Antioxidant capacity of human blood plasma and human urine: Simultaneous evaluation of the ORAC index and ascorbic acid concentration employing pyrogallol red as probe

2008 ◽  
Vol 16 (20) ◽  
pp. 9171-9175 ◽  
Author(s):  
P. Torres ◽  
P. Galleguillos ◽  
E. Lissi ◽  
C. López-Alarcón
Keyword(s):  
Ascorbic Acid ◽  
Blood Plasma ◽  
Antioxidant Capacity ◽  
Acid Concentration ◽  
Human Blood ◽  
Human Urine ◽  
Human Blood Plasma ◽  
Ascorbic Acid Concentration ◽  
Pyrogallol Red ◽  
Simultaneous Evaluation

scholarly journals Glucose Concentration Measurement in Human Blood Plasma Solutions with Microwave Sensors

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3779 ◽  
Author(s):  
Carlos G. Juan ◽  
Enrique Bronchalo ◽  
Benjamin Potelon ◽  
Cédric Quendo ◽  
José M. Sabater-Navarro
Keyword(s):  
Ascorbic Acid ◽  
Blood Plasma ◽  
Glucose Level ◽  
Human Blood ◽  
Human Blood Plasma ◽  
Dielectric Losses ◽  
Human Blood Sample ◽  
Glucose Concentration Measurement ◽  
Electromagnetic Signature ◽  
Microwave Sensors

Three microwave sensors are used to track the glucose level of different human blood plasma solutions. In this paper, the sensors are evaluated as glucose trackers in a context close to real human blood. Different plasma solutions sets were prepared from a human blood sample at several added glucose concentrations up to 10 wt%, adding also ascorbic acid and lactic acid at different concentrations. The experimental results for the different sensors/solutions combinations are presented in this work. The sensors show good performance and linearity as glucose level retrievers, although the sensitivities change as the rest of components vary. Different sensor behaviors depending upon the concentrations of glucose and other components are identified and characterized. The results obtained in terms of sensitivity are coherent with previous works, highlighting the contribution of glucose to the dielectric losses of the solution. The results are also consistent with the frequency evolution of the electromagnetic signature of glucose found in the literature, and are helpful for selecting frequency bands for sensing purposes and envisioning future approaches to the challenging measurement in real biological contexts. Discussion of the implications of the results and guidelines for further research and development of more accurate sensors is offered.

scholarly journals Gas phase oxidants of cigarette smoke induce lipid peroxidation and changes in lipoprotein properties in human blood plasma. Protective effects of ascorbic acid

1991 ◽  
Vol 277 (1) ◽  
pp. 133-138 ◽  
Author(s):  
B Frei ◽  
T M Forte ◽  
B N Ames ◽  
C E Cross
Keyword(s):  
Lipid Peroxidation ◽  
Ascorbic Acid ◽  
Blood Plasma ◽  
Gas Phase ◽  
Cigarette Smoke ◽  
Human Blood ◽  
Biological Fluids ◽  
Human Blood Plasma ◽  
Lipid Hydroperoxides ◽  
Protein Thiols

Cigarette smoke (CS) is known to contain a large number of oxidants. In order to assess the oxidative effects of CS on biological fluids, we exposed human blood plasma to filtered (gas phase) and unfiltered (whole) CS, and determined the rate of utilization of endogenous antioxidants in relation to the appearance of lipid hydroperoxides. Lipid peroxidation was measured with a specific and sensitive assay that can detect lipid hydroperoxides at plasma levels as low as 10 nM. We found that exposure of plasma to the gas phase of CS, but not to whole CS, induces lipid peroxidation once endogenous ascorbic acid has been oxidized completely. In addition, CS exposure caused oxidation of plasma protein thiols and albumin-bound bilirubin, whereas uric acid and alpha-tocopherol were not consumed at significant rates. In plasma exposed to the gas phase of CS, low-density lipoprotein exhibited slightly increased electrophoretic mobility, but there was no apparent degradation of apolipoprotein B. Our results support the concept of an increased vitamin C utilization in smokers, and suggest that lipid peroxidation induced by oxidants present in the gas phase of CS leads to potentially atherogenic changes in lipoproteins.

The Effect of Stress and Warfarin on the Adrenal Gland in Relation to Spontaneous Hemorrhage, as Judged by Measurement of Adrenal Ascorbic Acid and Serum Corticosterone

1971 ◽  
Vol 26 (02) ◽  
pp. 275-288 ◽  
Author(s):  
S Chattopadhyay ◽  
D. D Johnson ◽  
G. J Millar ◽  
L. B Jaques
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Ascorbic Acid Concentration ◽  
Corticosterone Concentration ◽  
Serum Corticosterone ◽  
Spontaneous Hemorrhage ◽  
Combined Action ◽  
Series Of Experiments ◽  
Pituitary Adrenal Axis

SummaryRats were subjected to the following procedures: No treatment, Stressor (10% NaCl i.p.), Warfarin for 7 days, Stressor followed by Warfarin; and groups were sacrificed at intervals for assessment of spontaneous hemorrhage and of adrenal ascorbic acid concentration. There was no hemorrhage in the no treatment and stressor groups; some hemorrhage in the warfarin group; profound hemorrhage with Warfarin + Stressor. The adrenal ascorbic acid concentration was found to be lower, 8 h and again 5 days after stress, and remained lower in the warfarin + stress animals. Warfarin had no effect on adrenal ascorbic acid level.In another series of experiments in which the stress consisted of an electric current to the cage floor for 6 sec over 15 min, rats were sacrificed daily for determination of serum corticosterone concentration and occurrence of spontaneous hemorrhage. There was a statistically significant increase of serum corticosterone concentration with stress, warfarin and combined warfarin and stress treatments (P< 0.001 for all three variables). There was a significant correlation (r = 0.96 and 0.89, P< 0.01) for serum corticosterone concentration with hemorrhage score and incidence of hemorrhage in stressed rats receiving warfarin, but not in those receiving only warfarin. The results indicate an activation, rather than an exhaustion, of the pituitary-adrenal axis during the combined action of anticoagulant and stress, which results in the development of spontaneous hemorrhage.

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