scholarly journals Diagnostic and Prognostic Possibilities of the Redox-Potential Electrochemical Measurements in Blood Plasma

2015 ◽  
Vol 70 (6) ◽  
pp. 627-632 ◽  
Author(s):  
Valeriy Ivanovich Sergienko ◽  
Mogeli Shalvovich Khubutiya ◽  
Anatoliy Konstantinovich Evseev ◽  
Aleksey Valer'evich Pinchuk ◽  
Murad Saftarovich Novruzbekov ◽  
...  
Keyword(s):  
Redox Potential ◽  
Blood Plasma ◽  
Healthy Volunteers ◽  
Postoperative Period ◽  
Reference Electrode ◽  
Oxygen Metabolism ◽  
Redox Potentials ◽  
Operating Characteristics ◽  
Transplanted Kidney ◽  
Potential Monitoring

Aims: Determination of operating characteristics of the test based on blood plasma redox potential monitoring in patients with different pathological conditions associated with impaired oxygen metabolism during treatment in postoperative period and expanding the range of parameters of the developed method of investigation of blood plasma redox potential.Methods: It were examined healthy volunteers group as following group (n =63), groups of patients with transplanted liver (n =64), kidney (n =59), and lungs (n =7). Redox potential measurements were done by platinum electrode, reference electrode was silver-chlorine one. Potentiostate IPC-ProL was used to registrate and record a dependence redox potential via time. Time of measurement was 15 min.Results: statistically significant differencees of redox potentials ranges was found in healthy volunteers and patients with transplanted kidney and liver. Ratio of measured redox potentials coincident with the values within the confidence interval in healthy volunteers was 12% in patients with transplanted kidney and 10% in patients with transplanted liver. We observed significant differences in the nature of changes of blood plasma's redox potential values in course of monitoring of subgroups of patients with and without complications after liver transplantation. It was found that sensitivity of electrochemical method was 85%, selectivity — 69,8%, precision — 85,2%.Conclusion: we discovered value ranges of blood plasma redox potential typical for different pathological states; we detected an interaction between the effect of treatment and quantitative changes in the values of the blood plasma redox potentials; criterion for early predicition of complications in patients with transplanted liver was proposed basing on redox potential monitoring during postoperative period.

scholarly journals Prediction of Complication Development After Kidney Transplantation Using Blood Plasma Redox Potential Monitoring

2015 ◽  
Vol 7 (4) ◽  
pp. 84-90 ◽  
Author(s):  
V.A. Kolesnikov ◽  
A.K. Evseyev ◽  
A.N. Elkov ◽  
A.V. Pinchuk ◽  
L.S. Kokov ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
Redox Potential ◽  
Blood Plasma ◽  
Potential Monitoring

scholarly journals Role of redox-inactive metals in controlling the redox potential of heterometallic manganese–oxido clusters

2021 ◽  
Author(s):  
Keisuke Saito ◽  
Minesato Nakagawa ◽  
Manoj Mandal ◽  
Hiroshi Ishikita
Keyword(s):  
Photosystem Ii ◽  
Redox Potential ◽  
Quantum Chemical Calculations ◽  
Catalytic Reaction ◽  
Quantum Chemical ◽  
Ionic Radius ◽  
Redox Potentials ◽  
Oxygen Evolving ◽  
Highest Occupied Molecular Orbitals

AbstractPhotosystem II (PSII) contains Ca2+, which is essential to the oxygen-evolving activity of the catalytic Mn4CaO5 complex. Replacement of Ca2+ with other redox-inactive metals results in a loss/decrease of oxygen-evolving activity. To investigate the role of Ca2+ in this catalytic reaction, we investigate artificial Mn3[M]O2 clusters redox-inactive metals  [M] ([M]  = Mg2+, Ca2+, Zn2+, Sr2+, and Y3+), which were synthesized by Tsui et al. (Nat Chem 5:293, 2013). The experimentally measured redox potentials (Em) of these clusters are best described by the energy of their highest occupied molecular orbitals. Quantum chemical calculations showed that the valence of metals predominantly affects Em(MnIII/IV), whereas the ionic radius of metals affects Em(MnIII/IV) only slightly.

scholarly journals Detecting Redox Potentials Using Porous Boron Nitride/ATP-DNA Aptamer/Methylene Blue Biosensor to Monitor Microbial Activities

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 83
Author(s):  
Kai Guo ◽  
Zirui Song ◽  
Gaoxing Wang ◽  
Chengchun Tang
Keyword(s):  
Methylene Blue ◽  
Microbial Community ◽  
Boron Nitride ◽  
Redox Potential ◽  
Microbial Activity ◽  
Potential Change ◽  
Dna Aptamer ◽  
Redox Potentials ◽  
Microplate Reader

Microbial activity has gained attention because of its impact on the environment and the quality of people’s lives. Most of today’s methods, which include genome sequencing and electrochemistry, are costly and difficult to manage. Our group proposed a method using the redox potential change to detect microbial activity, which is rooted in the concept that metabolic activity can change the redox potential of a microbial community. The redox potential change was captured by a biosensor consisting of porous boron nitride, ATP-DNA aptamer, and methylene blue as the fluorophore. This assembly can switch on or off when there is a redox potential change, and this change leads to a fluorescence change that can be examined using a multipurpose microplate reader. The results show that this biosensor can detect microbial community changes when its composition is changed or toxic metals are ingested.

scholarly journals Features of cytokine profile in patients with sarcoidosis

2020 ◽  
Vol 22 (5) ◽  
pp. 993-1002
Author(s):  
N. M. Lazareva ◽  
O. P. Baranova ◽  
I. V. Kudryavtsev ◽  
N. A. Arsentieva ◽  
N. E. Liubimova ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Healthy Volunteers ◽  
Peripheral Blood ◽  
Granulomatous Inflammation ◽  
Epithelioid Cell ◽  
Cytokine Profile ◽  
Unknown Etiology ◽  
Gm Csf ◽  
Peripheral Blood Plasma ◽  
Anti Inflammatory Cytokine

Sarcoidosis is an inflammatory disease of unknown etiology with damage to the lungs and other organs characterized by development of necrosis-free epithelioid cell granulomas. Granulomatous inflammation characterized by the activation of different immune systems cells, in particular T lymphocytes, and the cytokines production. Our study was aimed at investigating the characteristics of the cytokine profile of blood plasma in patients with sarcoidosis. We studied peripheral blood plasma samples of patients with sarcoidosis (n = 52). The control blood samples were taken from healthy volunteers (n = 22). The level of 46 cytokines (pg/ml) was determined, as follows: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL- 6, IL-7, IL-9, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17A, IFNα2, IFNγ, TNFα, TNFβ, IL- 1ra, IL-10, EGF, FGF-2, Flt3 Ligand, G-CSF, GM-CSF, PDGF-AA, PDGF-AB / BB, TGFα, VEGF-A, sCD40L, CCL2, CCL3, CCL4, CCL5, CCL7, CCL11, CCL17, CCL20, CCL22, CXCL1, CXCL8, CXCL9, CXCL10, CXCL11, CXCL13, CX3CL1. Significantly higher levels of interleukins and some proinflammatory cytokines were found in the patients with sarcoidosis, i.e., IL-3, 0.70 vs 0.20, p = 0.003; IL-4, 14.37 vs 3.15, p = 0.009; IL-5, 1.06 vs 0.89, p < 0.001; IL-12 (p70), 1.27 vs 0.56, p = 0.028; IL-17A, 1.48 vs 0.43, p < 0.001; IFNα2, 41.79 vs 25.04, p = 0.003; IFNγ, 4.13 vs 1.14, p < 0.001; TNFα, 21.67 vs 6.70, p < 0.001; anti-inflammatory cytokine IL-10, 1.03 vs 0.45, p = 0.019; growth factors: FGF-2, 40.08 vs 30.58, p = 0.008, G-CSF, 24.18 vs 8.21, p = 0.006, and VEGF-A, 42.52 vs 26.76, p = 0.048; chemokines: CCL3, 3.86 vs 1.33, p < 0,001; CCL17, 78.24 vs 26.24, p < 0.001; CCL20, 7.19 vs 5.64, p = 0.021; CCL22, 660.60 vs 405.00, p < 0,001; CXCL9, 4013 vs 1142, p < 0,001; CXCL10, 565.90 vs 196.60, p < 0.001; CXCL11, 230.20 vs 121.10, p = 0.018; CX3CL1, 56.99 vs 5.16, p < 0.001. Peripheral blood chemokine CCL11 levels were significantly lower in patients compared to the group of healthy volunteers: 77.58 vs 124.70, p = 0.022. The features of the cytokine profile in patients with sarcoidosis may indicate their important role in the processes of formation and outcomes of granulomas. These issues require an additional detailed study, comparison with phenotypes, differential course and outcomes of the disease.

scholarly journals Using Redox Potential as a Feasible Marker for Banked Blood Quality and the State of Oxidative Stress in Stored Red Blood Cells

2020 ◽  
Author(s):  
Rodney C Daniels ◽  
Hyesun Jun ◽  
Robertson D Davenport ◽  
Maryanne M Collinson ◽  
Kevin R Ward
Keyword(s):  
Oxidative Stress ◽  
Redox Potential ◽  
Red Blood Cells ◽  
Healthy Volunteers ◽  
Blood Cells ◽  
Storage Time ◽  
Cell Function ◽  
Venous Blood ◽  
Functional Changes ◽  
Over Time

Abstract Background Stored Red Blood Cells (RBCs) may undergo oxidative stress over time, with functional changes affecting critical tasks such as oxygen delivery. Central to these changes are oxidation-reduction (redox) reactions and the redox potential (RP) that must be maintained for proper cell function. RP imbalance can lead to oxidative stress that may contribute to storage lesions and transfusion-related morbidities. Direct measures of RP may allow for evaluation of erythrocyte quality and enable corrections of RP prior to transfusion. Methods Multiple random RBC segments were tested, ranging in age from 5 to 40 days at 5 day intervals. RP was recorded by measuring open circuit potential of RBCs using novel nanoporous gold electrodes with Ag/AgCl reference. RP measures were also performed on peripheral venous blood samples from 10 healthy volunteers. RP measures were compared between groups of aged RBCs, and with volunteer blood. Results Stored RBCs show time-dependent increases in RP. There were significant differences in Day 5 RP compared to all other groups (p≤0.005), Day 10-15 vs ages ≥ Day 20 (p≤0.025), Day 20-25 vs Day 40 (p=0.039), and all groups compared to healthy volunteers. RP became more positive over time suggesting ongoing oxidation as RBCs age. However, storage time alone does not predict the ultimate RP value measured from a given unit.Conclusions There are significant differences in RP between freshly stored RBCs and all others, with RP becoming more positive over time. However, storage time alone does not predict RP, indicating RP screening may be important independent of storage time and may serve as a marker of RBC quality and state of oxidative stress. RP measurements may also provide a target by which to restore RP balance in aged pRBCs, improving their clinical effectiveness while reducing associated morbidities.

scholarly journals Temperature-induced diurnal redox potential in soil

2021 ◽  
Author(s):  
Kristof Dorau ◽  
Bianca Bohn ◽  
Lutz Weihermüller ◽  
Tim Mansfeldt
Keyword(s):  
Redox Potential ◽  
Temporal Resolution ◽  
High Temporal Resolution ◽  
Redox Potentials ◽  
Soils And Sediments

With the capabilities to measure redox potentials (EH) at a high temporal resolution, scientists have observed diurnal EH that occur in a distinct periodicity in soils and sediments. These patterns...

scholarly journals Site-directed mutations in fungal laccase: effect on redox potential, activity and pH profile

1998 ◽  
Vol 334 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Feng XU ◽  
Randy M. BERKA ◽  
Jill A. WAHLEITHNER ◽  
Beth A. NELSON ◽  
Jeffrey R. SHUSTER ◽  
...  
Keyword(s):  
Redox Potential ◽  
Phenol Oxidase ◽  
Ascorbate Oxidase ◽  
Single Mutation ◽  
Redox Potentials ◽  
Wild Type ◽  
Ph Optimum ◽  
Ph Profile ◽  
Potential Activity

A Myceliophthora thermophila laccase and a Rhizoctonia solani laccase were mutated on a pentapeptide segment believed to be near the type-1 Cu site. The mutation L513F in Myceliophthora laccase and the mutation L470F in Rhizoctonia laccase took place at a position corresponding to the type-1 Cu axial methionine (M517) ligand in Zucchini ascorbate oxidase. The triple mutations V509L,S510E,G511A in Myceliophthora laccase and L466V,E467S,A468G in Rhizoctonia laccase involved a sequence segment whose homologue in ascorbate oxidase is flanked by the M517 and a type-1 Cu-ligating histidine (H512). The single mutation did not yield significant changes in the enzymic properties (including any significant increase in the redox potential of the type-1 Cu). In contrast, the triple mutation resulted in several significant changes. In comparison with the wild type, the Rhizoctonia and Myceliophthora laccase triple mutants had a phenol-oxidase activity whose pH optimum shifted 1 unit lower and higher, respectively. Although the redox potentials were not significantly altered, the Km, kcat and fluoride inhibition of the laccases were greatly changed by the mutations. The observed effects are interpreted as possible mutation-induced structural perturbations on the molecular recognition between the reducing substrate and laccase and on the electron transfer from the substrate to the type-1 Cu centre.

scholarly journals Contributions of Microbial “Contact Leaching” to Pyrite Oxidation under Different Controlled Redox Potentials

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 856
Author(s):  
Bingxu Dong ◽  
Yan Jia ◽  
Qiaoyi Tan ◽  
Heyun Sun ◽  
Renman Ruan
Keyword(s):  
Redox Potential ◽  
Dissolution Rate ◽  
Elemental Sulfur ◽  
Microbial Consortium ◽  
Pyrite Oxidation ◽  
Microbial Consortia ◽  
Redox Potentials ◽  
Sulfur Passivation ◽  
Sulfur Oxidizing ◽  
Contact Oxidation

The function of microbial contact leaching to pyrite oxidation was investigated by analyzing the differences of residue morphologies, leaching rates, surface products, and microbial consortia under different conditions in this study. This was achieved by novel equipment that can control the redox potential of the solution and isolate pyrite from microbial contact oxidation. The morphology of residues showed that the corrosions were a little bit severer in the presence of attached microbes under 750 mV and 850 mV (vs. SHE). At 650 mV, the oxidation of pyrite was undetectable even in the presence of attached microbes. The pyrite dissolution rate was higher with attached microbes than that without attached microbes at 750 mV and 850 mV. The elemental sulfur on the surface of pyrite residues with sessile microorganisms was much less than that without attached microbes at 750 mV and 850 mV, showing that sessile acidophiles may accelerate pyrite leaching by reducing the elemental sulfur inhibition. Many more sulfur-oxidizers were found in the sessile microbial consortium which also supported the idea. The results suggest that the microbial “contact leaching” to pyrite oxidation is limited and relies on the elimination of elemental sulfur passivation by attached sulfur-oxidizing microbes rather than the contact oxidation by EPS-Fe.

Stepwise reduction of samarium cryptates in propylene carbonate: anions and water concentration effects on the redox behavior of the Sm(III)/Sm(II) couple

1988 ◽  
Vol 66 (9) ◽  
pp. 2172-2176 ◽  
Author(s):  
Edouard Laurent Loufouilou ◽  
Jean Paul Gisselbrecht
Keyword(s):  
Redox Potential ◽  
Propylene Carbonate ◽  
Water Concentration ◽  
Oxidation States ◽  
Mixed Complex ◽  
Polarographic Reduction ◽  
Redox Behavior ◽  
Redox Potentials ◽  
Concentration Effects ◽  
Stepwise Reduction

The polarographic reduction of samarium(III) cryptates with cryptands 222, 221, and 22 was investigated in propylene carbonate. The samarium(III) cryptates are reduced in two consecutive steps, the first step was reversible and corresponded to the reduction of the Sm(III) to the Sm(II) cryptate. The Sm(III)/Sm(II) redox potential of the cryptates depended on the anion used in the complex and, in the case of the cryptate with chloride anions, a stable mixed complex was observed in propylene carbonate. The Sm(III)/Sm(II) redox potentials of the cryptates were more cathodic than the redox potential of the uncomplexed Sm(III)/Sm(II) couple, which is typical of a lower stability of the reduced cryptate. Propylene carbonate does not stabilize low oxidation states of lanthanides by cryptation. This is at variance with behavior observed previously in other media like water and methanol. Variations of redox potentials as a function of increasing amounts of water were accounted for by solvent shielding of samarium(III) upon encapsulation in cryptands.

The effect of ketanserin on cerebral blood flow and oxygen metabolism in healthy volunteers

1993 ◽  
Vol 125 (1-4) ◽  
pp. 83-85 ◽  
Author(s):  
K. S. Olsen ◽  
P. L. Madsen ◽  
T. B�rme ◽  
J. F. Schmidt
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Healthy Volunteers ◽  
Oxygen Metabolism
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