA gene abundance. Soil pH and C:N ratio were the major drivers for bacterial community structure in the most frequent fire treatment (B2), while other factors (EC, DOC, DON, MBC, NH4+, TC and TN) were significant in the less frequent burning and no burning treatments (B4 and B0). This study suggested that burning had a dramatic impact on bacterial diversity but not abundance with more frequent fire. PMID:26787458

Rifaximin has minor effects on bacterial composition, inflammation, and bacterial translocation in cirrhosis: A randomized trial.

PubMed

Kimer, Nina; Pedersen, Julie S; Tavenier, Juliette; Christensen, Jeffrey E; Busk, Troels M; Hobolth, Lise; Krag, Aleksander; Al-Soud, Waleed Abu; Mortensen, Martin S; Sørensen, Søren J; Møller, Søren; Bendtsen, Flemming

2018-01-01

Decompensated cirrhosis is characterized by disturbed hemodynamics, immune dysfunction, and high risk of infections. Translocation of viable bacteria and bacterial products from the gut to the blood is considered a key driver in this process. Intestinal decontamination with rifaximin may reduce bacterial translocation (BT) and decrease inflammation. A randomized, placebo-controlled trial investigated the effects of rifaximin on inflammation and BT in decompensated cirrhosis. Fifty-four out-patients with cirrhosis and ascites were randomized, mean age 56 years (± 8.4), and model for end-stage liver disease score 12 (± 3.9). Patients received rifaximin 550-mg BD (n = 36) or placebo BD (n = 18). Blood and fecal (n = 15) sampling were conducted at baseline and after 4 weeks. Bacterial DNA in blood was determined by real-time qPCR 16S rRNA gene quantification. Bacterial composition in feces was analyzed by 16S rRNA gene sequencing. Circulating markers of inflammation, including tumor necrosis factor alpha, interleukins 6, 10, and 18, stromal cell-derived factor 1-α, transforming growth factor β-1, and high sensitivity C-reactive protein, were unaltered by rifaximin treatment. Rifaximin altered abundance of bacterial taxa in blood marginally, only a decrease in Pseudomonadales was observed. In feces, rifaximin decreased bacterial richness, but effect on particular species was not observed. Subgroup analyses on patients with severely disturbed hemodynamics (n = 34) or activated lipopolysaccharide binding protein (n = 37) revealed no effect of rifaximin. Four weeks of treatment with rifaximin had no impact on the inflammatory state and only minor effects on BT and intestinal bacterial composition in stable, decompensated cirrhosis (NCT01769040). © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Hemorheological alterations in adults with prediabetes identified by hemoglobin A1c levels.

PubMed

Marini, M A; Fiorentino, T V; Andreozzi, F; Mannino, G C; Succurro, E; Sciacqua, A; Perticone, F; Sesti, G

2017-07-01

A link between increased blood viscosity and type 2 diabetes has been previously reported. Herein, we investigated the association of blood viscosity with prediabetes, identified by glycated hemoglobin A1c (HbA1c) according to the new American Diabetes Association criteria, and subclinical atherosclerosis. The study cohort includes 1136 non-diabetic adults submitted to anthropometrical evaluation, an oral glucose tolerance test and ultrasound measurement of carotid intima-media thickness (IMT). Whole blood viscosity was estimated using a validated formula based on hematocrit and total plasma proteins. After adjusting for age, and gender, individuals with HbA1c-defined prediabetes (HbA1c 5.7-6.4% [39-47 mmol/mol]) exhibited significantly higher values of hematocrit, and predicted blood viscosity as compared with controls. Increased levels of IMT were observed in subjects with HbA1c-defined prediabetes in comparison to controls. Predicted blood viscosity was positively correlated with age, waist circumference, blood pressure, cholesterol, triglycerides, fibrinogen, white blood cell, HbA1c, fasting and 2-h post-load glucose levels, fasting insulin, IMT and inversely correlated with HDL and Matsuda index of insulin sensitivity. Of the three glycemic parameters, i.e. HbA1c, fasting and 2-h post-load glucose, only HbA1c showed a significant correlation with predicted blood viscosity (β = 0.054, P = 0.04) in a multivariate regression analysis model including multiple atherosclerosis risk factors. The study shows that individuals with HbA1c-defined prediabetes have increased predicted blood viscosity and IMT. The HbA1c criterion may be helpful to capture individuals with an increased risk of diabetes and cardiovascular disease who may benefit from an intensive lifestyle intervention. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical

Analysis of the binding interaction in uric acid - Human hemoglobin system by spectroscopic techniques

NASA Astrophysics Data System (ADS)

Makarska-Bialokoz, Magdalena

2017-05-01

The binding interaction between human hemoglobin and uric acid has been studied for the first time, by UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence techniques. Characteristic effects observed for human hemoglobin intrinsic fluorescence during interaction with uric acid at neutral pH point at the formation of stacking non-covalent and non-fluorescent complexes. All the calculated parameters, the binding, fluorescence quenching and bimolecular quenching rate constants, as well as Förster resonance energy transfer parameters confirm the existence of static quenching. The results of synchronous fluorescence measurements indicate that the fluorescence quenching of human hemoglobin originates both from Trp and Tyr residues and that the addition of uric acid could significantly hinder the physiological functions of human hemoglobin.

Changes in bacterial community after application of three different herbicides.

PubMed

Moretto, Jéssica Aparecida Silva; Altarugio, Lucas Miguel; Andrade, Pedro Avelino; Fachin, Ana Lúcia; Andreote, Fernando Dini; Stehling, Eliana Guedes

2017-07-06

The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Arbuscular Mycorrhizal Fungal Hyphae Alter Soil Bacterial Community and Enhance Polychlorinated Biphenyls Dissipation

PubMed Central

Qin, Hua; Brookes, Philip C.; Xu, Jianming

2016-01-01

We investigated the role of arbuscular mycorrhizal fungal (AMF) hyphae in alternation of soil microbial community and Aroclor 1242 dissipation. A two-compartment rhizobox system with double nylon meshes in the central was employed to exclude the influence of Cucurbita pepo L. root exudates on hyphal compartment soil. To assess the quantitative effect of AMF hyphae on soil microbial community, we separated the hyphal compartment soil into four horizontal layers from the central mesh to outer wall (e.g., L1–L4). Soil total PCBs dissipation rates ranged from 35.67% of L4 layer to 57.39% of L1 layer in AMF inoculated treatment, which were significant higher than the 17.31% of the control (P < 0.05). The dissipation rates of tri-, tetrachlorinated biphenyls as well as the total PCBs were significantly correlated with soil hyphal length (P < 0.01). Real-time quantitative PCR results indicated that the Rhodococcus-like bphC gene was 2–3 orders of magnitude more than that of Pseudomonas-like bphC gene, and was found responded positively to AMF. Phylogenetic analyses of the 16S rDNA sequenced by the Illumina Miseq sequencing platform indicated that AMF hyphae altered bacterial community compositions. The phylum Betaproteobacteria and Actinobacteria were dominated in the soil, while Burkholderiales and Actinomycetales were dominated at the order level. Taxa from the Comamonadaceae responded positively to AMF and trichlorinated biphenyl dissipation, while taxa from the Oxalobacteraceae and Streptomycetaceae responded negatively to AMF and PCB congener dissipation. Our results suggested that the AMF hyphal exudates as well as the hyphae per se did have quantitative effects on shaping soil microbial community, and could modify the PCBs dissipation processes consequently. PMID:27379068

Preliminary Crystallographic Study of Hemoglobin from Buffalo (Bubalus bubalis): A Low Oxygen Affinity Species.

PubMed

Balasubramanian, Moovarkumudalvan; Moorthy, Ponnuraj Sathya; Neelagandan, Kamariah; Ponnuswamy, Mondikalipudur Nanjappa Gounder

2009-01-01

Hemoglobin is a tetrameric, iron-containing metalloprotein, which plays a vital role in the transportation of oxygen from lungs to tissues and carbon dioxide back to lungs. Though good amount of work has already been done on hemoglobins, the scarcity of data on three dimensional structures pertaining to low oxygen affinity hemoglobins from mammalian species, motivated our group to work on this problem specifically. Herein, we report the preliminary crystallographic analysis of buffalo hemoglobin, which belongs to low oxygen affinity species. The buffalo blood was collected, purified by anion exchange chromatography and crystallized with PEG 3350 using 50mM phosphate buffer at pH 6.7 as a precipitant by hanging drop vapor diffusion method. Data collection was carried out using mar345dtb image plate detector system. Buffalo hemoglobin crystallizes in orthorhombic space group P2(1)2(1)2(1) with one whole biological molecule (alpha2beta2) in the asymmetric unit with cell dimensions a=63.064A, b=74.677A, c=110.224A.

Influence of bacterial interactions on pneumococcal colonization of the nasopharynx

PubMed Central

Shak, Joshua R.; Vidal, Jorge E.; Klugman, Keith P.

2013-01-01

Streptococcus pneumoniae (the pneumococcus) is a common commensal inhabitant of the nasopharynx and a frequent etiologic agent in serious diseases such as pneumonia, otitis media, bacteremia, and meningitis. Multiple pneumococcal strains can colonize the nasopharynx, which is also home to many other bacterial species. Intraspecies and interspecies interactions influence pneumococcal carriage in important ways. Co-colonization by two or more pneumococcal strains has implications for vaccine serotype replacement, carriage detection, and pneumonia diagnostics. Interactions between the pneumococcus and other bacterial species alter carriage prevalence, modulate virulence, and affect biofilm formation. By examining these interactions, this review highlights how the bacterial ecosystem of the nasopharynx changes the nature and course of pneumococcal carriage. PMID:23273566

Hemoglobin Function in Stored Blood.

DTIC Science & Technology

1974-08-01

States during 1973. Several advantages over ACA) are important. Blood stored in CPD maintains higher ./ levels of 2,3-DPG (2,3- diphosphoglycerate ) and a...survival and ATP levels in stored blood is explained by the several functions of ATP which are necessary for cell viability. However, ATP levels do...not correlate with oxygen affinity during storage. Levels of 2,3-DPG determine oxygen affinity and thus hemoglobin function. (12,13) When normal levels

In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure.

PubMed

Wang, Yu; Hu, Song; Maslov, Konstantin; Zhang, Yu; Xia, Younan; Wang, Lihong V

2011-04-01

We developed dual-modality microscope integrating photoacoustic microscopy (PAM) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO₂) and oxygen partial pressure (pO₂) in vivo in single blood vessels with high spatial resolution. While PAM measures sO₂ by imaging hemoglobin optical absorption at two wavelengths, FCM quantifies pO₂ using phosphorescence quenching. The variations of sO₂ and pO₂ values in multiple orders of vessel branches under hyperoxic (100% oxygen) and normoxic (21% oxygen) conditions correlate well with the oxygen-hemoglobin dissociation curve. In addition, the total concentration of hemoglobin is imaged by PAM at an isosbestic wavelength.

The salivary microbiome is altered in the presence of a high salivary glucose concentration

PubMed Central

Hartman, Mor-Li; Shi, Ping; Hasturk, Hatice; Yaskell, Tina; Vargas, Jorel; Song, Xiaoqing; Cugini, Maryann; Barake, Roula; Alsmadi, Osama; Al-Mutawa, Sabiha; Ariga, Jitendra; Soparkar, Pramod; Behbehani, Jawad; Behbehani, Kazem

2017-01-01

Background Type II diabetes (T2D) has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects. Methods We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175) and those with low salivary glucose (LSG, glucose concentration < 0.1 mg/dL n = 2,537). Results HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness. Conclusions HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence

Fasting serum glucose and glycosylated hemoglobin level in obesity.

PubMed

Das, R K; Nessa, A; Hossain, M A; Siddiqui, N I; Hussain, M A

2014-04-01

Obesity is a condition in which the body fat stores are increased to an extent which impairs health and leads to serious health consequences. The amount of body fat is difficult to measure directly, and is usually determined from an indirect measure - the body mass index (BMI). Increased BMI in obese persons is directly associated with an increase in metabolic disease, such as type 2 diabetes mellitus. This Analytical cross sectional study was undertaken to assess the relation between obesity and glycemic control of body by measuring fasting serum glucose and glycosylated hemoglobin. This study was carried out in the Department of Physiology, Mymensingh Medical College, Mymensingh from 1st July 2011 to 30th June 2012 on 120 equally divided male and female persons within the age range of 25 to 55 years. Age more than 55 years and less than 25 years and diagnosed case of Hypothyroidism, Cushing's syndrome, polycystic ovary, Antipsychotic drug user and regular steroid users were excluded. Non probability purposive type of sampling technique was used for selecting the study subjects. Measurement of body mass index was done as per procedure. Fasting serum glucose was estimated by glucose oxidase method and Glycosylated hemoglobin by Boronate Affinity method. Statistical analysis was done by SPSS (version 17.0). Data were expressed as Mean±SE and statistical significance of difference among the groups were calculated by unpaired student's 't' test and Pearson's correlation coefficient tests were done as applicable. The Mean±SE of fasting serum glucose was significant at 1% level (P value <0.001) for obese group of BMI. There was no significant difference of glycosylated hemoglobin level between control and study groups. But there was positive correlation within each group. Fasting serum glucose also showed a bit stronger positive correlation with BMI. Both obese male and female persons showed higher levels of fasting serum glucose and glycosylated hemoglobin. The

U-shaped curve for risk associated with maternal hemoglobin, iron status, or iron supplementation.

PubMed

Dewey, Kathryn G; Oaks, Brietta M

2017-12-01

Both iron deficiency (ID) and excess can lead to impaired health status. There is substantial evidence of a U-shaped curve between the risk of adverse birth outcomes and maternal hemoglobin concentrations during pregnancy; however, it is unclear whether those relations are attributable to conditions of low and high iron status or to other mechanisms. We summarized current evidence from human studies regarding the association between birth outcomes and maternal hemoglobin concentrations or iron status. We also reviewed effects of iron supplementation on birth outcomes among women at low risk of ID and the potential mechanisms for adverse effects of high iron status during pregnancy. Overall, we confirmed a U-shaped curve for the risk of adverse birth outcomes with maternal hemoglobin concentrations, but the relations differ by trimester. For low hemoglobin concentrations, the link with adverse outcomes is more evident when hemoglobin concentrations are measured in early pregnancy. These relations generally became weaker or nonexistent when hemoglobin concentrations are measured in the second or third trimesters. Associations between high hemoglobin concentration and adverse birth outcomes are evident in all 3 trimesters but evidence is mixed. There is less evidence for the associations between maternal iron status and adverse birth outcomes. Most studies used serum ferritin (SF) concentrations as the indicator of iron status, which makes the interpretation of results challenging because SF concentrations increase in response to inflammation or infection. The effect of iron supplementation during pregnancy may depend on initial iron status. There are several mechanisms through which high iron status during pregnancy may have adverse effects on birth outcomes, including oxidative stress, increased blood viscosity, and impaired systemic response to inflammation and infection. Research is needed to understand the biological processes that underlie the U-shaped curves

Candidate Sequence Variants and Fetal Hemoglobin in Children with Sickle Cell Disease Treated with Hydroxyurea

PubMed Central

Green, Nancy S.; Ender, Katherine L.; Pashankar, Farzana; Driscoll, Catherine; Giardina, Patricia J.; Mullen, Craig A.; Clark, Lorraine N.; Manwani, Deepa; Crotty, Jennifer; Kisselev, Sergey; Neville, Kathleen A.; Hoppe, Carolyn; Barral, Sandra

2013-01-01

Background Fetal hemoglobin level is a heritable complex trait that strongly correlates swith the clinical severity of sickle cell disease. Only few genetic loci have been identified as robustly associated with fetal hemoglobin in patients with sickle cell disease, primarily adults. The sole approved pharmacologic therapy for this disease is hydroxyurea, with effects largely attributable to induction of fetal hemoglobin. Methodology/Principal Findings In a multi-site observational analysis of children with sickle cell disease, candidate single nucleotide polymorphisms associated with baseline fetal hemoglobin levels in adult sickle cell disease were examined in children at baseline and induced by hydroxyurea therapy. For baseline levels, single marker analysis demonstrated significant association with BCL11A and the beta and epsilon globin loci (HBB and HBE, respectively), with an additive attributable variance from these loci of 23%. Among a subset of children on hydroxyurea, baseline fetal hemoglobin levels explained 33% of the variance in induced levels. The variant in HBE accounted for an additional 13% of the variance in induced levels, while variants in the HBB and BCL11A loci did not contribute beyond baseline levels. Conclusions/Significance These findings clarify the overlap between baseline and hydroxyurea-induced fetal hemoglobin levels in pediatric disease. Studies assessing influences of specific sequence variants in these and other genetic loci in larger populations and in unusual hydroxyurea responders are needed to further understand the maintenance and therapeutic induction of fetal hemoglobin in pediatric sickle cell disease. PMID:23409025

Bohr effect of avian hemoglobins: Quantitative analyses based on the Wyman equation.

PubMed

Okonjo, Kehinde O

2016-12-07

The Bohr effect data for bar-headed goose, greylag goose and pheasant hemoglobins can be fitted with the Wyman equation for the Bohr effect, but under one proviso: that the pK a of His146β does not change following the T→R quaternary transition. This assumption is based on the x-ray structure of bar-headed goose hemoglobin, which shows that the salt-bridge formed between His146β and Asp94β in human deoxyhemoglobin is not formed in goose deoxyhemoglobin. When the Bohr data for chicken hemoglobin were fitted by making the same assumption, the pK a of the NH 3 + terminal group of Val1α decreased from 7.76 to 6.48 following the T→R transition. When the data were fitted without making any assumption, the pK a of the NH 3 + terminal group increased from 7.57 to 7.77 following the T→R transition. We demonstrate that avian hemoglobin Bohr data are readily fitted with the Wyman equation because avian hemoglobins lack His77β. From curve-fitting to Bohr data we estimate the pK a s of the NH 3 + terminal group of Val1α in the R and T states to be 6.33±0.1 and 7.22±0.1, respectively. We provide evidence indicating that these pK a s are more accurate than estimates from kinetic studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Reduction of rainbow trout spleen size by splenectomy does not alter resistance against bacterial cold water disease

USDA-ARS?s Scientific Manuscript database

In lower vertebrates, the contribution of the spleen to anti-bacterial immunity is poorly understood. Researchers have previously reported a phenotypic and genetic correlation between resistance to Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD) and spleen so...

A detailed spectroscopic study on the interaction of Rhodamine 6G with human hemoglobin.

PubMed

Mandal, Paulami; Bardhan, Munmun; Ganguly, Tapan

2010-05-03

UV-vis, time-resolved fluorescence and circular dichroism spectroscopic investigations have been made to reveal the nature of the interactions between xanthene dye Rhodamine 6G and the well known protein hemoglobin. From the analysis of the steady-state and time-resolved fluorescence quenching of Rhodamine 6G in aqueous solutions in presence of hemoglobin, it is revealed that the quenching is static in nature. The primary binding pattern between Rhodamine and hemoglobin has been interpreted as combined effect of hydrophobic association and electrostatic interaction. The binding constants, number of binding sites and thermodynamic parameters at various pH of the environment have been computed. The binding average distance between the energy donor Rhodamine and acceptor hemoglobin has been determined from the Forster's theory. Copyright 2010 Elsevier B.V. All rights reserved.

Age and anemia management: relationship of hemoglobin levels with mortality might differ between elderly and nonelderly hemodialysis patients

PubMed Central

Hanafusa, Norio; Nomura, Takanobu; Hasegawa, Takeshi; Nangaku, Masaomi

2014-01-01

Background The elderly hemodialyzed population is growing. However, little is known about the relationship between hemoglobin level and survival according to age. We investigated the effect of age on the relationship between hemoglobin and survival within the Japan Dialysis Outcomes and Practice Patterns Study (DOPPS) cohort. Methods We enrolled the entire Japan DOPPS phases 3 and 4 population. Patients were divided by the age of 75 years into two groups. Cox's proportional hazard model was used with hemoglobin at every 4 months treated as a time-dependent variable. The interaction of age and hemoglobin was analyzed. Results We included 3341 patients in the analyses. The primary outcome occurred in 567 patients during the median follow-up of 2.64 years. Hemoglobin of entire population was 10.3 ± 1.3 g/dL. The median of epoetin dose was 3000 IU/week. Interaction was found between ages stratified by the age of 75 years and hemoglobin values (P = 0.045) with use of Cox's proportional hazard model. The nonelderly population had poorer prognosis with hemoglobin <10 g/dL, while elderly population only with hemoglobin <9 g/dL. For both hemoglobin strata <9, ≥9 and <10 g/dL, interactions between age and hemoglobin were significant. Subgroup analysis indicated that interaction between age and Hb levels was observed only in the nondiabetic nephropathy group. Several sensitivity analyses demonstrated a similar trend with the original analyses and reinforced the robustness. Conclusions The elderly population might tolerate low hemoglobin levels. Our findings open the way for further investigation of individualized anemia management. PMID:25150218

Influence of low power CW laser irradiation on skin hemoglobin changes

NASA Astrophysics Data System (ADS)

Ferulova, Inesa; Lesins, Janis; Lihachev, Alexey; Jakovels, Dainis; Spigulis, Janis

2012-06-01

Influence of low power laser irradiance on healthy skin using diffuse reflectance spectroscopy and multispectral imaging was studied. Changes of diffuse reflectance spectra in spectral range from 500 to 600 nm were observed after 405 nm, 473 nm and 532 nm laser provocation, leading to conclusion that the content of skin hemoglobin has changed. Peaks in spectral absorbance (optical density) curves corresponded to well-known oxy-hemoglobin absorbance peaks at 542 and 577 nm.

Bacterial responses to environmental change on the Tibetan Plateau over the past half century.

PubMed

Liu, Yongqin; Priscu, John C; Yao, Tandong; Vick-Majors, Trista J; Xu, Baiqing; Jiao, Nianzhi; Santibáñez, Pamela; Huang, Sijun; Wang, Ninglian; Greenwood, Mark; Michaud, Alexander B; Kang, Shichang; Wang, Jianjun; Gao, Qun; Yang, Yunfeng

2016-06-01

Climate change and anthropogenic factors can alter biodiversity and can lead to changes in community structure and function. Despite the potential impacts, no long-term records of climatic influences on microbial communities exist. The Tibetan Plateau is a highly sensitive region that is currently undergoing significant alteration resulting from both climate change and increased human activity. Ice cores from glaciers in this region serve as unique natural archives of bacterial abundance and community composition, and contain concomitant records of climate and environmental change. We report high-resolution profiles of bacterial density and community composition over the past half century in ice cores from three glaciers on the Tibetan Plateau. Statistical analysis showed that the bacterial community composition in the three ice cores converged starting in the 1990s. Changes in bacterial community composition were related to changing precipitation, increasing air temperature and anthropogenic activities in the vicinity of the plateau. Collectively, our ice core data on bacteria in concert with environmental and anthropogenic proxies indicate that the convergence of bacterial communities deposited on glaciers across a wide geographical area and situated in diverse habitat types was likely induced by climatic and anthropogenic drivers. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Bacterial Inclusion Bodies Contain Amyloid-Like Structure

PubMed Central

Wang, Lei; Maji, Samir K; Sawaya, Michael R; Eisenberg, David; Riek, Roland

2008-01-01

Protein aggregation is a process in which identical proteins self-associate into imperfectly ordered macroscopic entities. Such aggregates are generally classified as amorphous, lacking any long-range order, or highly ordered fibrils. Protein fibrils can be composed of native globular molecules, such as the hemoglobin molecules in sickle-cell fibrils, or can be reorganized β-sheet–rich aggregates, termed amyloid-like fibrils. Amyloid fibrils are associated with several pathological conditions in humans, including Alzheimer disease and diabetes type II. We studied the structure of bacterial inclusion bodies, which have been believed to belong to the amorphous class of aggregates. We demonstrate that all three in vivo-derived inclusion bodies studied are amyloid-like and comprised of amino-acid sequence-specific cross-β structure. These findings suggest that inclusion bodies are structured, that amyloid formation is an omnipresent process both in eukaryotes and prokaryotes, and that amino acid sequences evolve to avoid the amyloid conformation. PMID:18684013

Top-Down-Assisted Bottom-Up Method for Homologous Protein Sequencing: Hemoglobin from 33 Bird Species

NASA Astrophysics Data System (ADS)

Song, Yang; Laskay, Ünige A.; Vilcins, Inger-Marie E.; Barbour, Alan G.; Wysocki, Vicki H.

2015-11-01

Ticks are vectors for disease transmission because they are indiscriminant in their feeding on multiple vertebrate hosts, transmitting pathogens between their hosts. Identifying the hosts on which ticks have fed is important for disease prevention and intervention. We have previously shown that hemoglobin (Hb) remnants from a host on which a tick fed can be used to reveal the host's identity. For the present research, blood was collected from 33 bird species that are common in the U.S. as hosts for ticks but that have unknown Hb sequences. A top-down-assisted bottom-up mass spectrometry approach with a customized searching database, based on variability in known bird hemoglobin sequences, has been devised to facilitate fast and complete sequencing of hemoglobin from birds with unknown sequences. These hemoglobin sequences will be added to a hemoglobin database and used for tick host identification. The general approach has the potential to sequence any set of homologous proteins completely in a rapid manner.

The interaction of C.I. acid red 27 with human hemoglobin in solution.

PubMed

Wang, Yan-Qing; Zhang, Hong-Mei; Tang, Bo-Ping

2010-08-02

The nature of the interaction between human hemoglobin and C.I. acid red 27 was investigated systematically by ultraviolet-vis absorbance, circular dichroism, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques at pH 7.40. The quenching mechanism, binding constants, and the number of binding sites were determined by the quenching of human hemoglobin fluorescence in presence of C.I. acid red 27. The results showed that the nature of the quenching was of static type and the process of binding acid red 27 on human hemoglobin was a spontaneous molecular interaction procedure. The electrostatic and hydrophobic interactions played a major role in stabilizing the complex; The distance r between donor and acceptor was obtained to be 4.40 nm according to Förster's theory; The effect of acid red 27 on the conformation of human hemoglobin was analyzed using synchronous fluorescence, circular dichroism and three-dimensional fluorescence spectra. 2010 Elsevier B.V. All rights reserved.

Direct sGC Activation Bypasses NO Scavenging Reactions of Intravascular Free Oxy-Hemoglobin and Limits Vasoconstriction

PubMed Central

Tabima, D. Marcela; Specht, Patricia A.C.; Tejero, Jesús; Champion, Hunter C.; Kim-Shapiro, Daniel B.; Baust, Jeff; Mik, Egbert G.; Hildesheim, Mariana; Stasch, Johannes-Peter; Becker, Eva-Maria; Truebel, Hubert

2013-01-01

Abstract Aims: Hemoglobin-based oxygen carriers (HBOC) provide a potential alternative to red blood cell (RBC) transfusion. Their clinical application has been limited by adverse effects, in large part thought to be mediated by the intravascular scavenging of the vasodilator nitric oxide (NO) by cell-free plasma oxy-hemoglobin. Free hemoglobin may also cause endothelial dysfunction and platelet activation in hemolytic diseases and after transfusion of aged stored RBCs. The new soluble guanylate cyclase (sGC) stimulator Bay 41-8543 and sGC activator Bay 60-2770 directly modulate sGC, independent of NO bioavailability, providing a potential therapeutic mechanism to bypass hemoglobin-mediated NO inactivation. Results: Infusions of human hemoglobin solutions and the HBOC Oxyglobin into rats produced a severe hypertensive response, even at low plasma heme concentrations approaching 10 μM. These reactions were only observed for ferrous oxy-hemoglobin and not analogs that do not rapidly scavenge NO. Infusions of L-NG-Nitroarginine methyl ester (L-NAME), a competitive NO synthase inhibitor, after hemoglobin infusion did not produce additive vasoconstriction, suggesting that vasoconstriction is related to scavenging of vascular NO. Open-chest hemodynamic studies confirmed that hypertension occurred secondary to direct effects on increasing vascular resistance, with limited negative cardiac inotropic effects. Intravascular hemoglobin reduced the vasodilatory potency of sodium nitroprusside (SNP) and sildenafil, but had no effect on vasodilatation by direct NO-independent activation of sGC by BAY 41-8543 and BAY 60-2770. Innovation and Conclusion: These data suggest that both sGC stimulators and sGC activators could be used to restore cyclic guanosine monophosphate-dependent vasodilation in conditions where cell-free plasma hemoglobin is sufficient to inhibit endogenous NO signaling. Antioxid. Redox Signal. 19, 2232–2243. PMID:23697678

Hemodynamic Response Alterations in Sensorimotor Areas as a Function of Barbell Load Levels during Squatting: An fNIRS Study

PubMed Central

Kenville, Rouven; Maudrich, Tom; Carius, Daniel; Ragert, Patrick

2017-01-01

Functional near-infrared spectroscopy (fNIRS) serves as a promising tool to examine hemodynamic response alterations in a sports-scientific context. The present study aimed to investigate how brain activity within the human motor system changes its processing in dependency of different barbell load conditions while executing a barbell squat (BS). Additionally, we used different fNIRS probe configurations to identify and subsequently eliminate potential exercise induced systemic confounders such as increases in extracerebral blood flow. Ten healthy, male participants were enrolled in a crossover design. Participants performed a BS task with random barbell load levels (0% 1RM (1 repetition maximum), 20% 1RM and 40% 1RM for a BS) during fNIRS recordings. Initially, we observed global hemodynamic response alterations within and outside the human motor system. However, short distance channel regression of fNIRS data revealed a focalized hemodynamic response alteration within bilateral superior parietal lobe (SPL) for oxygenated hemoglobin (HbO2) and not for deoxygenated hemoglobin (HHb) when comparing different load levels. These findings indicate that the previously observed load/force-brain relationship for simple and isolated movements is also present in complex multi-joint movements such as the BS. Altogether, our results show the feasibility of fNIRS to investigate brain processing in a sports-related context. We suggest for future studies to incorporate short distance channel regression of fNIRS data to reduce the likelihood of false-positive hemodynamic response alterations during complex whole movements. PMID:28555098

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

Elicitors and defense gene induction in plants with altered lignin compositions.

PubMed

Gallego-Giraldo, Lina; Posé, Sara; Pattathil, Sivakumar; Peralta, Angelo Gabriel; Hahn, Michael G; Ayre, Brian G; Sunuwar, Janak; Hernandez, Jonathan; Patel, Monika; Shah, Jyoti; Rao, Xiaolan; Knox, J Paul; Dixon, Richard A

2018-06-27

A reduction in the lignin content in transgenic plants induces the ectopic expression of defense genes, but the importance of altered lignin composition in such phenomena remains unclear. Two Arabidopsis lines with similar lignin contents, but strikingly different lignin compositions, exhibited different quantitative and qualitative transcriptional responses. Plants with lignin composed primarily of guaiacyl units overexpressed genes responsive to oomycete and bacterial pathogen attack, whereas plants with lignin composed primarily of syringyl units expressed a far greater number of defense genes, including some associated with cis-jasmone-mediated responses to aphids; these plants exhibited altered responsiveness to bacterial and aphid inoculation. Several of the defense genes were differentially induced by water-soluble extracts from cell walls of plants of the two lines. Glycome profiling, fractionation and enzymatic digestion studies indicated that the different lignin compositions led to differential extractability of a range of heterogeneous oligosaccharide epitopes, with elicitor activity originating from different cell wall polymers. Alteration of lignin composition affects interactions with plant cell wall matrix polysaccharides to alter the sequestration of multiple latent defense signal molecules with an impact on biotic stress responses. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Elevated Air Humidity Changes Soil Bacterial Community Structure in the Silver Birch Stand.

PubMed

Truu, Marika; Ostonen, Ivika; Preem, Jens-Konrad; Lõhmus, Krista; Nõlvak, Hiie; Ligi, Teele; Rosenvald, Katrin; Parts, Kaarin; Kupper, Priit; Truu, Jaak

2017-01-01

Soil microbes play a fundamental role in forest ecosystems and respond rapidly to changes in the environment. Simultaneously with the temperature increase the climate change scenarios also predict an intensified hydrological cycle for the Baltic Sea runoff region. The aim of this study was to assess the effect of elevated air humidity on the top soil microbial community structure of a silver birch ( Betula pendula Roth.) stand by using a free air humidity manipulation facility (FAHM). The bacterial community structures of bulk soil and birch rhizosphere were analyzed using high-throughput sequencing of bacteria-specific16S rRNA gene fragments and quantification of denitrification related genes. The increased air humidity altered both bulk soil and rhizosphere bacterial community structures, and changes in the bacterial communities initiated by elevated air humidity were related to modified soil abiotic and biotic variables. Network analysis revealed that variation in soil bacterial community structural units is explained by altered abiotic conditions such as increased pH value in bulk soil, while in rhizosphere the change in absorptive root morphology had a higher effect. Among root morphological traits, the absorptive root diameter was strongest related to the bacterial community structure. The changes in bacterial community structures under elevated air humidity are associated with shifts in C, N, and P turnover as well as mineral weathering processes in soil. Increased air humidity decreased the nir and nosZ gene abundance in the rhizosphere bacterial community. The potential contribution of the denitrification to the N 2 O emission was not affected by the elevated air humidity in birch stand soil. In addition, the study revealed a strong link between the bacterial community structure, abundance of denitrification related genes, and birch absorptive root morphology in the ecosystem system adaptation to elevated air humidity.

Elevated Air Humidity Changes Soil Bacterial Community Structure in the Silver Birch Stand

PubMed Central

Truu, Marika; Ostonen, Ivika; Preem, Jens-Konrad; Lõhmus, Krista; Nõlvak, Hiie; Ligi, Teele; Rosenvald, Katrin; Parts, Kaarin; Kupper, Priit; Truu, Jaak

2017-01-01

Soil microbes play a fundamental role in forest ecosystems and respond rapidly to changes in the environment. Simultaneously with the temperature increase the climate change scenarios also predict an intensified hydrological cycle for the Baltic Sea runoff region. The aim of this study was to assess the effect of elevated air humidity on the top soil microbial community structure of a silver birch (Betula pendula Roth.) stand by using a free air humidity manipulation facility (FAHM). The bacterial community structures of bulk soil and birch rhizosphere were analyzed using high-throughput sequencing of bacteria-specific16S rRNA gene fragments and quantification of denitrification related genes. The increased air humidity altered both bulk soil and rhizosphere bacterial community structures, and changes in the bacterial communities initiated by elevated air humidity were related to modified soil abiotic and biotic variables. Network analysis revealed that variation in soil bacterial community structural units is explained by altered abiotic conditions such as increased pH value in bulk soil, while in rhizosphere the change in absorptive root morphology had a higher effect. Among root morphological traits, the absorptive root diameter was strongest related to the bacterial community structure. The changes in bacterial community structures under elevated air humidity are associated with shifts in C, N, and P turnover as well as mineral weathering processes in soil. Increased air humidity decreased the nir and nosZ gene abundance in the rhizosphere bacterial community. The potential contribution of the denitrification to the N2O emission was not affected by the elevated air humidity in birch stand soil. In addition, the study revealed a strong link between the bacterial community structure, abundance of denitrification related genes, and birch absorptive root morphology in the ecosystem system adaptation to elevated air humidity. PMID:28421053

Iron Acquisition in Bacillus cereus: The Roles of IlsA and Bacillibactin in Exogenous Ferritin Iron Mobilization

PubMed Central

Buisson, Christophe; Daou, Nadine; Kallassy, Mireille; Lereclus, Didier; Arosio, Paolo; Bou-Abdallah, Fadi; Nielsen Le Roux, Christina

2014-01-01

In host-pathogen interactions, the struggle for iron may have major consequences on the outcome of the disease. To overcome the low solubility and bio-availability of iron, bacteria have evolved multiple systems to acquire iron from various sources such as heme, hemoglobin and ferritin. The molecular basis of iron acquisition from heme and hemoglobin have been extensively studied; however, very little is known about iron acquisition from host ferritin, a 24-mer nanocage protein able to store thousands of iron atoms within its cavity. In the human opportunistic pathogen Bacillus cereus, a surface protein named IlsA (Iron-regulated leucine rich surface protein type A) binds heme, hemoglobin and ferritin in vitro and is involved in virulence. Here, we demonstrate that IlsA acts as a ferritin receptor causing ferritin aggregation on the bacterial surface. Isothermal titration calorimetry data indicate that IlsA binds several types of ferritins through direct interaction with the shell subunits. UV-vis kinetic data show a significant enhancement of iron release from ferritin in the presence of IlsA indicating for the first time that a bacterial protein might alter the stability of the ferritin iron core. Disruption of the siderophore bacillibactin production drastically reduces the ability of B. cereus to utilize ferritin for growth and results in attenuated bacterial virulence in insects. We propose a new model of iron acquisition in B. cereus that involves the binding of IlsA to host ferritin followed by siderophore assisted iron uptake. Our results highlight a possible interplay between a surface protein and a siderophore and provide new insights into host adaptation of B. cereus and general bacterial pathogenesis. PMID:24550730

A role for bacterial urease in gut dysbiosis and Crohn’s disease

PubMed Central

Ni, Josephine; Shen, Ting-Chin David; Chen, Eric Z.; Bittinger, Kyle; Bailey, Aubrey; Roggiani, Manuela; Sirota-Madi, Alexandra; Friedman, Elliot S.; Chau, Lillian; Lin, Andrew; Nissim, Ilana; Scott, Justin; Lauder, Abigail; Hoffmann, Christian; Rivas, Gloriany; Albenberg, Lindsey; Baldassano, Robert N.; Braun, Jonathan; Xavier, Ramnik J.; Clish, Clary B.; Yudkoff, Marc; Li, Hongzhe; Goulian, Mark; Bushman, Frederic D.; Lewis, James D.; Wu, Gary D.

2018-01-01

Gut dysbiosis during inflammatory bowel disease involves alterations in the gut microbiota associated with inflammation of the host gut. We used a combination of shotgun metagenomic sequencing and metabolomics to analyze fecal samples from pediatric patients with Crohn’s disease and found an association between disease severity, gut dysbiosis, and bacterial production of free amino acids. Nitrogen flux studies using 15N in mice showed that activity of bacterial urease, an enzyme that releases ammonia by hydrolysis of host urea, led to the transfer of murine host-derived nitrogen to the gutmicrobiota where it was used for amino acid synthesis. Inoculation of a conventional murine host (pretreated with antibiotics and polyethylene glycol) with commensal Escherichia coli engineered to express urease led to dysbiosis of the gut microbiota, resulting in a predominance of Proteobacteria species. This was associated with a worsening of immune-mediated colitis in these animals. A potential role for altered urease expression and nitrogen flux in the development of gut dysbiosis suggests that bacterial urease may be a potential therapeutic target for inflammatory bowel diseases. PMID:29141885

Hemoglobin state-flux: A finite-state model representation of the hemoglobin signal for evaluation of the resting state and the influence of disease

PubMed Central

Barbour, Randall L.; Barbour, San-Lian S.

2018-01-01

Summary In this report we introduce a weak-model approach for examination of the intrinsic time-varying properties of the hemoglobin signal, with the aim of advancing the application of functional near infrared spectroscopy (fNIRS) for the detection of breast cancer, among other potential uses. The developed methodology integrates concepts from stochastic network theory with known modulatory features of the vascular bed, and in doing so provides access to a previously unrecognized dense feature space that is shown to have promising diagnostic potential. Notable features of the methodology include access to this information solely from measures acquired in the resting state, and analysis of these by treating the various components of the hemoglobin (Hb) signal as a co-varying interacting system. Approach The principal data-transform kernel projects Hb state-space trajectories onto a coordinate system that constitutes a finite-state representation of covariations among the principal elements of the Hb signal (i.e., its oxygenated (ΔoxyHb) and deoxygenated (ΔdeoxyHb) forms and the associated dependent quantities: total hemoglobin (ΔtotalHb = ΔoxyHb + ΔdeoxyHb), hemoglobin oxygen saturation (ΔHbO2Sat = 100Δ(oxyHb/totalHb)), and tissue-hemoglobin oxygen exchange (ΔHbO2Exc = ΔdeoxyHb—ΔoxyHb)). The resulting ten-state representation treats the evolution of this signal as a one-space, spatiotemporal network that undergoes transitions from one state to another. States of the network are defined by the algebraic signs of the amplitudes of the time-varying components of the Hb signal relative to their temporal mean values. This assignment produces several classes of coefficient arrays, most with a dimension of 10×10. Biological motivation Motivating our approach is the understanding that effector mechanisms that modulate blood delivery to tissue operate on macroscopic scales, in a spatially and temporally varying manner. Also recognized is that this behavior is

Evaluation of the Efficiency of the Reticulocyte Hemoglobin Content on Diagnosis for Iron Deficiency Anemia in Chinese Adults.

PubMed

Cai, Jie; Wu, Meng; Ren, Jie; Du, Yali; Long, Zhangbiao; Li, Guoxun; Han, Bing; Yang, Lichen

2017-05-02

Our aim was to evaluate the cut-off value and efficiency of using reticulocyte hemoglobin content as a marker to diagnose iron deficiency anemia in Chinese adults. 140 adults who needed bone marrow aspiration for diagnosis at the hematology department of the Peking Union Medical College Hospital were enrolled according to the inclusive and exclusive criteria. Venous blood samples were collected to detect complete blood count, including hemoglobin, reticulocyte hemoglobin content, hematocrit, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, free erythrocyte protoporphyrin; iron indexes of serum ferritin, serum transferrin receptor, and unsaturated iron-binding capacity; and inflammation markers of C-reactive protein and α-acid glycoprotein. Bone marrow samples were obtained for the bone marrow iron staining, which was used as the standard for the evaluation of iron status in this study. Subjects were divided into three groups according to hemoglobin levels and bone marrow iron staining results: the IDA (iron deficiency anemia) group, the NIDA (non-iron deficiency anemia) group, and the control group. The differences of the above-mentioned indexes were compared among the three groups and the effect of inflammation was also considered. The cut-off value of reticulocyte hemoglobin content was determined by receiver operation curves. The IDA group ( n = 56) had significantly lower reticulocyte hemoglobin content, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, and serum ferritin; and higher free erythrocyte protoporphyrin, unsaturated iron-binding capacity, and serum transferrin receptor ( p < 0.05) compared with the NIDA group ( n = 38) and control group ( n = 46). Hematocrit, serum ferritin, and unsaturated iron-binding capacity were significantly affected by inflammation while reticulocyte hemoglobin content and other parameters were not. The cut-off value of reticulocyte hemoglobin content for

Molecular dynamics simulations indicate that deoxyhemoglobin, oxyhemoglobin, carboxyhemoglobin, and glycated hemoglobin under compression and shear exhibit an anisotropic mechanical behavior.

PubMed

Yesudasan, Sumith; Wang, Xianqiao; Averett, Rodney D

2018-05-01

We developed a new mechanical model for determining the compression and shear mechanical behavior of four different hemoglobin structures. Previous studies on hemoglobin structures have focused primarily on overall mechanical behavior; however, this study investigates the mechanical behavior of hemoglobin, a major constituent of red blood cells, using steered molecular dynamics (SMD) simulations to obtain anisotropic mechanical behavior under compression and shear loading conditions. Four different configurations of hemoglobin molecules were considered: deoxyhemoglobin (deoxyHb), oxyhemoglobin (HbO 2 ), carboxyhemoglobin (HbCO), and glycated hemoglobin (HbA 1C ). The SMD simulations were performed on the hemoglobin variants to estimate their unidirectional stiffness and shear stiffness. Although hemoglobin is structurally denoted as a globular protein due to its spherical shape and secondary structure, our simulation results show a significant variation in the mechanical strength in different directions (anisotropy) and also a strength variation among the four different hemoglobin configurations studied. The glycated hemoglobin molecule possesses an overall higher compressive mechanical stiffness and shear stiffness when compared to deoxyhemoglobin, oxyhemoglobin, and carboxyhemoglobin molecules. Further results from the models indicate that the hemoglobin structures studied possess a soft outer shell and a stiff core based on stiffness.

Decreased nitrite levels in erythrocytes of children with β-thalassemia/hemoglobin E.

PubMed

Suvachananonda, Thitiwat; Wankham, Amara; Srihirun, Sirada; Tanratana, Pansakorn; Unchern, Supeenun; Fucharoen, Suthat; Chuansumrit, Ampaiwan; Sirachainan, Nongnuch; Sibmooh, Nathawut

2013-09-01

Nitrite anion is bioactive nitric oxide (NO) species circulating in blood, and represents the NO bioavailability and endothelial function. In this study, we aimed to investigate the nitrite levels and the correlation with hemolysis and severity in β-thalassemia/hemoglobin E (β-thal/HbE). 38 Children (12.0±1.9 years of age) with a diagnosis of mild, moderate and severe β-thalassemia were enrolled in the study. The blood nitrite levels and potential plasma NO consumption were measured by the chemiluminescence method. The nitrite levels in whole blood and erythrocytes of the severe thalassemia subjects were lower than those of the control subjects. At day 7 after transfusion of packed erythrocytes, the nitrite levels in erythrocytes increased. The plasma hemoglobin and NO consumption increased in the severe thalassemia subjects. The nitrite levels in erythrocytes inversely correlated with plasma hemoglobin, lactate dehydrogenase activity, potential NO consumption, and lipid peroxidation. Our studies demonstrate the decreased NO bioavailability in thalassemia, which could result from endothelial dysfunction, the increased potential NO consumption in plasma by cell-free hemoglobin and oxidative stress. Copyright © 2013 Elsevier Inc. All rights reserved.

Hemoglobin Dynamics in Red Blood Cells: Correlation to Body Temperature

PubMed Central

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

2008-01-01

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

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

PubMed

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

2008-12-01

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

[Molecular-genetic basis of regulation of the synthesis of individual types of hemoglobin].

PubMed

Starodub, N F

1980-01-01

The data on the control of ontogenetic hemoglobin type synthesis were analyzed in normal and pathological human and animal organisms. The assumption is made that such control depends on the level of erythroid cell differentiation and erythropoetic factors activity. The latters act as a trigger in switching of qualitative hemoglobin production.

Tendency for oxidation of annelid hemoglobin at alkaline pH and dissociated states probed by redox titration.

PubMed

Bispo, Jose Ailton Conceicao; Landini, Gustavo Fraga; Santos, Jose Luis Rocha; Norberto, Douglas Ricardo; Bonafe, Carlos Francisco Sampaio

2005-08-01

The redox titration of extracellular hemoglobin of Glossoscolex paulistus (Annelidea) was investigated in different pH conditions and after dissociation induced by pressure. Oxidation increased with increasing pH, as shown by the reduced amount of ferricyanide necessary for the oxidation of hemoglobin. This behavior was the opposite of that of vertebrate hemoglobins. The potential of half oxidation (E1/2) changed from -65.3 to +146.8 mV when the pH increased from 4.50 to 8.75. The functional properties indicated a reduction in the log P50 from 1.28 to 0.28 in this pH range. The dissociation at alkaline pH or induced by high pressure, confirmed by HPLC gel filtration, suggested that disassembly of the hemoglobin could be involved in the increased potential for oxidation. These results suggest that the high stability and prolonged lifetime common to invertebrate hemoglobins is related to their low tendency to oxidize at acidic pH, in contrast to vertebrate hemoglobins.

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

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 864.7415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7415 Abnormal...

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 864.7415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7415 Abnormal...

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

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 864.7415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7415 Abnormal...

Association between serum ferritin and hemoglobin levels and bone health in Korean adolescents

PubMed Central

Jung, Dong-Wook; Park, Joo-Hyun; Kim, Do-Hoon; Choi, Moonyoung; Kim, Shinhye; Kim, Hyonchong; Seul, Da-eun; Park, Soo Gyeong; Jung, Jin-Hyung; Han, Kyungdo; Park, Young-Gyu

2017-01-01

Abstract It is important to identify risk factors for low bone mass at a young age. An influence of iron store on bone health in the general population has been reported but has not been studied in adolescents. This study aimed to investigate the relationship between hemoglobin and serum ferritin levels and bone mineral content (BMC) in South Korean adolescents. This study was based on data collected during the 2009to 2010 Korea National Health and Nutrition Examination Survey. We included 1321 participants aged 10 to 18 years. BMC was measured at the femur and lumbar spine using dual-energy x-ray absorptiometry, and hemoglobin and serum ferritin levels were examined. In boys, hemoglobin and serum ferritin levels were positively associated with BMC of the total femur and lumbar spine after adjusting for confounders, and hemoglobin levels significantly increased as BMC increased at all sites (P for trend = .001 for total femur, .01 for femur neck, and <.001 for lumbar spine). Likewise, serum ferritin levels showed increasing trends according to increasing BMC of the total femur and lumbar spine in boys (P for trend = .04 for total femur; and <.001 for lumbar spine). However, these associations were not observed in girls. This study suggests a positive relationship between serum ferritin and hemoglobin levels and BMC in South Korean adolescent boys. PMID:29390554

Smartphone spectrometer for non-invasive diffuse reflectance spectroscopy based hemoglobin sensing (Conference Presentation)

NASA Astrophysics Data System (ADS)

Edwards, Perry S.

2016-10-01

Fiber-optic based diffuse reflectance spectroscopy (DRS) is shown to be a highly specific and highly sensitive method for non-invasive detection of various cancers (e.g. cervical and oral) as well as many other diseases. Fiber-optic DRS diagnosis relies on non-invasive biomarker detection (e.g. oxy- and deoxy-hemoglobin) and can be done without the need for sophisticated laboratory analysis of samples. Thus, it is highly amenable for clinical adoption especially in resource scarce regions that have limited access to such developed laboratory infrastructure. Despite the demonstrated effectiveness of fiber-optic DRS, such systems remain cost prohibitive in many of these regions, mainly due to the use of bulky and expensive spectrometers. Here, a fiber-optic DRS system is coupled to a smartphone spectrometer and is proposed as a low-cost solution for non-invasive tissue hemoglobin sensing. The performance of the system is assessed by measuring tissue phantoms with varying hemoglobin concentrations. A DRS retrieval algorithm is used to extract hemoglobin parameters from the measurements and determine the accuracy of the system. The results are then compared with those of a previously reported fiber-optic DRS system which is based on a larger more expensive spectrometer system. The preliminary results are encouraging and indicate the potential of the smartphone spectrometer as a viable low-cost option for non-invasive tissue hemoglobin sensing.

Influence of bacterial interactions on pneumococcal colonization of the nasopharynx.

PubMed

Shak, Joshua R; Vidal, Jorge E; Klugman, Keith P

2013-03-01

Streptococcus pneumoniae (the pneumococcus) is a common commensal inhabitant of the nasopharynx and a frequent etiologic agent in serious diseases such as pneumonia, otitis media, bacteremia, and meningitis. Multiple pneumococcal strains can colonize the nasopharynx, which is also home to many other bacterial species. Intraspecies and interspecies interactions influence pneumococcal carriage in important ways. Co-colonization by two or more pneumococcal strains has implications for vaccine serotype replacement, carriage detection, and pneumonia diagnostics. Interactions between the pneumococcus and other bacterial species alter carriage prevalence, modulate virulence, and affect biofilm formation. By examining these interactions, this review highlights how the bacterial ecosystem of the nasopharynx changes the nature and course of pneumococcal carriage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fluorescence and reflectance properties of hemoglobin-pigmented skin disorders

NASA Astrophysics Data System (ADS)

Troyanova, P.; Borisova, E.; Avramov, L.

2007-06-01

There has been growing interest in clinical application of laser-induced autofluorescence (LIAF) and reflectance spectroscopy (RS) to differentiate disease from normal surrounding tissue, including skin pathologies. Pigmented cutaneous lesions diagnosis plays important role in clinical practice, as malignant melanoma, which is characterized with greatest mortality from all skin cancer types, must be carefully discriminated form other colorized pathologies. The goals of this work were investigation of cutaneous hemoglobin-pigmented lesions (heamangioma, angiokeratoma, and fibroma) by the methods of LIAFS and RS. Spectra from healthy skin areas near to the lesion were detected to be used posteriori in analysis. Fluorescence and reflectance of cutaneous hemoglobin-pigmented lesions are used to develop criterion for differentiation from other pigmented pathologies. Origins of the spectral features obtained are discussed and determination of lesion types is achieved using selected spectral features. The spectral results, obtained were used to develop multispectral diagnostic algorithms based on the most prominent spectral features from the fluorescence and reflectance spectra of the lesions investigated. In comparison between normal skin and different cutaneous lesion types and between lesion types themselves sensitivities and specificities higher than 90 % were achieved. These results show a perspective possibility to differentiate hemoglobin-pigmented lesions from other pigmented pathologies using non-invasive and real time discrimination procedure.

Bohr effect of human hemoglobin: Separation of tertiary and quaternary contributions based on the Wyman equation.

PubMed

Okonjo, Kehinde Onwochei

2017-09-01

As a prelude to separating tertiary from quaternary structure contributions to the Bohr effect, we employed the Wyman equation to analyze Bohr data for human hemoglobin to which 2,3-bisphosphoglycerate, 2,3-BPG, is bound. Changes in the pK a s of the histidine Bohr groups result in a net reduction of their contributions to the Bohr effect at pH 7.4 compared to their contributions in stripped hemoglobin. The non-histidine 2,3-BPG binding groups - the β-chain terminal amino group and Lys82β - make negative and positive contributions, respectively, to the Bohr effect. The final result is that the Bohr effect at physiological pH is higher for 2,3-BPG bound compared to stripped hemoglobin. Contributions linked to His2β, His77β and His143β enable us to separate tertiary from quaternary Bohr contributions in stripped and in 2,3-BPG bound hemoglobin. Both contributions serve to make the Bohr effect for 2,3-BPG bound hemoglobin higher than for stripped hemoglobin at physiological pH. Copyright © 2017 Elsevier B.V. All rights reserved.

[Noninvasive total hemoglobin monitoring based on multiwave spectrophotometry in obstetrics and gynecology].

PubMed

Pyregov, A V; Ovechkin, A Iu; Petrov, S V

2012-01-01

Results of prospective randomized comparative research of 2 total hemoglobin estimation methods are presented. There were laboratory tests and continuous noninvasive technique with multiwave spectrophotometry on the Masimo Rainbow SET. Research was carried out in two stages. At the 1st stage (gynecology)--67 patients were included and in second stage (obstetrics)--44 patients during and after Cesarean section. The standard deviation of noninvasive total hemoglobin estimation from absolute values (invasive) was 7.2 and 4.1%, an standard deviation in a sample--5.2 and 2.7 % in gynecologic operations and surgical delivery respectively, that confirms lack of reliable indicators differences. The method of continuous noninvasive total hemoglobin estimation with multiwave spectrophotometry on the Masimo Rainbow SET technology can be recommended for use in obstetrics and gynecology.

Balanced globin protein expression and heme biosynthesis improve production of human hemoglobin in Saccharomyces cerevisiae.

PubMed

Liu, Lifang; Martínez, José L; Liu, Zihe; Petranovic, Dina; Nielsen, Jens

2014-01-01

Due to limitations associated with whole blood for transfusions (antigen compatibility, transmission of infections, supply and storage), the use of cell-free hemoglobin as an oxygen carrier substitute has been in the center of research interest for decades. Human hemoglobin has previously been synthesized in yeast, however the challenge is to balance the expression of the two different globin subunits, as well as the supply of the prosthetic heme required for obtaining the active hemoglobin (α2β2). In this work we evaluated the expression of different combinations of α and β peptides and combined this with metabolic engineering of the heme biosynthetic pathway. Through evaluation of several different strategies we showed that engineering the biosynthesis pathway can substantially increase the heme level in yeast cells, and this resulted in a significant enhancement of human hemoglobin production. Besides demonstration of improved hemoglobin production our work demonstrates a novel strategy for improving the production of complex proteins, especially multimers with a prosthetic group. © 2013 Published by International Metabolic Engineering Society on behalf of International Metabolic Engineering Society.

Comparison of the BioRad Variant and Primus Ultra2 high-pressure liquid chromatography (HPLC) instruments for the detection of variant hemoglobins.

PubMed

Gosselin, R C; Carlin, A C; Dwyre, D M

2011-04-01

Hemoglobin variants are a result of genetic changes resulting in abnormal or dys-synchronous hemoglobin chain production (thalassemia) or the generation of hemoglobin chain variants such as hemoglobin S. Automated high-pressure liquid chromatography (HPLC) systems have become the method of choice for the evaluation of patients suspected with hemoglobinopathies. In this study, we evaluated the performance of two HPLC methods used in the detection of common hemoglobin variants: Variant and Ultra2. There were 377 samples tested, 26% (99/377) with HbS, 8.5% (32/377) with HbC, 20.7% (78/377) with other hemoglobin variant or thalassemia, and 2.9% with increased hemoglobin A(1) c. The interpretations of each chromatograph were compared. There were no differences noted for hemoglobins A(0), S, or C. There were significant differences between HPLC methods for hemoglobins F, A(2), and A(1) c. However, there was good concordance between normal and abnormal interpretations (97.9% and 96.2%, respectively). Both Variant and Ultra2 HPLC methods were able to detect most common hemoglobin variants. There was better discrimination for fast hemoglobins, between hemoglobins E and A(2), and between hemoglobins S and F using the Ultra2 HPLC method. © 2010 Blackwell Publishing Ltd.

Hemoglobin Cleavage Site-Specificity of the Plasmodium falciparum Cysteine Proteases Falcipain-2 and Falcipain-3

PubMed Central

Subramanian, Shoba; Hardt, Markus; Choe, Youngchool; Niles, Richard K.; Johansen, Eric B.; Legac, Jennifer; Gut, Jiri; Kerr, Iain D.; Craik, Charles S.; Rosenthal, Philip J.

2009-01-01

The Plasmodium falciparum cysteine proteases falcipain-2 and falcipain-3 degrade host hemoglobin to provide free amino acids for parasite protein synthesis. Hemoglobin hydrolysis has been described as an ordered process initiated by aspartic proteases, but cysteine protease inhibitors completely block the process, suggesting that cysteine proteases can also initiate hemoglobin hydrolysis. To characterize the specific roles of falcipains, we used three approaches. First, using random P1 – P4 amino acid substrate libraries, falcipain-2 and falcipain-3 demonstrated strong preference for cleavage sites with Leu at the P2 position. Second, with overlapping peptides spanning α and β globin and proteolysis-dependent 18O labeling, hydrolysis was seen at many cleavage sites. Third, with intact hemoglobin, numerous cleavage products were identified. Our results suggest that hemoglobin hydrolysis by malaria parasites is not a highly ordered process, but rather proceeds with rapid cleavage by falcipains at multiple sites. However, falcipain-2 and falcipain-3 show strong specificity for P2 Leu in small peptide substrates, in agreement with the specificity in optimized small molecule inhibitors that was identified previously. These results are consistent with a principal role of falcipain-2 and falcipain-3 in the hydrolysis of hemoglobin by P. falciparum and with the possibility of developing small molecule inhibitors with optimized specificity as antimalarial agents. PMID:19357776

Hemoglobin protein hollow shells fabricated through covalent layer-by-layer technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan Li; He Qiang; Max Planck Institute of Colloids and Interfaces, Golm/Potsdam D-14476

2007-03-09

Hemoglobin (Hb) protein microcapsules held together by cross-linker, glutaraldehyde (GA), were successfully fabricated by covalent layer-by-layer (LbL) technique. The Schiff base reaction occurred on the colloid templates between the aldehyde groups of GA and free amino sites of Hb results in the formation of GA/Hb microcapsules after the removal of the templates. The structure of obtained monodisperse protein microcapsule was characterized by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The UV-Vis spectra measurements demonstrate the existence of Hb in the assembled capsules. Cyclic voltammetry (CV) and potential-controlled amperometric measurements (I-t curve) confirm that hemoglobin microcapsules after fabricationmore » remain their heme electroactivity. Moreover, direct electron transfer process from protein to electrode surface was performed to detect the heme electrochemistry without using any mediator or promoter. The experiments of fluorescence recovery after photobleaching (FRAP) by CLSM demonstrate that the hemoglobin protein microcapsules have an improved permeability comparing to the conventional polyelectrolyte microcapsules.« less

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

High Presence of Extracellular Hemoglobin in the Periventricular White Matter Following Preterm Intraventricular Hemorrhage

PubMed Central

Ley, David; Romantsik, Olga; Vallius, Suvi; Sveinsdóttir, Kristbjörg; Sveinsdóttir, Snjolaug; Agyemang, Alex A.; Baumgarten, Maria; Mörgelin, Matthias; Lutay, Nataliya; Bruschettini, Matteo; Holmqvist, Bo; Gram, Magnus

2016-01-01

Severe cerebral intraventricular hemorrhage (IVH) in preterm infants continues to be a major clinical problem, occurring in about 15–20% of very preterm infants. In contrast to other brain lesions the incidence of IVH has not been reduced over the last decade, but actually slightly increased. Currently over 50% of surviving infants develop post-hemorrhagic ventricular dilatation and about 35% develop severe neurological impairment, mainly cerebral palsy and intellectual disability. To date there is no therapy available to prevent infants from developing either hydrocephalus or serious neurological disability. It is known that blood rapidly accumulates within the ventricles following IVH and this leads to disruption of normal anatomy and increased local pressure. However, the molecular mechanisms causing brain injury following IVH are incompletely understood. We propose that extracellular hemoglobin is central in the pathophysiology of periventricular white matter damage following IVH. Using a preterm rabbit pup model of IVH the distribution of extracellular hemoglobin was characterized at 72 h following hemorrhage. Evaluation of histology, histochemistry, hemoglobin immunolabeling and scanning electron microscopy revealed presence of extensive amounts of extracellular hemoglobin, i.e., not retained within erythrocytes, in the periventricular white matter, widely distributed throughout the brain. Furthermore, double immunolabeling together with the migration and differentiation markers polysialic acid neural cell adhesion molecule (PSA-NCAM) demonstrates that a significant proportion of the extracellular hemoglobin is distributed in areas of the periventricular white matter with high extracellular plasticity. In conclusion, these findings support that extracellular hemoglobin may contribute to the pathophysiological processes that cause irreversible damage to the immature brain following IVH. PMID:27536248

The Relationship Between Preoperative Hemoglobin Concentration, Use of Hospital Resources, and Outcomes in Cardiac Surgery.

PubMed

Hallward, George; Balani, Nikhail; McCorkell, Stuart; Roxburgh, James; Cornelius, Victoria

2016-08-01

Preoperative anemia is an established risk factor associated with adverse perioperative outcomes after cardiac surgery. However, limited information exists regarding the relationship between preoperative hemoglobin concentration and outcomes. The aim of this study was to investigate how outcomes are affected by preoperative hemoglobin concentration in a cohort of patients undergoing cardiac surgery. A retrospective, observational cohort study. A single-center tertiary referral hospital. The study comprised 1,972 adult patients undergoing elective and nonelective cardiac surgery. The independent relationship of preoperative hemoglobin concentration was explored on blood transfusion rates, return to the operating room for bleeding and/or cardiac tamponade, postoperative intensive care unit (ICU) and in-hospital length of stay, and mortality. The overall prevalence of anemia was 32% (629/1,972 patients). For every 1-unit increase in hemoglobin (g/dL), blood transfusion requirements were reduced by 11%, 8%, and 3% for red blood cell units, platelet pools, and fresh frozen plasma units, respectively (adjusted incident rate ratio 0.89 [95% CI 0.87-0.91], 0.92 [0.88-0.97], and 0.97 [0.96-0.99]). For each 1-unit increase in hemoglobin (g/dL), the probability (over time) of discharge from the ICU and hospital increased (adjusted hazard ratio estimates 1.04 [1.00-1.08] and 1.12 [1.12-1.16], respectively). A lower preoperative hemoglobin concentration resulted in increased use of hospital resources after cardiac surgery. Each g/dL unit fall in preoperative hemoglobin concentration resulted in increased blood transfusion requirements and increased postoperative ICU and hospital length of stay. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular Cloning and Sequencing of Hemoglobin-Beta Gene of Channel Catfish, Ictalurus Punctatus Rafinesque

USDA-ARS?s Scientific Manuscript database

: Hemoglobin-y gene of channel catfish , lctalurus punctatus, was cloned and sequenced . Total RNA from head kidneys was isolated, reverse transcribed and amplified . The sequence of the channel catfish hemoglobin-y gene consists of 600 nucleotides . Analysis of the nucleotide sequence reveals one o...

Selection for Cu-Tolerant Bacterial Communities with Altered Composition, but Unaltered Richness, via Long-Term Cu Exposure

PubMed Central

Berg, Jeanette; Brandt, Kristian K.; Al-Soud, Waleed A.; Holm, Peter E.; Hansen, Lars H.; Sørensen, Søren J.

2012-01-01

Toxic metal pollution affects the composition and metal tolerance of soil bacterial communities. However, there is virtually no knowledge concerning the responses of members of specific bacterial taxa (e.g., phyla or classes) to metal toxicity, and contradictory results have been obtained regarding the impact of metals on operational taxonomic unit (OTU) richness. We used tag-coded pyrosequencing of the 16S rRNA gene to elucidate the impacts of copper (Cu) on bacterial community composition and diversity within a well-described Cu gradient (20 to 3,537 μg g−1) stemming from industrial contamination with CuSO4 more than 85 years ago. DNA sequence information was linked to analysis of pollution-induced community tolerance (PICT) to Cu, as determined by the [3H]leucine incorporation technique, and to chemical characterization of the soil. PICT was significantly correlated to bioavailable Cu, as determined by the results seen with a Cu-specific bioluminescent biosensor strain, demonstrating a specific community response to Cu. The relative abundances of members of several phyla or candidate phyla, including the Proteobacteria, Bacteroidetes, Verrumicrobia, Chloroflexi, WS3, and Planctomycetes, decreased with increasing bioavailable Cu, while members of the dominant phylum, the Actinobacteria, showed no response and members of the Acidobacteria showed a marked increase in abundance. Interestingly, changes in the relative abundances of classes frequently deviated from the responses of the phyla to which they belong. Despite the apparent Cu impacts on Cu resistance and community structure, bioavailable Cu levels did not show any correlation to bacterial OTU richness (97% similarity level). Our report highlights several bacterial taxa responding to Cu and thereby provides new guidelines for future studies aiming to explore the bacterial domain for members of metal-responding taxa. PMID:22904046

Selective Removal of Hemoglobin from Blood Using Hierarchical Copper Shells Anchored to Magnetic Nanoparticles

PubMed Central

Wang, Yaokun; Yan, Mingyang

2017-01-01

Hierarchical copper shells anchored on magnetic nanoparticles were designed and fabricated to selectively deplete hemoglobin from human blood by immobilized metal affinity chromatography. Briefly, CoFe2O4 nanoparticles coated with polyacrylic acid were first synthesized by a one-pot solvothermal method. Hierarchical copper shells were then deposited by immobilizing Cu2+ on nanoparticles and subsequently by reducing between the solid CoFe2O4@COOH and copper solution with NaBH4. The resulting nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The particles were also tested against purified bovine hemoglobin over a range of pH, contact time, and initial protein concentration. Hemoglobin adsorption followed pseudo-second-order kinetics and reached equilibrium in 90 min. Isothermal data also fit the Langmuir model well, with calculated maximum adsorption capacity 666 mg g−1. Due to the high density of Cu2+ on the shell, the nanoparticles efficiently and selectively deplete hemoglobin from human blood. Taken together, the results demonstrate that the particles with hierarchical copper shells effectively remove abundant, histidine-rich proteins, such as hemoglobin from human blood, and thereby minimize interference in diagnostic and other assays. PMID:28316987

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.

Spectrum and Prevalence of Pathological Intracranial Magnetic Resonance Imaging Findings in Acute Bacterial Meningitis.

PubMed

Lummel, N; Koch, M; Klein, M; Pfister, H W; Brückmann, H; Linn, J

2016-06-01

Aim of this study was to determine the spectrum and prevalence of pathological intracranial magnetic resonance imaging (MRI) findings in patients with acute bacterial meningitis. We retrospectively identified all consecutive patients with cerebral spinal fluid proven bacterial meningitis who presented at our neurology department between 2007 and 2012. Pathogenic agents and clinical symptoms were noted. MR-examinations were evaluated regarding presence and localization of pathological signal alterations in the different sequences by two neuroradiologists in consensus. A total of 136 patients with purulent bacterial meningitis were identified. In 114 cases the bacterial pathogen agent was proven and in 75 patients an MRI was available. In 62 of the 75 (82.7 %) patients meningitis-associated pathologic imaging findings were evident on MRI. Overall, intraventricular signal alterations, i.e., signs of pyogenic ventriculitis, were present in 41 cases (54.7 %), while sulcal signal changes were found in 22 cases (29.3 %). Intraparenchymatous signal alterations affected the cortex in 15 cases (20 %), and the white matter in 20 patients (26.7 %). The diffusion-weighted imaging and fluid attenuated inversion recovery sequences were most sensitive in the detection of these changes and showed any pathologic findings in 67.6 and 79.6 %, respectively. Patients with streptococcal meningitis showed significantly more often (n = 29 of 34, 85.3 %) intraventricular and/or sulcal diffusion restrictions than patients with meningitis caused by other agents (n = 12 of 37, 32.4 %) (p< 0.0001). Pathological MR findings are frequently found in patients with acute bacterial meningitis. Intraventricular diffusion restrictions, i.e., signs of pyogenic ventriculitis, are more often found in patients with streptococcal, especially pneumococcal, infection.

Rifaximin alters intestinal bacteria and prevents stress-induced gut inflammation and visceral hyperalgesia in rats.

PubMed

Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y; Owyang, Chung

2014-02-01

Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction (PCR) and 454 pyrosequencing were used to analyze bacterial 16S ribosomal RNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

Rifaximin Alters Intestinal Bacteria and Prevents Stress-Induced Gut Inflammation and Visceral Hyperalgesia in Rats

PubMed Central

Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y.; Owyang, Chung

2014-01-01

Background & Aims Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. Methods We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction and 454 pyrosequencing were used to analyze bacterial 16S rRNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Results Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Conclusions Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. PMID:24161699

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.

The Nernst equation applied to oxidation-reduction reactions in myoglobin and hemoglobin. Evaluation of the parameters.

PubMed

Saroff, Harry A

Analyses of the binding of oxygen to monomers such as myoglobin employ the Mass Action equation. The Mass Action equation, as such, is not directly applicable for the analysis of the binding of oxygen to oligomers such as hemoglobin. When the binding of oxygen to hemoglobin is analyzed, models incorporating extensions of mass action are employed. Oxidation-reduction reactions of the heme group in myoglobin and hemoglobin involve the binding and dissociation of electrons. This reaction is described with the Nernst equation. The Nernst equation is applicable only to a monomeric species even if the number of electrons involved is greater than unity. To analyze the oxidation-reduction reaction in a molecule such as hemoglobin a model is required which incorporates extensions of the Nernst equation. This communication develops models employing the Nernst equation for oxidation-reduction reactions analogous to those employed for hemoglobin in the analysis of the oxygenation (binding of oxygen) reaction.

Marine mesocosm bacterial colonisation of volcanic ash

NASA Astrophysics Data System (ADS)

Witt, Verena; Cimarelli, Corrado; Ayris, Paul; Kueppers, Ulrich; Erpenbeck, Dirk; Dingwell, Donald; Woerheide, Gert

2015-04-01

Volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, wind-delivered volcanic ash may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, which bacteria are involved in pioneer colonisation remain unknown. We hypothesize that physico-chemical properties (i.e., morphology, mineralogy) of the ash may dictate bacterial colonisation. The effect of substrate properties on bacterial colonisation was tested by exposing five substrates: i) quartz sand ii) crystalline ash (Sakurajima, Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size, in controlled marine coral reef aquaria under low light conditions for six months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis of Similarity supported significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community with the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community composition during colonisation of volcanic ash in a coral reef-like environment is controlled by the

Marine Mesocosm Bacterial Colonisation of Volcanic Ash

NASA Astrophysics Data System (ADS)

Witt, V.; Cimarelli, C.; Ayris, P. M.; Kueppers, U.; Erpenbeck, D.; Dingwell, D. B.; Woerheide, G.

2014-12-01

Explosive volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local or regional scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, ash deposition may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, it is currently unknown which bacteria are involved in pioneer colonisation. We hypothesize that physico-chemical properties (i.e., morphology, chemistry, mineralogy) of the ash may dictate bacterial colonisation. We have tested the effect of substrate properties on bacterial diversity and abundance colonising five substrates: i) quartz sand ii) crystalline ash from the Sakurajima volcano (Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size - by incubation in a controlled marine mesocosm (coral reef aquarium) under low light conditions for three months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis Of Similarity supports significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community and carried the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community

The accuracy of noninvasive hemoglobin measurement by multiwavelength pulse oximetry after cardiac surgery.

PubMed

Nguyen, Ba-Vinh; Vincent, Jean-Louis; Nowak, Emmanuel; Coat, Michelle; Paleiron, Nicolas; Gouny, Pierre; Ould-Ahmed, Mehdi; Guillouet, Maité; Arvieux, Charles Christian; Gueret, Gildas

2011-11-01

In March 2008, a new multiwavelength pulse oximeter, the Radical 7 (Rad7; Masimo Corp., Irvine, CA), was developed that offers noninvasive measurement of hemoglobin concentration. Accuracy has been established in healthy adults and some surgical patients, but not in cardiac surgery intensive care patients, a group at high risk of postoperative bleeding events and anemia in whom early diagnosis could improve management. In this prospective, observational study conducted in a cardiovascular intensive care unit, we compared hemoglobin concentrations shown by the Rad7 with arterial hemoglobin concentrations determined by an automated hematology analyzer, XE-2100 (Roche, Neuilly sur Seine, France). Two software versions of Rad7 (V 7.3.0.1 [42 points of comparison in 14 patients] and the updated V 7.3.1.1 [61 points of comparison in 27 patients]) were studied during two 1-week periods. Bias, defined as the difference between the 2 methods (Masimo SpHb-XE-2100 laboratory hemoglobin), was calculated. A negative bias indicated that the Masimo underestimated hemoglobin compared with the laboratory analyzer. Correlation between the perfusion index given by Rad7 and the hemoglobin bias was also studied. Correlations between Rad7 and XE-2100 were weak for both software versions (R2=0.11 for V 7.3.0.1 and R2=0.27 for V 7.3.1.1). Mean bias was -1.3 g/dL for V 7.3.0.1 and -1.7 g/dL for V 7.3.1.1, with wide 95% prediction intervals for the bias (respectively, -4.6 to 2.1 g/dL and -5.7 to 2.3 g/dL). The absolute hemoglobin bias tended to increase when the perfusion index decreased. For the V 7.3.0.1 software, the average absolute bias was 1.9 g/dL for perfusion index<2 and 0.8 g/dL for perfusion index>2 (P=0.03). For V 7.3.1.1, the mean absolute bias was 2.1 g/dL when the perfusion index was <2, and 1.6 g/dL when the perfusion index was >2 (P=0.26). Our study demonstrates poor correlation between hemoglobin measured noninvasively by multiwavelength pulse oximetry and a laboratory

Inoculation of a phenanthrene-degrading endophytic bacterium reduces the phenanthrene level and alters the bacterial community structure in wheat.

PubMed

Liu, Juan; Xiang, Yanbing; Zhang, Zhiming; Ling, Wanting; Gao, Yanzheng

2017-06-01

Colonization by polycyclic aromatic hydrocarbon (PAH)-degrading endophytic bacteria (PAHDEB) can reduce the PAH contamination risk in plant. However, little information is available on the impact of PAHDEB colonization on the endophytic bacterial community of inner plant tissues. A phenanthrene-degrading endophytic bacterium (PDEB), Massilia sp. Pn2, was inoculated onto the roots of wheat and subjected to greenhouse container experiments. The endophytic bacterial community structure in wheat was investigated using high-throughput sequencing technology. The majority of endophytic bacteria in wheat were Proteobacteria, and the dominant genus was Pseudomonas. Phenanthrene contamination clearly increased the diversity of endophytic bacteria in wheat. The cultivable endophytic bacteria counts in wheat decreased with increasing the level of phenanthrene contamination; the endophytic bacterial community structure changed correspondingly, and the bacterial richness first increased and then decreased. Inoculation of strain Pn2 reduced the phenanthrene contamination in wheat, enlarged the biomass of wheat roots, changed the bacterial community structure and enhanced the cell counts, diversity and richness of endophytic bacteria in phenanthrene-contaminated wheat in a contamination level-dependent manner. The findings of this investigation provide insight into the responses of endophytic bacterial community in plant to external PAH contamination and PAHDEB colonization.

Mild splenic sequestration crises in sickle-hemoglobin C disease.

PubMed

Andrews, J; Buchanan, G R

1984-06-01

Acute splenic sequestration crisis ( ASSC ), a common complication in homozygous sickle cell anemia, has been described infrequently in sickle-hemoglobin C (SC) disease in the absence of high altitude exposure. In this report, we describe three children with hemoglobin SC disease who developed episodes of ASSC that were milder than those generally described in sickle cell anemia. In one patient, an antecedent triggering event was not recognized. The other two children may have had a predisposing cause for massive intrasplenic sickling in that one had an associated mononucleosis syndrome and the other an episode of hypovolemic shock following severe epistaxis. ASSC may occur in patients with SC disease and does not necessarily require a hypoxic trigger associated with high altitudes.

Identification of a Novel Class of Covalent Modifiers of Hemoglobin as Potential Antisickling Agents

PubMed Central

Omar, A. M.; Mahran, M. A.; Ghatge, M. S.; Chowdhury, N.; Bamane, F. H. A.; El-Araby, M. E.; Abdulmalik, O.; Safo, M. K.

2015-01-01

Aromatic aldehydes and ethacrynic acid (ECA) exhibit antipolymerization properties that are beneficial for sickle cell disease therapy. Based on ECA pharmacophore and its atomic interaction with hemoglobin, we designed and synthesized several compounds--designated as KAUS (imidazolylacryloyl derivatives)--that we hypothesized would bind covalently to βCys93 of hemoglobin and inhibit sickling. The compounds surprisingly showed weak allosteric and antisickling properties. X-ray studies of hemoglobin in complex with representative KAUS compounds revealed an unanticipated mode of Michael addition reaction between the β-unsaturated carbon and the N-terminal αVal1 nitrogen at the α-cleft of hemoglobin, with no observable interaction with βCys93. Interestingly, the compounds exhibited almost no reactivity with the free amino acids, L-Val, L-His and L-Lys, however showed some reactivity with both glutathione and L-Cys. Our findings provide a molecular level explanation to the compounds biological activities and an important framework for targeted modifications that would yield novel potent antisickling agents. PMID:25974708