Increased Oxidative Stress in the Proximal Stomach of Patients with Barrett's Esophagus and Adenocarcinoma of the Esophagus and Esophagogastric Junction

OBJECTIVES: Oxidative stress (OS) is an essential element in the pathogenesis of Barrett's esophagus (BE) and its transformation to adenocarcinoma (EAC). The state of OS in the proximal stomach of patients with BE and EAC is unknown. Isoprostanes are a specific marker of OS not previously used to determine OS from BE/EAC tissue samples. PATIENTS AND METHODS: OS was measured in 42 patients with BE (n = 9), EAC (n = 9), or both (n = 24) and 15 control patients. A STAT-8-Isoprostane EIA Kit served to identify 8-Isoprostanes (8-IP), and a Glutathione Assay Kit was used to measure glutathione reduced form(GSH) and glutathione oxidized form. An OxiSelect Oxidative DNA Damage ELISA Kit (8-OHdG) served to measure 8-OH-deoxyguanosine. RESULTS: The 8-IP (P = .039) and 8-OHdG (P = .008) levels were higher, and the GSH level lower (P = .031), in the proximal stomach of the study group than in that of the controls. Helicobacter pylori infection was present in 8% of the study patients. CONCLUSIONS: In the proximal stomach of BE and EAC patients, OS was elevated and antioxidative capacity was reduced. This finding suggests that the gastroesophageal reflux causing BE also induces oxidative stress in the proximal stomach and may contribute to the development of cancer in the proximal stomach and gastric cardia.Peer reviewe

The associations of oxidized lipoprotein lipids with lipoprotein subclass particle concentrations and their lipid compositions. The Cardiovascular Risk in Young Finns Study

ObjectiveOxidation of low-density lipoprotein (LDL) may promote atherosclerosis, whereas the reverse transport of oxidized lipids by high-density lipoprotein (HDL) may contribute to atheroprotection. To provide insights into the associations of lipoprotein lipid oxidation markers with lipoprotein subclasses at the population level, we investigated the associations of oxidized HDL lipids (oxHDLlipids) and oxidized LDL lipids (oxLDLlipids) with lipoprotein subclasses in a population-based cross-sectional study of 1395 Finnish adults ages 24–39 years.MethodsThe analysis of oxidized lipids was based on the determination of the baseline level of conjugated dienes in lipoprotein lipids. A high-throughput nuclear magnetic resonance (NMR) platform was used to quantify circulating lipoprotein subclass concentrations and analyze their lipid compositions.ResultsOxHDLlipids were mainly not associated with lipoprotein subclass lipid concentrations and lipid composition after adjustment for Apolipoprotein-A1 (Apo-A1), waist circumference and age. OxLDLlipids were associated with several markers of lipoprotein subclass lipid concentrations and composition after adjustment for Apolipoprotein-B (Apo-B), age and waist circumference. Several measures of HDL and LDL subclasses, including phospholipid and triglyceride composition, associated directly with oxLDLlipids. Cholesterol ester and free cholesterol composition in HDL and LDL associated inversely with oxLDLlipids.ConclusionWe conclude that these results do not support the idea that HDL's particle size or composition would reflect its functional capacity in the reverse transport of oxidized lipids. On the contrary, oxLDLlipids were associated with the entire lipoprotein subclass profile, including numerous associations with the compositional descriptors of the particles. This is in line with the suggested role of LDL oxidation in atherogenesis.</p

Oxidized lipoprotein lipids and atherosclerosis

<p>Plasma lipoproteins contain variable amounts of lipid oxidation products (LOP), which are known to impair normal physiological functions and stimulate atherosclerotic processes. Recent evidence indicates that plasma lipoproteins are active carriers of LOP, low-density lipoprotein (LDL) directing transport toward peripheral tissues, and high-density lipoprotein (HDL) being active in the reverse transport. It has been proposed that the lipoprotein-specific transport of LOP could play a role in atherosclerosis-related effects of LDL and HDL. This article gives an overview of the present knowledge of lipoprotein LOP transport and its association with the risk of atherosclerosis and cardiovascular diseases (CVD). Evidence of the significance of lipoprotein LOP transport comes mainly from studies of physiological oxidative stress and is supported by studies of the functionality apolipoprotein A-1 mimetic peptides. A large body of data has accumulated indicating that lipoprotein LOP transport is connected to the risk of atherosclerosis. While high levels of LOP carried by LDL are indicative of elevated risk, high LOP level in HDL appears to associate with protection. If confirmed, the proposed lipoprotein LOP transport function would affect conception of the etiology of atherosclerosis, but would not conflict current views of the pathophysiological mechanisms. It could open new perspectives, such as the dietary origin of LOP, and the protective function of HDL in clearance of LOP. Focusing on LOP could give additional tools especially for prevention and diagnosis, but would not radically change the management of atherosclerosis and CVD.</p

Maidon bioaktiiviset tekijät ja niiden hyödyntäminen elintarvikkeissa ja erityisvalmisteissa Osaprojekti: Maidon antioksidanttitekijöiden karakterisointi, eristäminen ja hyväksikäyttö

vEK

Antioxidant capacity of bovine milk

vokETL22ET

Antioxidant properties of cow's milk

vokET

Characterization of antioxidant activity in milk proteins

vokET