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PubMed1998

Trimidox-mediated morphological changes during erythroid differentiation is associated with the stimulation of hemoglobin and F-cell production in human K562 cells.

Trimidox (3,4,5-trihdroxybenzamidoxime) has been shown to reduce the activity of ribonucleotide reductase with accompanied growth inhibition and differentiation of mammalian cells. Hydroxyurea (HU) is the only ribonucleotide reductase inhibitor in clinical use for the treatment and management of sickle cell anemia, since this compound increases fetal hemoglobin (Hb F) production: a potent inhibitor of sickle hemoglobin (Hb SS) polymerization. However, the main limitations of HU is its lack of potency, myelosuppression and short half life. These studies investigated the effects of trimidox on the induction of hemoglobin and F-cells production in K562 erythroleukemia cells. Our study reveals that trimidox exhibits concentration dependent inhibitory effect on K562 cells with increase in benzidine positive normoblasts and F-cells production as well as morphological changes typical of erythroid differentiation. These findings provide the first evidence that the growth inhibitory differentiation of cells induced by trimidox enhance hemoglobin and F-cells production.

Benzamidines↗
PubMed2004

Phenoxazine compounds produced by the reactions with bovine hemoglobin show antimicrobial activity against non-tuberculosis mycobacteria.

We studied the anti-microbial effects of phenoxazines produced by the reaction of o-aminophenol or its derivatives with bovine hemoglobin, on seven species of mycobacteria such as Mycobacterium tuberculosis, Mycobacterium marinum, Mycobacterium intracellulare, Mycobacterium scrofulaceum, Mycobacterium fortuitum, Mycobacterium kansasii and Mycobacterium smegmatis and some bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogeneses. These phenoxazines, including 2-amino-4, 4alpha-dihydro-4alpha, 7-dimethyl-3H-phenoxzine-3-one (Phx-1), 3-amino-1, 4alpha-dihydro-4alpha, 8-dimethyl-2H-phenoxazine-2-one (Phx-2), and 2-aminophenoxazine-3-one (Phx-3), prevented the proliferation of four non-tuberculosis mycobacteria including M. scrofulaceum, M. kansasii, M. marinum, and M. intracellulare dose-dependently, though the inhibitory effects of these phenoxazines differed according to the species of mycobacteria. However these phenoxazines failed to prevent the proliferation of M. tuberculosis, M. fortuitum, and M. smegmatis, and the concerned bacteria other than mycobacteria. The present results may contribute to development of novel antibiotics against non-tuberculolsis mycobacteria.

Animals↗
PubMed1999

Biological fate of [14C]-1-nitropyrene in rats following intragastric administration.

1-Nitropyrene (1-NP), a weak carcinogen associated with diesel exhaust particles, has previously been detected in workplace atmospheres with in-use diesel engines and in the general environment. In order to gain insight in its biological fate, a single dose of [14C]-1-NP (27.6 microCi, 750 mg/kg body weight, b.w.) was administered intragastrically to rats and the presence of metabolites in blood and tissue homogenates, and radioactivity associated with blood proteins and tissue DNA, were studied. Early peak levels of radioactivity observed in blood and tissue homogenates indicated a rapid absorption of [14C]-1-NP from the gastrointestinal tract. Metabolite patterns observed in plasma, liver and kidney homogenates strongly suggested an important role of the intestinal microflora in the enterohepatic recirculation, but not in nitroreduction of 1-NP prior to absorption from the gastrointestinal tract. This might explain the low levels of radioactivity associated with blood proteins, since 1-nitrosopyrene, a product of nitroreduction of 1-NP, is likely to be involved in protein binding. Levels of radioactivity associated with plasma proteins were approximately four times higher than the levels of radioactivity associated with hemoglobin (401.0 and 84.1 pmol/g protein per micromol 1-NP kg b.w., respectively, at 24 h). Maximal 25% of the associated radioactivity was released following mild alkaline hydrolysis of either hemoglobin or plasma proteins. 1-Aminopyrene was the only released compound after hydrolysis of hemoglobin. In addition to 1-aminopyrene, two more polar unidentified metabolites were detected following hydrolysis of plasma proteins. Association of radioactivity with DNA was highest in the liver at the first moments of observation (7.4 pmol 14C Eq./mg DNA per micromol 1-NP kg b.w.), but decreased rapidly to levels lower than observed for kidney DNA (max. 3.0 pmol 14C Eq./mg DNA per micromol 1-NP kg b.w. at 24 h). In lungs 8-50 times less radioactivity was associated with DNA than observed in the liver and kidneys. The results of this study show, that 1-NP undergoes an extensive and complex biotransformation in vivo, resulting in a variety of metabolites present in blood and tissue homogenates and a diversity of blood protein adducts. Concentrations of plasma metabolites, blood protein adducts and DNA adducts were rather low. In addition, previous studies also showed relatively low concentrations of metabolites present in urine. Therefore, sensitive and selective methods will be needed in order to evaluate the biological fate of 1-NP, associated with diesel exhaust particles, in humans.

Animals↗
PubMed1994

[Studies on the chronic toxicity of a mixture of lead, cadmium and iron given to white rats with drinking water].

The experiment was carried out on male white rats of own breed which were receiving for 8 months lead acetate 200 mg/l, cadmium acetate 50 mg/l and ferrous chloride 100 mg/l with drinking water. The experimental groups received lead, cadmium, lead with cadmium, and the last group received every other day alternatingly iron or lead with cadmium. The activity of selected blood enzymes, haematological indices was determined and the memory test was carried out. In all experimental groups a decrease was noted of haemoglobin level and haematocrit value, with an increase of choline esterase and reduced learning effectiveness--most pronounced in the group treated with cadmium, less evident in groups drinking water with lead or cadmium and lead, and not significant in the group receiving iron with lead and cadmium.

Acetates↗
PubMed2000

beta-thalassemia intermedia caused by compound heterozygosity for Hb Malay (beta codon 19 AAC-->AGC; asn-->Ser) and codons 41/42 (-CTTT) beta(0)-thalassemia mutation.

We report a case of beta-thalassemia intermedia caused by compound heterozygosity for hemoglobin (Hb) Malay and codon 41/42 (-CTTT) beta(0)-thalassemia mutation in a 38-year-old Chinese woman. This patient has long-standing anemia with a baseline Hb level of around 70 g/L. She worked as a full-time cashier and had not required regular blood transfusions. Nevertheless, she had splenomegaly necessitating splenectomy, cholelithiasis, and iron overload. This case illustrates the varied phenotypic expression associated with compound heterozygosity for Hb Malay and other beta-thalassemia mutations. Since Hb Malay migrates as Hb A on electrophoresis and chromatography, this variant Hb mutation ought to be included in the differential diagnosis for beta-thalassemia major or intermedia patients of Southeast Asian descent who are reported to have Hb A on the basis of Hb analysis. The possible presence of this mutation should also be considered in appropriate cases for genetic counseling in couples at risk of conceiving fetuses with beta-thalassemia major or intermedia.

Adult↗
PubMed1977

Nitrosoalkanes as Fe(II) ligands in the hemoglobin and myoglobin complexes formed from nitroalkanes in reducing conditions.

Primary and secondary aliphatic nitro compounds, R2CHNO2, react with myoglobin and hemoglobin, in the presence of sodium dithionite, leading to new complexes with Soret peaks respectively at 425 and 421 nm. These complexes are very stable even after disappearance of the starting nitro compounds and do not exchange their exogenous ligand after 10 h under 1 atm (101 325 Pa) CO. They are low-spin hexacoordinated myoglobin or hemoglobin complexes, as shown by the resonance Raman spectrum of the nitromethane-derived human hemoglobin complex which is similar to those of the known hemoglobin complexes with O2, CO, NO and nitrosobenzene. Evidence has been produced to show that the nitro compounds themselves do not bind to the hemoproteins; we propose that among the reduction derivatives produced in situ by dithionite, the corresponding unstable nitroso monomers, whose nitroso group is isoelectronic with dioxygen, are the actual ligands of the 425-nm or 421-nm-absorbing complexes.

Alkanes↗
PubMed1990

Ischemia-reperfusion in humans. Appearance of xanthine oxidase activity.

We evaluated effluent blood from extremities of human patients undergoing reconstructive surgical treatment, which is routinely accompanied by upper-extremity exsanguination and application of a tourniquet, resulting in total interruption of arterial blood flow to one upper extremity. After tourniquet release (reperfusion), there were immediate increases in the plasma levels of xanthine oxidase activity, uric acid, and histamine in the ipsilateral limb and much smaller increases, if any, in levels of the same materials in plasma obtained from the contralateral extremity. There was no detectable xanthine dehydrogenase activity in plasma from either limb. Plasma also contained evidence of products consistent with the formation of oxygen-derived free radicals, namely, the appearance predominantly in the reperfused limb of hemoglobin and fluorescent compounds. These data indicate for the first time in humans that ischemia-reperfusion events are associated with the appearance of xanthine oxidase activity and its products in the plasma effluent.

Adult↗
PubMed2002

Control of the allosteric equilibrium of hemoglobin by cross-linking agents.

The kinetics of ligand rebinding have been studied for modified or cross-linked hemoglobins (Hbs). Several compounds were tested that interact with alpha Val 1 or involve a cross-link between alpha Val 1 and alpha Lys 99 of the opposite dimer. By varying the length of certain cross-linking molecules, a wide range in the allosteric equilibrium could be obtained. Several of the mono-aldehyde modified Hbs show a shift toward the high affinity conformation of Hb. At the other extreme, for certain di-aldehyde cross-linked Hbs, the CO kinetics are typical of binding to deoxy Hb, even at low photodissociation levels, with which the dominant photoproduct is the triply liganded species; in these cases the hemoglobin does not switch from the low to high affinity state until after the fourth ligand is bound. Although each modified Hb shows only two distinct rates, the kinetic data as a function of dissociation level cannot be simulated with a simple two-state model. A critical length is observed for the maximum shift toward the low affinity T-state. Longer or shorter lengths of the cross-linker yielded more high affinity R-state. Unlike native Hb, which is in equilibrium with free dimers, the cross-linked Hbs maintain the fraction slow kinetics, which is unique to Hb tetramers, even at 0.5 microM (total heme). Addition of HbCN to unmodified HbCO solutions results in dimer exchange, which decreases the relative fraction of slow bimolecular kinetics; the cross-linked Hbs did not show such an effect, indicating that they do not participate in dimer exchange.

Aldehydes↗
PubMed1988

Physical basis of the effect of hemoglobin on the 31P NMR chemical shifts of various phosphoryl compounds.

The marked difference between the intra- and extracellular 31P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the 31P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethyl-phosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the 31P NMR resonances to shift to lower frequency in a manner that cannot be accounted for in terms of magnetic susceptibility. Lysozyme is a protein structurally unrelated to hemoglobin and was shown to cause similar shifts to lower frequency of the resonances of these six compounds; this suggests that the mechanism may involve a property of proteins in general and not a specific property of hemoglobin. The effect of different solvents on the chemical shifts of the eight phosphoryl compounds provided an insight into the possible physical basis of the effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemoglobins↗
PubMed1988

LR16, a compound with potent effects on the oxygen affinity of hemoglobin, on blood cholesterol, and on low density lipoprotein.

2-[4-(3,4-Dichlorophenylureido)phenoxy]-2-methylpropionic acid, LR16, combines with two symmetrically related sites in the central cavity of deoxyhemoglobin, 20 A away from the binding site of 2,3-bisphosphoglycerate, and acts as an allosteric effector synergistic with 2,3-bisphosphoglycerate. LR16 (1 mM) raises P50, the partial pressure of oxygen needed to achieve half-saturation with oxygen of a hemolysate of human hemoglobin, about 50 times more strongly than 1 mM 2,3-bisphosphoglycerate. Oral administration of LR16 (at small doses that produced no ill effects) to rats that were fed a diet rich in cholesterol caused substantial reductions of total serum cholesterol and low density lipoprotein-cholesterol, while high density lipoprotein-cholesterol remained unchanged.

Animals↗
PubMed1988

A yellow-stained human femur from Tell esh-Shuqafiya, Egypt: evidence of ancient trauma.

Excavation at Tell esh-Shuqafiya, Egypt, during the 1982 season exposed several Ptolemaic Period burials. One of these, a young adult male, showed a bright yellow stain on the right femur. Analysis of the stain demonstrated it to be hematoidin, a degradation compound derived from hemoglobin associated with old hemorrhage. The specific location of the stain on the skeleton suggests death a few weeks after a severe injury to the thigh.

Adult↗
PubMed1991

Role of oxygen radicals in tourniquet-related ischemia-reperfusion injury of human patients.

In the current study we evaluated effluent blood from extremities of human patients undergoing reconstructive surgical treatment which is routinely accompanied by upper extremity exsanguination and application of a tourniquet. Following tourniquet release (reperfusion), there were immediate increases in the plasma levels of xanthine oxidase activity, uric acid, and histamine. Xanthine dehydrogenase activity was not detectable. Plasma also contained products consistent with the formation of oxygen-derived free radicals, namely hemoglobin and fluorescent compounds. Our data indicate in humans that ischemia-reperfusion events are associated with the appearance of xanthine oxidase activity and its products in the plasma effluent.

Adult↗
PubMedDate not supplied

Cloning and expression of fructosyl-amine oxidase from marine yeast Pichia species N1-1.

The gene encoding the fructosyl-amine oxidase (FAOD) from the marine yeast Pichia sp. N1-1 was cloned and expressed in Escherichia coli. Partial amino acid sequence analysis of the Pichia sp. N1-1 FAOD allowed the design of oligonucleotide primers for the amplification of the gene by inverse polymerase chain reaction. The FAOD gene was found to be devoid of introns and to encode a 48-kDa protein composed of 429 amino acid residues. The FAD-binding consensus sequence GXGXXG: and the FAD covalent attachment-site cysteine residue have been identified within the predicted amino acid sequence. Comparisons with the amino acid sequences of other eukaryotic FAODs showed only 30% to 40% identities, establishing that the isolated Pichia N1-1 gene encodes a unique FAOD. Recombinant FAOD expression levels in E. coli reached 0.48 U/mg of soluble protein, which is considerably greater than native expression levels by inducing Pichia sp. N1-1 with fructosyl-valine (f-Val). The kinetic properties of the recombinant enzyme were almost indistinguishable from those of the native enzyme. We previously reported on the construction of a number of effective Pichia sp. N1-1 FAOD-based biosensors for measuring f-Val, a model compound for glycated hemoglobin. The further development of these biosensor systems can now greatly benefit from protein engineering and recombinant expression of the FAOD from Pichia N1-1.

Amino Acid Oxidoreductases↗