Use of proteomics to identify biomarkers associated with chronic kidney disease and long-term outcomes in patients with myocardial infarction.

BACKGROUND: Patients with chronic kidney disease (CKD) have poor outcomes following myocardial infarction (MI). We performed an untargeted examination of 175 biomarkers to identify those with the strongest association with CKD and to examine the association of those biomarkers with long-term outcomes. METHODS: A total of 175 different biomarkers from MI patients enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry were analysed either by a multiple reaction monitoring mass spectrometry assay or by a multiplex assay (proximity extension assay). Random forests statistical models were used to assess the predictor importance of biomarkers, CKD and outcomes. RESULTS: A total of 1098 MI patients with a median estimated glomerular filtration rate of 85 mL min-1 /1.73 m2 were followed for a median of 3.2 years. The random forests analyses, without and with adjustment for differences in demography, comorbidities and severity of disease, identified six biomarkers (adrenomedullin, TNF receptor-1, adipocyte fatty acid-binding protein-4, TNF-related apoptosis-inducing ligand receptor 2, growth differentiation factor-15 and TNF receptor-2) to be strongly associated with CKD. All six biomarkers were also amongst the 15 strongest predictors for death, and four of them were amongst the strongest predictors of subsequent MI and heart failure hospitalization. CONCLUSION: In patients with MI, a proteomic approach could identify six biomarkers that best predicted CKD. These biomarkers were also amongst the most important predictors of long-term outcomes. Thus, these biomarkers indicate underlying mechanisms that may contribute to the poor prognosis seen in patients with MI and CKD.

New candidate genes for ST-elevation myocardial infarction.

BACKGROUND: Despite extensive research in atherosclerosis, the mechanisms of coronary atherothrombosis in ST-elevation myocardial infarction (STEMI) patients are undetermined. OBJECTIVES: Our aim was to find candidate genes involved in STEMI by analysing leucocyte gene expression in STEMI patients, without the influence of secondary inflammation from innate immunity, which was assumed to be a consequence rather than the cause of coronary atherothrombosis. METHODS: Fifty-one patients were included at coronary angiography because of STEMI. Arterial blood was sampled in the acute phase (P1), at 24-48 h (P2) and at 3 months (P3). Leucocyte RNA was isolated and gene expression analysis was performed by Affymetrix Human Transcriptome Array 2.0. By omission of up- or downregulated genes at P2, secondary changes from innate immunity were excluded. Genes differentially expressed in P1 when compared to the convalescent sample in P3 were determined as genes involved in STEMI. RESULTS: Three genes were upregulated at P1 compared to P3; ABCG1 (P = 5.81 × 10-5 ), RAB20 (P = 3.69 × 10-5 ) and TMEM2 (P = 7.75 × 10-6 ) whilst four were downregulated; ACVR1 (P = 9.01 × 10-5 ), NFATC2IP (P = 8.86 × 10-5 ), SUN1 (P = 3.87 × 10-5 ) and TTC9C (P = 7.18 × 10-6 ). These genes were also highly expressed in carotid atherosclerotic plaques. CONCLUSIONS: We found seven genes involved in STEMI. The study is unique regarding the blood sampling in the acute phase and omission of secondary expressed genes from innate immunity. However, the results need to be replicated by future studies.

Genetic testing for familial hypercholesterolemia among survivors of acute coronary syndrome.

BACKGROUND: Familial hypercholesterolemia could be prevalent among patients with acute coronary syndrome. OBJECTIVE: To investigate both the frequency of causative mutations for familial hypercholesterolemia (FH) and the optimal selection of patients for genetic testing among patients with an acute coronary syndrome (ACS). METHODS: One hundred and sixteen patients with an ACS during 2009-2015 were identified through the SWEDEHEART registry. Patients who had either a high total cholesterol level ≥7 mmol L-1 combined with a triglyceride level ≤2.6 mmol L-1 , or were treated with lipid-lowering medication and had a total cholesterol level >4.9 mmol L-1 and a triglyceride level ≤2.6 mmol L-1 were included. Genetic testing was performed first with a regionally designed FH mutation panel (118 mutations), followed by testing with a commercially available FH genetic analysis (Progenika Biopharma). RESULTS: A total of 6.9% (8/116) patients had a FH-causative mutation, all in the LDL-receptor. Five patients were detected on the panel, and further testing of the remaining 111 patients detected an additional 3 FH-causative mutations. Baseline characteristics were similar in FH-positive and FH-negative patients with respect to age, gender, prior ACS and diabetes. Patients with a FH-causative mutation had higher Dutch Lipid Clinical Network (DLCN) score (5.5 (5.0-6.5) vs 3.0 (2.0-5.0), P < 0.001) and a higher low-density lipoprotein level (5.7 (4.7-6.5) vs 4.9 (3.5-5.4), P = 0.030). The Dutch Lipid Clinical Network (DLCN) score had a good discrimination with an area under the curve of 0.856 (95% CI 0.763-0.949). CONCLUSION: Genetic testing for FH should be considered in patients with ACS and high DLCN score.

VIIaAT complexes, procoagulant phospholipids, and thrombin generation during postprandial lipemia.

INTRODUCTION: Factor VII activation occurs postprandially. A proportion of activated factor VII (VIIa) circulates in complex with antithrombin (VIIaAT). Our primary objective was to assess the effects of postprandial lipemia on circulating VIIaAT, procoagulant phospholipid (PPL) activity, and thrombin generation. METHODS: Plasma samples from postmyocardial infarction patients (n = 40) and controls (n = 39) were taken before and at 3 and 6 hours during a standardized oral fat tolerance test (OFTT). Fasting PPL activity measurements were also made in a second cohort of 108 postinfarction patients and 109 controls. VIIaAT was analyzed with the Asserachrom VIIaAT ELISA, PPL activity with the STA-Procoag-PPL kit, and thrombin generation with calibrated automated thrombogram with PRP-Reagent as trigger (all Diagnostica Stago products). RESULTS: Postprandially, VIIaAT increased in all samples without significant case-control differences in the overall response during the OFTT. Thrombin generation measures peak height and velocity, and PPL activity, were marginally affected by the test meal in the controls. Levels of all patient baseline measures were significantly different from controls, indicating a more hypercoagulable state, and these differences were maintained throughout the OFTT. Fasting samples from cases showed higher PPL activity than control samples. CONCLUSION: Viewing VIIaAT quantitation as a surrogate for TF activity measurement, postprandial increase in VIIaAT may reflect a mechanism that adds to the cardiovascular risk associated with postprandial lipemia. On the other hand, the impact of postprandial lipemia on PPL activity and thrombin generation seems to be minor.

Sitagliptin improves beta-cell function in patients with acute coronary syndromes and newly diagnosed glucose abnormalities--the BEGAMI study.

BACKGROUND: Newly detected impaired glucose tolerance (IGT) or type 2 diabetes mellitus (T2DM) are common in patients with acute coronary syndrome (ACS; i.e. unstable angina/myocardial infarction) and related to disturbed beta-cell function. The aim of this study is to test the hypothesis that treatment with a dipeptidyl peptidase-4 inhibitor initiated soon after a coronary event improves beta-cell function. METHODS: Acute coronary syndrome ACS patients with IGT or T2DM (n = 71), screened by oral glucose tolerance test (OGTT) 4-23 days (median 6 days) after hospital admission, were randomly assigned to sitagliptin 100 mg (n = 34) or placebo (n = 37) and treated for a duration of 12 weeks. All patients received lifestyle advice but no glucose-lowering agents other than the study drug. The study end-point was beta-cell function assessed using the insulinogenic index (IGI = ΔInsulin30 /ΔGlucose30 ), derived from an OGTT, and acute insulin response to glucose (AIRg) assessed by a frequently sampled intravenous glucose tolerance test. RESULTS: The IGI and AIRg did not differ at baseline between the sitagliptin and placebo groups (69.9 vs. 66.4 pmol mmol(-1) and 1394 vs. 1106 pmol L(-1) min(-1) respectively). After 12 weeks, the IGI was 85.0 in the sitagliptin and 58.1 pmol/mmol in the placebo group (P = 0.013) and AIRg was 1909 and 1043 pmol L(-1) min(-1) (P < 0.0001) in the sitagliptin and placebo groups respectively. Fasting glucose at baseline was 6.1 mmol L(-1) in sitagliptin-treated patients and 6.0 mmol L(-1) in those who received placebo compared with 5.8 and 5.9 mmol L(-1) respectively, after 12 weeks of treatment. Post load glucose metabolism improved in significantly more sitagliptin-treated patients compared with the placebo group (P = 0.003). Sitagliptin was well tolerated. CONCLUSION: Sitagliptin improved beta-cell function and glucose perturbations in patients with ACS and newly diagnosed glucose disturbances.

Comparison of the effects of different statins and doses on lipid levels in patients with diabetes: results from VOYAGER.

BACKGROUND AND AIMS: Diabetes mellitus is a well-known risk factor for cardiovascular disease, and brings an increased risk of vascular events and a higher mortality rate. Treatment guidelines recommend statins in patients with diabetes, with low-density lipoprotein cholesterol (LDL-C) targets of 100 mg dl(-1) (∼2.5 mmol l(-1)), and 80 (∼2.0 mmol l(-1)) or 70 mg dl(-1) (∼1.8 mmol l(-1)) in especially high-risk patients. The current study used the VOYAGER (an indiVidual patient data-meta-analysis Of statin therapY in At risk Groups: Effects of Rosuvastatin, atorvastatin, and simvastatin) database to characterise effects of rosuvastatin, atorvastatin and simvastatin in different doses on lipid levels in diabetes patients. METHODS AND RESULTS: The VOYAGER database included individual patient data from 37 studies involving comparisons of rosuvastatin with either atorvastatin or simvastatin. Of the 32 258 patients included, 8859 (27.5%) had diabetes. Rosuvastatin appeared to be the most efficacious of the three statins, both for lowering LDL-C and for reaching a target level of <70 mg dl(-1) for LDL-C. It was also more effective than atorvastatin at raising high-density lipoprotein cholesterol in the diabetes population. These results are consistent with the overall VOYAGER results. CONCLUSIONS: This meta-analysis of 8859 patients with diabetes mellitus shows favourable effects on lipids with the three statins studied, in line with results for the overall VOYAGER population. The importance of using an effective statin at an effective dose to reach treatment goals for such high-risk patients is evident.

Persistent lipid abnormalities in statin-treated patients with diabetes mellitus in Europe and Canada: results of the Dyslipidaemia International Study.

AIM: To assess the prevalence of persistent lipid abnormalities in statin-treated patients with diabetes with and without the metabolic syndrome. METHODS: This was a cross-sectional study of 22,063 statin-treated outpatients consecutively recruited by clinicians in Canada and 11 European countries. Patient cardiovascular risk factors, risk level, lipid measurements and lipid-modifying medication regimens were recorded. RESULTS: Of the 20,129 subjects who had documented diabetes and/or metabolic syndrome status, 41% had diabetes (of whom 86.8% also had the metabolic syndrome). Of those with diabetes, 48.1% were not at total cholesterol target compared with 58% of those without diabetes. Amongst those with diabetes, 41.6 and 41.3% of those with and without the metabolic syndrome, respectively, were not at their LDL cholesterol goal relative to 54.2% of those with metabolic syndrome and without diabetes, and 52% of those with neither condition. Twenty per cent of people with diabetes but without the metabolic syndrome were not at the optimal HDL cholesterol level compared with 9% of those with neither condition. Of people with diabetes and the metabolic syndrome, 49.9% were not at optimal triglyceride level relative to 13.5% of people with neither diabetes nor the metabolic syndrome. Simvastatin was the most commonly prescribed statin (>45%) and the most common statin potency was 20-40 mg/day (simvastatin equivalent). Approximately 14% of patients were taking ezetimibe alone or in combination with a statin. CONCLUSIONS: Despite evidence supporting the benefits of lipid modification and international guideline recommendations, statin-treated patients with diabetes had a high prevalence of persistent lipid abnormalities. There is frequently room to optimize therapy through statin dose up-titration and/or addition of other lipid-modifying therapies.

Low plasma adiponectin concentration is associated with myocardial infarction in young individuals.

OBJECTIVE: The importance of adiponectin in coronary heart disease remains to be elucidated. Therefore, the associations between plasma adiponectin levels and i) myocardial infarction and ii) genetic variation within the adiponectin gene were investigated. METHODS: The study included young survivors (age <60 years) of a first myocardial infarction and gender- and age-matched controls (244 pairs). Adiponectin concentrations were analysed by radioimmunoassay. Two polymorphisms, rs266729 and rs1501299, of the adiponectin gene ADIPOQ were genotyped. RESULTS: Adiponectin levels were inversely associated with myocardial infarction [odds ratio (OR) 9.3, 95% confidence interval (CI) 4.7-18.2, for the lowest quartile compared to the highest quartile]. This persisted after adjustment for history of hypertension, HDL cholesterol, smoking and body mass index (BMI) (OR 3.1, 95% CI 1.3-7.6). The rs266729 polymorphism was associated with adiponectin levels. Plasma adiponectin concentrations were lower in individuals with the rare G/G genotype [median 4.3 mg/L, [corrected] interquartile range (IQR) 2.8-6.2] compared to the C/G (median 5.8 mg/L), [corrected] IQR 3.9-8.0; P = 0.035) and C/C genotypes (median 5.5 mg/L, [corrected] IQR 4.0-7.5; P = 0.083). CONCLUSION: Low plasma adiponectin concentrations are associated with myocardial infarction in individuals below the age of 60, and this remains significant after adjustment for history of hypertension, HDL cholesterol, smoking and BMI. In addition, adiponectin levels differ according to rs266729 genotype.

Relation between renal function, presentation, use of therapies and in-hospital complications in acute coronary syndrome: data from the SWEDEHEART register.

OBJECTIVE: To examine clinical characteristics, presenting symptoms, use of therapy and in-hospital complications in relation to renal function in patients with myocardial infarction (MI). DESIGN: Observational study. SETTING: Nationwide coronary care unit registry between 2003-2006 in Sweden. SUBJECTS: Consecutive MI patients with available creatinine (n = 57,477). RESULTS: Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study formula. With declining renal function patients were older, had more co-morbidities and more often used cardio-protective medication on admission. Compared to patients with normal renal function, fewer with renal failure presented with chest pain (90% vs. 67%, P < 0.001), Killip I (89% vs. 58%, P < 0.001) and ST-elevation myocardial infarction (STEMI) (41% vs. 22%, P < 0.001). In a logistic regression model lower renal function was independently associated with a less frequent use of anticoagulant and revascularization in non-ST-elevation MI. The likelihood of receiving reperfusion therapy for STEMI was similar in patients with normal-to-moderate renal dysfunction, but decreased in severe renal dysfunction or renal failure. Reperfusion therapy shifted from primary percutaneous coronary intervention in 71% of patients with normal renal function to fibrinolysis in 58% of those with renal failure. Renal function was associated with a higher rate of complications and an exponential increase in in-hospital mortality from 2.5% to 24.2% across the renal function groups. CONCLUSION: Renal insufficiency influences the presentation and reduces the likelihood of receiving treatment according to current guidelines. Short-term prognosis remains poor.

Serum matrix metalloproteinase-3 concentration is influenced by MMP-3 -1612 5A/6A promoter genotype and associated with myocardial infarction.

OBJECTIVES: Matrix metalloproteinase-3 (MMP-3) is implicated in the formation of atherosclerotic plaques, and the MMP-3 -1612 5A/6A polymorphism is associated with myocardial infarction (MI) and stable coronary artery disease (CAD). The present study examined whether the -1612 5A/6A polymorphism in the promoter region of the MMP-3 gene influences serum concentrations of MMP-3 and whether serum concentrations of MMP-3 are related to extent of coronary atherosclerosis and risk of MI. DESIGN AND SUBJECTS: This case-control study was conducted in three hospitals in the northern part of Stockholm. A total of 755 MI patients aged below 60 were screened, 433 entered and 387 completed the study. Three hundred and eighty-seven sex- and age-matched control subjects were recruited from the general population of the same county. METHODS: The MMP-3 genotype was determined by Pyrosequencing(TM) and the serum MMP-3 concentration was quantified with an immunoassay. Severity and extension of CAD was assessed by quantitative coronary angiography in a subgroup of patients (n=243). RESULTS: Patients had lower serum MMP-3 concentration than controls. There was a strong association between MMP-3 -1612 5A/6A genotype and serum concentrations of MMP-3. The presence of one or two copies of the 6A-allele was associated with a graded increase in serum MMP-3. In female patients there was an inverse correlation (r=-0.39, P<0.05) between serum MMP-3 concentration and plaque area. Conclusion. In conclusion, the serum concentration of MMP-3 is influenced by MMP-3 -1612 5A/6A genotype and associated with MI.

Severity of coronary artery stenosis is associated with a polymorphism in the CXCL16/SR-PSOX gene.

OBJECTIVE: Enhanced expression of CXCL16 has been demonstrated in atherosclerotic plaques and several properties have been attributed to CXCL16 that could influence the atherosclerotic process. CXCL16 exists in transmembrane and soluble forms. The transmembrane form acts as a scavenger receptor for oxidised LDL whereas the soluble form acts a chemoattractant for mainly CD8+ T cells. In addition, the soluble form of CXCL16 influences human aortic smooth muscle cell proliferation in vitro. In the present work, a human molecular genetic approach employing a common polymorphism within exon 4 of CXCL16 (181 Ala>Val) was used to investigate whether CXCL16 may be involved in the development of coronary artery disease. The polymorphism is located within the spacer region between the chemokine and transmembrane region and potentially influences an Ala/Val cleavage site, a site commonly used for the release of chemokines by tumour necrosis factor-alpha converting enzyme. DESIGN AND SUBJECTS: We first genotyped 387 unselected survivors of a first myocardial infarction aged <60 years and 387 sex- and age-matched controls. A subset of patients (n = 236) was evaluated by quantitative coronary angiography. Secondly, a cohort of 468 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with stent implantation was genotyped. RESULTS: No significant difference in allele frequency between patient and controls of the 181 A>V polymorphism was detected. However, the V-allele was associated with increased severity of coronary stenoses. Secondly, the V-allele was associated with smaller minimal luminal diameter in the coronary segment subjected to intervention in a second cohort of patients undergoing PTCA with stent implantation. CONCLUSIONS: The present work provides evidence that CXCL16 is involved in processes leading to enhanced stenosis in atherosclerotic coronary arteries.

Low-grade inflammation may play a role in the etiology of the metabolic syndrome in patients with coronary heart disease: the HIFMECH study.

Risk of coronary heart disease has been related to insulin resistance, but the mechanism for this is incompletely understood. Variables attributed to insulin resistance are associated with low-grade inflammation. A case-control study was performed of 469 male myocardial infarction (MI) survivors aged < 60 years and 575 control subjects recruited from centers in northern and southern Europe. Principal factor analysis was used to explore correlations between insulin resistance and inflammatory variables. Three factors resulted: (a) "Metabolic Syndrome" (insulin/proinsulin/ triglyceride/body mass index [BMI]); (b) "Inflammation" (fibrinogen/C-reactive protein [CRP]/interleukin-6 [IL-6]); and (c) "Blood Pressure" (systolic and diastolic blood pressure). The "Metabolic Syndrome" factor was related to the "Inflammation" factor (largely independently of obesity), the "Blood Pressure" factor, smoking, and south location (all P < or = .0002). There were significant relationships between all 3 factors and case status (P < or = .0002). Markers of low-grade inflammation are strongly related to metabolic syndrome variables independently of obesity. This raises the possibility that links between insulin resistance and cardiovascular disease could, in part, represent common consequences of low-grade inflammation.

A triglyceride-rich fat emulsion and free fatty acids but not very low density lipoproteins impair endothelium-dependent vasorelaxation.

OBJECTIVE: To investigate the effects of triglycerides and free fatty acids on endothelium-dependent and endothelium-independent vasorelaxation. METHODS: Femoral arterial rings from rats were studied in organ baths. The vascular segments were constricted with phenylephrine after 20 min of preincubation with the triglyceride-rich fat emulsion Intralipid, free fatty acids (16:0, 18:1, 18:3) bound to bovine serum albumin, or very low density lipoproteins. Endothelium-dependent and endothelium-independent relaxations were determined after administration of acetylcholine and nitric oxide donors, respectively. RESULTS: Preincubation with Intralipid caused a concentration-dependent impairment of endothelium-dependent but not endothelium-independent relaxation. Very low density lipoproteins did not affect vascular function. All free fatty acids impaired endothelium-dependent relaxation, whereas endothelium-independent relaxation was unaffected. Administration of the antioxidant vitamin C partly reversed the impairment of the endothelium-dependent relaxation induced by Intralipid and free fatty acids. CONCLUSIONS: The present study demonstrates that the triglyceride-rich fat emulsion Intralipid and individual FFAs impair endothelium-dependent relaxation of arterial rings from rat, whereas triglycerides in the form of VLDL do not affect endothelial function. The finding that the antioxidant vitamin C partly reverses this impairment indicates the involvement of oxidative mechanisms.

Mild-to-moderate hypertriglyceridemia in young men is associated with endothelial dysfunction and increased plasma concentrations of asymmetric dimethylarginine.

OBJECTIVES: The aim of this study was to investigate endothelial function and common carotid intima-media thickness (IMT) in healthy young men with mild-to-moderate hypertriglyceridemia. Plasma asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, was measured to further elucidate the mechanisms involved. BACKGROUND: Hypertriglyceridemia is a risk factor for coronary heart disease although the mechanisms behind the increased risk remain to be defined. Acute elevation of plasma triglycerides induced by an intravenous fat load is associated with impaired endothelial function. The results of studies examining acute effects induced by a high-fat meal or effects of chronic hypertriglyceridemia on endothelial function are more inconsistent. METHODS: Flow-mediated vasodilation and nitroglycerin-induced vasodilation of the brachial artery and common carotid IMT were measured noninvasively by ultrasound technique in 15 hypertriglyceridemic (HTG) subjects and 15 matched controls, mean age 34 years. Plasma concentrations of ADMA were measured by high-performance liquid chromatography. RESULTS: Flow-mediated vasodilation was decreased in the HTG group (p < 0.0001), whereas nitroglycerin-induced vasodilation and carotid IMT did not differ significantly. Asymmetric dimethylarginine concentrations were higher in the HTG group (p < 0.05). CONCLUSIONS: Hypertriglyceridemia in young men is associated with endothelial dysfunction and increased plasma concentration of ADMA but not with increased IMT of the common carotid artery. The corollary is that chronic hypertriglyceridemia results in endothelial dysfunction, possibly due to increased ADMA concentration, and that endothelial dysfunction might precede increased IMT among the early manifestations of atherosclerosis.

Greater than normal prevalence of seropositivity for Helicobacter pylori among patients who have suffered myocardial infarction.

BACKGROUND: There is evidence to suggest that inflammation plays a role in the development of atherosclerosis. Chronic infections may activate an inflammatory response in the walls of blood vessels. OBJECTIVE: To investigate the possibility of there being an association between infection with Helicobacter pylori (H. pylori) and coronary heart disease. METHODS: We examined 100 consecutive patients documented to have recently suffered acute myocardial infarction and 100 control subjects from the same geographical area for whom there was no evidence of coronary heart disease, carefully matched both for age and sex. Blood samples were tested for the presence of immunoglobulin G antibodies against H. pylori with a serological test. RESULTS: In comparison with controls, patients were more commonly smokers (26 versus 12%/0, P < 0.05) and had more commonly been treated for hypertension (37 versus 20%, P< 0.01). There was a significant association between seropositivity for H. pylori and having previously suffered acute myocardial infarction (68 versus 53%, odds ratio 1.36 with 95% confidence interval 1.02-1.82, P=0.034). These findings remained valid in a multivariate analysis including possible confounding factors (age, sex, smoking and hypertension; odds ratio 1.35 with 95% confidence interval 1.01-1.83, P=0.046). CONCLUSIONS: The positive association between seropositivity for H. pylori and having previously suffered acute myocardial infarction found in this study provides further support for the hypothesis that there is a causal association between chronic infection with H. pylori and the development of coronary heart disease.

Accumulation of apolipoprotein C-I-rich and cholesterol-rich VLDL remnants during exaggerated postprandial triglyceridemia in normolipidemic patients with coronary artery disease.

BACKGROUND: Exaggerated postprandial triglyceridemia is common in normolipidemic patients with coronary artery disease (CAD). Alterations in the composition of triglyceride-rich lipoproteins (TRLs) are likely to underlie this metabolic disturbance. However, the composition of very-low-density lipoproteins (VLDLs), which are the most abundant postprandial TRLs, has never been defined in CAD patients. METHODS AND RESULTS: We examined postprandial changes in the number and composition of VLDLs in middle-aged, normolipidemic CAD patients and control subjects. TRLs from 14 patients and 14 control subjects aged 45 to 55 years were subfractionated by density gradient ultracentrifugation into Svedberg flotation rate (Sf) fractions >400, 60 to 400, and 20 to 60. The VLDLs were separated from chylomicron remnants by immunoaffinity chromatography. In CAD patients, the postprandial concentrations of triglycerides and large (Sf 60 to 400) VLDL particles were elevated. In addition, their postprandial large VLDLs were enriched in apolipoprotein (apo) C-I and their postprandial small (Sf 20 to 60) VLDL remnants were enriched with apo C-I and cholesterol. CONCLUSIONS: Perturbed handling of postprandial triglycerides in normolipidemic CAD patients involves the accumulation of apo C-I-rich large VLDL particles and the generation of small, apo C-I- and cholesterol-rich VLDL remnants.

Transient triglyceridemia decreases vascular reactivity in young, healthy men without risk factors for coronary heart disease.

BACKGROUND: Hypertriglyceridemia is now accepted as a risk factor for coronary heart disease, although the mechanism behind the increased risk is not well understood. The present study was undertaken to investigate the effects of triglyceridemia on endothelial function, because impaired endothelial function is considered a marker of atherogenesis. METHODS AND RESULTS: Flow- and nitroglycerin-induced dilatation of the brachial artery was investigated noninvasively by high-resolution ultrasound technique in seven young, healthy men without risk factors for coronary heart disease. Transient triglyceridemia was induced by infusion of a triglyceride emulsion, Intralipid, which raised free fatty acid concentrations twofold and triglyceride levels fourfold. Flow-induced vasodilatation decreased from 7.1+/-3.0% to 1.6+/-2.6% (P<.0002), whereas nitroglycerin-induced vasodilatation decreased from 20.5+/-5.8% to 11.5+/-3.2% (P<.002) before and after 1 hour of infusion of Intralipid, respectively. CONCLUSIONS: Transient triglyceridemia decreases vascular reactivity, presumably by both endothelium-dependent and endothelium-independent mechanisms.

A CD4+ T cell line-secreted factor, growth promoting for normal and leukemic B cells, identified as thioredoxin.

In this study, a B cell growth stimulatory factor, constitutively secreted by a human CD4+ T cell hybridoma clone, MP6, has been purified and characterized. Serum-free 24 h culture media from MP6 cells were collected, concentrated by ultrafiltration and separated by gel chromatography. Fractions were analyzed for stimulatory activity using [3H]thymidine incorporation in normal and leukemic (B-CLL) B cells as target cells. Activity was present in a 12 kDa protein peak. Upon storage this lost activity indicating that the factor was sensitive to air oxidation, a well-known property of mammalian thioredoxins (Trxs). Treatment of the inactive fraction with dithiothreitol restored full activity. When culture medium was analyzed with a radioimmunoassay for human placenta Trx, the MP6 clone was shown to release 30-50 ng/ml per million cells during 24 h. The B cell stimulatory activity of the MP6 medium was removed by Sepharose-bound anti-human placenta Trx IgG and activity was recovered by elution from the antibodies. Furthermore, MP6 medium showed Trx activity with NADPH and Trx reductase using an insulin disulfide reduction assay. Starting from 5 l of serum-free MP6 conditioned medium, the Trx was purified approximately 100,000-fold. After gel electrophoresis banding, the material was analyzed by peptide sequencing and a full length sequence of an 104 amino acid long protein was obtained. This Trx sequence was identical to the previously published sequence of human Trx from HTLV-1 transformed T cells, adult T cell leukemia-derived factor/Trx.(ABSTRACT TRUNCATED AT 250 WORDS)