Search results for "Vitamin"
showing 10 items of 931 documents
Metabolic Clearance of the Antioxidant Ascorbic Acid in Surgical Patients1
2005
Background A reduction of plasma ascorbic acid concentration in the post-operative period has been well documented and is associated with an increase in post-operative complications. The underlying reason for the decreased concentration of ascorbic acid in the plasma is not clear. However, only an increased post-operative requirement for ascorbic acid would justify a substitution. Therefore, we investigated the pre-operative and post-operative metabolic clearance of ascorbic acid. Materials and Methods We calculated the metabolic clearance subsequent to intravenous bolus injection of 6 mg ascorbic acid/kg body weight in 15 patients before and after they underwent major maxillofacial surgery…
Oxidative stress and antioxidant status in beta-thalassemia major: iron overload and depletion of lipid-soluble antioxidants
1996
Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of h…
Vitamin A Inhibits Doxorubicin-Induced Membrane Lipid Peroxidation in Rat Tissues in Vivo
1993
The antioxidant activity of vitamin A against lipid peroxidation induced by doxorubicin in rat tissues in vivo was investigated. A single ip injection of doxorubicin (30 mg/kg body wt) markedly raised the level of peroxidated lipids measured as TBARS and conjugated dienes in heart and brain membrane preparations. Other tissues, such as retina and liver, did not show any increase of lipid peroxides over control values. Pretreatment of rats with two daily subcutaneous injections of retinol palmitate (0.25 g/kg body wt), for 2 days, before injecting doxorubicin, inhibited peroxidation of heart and brain membrane lipids. The antioxidant action of vitamin A does not appear to be mediated by enha…
Oxidative markers in children with severe obesity following low-calorie diets supplemented with mandarin juice
2010
Aim: To evaluate the effect of supplementing a hypocaloric diet with mandarin juice, a food with a high content of antioxidants (vitamin C, flavonoids and carotenoids), on biomarkers of oxidant/antioxidant status of severe obese children. Methods: Forty obese children were randomized into two groups pair-wise in a 4-week controlled intervention study. Both groups followed a hypocaloric diet. One group received additionally a supplementation of 500 mL of 100% mandarin juice daily. Clinical data, anthropometry, dietary intake and fasting blood samples were collected at baseline and after the intervention. Lipid peroxidation was assessed by circulating levels of malondialdehyde, and protein …
α-Tocopherol Modulates Phosphatidylserine Externalization in Erythrocytes
2006
Objective— The aim of the present study was to assess the effect of α-tocopherol, the main vitamin E isomer on phosphatidylserine (PS) exposure at the surface of circulating erythrocytes, and to determine consequences on erythrocyte properties. Methods and Results— In vitro α-tocopherol enrichment of isolated erythrocytes significantly decreased PS externalization as assessed by lower Annexin V-fluorescein isothiocyanate labeling. Plasma phospholipid transfer protein (PLTP) transfers vitamin E, and both α-and γ-tocopherol accumulated in circulating erythrocytes from PLTP-deficient homozygous (PLTP −/− ) mice as compared with wild-type mice. In agreement with in vitro studies, vitamin E–enr…
Folate deficiencies and cardiovascular pathologies.
1998
Abstract Although folates are widely distributed in foods, folate deficiencies may be more frequent than expected because their true availability may be impaired due to their lability under various food cooking and processing conditions. Folate deficiency is frequently observed in elderly people, smokers, alcoholics and oral contraceptive users. It is also associated with the mutation leading to the thermolabile variant of N5, 10-methylenetetrahydrofolate reductase which is observed in about 10 % of the population. In addition to the essential role of the intracellular pool of polyglutamates in de novo biosynthesis of deoxyribonucleotides which allow cell growth and division, the reduced an…
J15 Validation Of 24 H Dietary Recalls To Assess Dietary Intake For Patients With Huntington's Disease. Spanish Multicenter Study Of The European Gro…
2014
Background Weighed dietary records are considered as the gold standard in nutrition assessment, but 24 h dietary recalls (24-h) and 3 days dietary record (3-d) are usually used. The 24-h is less laborious and cheaper but is necessary to have an experienced interviewer; while the 3-d are completed by the same participant/caregiver, it is more reliable but more expensive, time consuming is high, require previous training and have more dropouts. Our aim was to compare the two procedures to assess dietary intake in HD. Objectives To validate a 24-h vs 3-d to assess dietary intake for patients with HD. Methods Spanish multicenter, longitudinal study (EHDN). A 24-h was administered (with a one-mo…
Optimal diet composition for European whitefish (Coregonus lavaretus): carbohydrate stress and immune parameter responses
2003
Abstract A feeding trial was conducted on the European whitefish to study the effects of replacing fish meal with fish oil and corn starch on the stress response and immune system parameters. Nine diets with varying levels of fish meal (FM; 38–86%), fish oil (FO; 2–22%) and corn starch (CS; 0–33%), and fixed levels of wheat meal (10%) and vitamin–mineral premix (2%) were formulated and replicates were allocated among 25 tanks following the D-optimality criteria. Fish were fed the extruded diets to satiation for 10 weeks in a flow-through freshwater system at 15 °C. The liver and plasma were sampled at the termination of the trial, and the response surfaces were modeled as Scheffe polynomial…
Vitamin A deficiency. New knowledge on diagnosis, consequences and therapy
1989
Due to the rapid development of biochemical analyses in the last 10 years different substances like vitamin A, with an apparent clarified metabolism and action, were re-estimated. As a result, new knowledge was presented which could be essential for human health. Some details and consequences are reviewed in this paper. Marginal deficiency, which also may occur in industrialized nations, cannot be determined with certainty by usual blood analyses. The reasons for marginal deficiency are either different diseases or unbalanced nutrition. From epidemiological research it is argued that low vitamin A intake is associated with a higher incidence of cancer in different tissues. However, vitamin …
Intraoperative alteration of the total clearance of ascorbic acid in plasma
2003
Ascorbic acid (AA) is an important antioxidant in the plasma and has the tendency to postoperatively reduced values. This could be caused by an increased antioxidative activity of AA as a radical scavenger since operations are a well-known scenario of oxidative stress with increased radical production. There is some evidence for an intraoperative onset of oxidative stress which could be related to an increased antioxidative activity of AA. Therefore, the total clearance (Cltot) of AA was calculated pre- and intraoperatively in 20 neurosurgical patients. At both times plasma samples were taken before, and 15, 30, 60 and 120 minutes after an iv. AA-bolus of 4 mg/kg AA/body weight. Cltot of AA…