Search results for "oxidation"
showing 10 items of 1913 documents
Impairment of antioxidant enzymes, lipid peroxidation and 8-oxo-2'-deoxyguanosine in advanced epithelial ovarian carcinoma of a Spanish community.
2006
In the present study, we describe the changes of antioxidant enzyme activities and other oxidative stress-related parameters in a mediterranean cohort of women affected with epithelial ovarian carcinoma (EOC). For that purpose, the most representative enzymatic activities, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the oxidized/reduced glutathione (GSSG/GSH) ratio have been analyzed in tumor tissue biopsies and compared with the normal tissue of the same patient. As oxidation products, the levels of malondialdehyde (MDA) as an indication of lipid peroxidation, and the DNA damaged base 8-oxo-2'-deoxyguanosine (8-oxo-dG) have been also measured. Ad…
Effect of gut-derived acetate on glucose turnover in man
1988
1. The effect of acetate absorbed from the gut on glucose turnover has been determined in four healthy subjects during both fasting and an intravenous glucose infusion by using [U-13C]glucose. 2. In the first part of the study, after an overnight fast, a tracer dose of [U-13C]glucose was infused at a constant rate along with an infusion of saline for 7 h. In the second part the saline infusion was replaced by glucose at 4.25 mg min−1 kg−1. In both studies 15 mmol of sodium acetate was given by mouth at 15 min intervals from the fourth to the sixth hour. Glucose turnover, respiratory quotient, metabolic rate and blood levels of acetate, 3-hydroxybutyrate, lactate, insulin, glucagon and gastr…
Potential effects of age-associated oxidative stress on mammalian oocytes/embryos
1996
This bioessay aims to explain the different effects of maternal ageing and postovulatory oocyte ageing on mammalian oocytes/embryos under the scope of 'the oxygen radical-mitochondrial injury hypothesis of ageing'. This hypothesis assumes a key role in the senescent process of oxygen radical damage to mitochondrial DNA, proteins and lipids. It is proposed that a decrease in intracellular ATP concentrations and glutathione (GSH)/glutathione disulphide (GSSG) ratio together with a concomitant increase in cytosolic Ca2+ are major factors causing the observed detrimental effects of ageing on cytoskeletal fibres, fertilization and embryo development.
Genetic alterations and oxidative metabolism in sporadic colorectal tumors from a Spanish community
1997
Deletions of loci on chromosomes 5q, 17p, 18q, and 22q, together with the incidence of p53 mutations and amplification of the double minute-2 gene were investigated in the sporadic colorectal tumors of 44 patients from a Spanish community. Chromosome deletions were analyzed by means of loss of heterozygosity analysis using a restriction fragment length polymorphism assay. Allelic losses were also detected by polymerase chain reaction (PCR)-single-stranded conformation polymorphism (SSCP) analysis of a polymorphic site in intron 2 of the p53 gene. The percentages of genetic deletions on the screened chromosomes were 39.3% (5q), 58.3% (17p), 40.9% (18q), and 40% (22q). Mutations in p53 exons …
Differences in the behavior of advanced glycation end products and advanced oxidation protein products in patients with allergic rhinitis
2013
BACKGROUND: The presence of oxidative stress in patients with asthma is well documented; however, the role of oxidative stress in allergic rhinitis has received less attention, although it is likely to be similar to that observed in patients with asthma. Advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs) are compounds formed by the transformation of macromolecules, including proteins, which can serve as densitometric markers of oxidative stress and inflammation in several diseases. OBJECTIVE: The aim of this study was to investigate the role of AGEs and AOPPs as new markers of oxidative stress and inflammation in patients affected by allergic rhinitis. ME…
Lipid peroxidation products and antioxidants in human disease.
1998
Lipid peroxidation (LPO) is a free radical-related process that in biologic systems may occur under enzymatic control, e.g., for the generation of lipid-derived inflammatory mediators, or nonenzymatically. This latter form is associated mostly with cellular damage as a result of oxidative stress, which also involves cellular antioxidants in this process. This article focuses on the relevance of two LPO products, malondialdehyde (MDA) and 4-hydroxynonenal (HNE), to the pathophysiology of human disease. The former has been studied in human serum samples of hepatitis C virus-infected adults and human immunodeficiency virus-infected children. In these two cases it is shown that the specific ass…
Sprint and endurance training in relation to redox balance, inflammatory status and biomarkers of aging in master athletes
2019
Purpose: Studies have shown a positive influence of intense athletic training on several biomarkers of aging, but it remains unclear whether this influence is dependent of exercise-training-mode. This study compared redox balance, cytokine levels and biomarkers of aging between master sprinters and endurance athletes, as well as in young and middle-aged individuals as controls. Methods: Participants were male master sprinters (SA, 50±8.9yrs; n=13) and endurance runners (EA, 53±8.2yrs; n=18) with remarkable athletic experience (∼25yrs of practice), besides untrained young (YC, 22.7±3.9yrs; n=17) and age-matched controls (MC, 45.5±9.8yrs; n=12). Anamnesis, anthropometrics, biomarkers of aging…
Active paraplegics are protected against exercise-induced oxidative damage through the induction of antioxidant enzymes
2016
Exercise improves functional capacity in spinal cord injury (SCI). However, exhaustive exercise, especially when sporadic, is linked to the production of reactive oxygen species that may have a detrimental effect on SCI. We aimed to study the effect of a single bout of exhaustive exercise on systemic oxidative stress parameters and on the expression of antioxidant enzymes in individuals with paraplegia. The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia. Sixteen paraplegic subjects were submitted to a graded exercise test (GET) until volitional exhaustion. They were divided into active or non-active group…
Stimulatory TSH-Receptor Antibodies and Oxidative Stress in Graves Disease
2018
CONTEXT: We hypothesized that TSH-receptor (TSHR) stimulating antibodies (TSAbs) are involved in oxidative stress mechanisms in patients with Graves disease (GD). METHODS: Nicotinamide adenine dinucleotide phosphate oxidase, isoform 2 (NOX2); oxidative parameters; and oxidative burst were measured in serum, urine, and whole blood from patients with GD and control subjects. Superoxide production was investigated in human embryonic kidney (HEK)-293 cells stably overexpressing the TSHR. Lipid peroxidation was determined by immunodot-blot analysis for protein-bound 4-hydroxy-2-nonenal (4-HNE) in human primary thyrocytes and HEK-293–TSHR cells. RESULTS: Serum NOX2 levels were markedly higher in …
Internal exposure of the general population to DEHP and other phthalates--determination of secondary and primary phthalate monoester metabolites in u…
2003
A number of phthalates and their metabolites are suspected of having teratogenic and endocrine disrupting effects. Especially the developmental and reproductive effects of di(2-ethylhexyl)phthalate (DEHP) are under scrutiny. In this study we determined the concentrations of the secondary, chain oxidized monoester metabolites of DEHP, mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP) and mono(2-ethyl-5-oxo-hexyl)phthalate (5oxo-MEHP) in urine samples from the general population. The utilization of the secondary metabolites minimized any risk of contamination by the ubiquitously present phthalate parent compounds. Included in the method were also the simple monoester metabolites of DEHP, dioct…