scholarly journals Collagen remodelling and plasma ascorbic acid levels in patients suspected of inherited bleeding disorders harbouring germline variants in collagen‐related genes

Haemophilia ◽  
2020 ◽  
Author(s):  
Marcus Fager Ferrari ◽  
Eva Zetterberg ◽  
Maria Rossing ◽  
Tina Manon‐Jensen ◽  
Martin Pehrsson ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Bleeding Disorders ◽  
Plasma Ascorbic Acid ◽  
Germline Variants ◽  
Collagen Remodelling

Stability of antioxidant vitamins in whole human blood during overnight storage at 4°C and frozen storage up to 6 months

2018 ◽  
Vol 88 (3-4) ◽  
pp. 151-157 ◽  
Author(s):  
Scott W. Leonard ◽  
Gerd Bobe ◽  
Maret G. Traber
Keyword(s):  
Ascorbic Acid ◽  
Whole Blood ◽  
Healthy Subjects ◽  
Frozen Storage ◽  
Blood Collection ◽  
Plasma Samples ◽  
Optimal Conditions ◽  
Plasma Ascorbic Acid ◽  
Blood Samples ◽  
Sample Handling

Abstract. To determine optimal conditions for blood collection during clinical trials, where sample handling logistics might preclude prompt separation of erythrocytes from plasma, healthy subjects (n=8, 6 M/2F) were recruited and non-fasting blood samples were collected into tubes containing different anticoagulants (ethylenediaminetetra-acetic acid (EDTA), Li-heparin or Na-heparin). We hypothesized that heparin, but not EDTA, would effectively protect plasma tocopherols, ascorbic acid, and vitamin E catabolites (α- and γ-CEHC) from oxidative damage. To test this hypothesis, one set of tubes was processed immediately and plasma samples were stored at −80°C, while the other set was stored at 4°C and processed the following morning (~30 hours) and analyzed, or the samples were analyzed after 6 months of storage. Plasma ascorbic acid, as measured using HPLC with electrochemical detection (LC-ECD) decreased by 75% with overnight storage using EDTA as an anticoagulant, but was unchanged when heparin was used. Neither time prior to processing, nor anticoagulant, had any significant effects upon plasma α- or γ-tocopherols or α- or γ-CEHC concentrations. α- and γ-tocopherol concentrations remained unchanged after 6 months of storage at −80°C, when measured using either LC-ECD or LC/mass spectrometry. Thus, refrigeration of whole blood at 4°C overnight does not change plasma α- or γ-tocopherol concentrations or their catabolites. Ascorbic acid is unstable in whole blood when EDTA is used as an anticoagulant, but when whole blood is collected with heparin, it can be stored overnight and subsequently processed.

Influence of Ascorbic Acid on the Structure and Function of Alpha-2- macroglobulin: Investigations using Spectroscopic and Thermodynamic Techniques

2020 ◽  
Vol 27 (3) ◽  
pp. 201-209
Author(s):  
Syed Saqib Ali ◽  
Mohammad Khalid Zia ◽  
Tooba Siddiqui ◽  
Haseeb Ahsan ◽  
Fahim Halim Khan
Keyword(s):  
Ascorbic Acid ◽  
Conformational Changes ◽  
Structural Changes ◽  
The Body ◽  
Titration Calorimetry ◽  
Spectroscopic Techniques ◽  
Human Beings ◽  
Plasma Ascorbic Acid ◽  
Dietary Antioxidant ◽  
And Function

Background: Ascorbic acid is a classic dietary antioxidant which plays an important role in the body of human beings. It is commonly found in various foods as well as taken as dietary supplement. Objective: The plasma ascorbic acid concentration may range from low, as in chronic or acute oxidative stress to high if delivered intravenously during cancer treatment. Sheep alpha-2- macroglobulin (α2M), a human α2M homologue is a large tetrameric glycoprotein of 630 kDa with antiproteinase activity, found in sheep’s blood. Methods: In the present study, the interaction of ascorbic acid with alpha-2-macroglobulin was explored in the presence of visible light by utilizing various spectroscopic techniques and isothermal titration calorimetry (ITC). Results: UV-vis and fluorescence spectroscopy suggests the formation of a complex between ascorbic acid and α2M apparent by increased absorbance and decreased fluorescence. Secondary structural changes in the α2M were investigated by CD and FT-IR spectroscopy. Our findings suggest the induction of subtle conformational changes in α2M induced by ascorbic acid. Thermodynamics signatures of ascorbic acid and α2M interaction indicate that the binding is an enthalpy-driven process. Conclusion: It is possible that ascorbic acid binds and compromises antiproteinase activity of α2M by inducing changes in the secondary structure of the protein.

Plasma ascorbic acid concentrations relate inversely to blood pressure in human subjects

1993 ◽  
Vol 57 (2) ◽  
pp. 213-217 ◽  
Author(s):  
J P Moran ◽  
L Cohen ◽  
J M Greene ◽  
G Xu ◽  
E B Feldman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Human Subjects ◽  
Plasma Ascorbic Acid

scholarly journals Reduced plasma ascorbic acid levels in recipients of myeloablative conditioning and hematopoietic cell transplantation

2019 ◽  
Vol 103 (4) ◽  
pp. 329-334 ◽  
Author(s):  
Mahmood Rasheed ◽  
Gary Simmons ◽  
Bernard Fisher ◽  
Kevin Leslie ◽  
Jason Reed ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Cell Transplantation ◽  
Hematopoietic Cell Transplantation ◽  
Hematopoietic Cell ◽  
Myeloablative Conditioning ◽  
Plasma Ascorbic Acid

Influence of Controlled Temperatures on Growth Rate and Plasma Ascorbic Acid Values in Swine

1967 ◽  
Vol 92 (1) ◽  
pp. 99-103 ◽  
Author(s):  
J. T. Riker ◽  
T. W. Perry ◽  
R. A. Pickett ◽  
C. J. Heidenreich
Keyword(s):  
Growth Rate ◽  
Ascorbic Acid ◽  
Plasma Ascorbic Acid

scholarly journals Plasma ascorbic acid and the risk of islet autoimmunity and type 1 diabetes: the TEDDY study

Diabetologia ◽  
2019 ◽  
Vol 63 (2) ◽  
pp. 278-286 ◽  
Author(s):  
Markus Mattila ◽  
◽  
Iris Erlund ◽  
Hye-Seung Lee ◽  
Sari Niinistö ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Type 1 Diabetes ◽  
Vitamin C ◽  
Data Availability ◽  
Islet Autoimmunity ◽  
Plasma Ascorbic Acid ◽  
Background Population ◽  
Increased Risk ◽  
Nested Case Control

Abstract Aims/hypothesis We studied the association of plasma ascorbic acid with the risk of developing islet autoimmunity and type 1 diabetes and examined whether SNPs in vitamin C transport genes modify these associations. Furthermore, we aimed to determine whether the SNPs themselves are associated with the risk of islet autoimmunity or type 1 diabetes. Methods We used a risk set sampled nested case–control design within an ongoing international multicentre observational study: The Environmental Determinants of Diabetes in the Young (TEDDY). The TEDDY study followed children with increased genetic risk from birth to endpoints of islet autoantibodies (350 cases, 974 controls) and type 1 diabetes (102 cases, 282 controls) in six clinical centres. Control participants were matched for family history of type 1 diabetes, clinical centre and sex. Plasma ascorbic acid concentration was measured at ages 6 and 12 months and then annually up to age 6 years. SNPs in vitamin C transport genes were genotyped using the ImmunoChip custom microarray. Comparisons were adjusted for HLA genotypes and for background population stratification. Results Childhood plasma ascorbic acid (mean ± SD 10.76 ± 3.54 mg/l in controls) was inversely associated with islet autoimmunity risk (adjusted OR 0.96 [95% CI 0.92, 0.99] per +1 mg/l), particularly islet autoimmunity, starting with insulin autoantibodies (OR 0.94 [95% CI 0.88, 0.99]), but not with type 1 diabetes risk (OR 0.93 [95% Cl 0.86, 1.02]). The SLC2A2 rs5400 SNP was associated with increased risk of type 1 diabetes (OR 1.77 [95% CI 1.12, 2.80]), independent of plasma ascorbic acid (OR 0.92 [95% CI 0.84, 1.00]). Conclusions/interpretation Higher plasma ascorbic acid levels may protect against islet autoimmunity in children genetically at risk for type 1 diabetes. Further studies are warranted to confirm these findings. Data availability The datasets generated and analysed during the current study will be made available in the NIDDK Central Repository at https://www.niddkrepository.org/studies/teddy.

Non-Urate Chromogens in Body Fluids

1969 ◽  
Vol 15 (8) ◽  
pp. 720-726 ◽  
Author(s):  
Wendell T Caraway
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Phosphotungstic Acid ◽  
Alkaline Treatment ◽  
Body Fluids ◽  
Plasma Ascorbic Acid ◽  
A Value ◽  
Fresh Plasma ◽  
Average Serum

Abstract Compounds which interfere in the analytic determination of uric acid are referred to as "non-urate chromogens." Ascorbic acid, when added to serum, causes a significant increase in apparent uric acid levels as determined by a carbonate-phosphotungstate method. The ratio of apparent urate to ascorbic acid is 1:3, a value in close agreement with that obtained for the ratio of labile non-urate chromogens to ascorbic acid in fresh plasma. Ascorbic acid, as well as most of the non-urate chromogens, can be eliminated by mild alkaline treatment prior to adding phosphotungstic acid. These results indicate that the major non-urate chromogen in the average serum is ascorbic acid. The nature of other non-urate chromogens in body fluids is reviewed.

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