[42] Hemoglobinometry in human blood

Tentori, L; Salvati, Anna Maria

doi:10.1016/0076-6879(81)76152-4

Cited by 114 publications

(57 citation statements)

References 19 publications

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“…Reversibility of azide inhibition was tested after dialysis of azide-treated catalase against 0.1 M-PBS, pH 7.35 (three changes of buffer over 18 h at 4 "C). The spectrophotometric profile of the catalase was determined by scanning both the native protein and enzyme treated with K3Fe(CN),/KCN (Tentori & Salvati, 1981) in the range 260-680 nm.…”

Section: Methodsmentioning

confidence: 99%

Helicobacter pylori catalase

1991

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Helicobacter pylori is the major aetiological agent of gastroduodenitis in humans. Due to the potential importance of catalase in the growth and survival of Helicobacter pylori on the surface of inflamed mucosae, we have characterized catalase from H. pyfori as a prelude to further studies on the function of the enzyme in uiuo. The catalase activity of H. pylori was significantly affected by the presence of blood, serum or erythrocytes in the growth medium: the greatest activity was expressed when the bacterium was grown on medium containing serum. H.pyloricatalase is a tetramer with a subunit M, of 50000. The enzyme had a PI of 94-9.3, was active over a broad pH range and was stable at 56 OC. It was non-competitively inhibited by sodium azide, and had no detectable

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Section: Methodsmentioning

confidence: 99%

Helicobacter pylori catalase

1991

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“…The blood was collected in heparinized tubes, and centrifuged at 5,000 ϫ g for 5 min to obtain plasma samples. Hemoglobin concentration in the plasma was determined using the analytical technique of Tentori and Salvati (39).…”

Section: Evaluation Of Hemodynamic Responsesmentioning

confidence: 99%

Glutaraldehyde Modification of Recombinant Human Hemoglobin Alters Its Hemodynamic Properties

Doyle

Apostoł

Kerwin

1999

Journal of Biological Chemistry

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Many cell-free hemoglobin solutions designed as oxygen-carrying therapeutics produce a hypertensive effect in animals. The response is likely due to oxidation of nitric oxide by hemoglobin. Since the site of oxidation may lie outside the vascular compartment, we tested the hypothesis that polymerization of hemoglobin, rHb1.1, by glutaraldehyde would attenuate the hypertensive response. Two products of the cross-linking reaction were isolated, a glutaraldehyde-derivatized monomer (monoglxrHb) and a glutaraldehyde cross-linked polymer (poly-glxrHb), and evaluated for their effects on systemic hemodynamics in conscious rats. Administration of rHb1.1 caused a mean arterial pressure elevation of approximately 20 mm Hg and an increase in total peripheral resistance of approximately 30%. Administration of mono-glxrHb induced changes in mean arterial pressure and vascular resistance that were significantly diminished relative to those observed with rHb1.1. PolyglxrHb elicited a mean arterial pressure response that was further reduced compared with that obtained with mono-glxrHb and a change in vascular resistance that was the same as the response to mono-glxrHb. These results suggest that rHb peripheral vasoconstriction elicited by rHb1.1 is significantly attenuated by glutaraldehyde modification of the hemoglobin monomer and that the effect of glutaraldehyde polymerization is likely due to surface modification and/or intramolecular cross-linking, rather than an increase in molecular size.As reviewed elsewhere (1-3), the search for a safe and efficacious oxygen-delivering therapeutic has been ongoing for many years. Limitations to the use of hemoglobin solutions as therapeutics have included renal toxicities due to the presence of stromal elements (4, 5), dissociation into ␣␤ dimers (6), high oxygen affinities (7), and short intravascular retention times (1). Multiple approaches have been taken to modify hemoglobins to address these limitations (1, 3), including chemical cross-linking of purified human or bovine hemoglobin to prevent dissociation and chemical modification to increase the P 50 to a physiologically suitable level (approximately 25-35 mm Hg, (7)). Recombinant technology was employed to genetically cross-link the ␣-globins to form a di-␣-globin and thereby prevent dissociation. In addition, the P 50 was increased by substitution of Lys for Asn at the ␤108 position. The resultant hemoglobin molecule, rHb1

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“…Accurate hemoglobinometry is extremely important for the precise determination of Hi fner's factor, and we used the cyanomethemoglobin method with millimolar extinction coefficient of 11.00 at 540 nm (on heme basis) (ICSH, 1978) for this purpose. In view of recent reviewers' comments (TENTORI and SALVATI, 1981), special care was taken in the exact dilution of blood samples. Carboxyhemoglobin (HbCO) content was measured by the method of COMMINS and LAWTHER (1965), and methemoglobin (Hb+) content by a presently developed difference spectrum method in near infrared region (ENOKI et al, unpublished).…”

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confidence: 99%