The relationship of oxidized lipids to coronary artery stenosis

Association of dyslipidemia with chronic non-malignant pain in elderly patients with femoral neck fractures treated by primary total hip arthroplasty: a retrospective study

OBJECTIVE

The association of chronic non-malignant pain (CNP) with dyslipidemia is unclear. This retrospective study was performed to evaluate the association between CNP and dyslipidemia in elderly patients with femoral neck fractures (FNFs) treated by primary unilateral total hip arthroplasty (THA).

METHODS

We retrospectively identified 521 consecutive patients with FNFs (AO/OTA type 31B) who underwent primary unilateral THA from 2009 to 2021. The study population was divided into patients with and without CNP. Serum lipids were measured for each patient. The association between CNP and dyslipidemia was assessed using a multivariate binary logistic regression model.

RESULTS

In total, 436 patients (220 with CNP, 216 without CNP) were eligible for analysis. In the quantile regression, the adverse effect of CNP was significantly attenuated by resilience in patients with a high high-density lipoprotein (HDL) concentration and low low-density lipoprotein (LDL) concentration. The multivariate binary logistic regression model showed that the HDL and LDL concentrations were the only variables significantly associated with the development of CNP.

CONCLUSION

Both a low HDL and high LDL concentration may result in the occurrence of CNP in elderly patients with FNFs treated by primary unilateral THA.

High Cholesterol Diet-Induced Changes in Oxysterol and Scavenger Receptor Levels in Heart Tissue

Involvement of high cholesterol and oxidative stress in cardiovascular diseases is well studied, as it can be hypothesized that various products originated from lipid peroxidation, such as oxysterols, or affected protein expression might lead to cardiomyocyte damage followed by the pathological modifications. Although oxidation of excessive cholesterol to oxysterols in elevated stress conditions is identified by a number of studies, the role of a high cholesterol diet in regulating fatty acid and oxysterol accumulation, together with scavenger receptor mRNA levels, in the heart remains little investigated. Our study provides a detailed analysis of the changes in fatty acid, oxysterol, and scavenger receptor profiles and its relation with histological alterations in the heart tissue. We evaluated alterations of fatty acid composition, by the GC-MS method, while 4β-, 25-, and 27-hydroxycholesterol and 7-ketocholesterol levels by means of LC-MS/MS in high cholesterol diet-fed rabbits. Additionally, a number of proteins related to lipid metabolism and scavenger receptor mRNA expressions were evaluated by Western blotting and RT-PCR. According to our in vivo results, a high cholesterol diet enhances a number of unsaturated fatty acids, oxysterols, and LXRα, in addition to CD36, CD68, CD204, and SR-F1 expressions while α-tocopherol supplementation decreases LXRα and SR expressions together with an increase in 27-hydroxycholesterol and ABCA1 levels. Our results indicated that the high cholesterol diet modulates proteins related to lipid metabolism, which might result in the malfunction of the heart and α-tocopherol shows its beneficial effects. We believe that this work will lead the generation of different theories in the development of heart diseases.

Uric Acid and Coronary Artery Disease, Two Sides of a Single Coin: A Determinant of Antioxidant System or a Factor in Metabolic Syndrome

INTRODUCTION

Uric acid has antioxidant activity and it is expected to protect against coronary artery disease (CAD). Contradictory, it is a component of metabolic syndrome and so a risk factor for CAD. The associations of plasma total antioxidant capacity (TAOC) and uric acid (UA) as well as other risk factors were investigated relative to the occurrence and severity of CAD.

MATERIALS AND METHODS

The study population consisted of 148 males and 152 females aged 35-76 years who were classified as CAD cases and controls according to the results of coronary angiography. The severity of CAD was scored on the basis of the number and the extent of lesions at coronary arteries. The concentrations of UA and TAOC were measured by using of FRAP and enzymatic uricase methods.

RESULTS

The prevalence of hypertension, cigarette smoking and diabetes mellitus was more frequent in CAD cases than controls. Patients with CAD when compared with the controls had increased levels of glucose, triglycerides, creatinine, UA, TAOC and decreased levels of HDL- cholesterol. Serum UA was high positive correlate of serum total and LDL-cholesterol, triglyceride, creatinine, BUN, bilirubin, TAOC and negative correlate of glucose and HDL-C. TAOC and its major determinant UA but not bilirubin and albumin are significantly associated with the prevalence and severity of CAD. In multivariate analysis and in the absence of hypertension, UA but not TAOC would remain and be associated with CAD by the OR of 1.57 (1.07-2.29), p=0.02. If the results adjusted for all major risk factors including hypertension, neither TAOC nor UA would remain in the regression equation.

CONCLUSION

The results suggest that TAOC and UA but not bilirubin and albumin are associated with CAD significantly. But, the correlation is not independent and is attributed to the metabolic syndrome. The measurement of UA and TAOC will not improve the prognostic power beyond the classical risk factors.

Tocopherols in the Prevention and Treatment of Atherosclerosis and Related Cardiovascular Disease

Oxidants/antioxidants play an important role in cellular homeostasis. The human body has endogenous molecules that work as antioxidants, such as glutathione, superoxide dismutase, peroxidases, and catalase. Exogenous substances in the diet, such as β-carotene, ascorbate, and vitamin E, are vital antioxidants. Of these, vitamin E is likely the most important antioxidant in the human diet, and many studies have been performed to elucidate its role in health and disease. Vitamin E is a family of several compounds, of which α-tocopherol is the most widely known analog. α-Tocopherol exhibits antioxidative property in vitro and inhibits oxidation of low-density lipoprotein cholesterol. In addition, α-tocopherol shows anti-inflammatory activity and modulates expression of proteins involved in the uptake, transport, and degradation of atherogenic lipids. Though α-tocopherol exhibits important antioxidant, anti-inflammatory, and antiatherogenic features in vitro, α-tocopherol supplements have failed to consistently reduce atherosclerosis-related events in human trials. The conflicting results have led to reconsideration of the importance previously given to α-tocopherol and led to interest in other members of vitamin E family, especially γ-tocopherol, which exerts a much more potent antioxidant, anti-inflammatory, and cardioprotective effect than α-tocopherol. This reconsideration has been backed by solid laboratory and clinical research. We suggest that the absence of γ-tocopherol in traditional preparations may be one reason for the lack of consistent salutary effects of vitamin E preparations in clinical trials. This review summarizes our current understanding of tocopherols as antioxidant molecules and emerging evidence of an important role of γ-tocopherol in the pathophysiology of atherosclerosis-related cardiovascular disease.

The Pivotal Role of a Novel Biomarker of Reactive Oxygen Species in Chronic Kidney Disease

Risk stratification of chronic kidney disease (CKD) is clinically important because such patients are at high risk of cardiovascular events. Although reactive oxygen species (ROS) are reported to be closely associated with the pathophysiology of CKD, there are few useful ROS biomarkers known for CKD patients. Hence, our objectives in this study were to investigate whether serum derivatives of reactive oxygen metabolites (DROM), a novel biomarker of ROS, is involved in the pathophysiology of CKD (case-control study), and is a significant predictor of future cardiovascular events in CKD patients (follow-up study).Patients with suspected coronary artery disease (CAD) were enrolled and underwent coronary angiography. Patients with CKD (estimated glomerular filtration ratio <60  mL/min/1.73 m(2)  and/or proteinuria, n = 324) were compared with those without CKD (non-CKD). Serum DROM was measured at stable conditions. A case-control study of the 324 CKD patients and 263 non-CKD patients was conducted after matching risk factors, and a follow-up study of the 324 CKD patients was performed. CKD patients were divided into low- and high-DROM groups using their median value (348 unit; called the Carratelli unit [U.CARR]), and followed until the occurrence of cardiovascular events.DROM levels were significantly higher in risk factors-matched CKD patients than in risk factors-matched non-CKD patients (347.0 [301.8-391.8] U.CARR vs. 338.5 [299.8-384.3] U.CARR, P = 0.03). During mean 23 ± 14 months follow-up of 324 CKD patients, 83 cardiovascular events were recorded. Kaplan-Meier analysis demonstrated a higher probability of cardiovascular events in CKD patients with high DROM than in those with low DROM (P < 0.001, log-rank test). Multivariate Cox hazard analysis including significant predictors in simple Cox hazard analysis demonstrated that high DROM was a significant and independent predictor of cardiovascular events in CKD patients (hazard ratio: 1.76, 95% confidence interval: 1.10-2.82, P = 0.02).In conclusion, serum DROM values were significant and independent predictors of cardiovascular events in CKD patients, indicating that the measurements of DROM might provide clinical benefits for risk stratification of CKD patients.

Reactive oxygen metabolites are closely associated with the diagnosis and prognosis of coronary artery disease

Background

Reactive oxygen species (ROS) are associated with development of coronary artery disease (CAD). However, there's no useful biomarker of ROS in CAD.

Methods and Results

We recruited 395 consecutive CAD patients who were performed coronary angiography (262 male and 133 female, age 70.2±10), and we measured serum derivatives of reactive oxidative metabolites (DROM) were measured. Two hundred twenty‐seven non‐CAD patients were also enrolled. We performed follow‐up study in these 395 CAD patients and case‐control study after risk factor and 1:1 pair matching (both, n=163). As subgroup analysis, DROM were also measured at the aortic root and the coronary sinus in 59 CAD patients. DROM were significantly higher in CAD patients (n=163, median [inter‐quartile range, IQR]=338 [302 to 386]) than in risk factor‐matched non‐CAD patients (n=163, 311 [282 to 352.5], effect size=0.33, P<0.001). During a mean follow‐up period of 20 months of 395 CAD patients, 83 cardiovascular events were recorded. Kaplan‐Meier analysis showed a higher probability of cardiovascular events in the high‐DROM group (>346 U.CARR) than in the low‐DROM group (≤346 U.CARR) (P=0.001 [log‐rank test]). Multivariate Cox hazard analysis identified ln‐DROM as an independent predictor for cardiovascular events (hazard ratio: 10.8, 95% confidence interval: 2.76 to 42.4, P=0.001). The transcardiac gradient of DROM was significantly higher in CAD patients than in non‐CAD patients (−2.0 [−9.0 to 9.0] versus 8 [−8.0 to 28.3], effect size=0.21, P=0.04), indicating that DROM production in coronary circulation is associated with development of CAD.

Conclusion

DROM are increased in CAD patients and associated with future cardiovascular events. DROM might provide clinical benefits for risk stratification of CAD.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000012990.

Antioxidants and cardiovascular disease: Still a topic of interest

Cardiovascular disease constitutes a major public health concern in industrialised nations. Over recent decades, a large body of evidence has accumulated indicating that free radicals play a critical role in cellular processes implicated in atherosclerosis. Herein, we present a mechanism of oxidative stress, focusing mainly on the development of an oxidised low density lipoprotein, and the results of a clinical trial of antioxidant therapy and epidemiological studies on the relationships between nutrient antioxidants, such as vitamin E, vitamin C, β-carotene, coenzyme Q, flavonoids and L-arginine, and coronary events. These studies indicated that a diet high in antioxidants is associated with a reduced risk of cardiovascular disease, but did not confirm a strong causality link. With regard to vitamin E, observational studies suggested that the daily use of at least 400 International Units of vitamin E is associated with beneficial effects on coronary events. However, it is apparently too early to define the clinical benefits of vitamin E for cardiovascular disease. From the results of several randomised interventional trials, it appears that no single antioxidant given to subjects at high doses has substantial benefits, and the question of whether nutrient antioxidants truly protect against cardiovascular disease remains open. This article provides an overview of the epidemiological and clinical studies related to antioxidants and cardiovascular disease.

Prenatal exposure to cigarette smoke induces diet- and sex-dependent dyslipidemia and weight gain in adult murine offspring

BACKGROUND

Cardiovascular disease (CVD) affects 71 million American adults and remains the leading cause of death in the United States and Europe. Despite studies that suggest that the development of CVD may be linked to intrauterine growth or early events in childhood, little direct experimental evidence supports the notion.

OBJECTIVE

We investigated whether exposure to cigarette smoke in utero alters the risk of developing CVD later in life.

METHODS

We exposed B(6)C(3)F(1) mice (via whole-body inhalation) to either filtered air or mainstream cigarette smoke (MCS, at a particle concentration of 15 mg/m(3)) from gestational day 4 to parturition. Adult offspring were fed a normal chow diet or switched to a high-fat diet 2 weeks before sacrifice. We measured dam and offspring body weight, plasma lipid parameters, lipoprotein subclass particle numbers and sizes, and total antioxidant capacities.

RESULTS

Adult female mice prenatally exposed to MCS demonstrated significantly higher body weight and levels of plasma high-density lipoprotein (HDL) and low-density lipoprotein than did their air-exposed counterparts. When fed a high-fat diet for 2 weeks, males, but not females, exposed prenatally to MCS gained substantially more weight and exhibited dramatic alterations in total cholesterol and HDL levels compared with their air-exposed counterparts.

CONCLUSIONS

These data provide, for the first time, direct experimental evidence supporting the notion that prenatal exposure to cigarette smoke affects offspring weight gain and induces a lipid profile that could alter the offspring's risk of developing CVD later in life.

The negative effects of hydrogenated trans fats and what to do about them

Partially hydrogenated vegetable oils have been in the American diet since 1900. More than 50 years ago they were found to contain trans fatty acids that were different from natural fatty acids in plant oils and in animal fat. There was growing evidence that the consumption of trans fats have negative health effects, including increasing plasma lipid levels. In 2003, the Food and Drug Administration (FDA) ruled that the amount of trans fat in a food item must be stated on the label after January 1, 2006; food items could be labeled 0% trans if they contain less than 0.5g/serving. Since the initial ruling, it is now known that the fatty acids in partially hydrogenated vegetable oil are 14 cis and trans isomers of octadecenoic and octadecadienoic acids that are formed during hydrogenation. They cause inflammation and calcification of arterial cells: known risk factors for coronary heart disease (CHD). They inhibit cyclooxygenase, an enzyme required for the conversion of arachidonic acid to prostacyclin, necessary for the regulation of blood flow. There have been several reformulations of hydrogenated fat containing varying amounts of trans fatty acids and linoleic acid, an essential fatty acid that is converted to arachidonic acid. Epidemiological data suggest that when trans fat percentages go up and linoleic acid percentages go down, death rates rise; when trans goes down, death rates go down. In spite of the harmful effects of trans fats, the FDA allows it in the food supply as long as the amount in a food item is declared on the label. Trans fat should be banned from the food supply.

Circulating lipid hydroperoxides predict cardiovascular events in patients with stable coronary artery disease: the PREVENT study

OBJECTIVES

This study was designed to determine the predictive value of lipid hydroperoxide (LOOH) levels for adverse cardiovascular outcomes in patients with stable coronary artery disease (CAD).

BACKGROUND

Oxidative modification of circulating lipids contributes to inflammation and endothelial dysfunction, which are hallmark features of atherosclerosis. A serum biomarker of oxidation is LOOH, which is a primary product of fatty acid peroxidation.

METHODS

Serum LOOH levels were measured and correlated with clinical events over a 3-year period in 634 patients with angiographic evidence of CAD.

RESULTS

Baseline LOOH levels in the highest quartile were associated with hazard ratios of 3.24 (95% confidence interval [CI] 1.86 to 5.65; p = 0.0001) for nonfatal vascular events (n = 149), 1.80 (95% CI 1.13 to 2.88; p = 0.014) for major vascular procedures (n = 139), and 2.23 (95% CI 1.44 to 3.44; p = 0.0003) for all vascular events and procedures. Baseline LOOH levels correlated with serum levels of soluble intercellular adhesion molecule-1 (p = 0.001) and thiobarbituric acid reactive substances (p = 0.001) as well as the mean percent change in stenosis for large segments >50% stenosed (p = 0.048). A multivariate proportional hazards model, adjusted for traditional risk factors and inflammatory markers, showed an independent effect of LOOH on nonfatal vascular events, vascular procedures, and all events or procedures. Amlodipine treatment was associated with reduced cardiovascular events and changes in LOOH levels compared with placebo.

CONCLUSIONS

Elevated LOOH levels were predictive of nonfatal vascular events and procedures in patients with stable CAD, independent of traditional risk factors and inflammatory markers.

Identification of mildly oxidized low-density lipoprotein (electronegative LDL) and its auto-antibodies IgG in children and adolescents hypercholesterolemic offsprings

BACKGROUND

Oxidative modification of low-density lipoproteins (LDL) is an essential step in atherogenesis, generating minimally oxidized LDL, also called electronegative LDL [LDL(-)], which has chemotactic, cytotoxic and immunogenic properties.

METHODS AND RESULTS

Serum LDL(-) and anti-LDL(-) auto-antibodies (IgG) were evaluated in 28 children and adolescents with familial hypercholesterolemia (FH) antecedents, with or without early coronary artery disease in first-degree relatives (eCAD), hypercholesterolemic (hc) or normocholesterolemic (nc) versus a control group of normocholesterolemic children without pathologic antecedents (C). ELISA method was used for detection of LDL(-) and anti-LDL(-) IgG. LDL(-) serum levels did not differ among the four groups (FH-eCAD-hc 41.4 +/- 24.9 microg/dl; FH-hc 38.3 +/- 11.2 microg/dl; FH-nc 47.3 +/- 17.0 microg/dl and C 44.2 +/- 28.8 microg/dl, p = 0.659). However, IgG anti-LDL(-) auto-antibodies were significantly higher in the control group in comparison to the FH groups with or without eCAD, independent of hypercholesterolemia or normocholesterolemia (FH-eCAD-hc 0.825 +/- 0.289 microg/dl; FH-hc 0.667 +/- 0.307 microg/dl; FH-nc 0.763 +/- 0.204 microg/dl and C 1.105 +/- 0.233 microg/dl, p = 0.006). When the auto-antibodies of groups with FH, with or without eCAD and with or without hypercholesterolemia were compared, no differences were found (p = 0.509).

CONCLUSION

These results showed that FH and/or eCAD children and adolescents have lower titers of auto-antibodies anti-LDL(-) than children from normal families, independent of serum LDL-cholesterol or serum LDL(-).

27-Hydroxycholesterol causes remodeling in endothelial cell membrane lipid composition comparable to remodeling in the failed vein grafts of CABG patients

Our objective is to determine if vascular remodeling in CABG patients is related to oxysterols, therefore, we compared failed vein grafts from 18 patients, available after a second coronary artery bypass grafting (CABG), with human endothelial cells (ECs). The ECs were cultured in minimum essential medium (MEM) with or without 27-hydroxycholesterol (27OHC), one of the oxysterol products of oxidatively modified low density lipoproteins (ox-LDL), as an agent to alter molecular mechanisms in vascular cells. Significant changes in phospholipid composition, in fatty acid profile and in calcium concentration were found in the failed vein compared to the native saphenous vein from the same (CABG) patient. The failed vein contained significantly less phosphatidylethanolamine, more sphingomyelin, less arachidonic acid, more linoleic acid and more calcium than the native saphenous vein. Comparable changes in phospholipid composition, in fatty acid profile and increased calcium influx were reproduced in ECs cultured in medium containing 27OHC indicating that an oxysterol is an agent that can alter the lipid composition of vascular cell membranes. Our study indicates that a lipid agent, as well as protein agents that have previously been linked to the process of vascular remodeling, may be fundamental to many vascular diseases.

Effects of Fluvastatin in Type 2 Diabetic Patients with Hyperlipidemia: Reduction in Cholesterol Oxidation Products and VCAM-1

The purpose of this study was to investigate the lipid-lowering and anti-oxidative effects of fluvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, in type 2 diabetic patients. Six patients (3 men and 3 women, mean age = 56.2) took 20 mg of fluvastatin once daily (at night) for 12 weeks. Several markers of oxidative stress were then measured in these patients including plasma cholesterol oxidation products, i.e. oxysterols, and the levels of circulating adhesion molecules. Plasma total cholesterol levels were reduced by 12.3% in these individuals after 4 weeks of treatment, with levels remaining below 220 mg/dl for the entire treatment period. LDL levels were significantly reduced at 4 (18.1%) and 12 weeks (16.1%), and triglyceride levels were significantly reduced after 8 (22.5%) and 12 (37.7%) weeks of treatment. HDL-C levels increased from 50.7 +/- 15.4 prior to treatment to 63.8 +/- 24.3 mg/dl after 12 weeks of treatment, though this increase was not statistically significant. Lipid hydroperoxide, thiobarbituric acid-reactive substance (TBARS), and oxysterol levels were also reduced, suggesting that fluvastatin also had anti-oxidative effects. Finally, VCAM-1 levels were similarly reduced by fluvastatin treatment. We conclude that fluvastatin safely improves the plasma lipid profile in type 2 diabetic patients with hyperlipidemia. We speculate that this drug might be doubly effective in reducing atherosclerosis and cardiac events in these patients as a result of its demonstrated anti-oxidative effects and its ability to reduce VCAM-1 levels.

Evaluation of the atherogenic tendency of lipids and lipoprotein content and their relationships with oxidant-antioxidant system in patients with psoriasis

BACKGROUND

Psoriasis is a common chronic and recurrent inflammatory skin disease that can occur due to abnormalities in essential fatty acid metabolism, lymphokine secretion, free radical generation, lipid peroxidation and eicosanoid metabolism, and has been associated with increased frequency of cardiovascular events. The current study was designed to evaluate plasma lipids, susceptibility of LDL to oxidation and oxidant-antioxidant status and their relationships in patients with psoriasis.

METHODS

The study group included 35 patients with psoriasis (18 females and 17 males), and 35 sex- and age-matched healthy volunteers (16 females and 19 males). From blood samples, their lipids, lipoproteins, acute phase reactants, lipid peroxidation products [lipid hydroperoxide (LHP) and malondialdehyde (MDA)], antioxidant enzymes [glutathione peroxidase (GSH-Px), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT)], total antioxidant status (TAS) and autoantibodies against oxidized low-density lipoprotein (AuAb-oxLDL) levels were determined. Moreover, the susceptibility of copper-induced in vitro oxidation of LDL was examined.

RESULTS

The mean levels of atherogenic lipids (total cholesterol [TC], triacylglycerol [TG] and LDL cholesterol [LDL-C]), acute-phase reactants (CRP, ESR, PMNLs, ceruloplasmin and fibrinogen) and lipid peroxidation products, AuAb-oxLDL levels in patients with psoriasis were found to be significantly higher than those of healthy subjects. On the other hand, TAS and antioxidant enzyme activities (CAT, SOD and GSH-Px in erythrocyte and SOD in plasma) were significantly lower when compared to healthy subjects. The lag times [t(lag)], a measure of resistance to oxidation of LDL, were also lower. The levels of AuAb-oxLDL in patients were correlated with TC, LDL-C, plasma LHP, erythrocyte MDA, oxidized LDL-MDA (oxLDL-MDA), fibrinogen, CRP, PMNL levels and plasma SOD activities (r = 0.69, P < 0.01; r = 0.64, P < 0.01; r = 0.38, P < 0.05; r = 0.65, P < 0.01; r = 0.34, P < 0.05; r = 0.34, P < 0.05; r = 0.53, P < 0.01, r = 0.34, P < 0.05; r = -0.67, P < 0.01, respectively). On the other hand, t(lag) was correlated negatively with the levels of VLDL-TG, VLDL-TC and LDL-TG but positively correlated with the levels of TAS in psoriatics (r = -0.49, P < 0.01; r = -0.49, P < 0.01, r = -0.65, P < 0.05; r = 0.37, P < 0.05).

CONCLUSIONS

It was concluded that the psoriatic patients could be considered as a group with an increased atherosclerotic risk because of increased oxidant stress, decreased antioxidant capacity and susceptibility in lipid profile and lipoprotein content to atherogenicity.

Hypercholesterolemia treatment: a new hypothesis or just an accident?

A new hypothesis concerning the association of low levels of steroid hormones and hypercholesterolemia is proposed. This study presents data that concurrent restoration to youthful levels of multiple normally found steroid hormones is able to normalize or improve serum total cholesterol (TC). We evaluated 20 patients with hypercholesterolemia who received hormonorestorative therapy (HT) with natural hormones. Hundred percent of patients responded. Mean serum TC was 263.5 mg/dL before and 187.9 mg/dL after treatment. Serum TC dropped below 200 mg/dL in 60.0%. No morbidity or mortality related to HT was observed. In patients characterized by hypercholesterolemia and sub-youthful serum steroidal hormones, our findings support the hypothesis that hypercholesterolemia is a compensatory mechanism for life-cycle related down-regulation of steroid hormones, and that broadband steroid hormone restoration is associated with a substantial drop in serum TC in many patients.

The composition of bovine milk lipids: January 1995 to December 2000

Data from recent publications on bovine milk lipids are presented and discussed. This includes extraction of lipids, triacylglycerols, phospholipids, other complex lipids, sterols, isoflavones, and fatty acids. Improved gas-liquid and high performance liquid chromatography were used. Data on the trans and cis isomers of fatty acid and of conjugated linoleic acids are given, and the analyses are described. Papers about the lipids in milks and dairy products from the United States are few; where with the exception of trans-fatty acid isomers and conjugated linoleic acids, almost no research has been reported.

Changes in the phospholipid composition of the arterial cell can result in severe atherosclerotic lesions

The oxysterol concentration in the plasma and the phospholipid composition of vascular tissue obtained by coronary artery bypass grafting (CABG) were compared with plasma and vascular tissue from age and sex matched controls. The plasma from CABG patients had a higher concentration of oxysterols than was present in the controls. Human endothelial cells were cultured for 72 hours in a medium containing plasma obtained from CABG patients, from controls or from the same controls to which 5 oxysterols were added to make the total oxysterol level equivalent to that in the CABG plasma and then pulsed with calcium (45Ca(2+)) for one hr. A significantly higher influx of 45Ca(2+) was noted in the endothelial cells cultured in the plasma obtained from CABG patients and from the controls with 5 added oxysterols, but not in those cultured without added oxysterols indicating that oxysterols increased calcium influx into endothelial cells. A phospholipid analysis indicated that the arterial tissue from CABG patients had 48.2% sphingomyelin in its phospholipid fraction compared to 10% in arterial tissue from umbilical cords. The saphenous vein obtained during CABG surgery from the same patient had only 24% sphingomyelin in its phospholipid fraction and unlike the coronary arteries had no atherosclerotic lesions. The higher level of oxysterol in the plasma of patients suffering from severe atherosclerosis could increase the concentration of sphingomyelin in the arterial cell membrane and thereby increase calcium influx required for producing the calcific type VII lesions in the coronary arteries.

Fibrinogen is an efficient antioxidant

Fibrinogen has been included among the risk factors for vascular disease. Fibrinogen belongs with albumin, ceruloplasmin and transferrin to an acute phase protein group in the plasma. Albumin, ceruloplasmin and transferrin are already recognized as natural antioxidants. In the present study we used three different oxygen generating systems in order to test whether fibrinogen is able to act as an antioxidant in an in vitro system. We used 1) pyrogallol auto-oxidation, 2) the reaction catalysed by xanthine oxidase coupled with the reduction of ferricytochrome c and 3) chemiluminescence. We found that in a dose-dependent manner fibrinogen inhibited superoxide generation (pyrogallol and xanthine-xanthine oxidase reactions), ferrous ion oxidation and hydroxyl radical dependent degradation (of deoxyribose). Fibrinogen also inhibited LDL oxidation (copper and azo compound-induced), hydrogen peroxide oxidation and chemiluminescence produced by polymorphonuclear leukocytes. Fibrinogen, albumin, ceruloplasmin and transferrin act as a supplementary antioxidant defense mechanism against oxidative stress arising from inflammatory conditions.