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LDL Particles (ldl + particle)
Selected AbstractsCharge density profiling of circulating human low-density lipoprotein particles by capillary zone electrophoresisELECTROPHORESIS, Issue 17 2004Mine-Yine Liu Abstract Capillary zone electrophoresis (CZE) has been utilized to profile the low-density (LDL) particles in human blood serum in this study. A 5 mM sodium phosphate buffer, pH 7.40, was chosen as the most suitable CE buffer and an extensive ultrafiltration (UF) procedure was applied to purify the LDL sample. Two LDL particle species, LDL with lower mobility and LDL, with higher mobility were observed. The electropherograms were highly reproducible with good precision of effective mobilities, corrected peak areas (CPAs) and CPA ratio of LDL,/LDL. LDL particles shown on the electropherogram were also characterized by several procedures. The applications of Sigma HDL cholesterol reagent and CE on-line 2-propanol precipitation indicated that the two particle species shown in the electropherogram belong to LDL. The LDL particles were found to associate with the buoyant LDL fraction and the LDL, particles associate with the dense LDL fraction. This study utilizes CZE for the profiling of LDL isoforms and provides a new analytical method for the resolution of LDL subspecies. It demonstrates a high-mobility LDL particle which circulates in healthy subjects and diminishes in atherosclerotic patients. Diminution of the high-mobility LDL subspecies may be linked to minimal formation of arterial plaque in atherosclerotic patients. [source] Interpreting clinical trials of diabetic dyslipidaemia: new insightsDIABETES OBESITY & METABOLISM, Issue 3 2009A. S. Wierzbicki Current treatment guidelines highlight the importance of aggressive lipid-modifying therapy in reducing cardiovascular risk in patients with type 2 diabetes. Statins are established as the cornerstone of dyslipidaemia management in diabetic patients, based on their efficacy in lowering levels of low-density lipoprotein cholesterol (LDL-C). However, statins fail to address the high residual cardiovascular risk in treated patients, some of which may be attributable to low HDL cholesterol (HDL-C) and elevated triglycerides and to a preponderance of small, dense LDL particles, indicating the need for further intervention. Fibrates are effective against all components of atherogenic dyslipidaemia associated with type 2 diabetes. Clinical studies, most notably the Fenofibrate Intervention and Event Lowering in Diabetes, indicate that fibrates, most likely in combination with a statin, have a secondary role in reducing cardiovascular risk in patients with type 2 diabetes, particularly in those without prior cardiovascular disease or patients with low HDL-C. Results are awaited from the ongoing Action to Control Cardiovascular Risk in Diabetes trial to fully evaluate the outcome benefits of this combination strategy. [source] Charge density profiling of circulating human low-density lipoprotein particles by capillary zone electrophoresisELECTROPHORESIS, Issue 17 2004Mine-Yine Liu Abstract Capillary zone electrophoresis (CZE) has been utilized to profile the low-density (LDL) particles in human blood serum in this study. A 5 mM sodium phosphate buffer, pH 7.40, was chosen as the most suitable CE buffer and an extensive ultrafiltration (UF) procedure was applied to purify the LDL sample. Two LDL particle species, LDL with lower mobility and LDL, with higher mobility were observed. The electropherograms were highly reproducible with good precision of effective mobilities, corrected peak areas (CPAs) and CPA ratio of LDL,/LDL. LDL particles shown on the electropherogram were also characterized by several procedures. The applications of Sigma HDL cholesterol reagent and CE on-line 2-propanol precipitation indicated that the two particle species shown in the electropherogram belong to LDL. The LDL particles were found to associate with the buoyant LDL fraction and the LDL, particles associate with the dense LDL fraction. This study utilizes CZE for the profiling of LDL isoforms and provides a new analytical method for the resolution of LDL subspecies. It demonstrates a high-mobility LDL particle which circulates in healthy subjects and diminishes in atherosclerotic patients. Diminution of the high-mobility LDL subspecies may be linked to minimal formation of arterial plaque in atherosclerotic patients. [source] Roles of oxidized low-density lipoprotein and its receptors in the pathogenesis of atherosclerotic diseasesGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2002Noriaki Kume In elderly populations, atherosclerotic diseases, including ischemic heart disease and stroke, frequently impair quality of life and affect mortality. Hypercholesterolemia, especially increased plasma low-density lipoprotein (LDL), is one of the strongest risk factors for atheroscletorotic diseases. Oxidative modification of LDL appears to convert LDL particles to more atherogenic forms. Scavenger receptor class A (SR-A) and CD36 have been identified and well-characerized as receptors for Ox-LDL in macrophages. In addition to these molecules, lectin-like oxidized LDL receptor (LOX)-1 and scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX) are type II and I membrane glycoproteins, respectively, both of which can act as cell-surface endocytosis receptors for atherogenic oxidized LDL (Ox-LDL). LOX-1 expression can dynamically be induced by pro-inflammatory stimuli, and is detectable in cultured macrophages and activated vascular smooth muscle cells (VSMC), in addition to endothelial cells. LOX-1-dependent uptake of Ox-LDL induces apoptosis of cultured VSMC. In vivo, endothelial cells that cover early atherosclerotic lesions, and intimal macrophages and VSMC in advanced atherosclerotic plaques dominantly express LOX-1. LOX-1 expressed on the cell-surface can be cleaved in part and released as soluble molecules, suggesting the diagnostic value of soluble LOX-1. SR-PSOX is a newly identified receptor for Ox-LDL, which appears to be identical to CXCL16, a novel membrane-anchored chemokine directed to CXCR6-positive lymphocytes. In contrast to LOX-1, which is expressed by a variety of cell types, SR-PSOX expression appeared relatively confined to macrophages in atherogenesis. Taken together, oxidized LDL receptors, including LOX-1 and SR-PSOX, may play important roles in atherogenesis and atherosclerotic plaque rupture. [source] Clinical Update on the Use of Niacin for the Treatment of DyslipidemiaJOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 12 2004Kathy Berra MSN Purpose To provide nurse practitioners (NPs) with clinical and practical information about the use of niacin in the treatment of dyslipidemia. Data Sources Research-based and review articles in the medical literature and National Cholesterol Education Program guidelines. Conclusions Niacin provides beneficial effects on all major lipid fractions, particularly high-density lipoprotein cholesterol and triglycerides. Niacin also reduces low-density lipoprotein (LDL) cholesterol; lipoprotein (a); and the number of highly atherogenic small, dense LDL particles. Niacin promotes angiographic regression when used in combination with other drugs that lower LDL cholesterol and can reduce cardiovascular risk in patients with coronary heart disease. Several niacin formulations are available, but the safety (i.e., from hepato-toxicity) and tolerability (i.e., severity of flushing) of these niacin formulations may differ. Implications for Practice Niacin therapy is appropriate for many types of lipid abnormalities, including complex dyslipidemias. NPs can take several steps to minimize potential side effects of niacin therapy and to ensure that patients adhere to this important intervention. [source] Accumulation of cholesterol in the lesions of focal segmental glomerulosclerosisNEPHROLOGY, Issue 5 2003HYUN SOON LEE SUMMARY: Intraglomerular deposition of low-density lipoprotein (LDL) and oxidized LDL has been described in various human glomerular diseases. Yet it is not clear whether esterified cholesterol (EC) and unesterified cholesterol (UC) carried in LDL are mobilized from deposited LDL particles or accumulate in the diseased human glomeruli, particularly in the segmentally sclerotic lesions. To address this issue, frozen sections of renal biopsies were first immunostained to localize apolipoprotein B (apo B) and then oil red O (ORO) stained to colocalize neutral lipids. By using 124 ORO-positive biopsies and nine ORO-negative ones, UC was visualized directly with filipin staining, and EC was visualized after its enzymatic hydrolysis and staining with filipin. Seventy-seven biopsies (58%) showed filipin staining of accumulated EC and/or UC in the glomeruli. Of these, 11 showed heavy filipin staining for both EC and UC in the segmentally sclerotic lesions. In a group with UC deposits in the sclerotic segments, the percentage of the glomeruli affected by sclerosis and the intensity of filipin fluorescence for UC were significantly higher than biopsies with only mesangial UC deposits. Most filipin-positive biopsies showed apo B staining mainly in the mesangium. Yet in the sclerotic segments, apo B staining was rarely noted. Accumulated apo B-stained lipoprotein was not coincident with ORO-stained lipid in the diseased glomeruli. These results suggest that both EC and UC accumulate in the sclerotic glomerular segments as the glomerular lesions are advanced, and that these EC and UC appear to be derived from altered LDL with progressive loss of apo B. [source] Pleiotropic effects on subclasses of HDL, adiposity, and glucose metabolism in adult Alaskan EskimosAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2010M. Elizabeth Tejero The aim of this study was to analyze the heritability and the presence of pleiotropic effects on subfractions of high-density lipoproteins (HDLs) as measured by nuclear magnetic resonance (NMR), parameters for adiposity, and glucose metabolism in adult Alaskan Eskimos. The present family study included 1,214 adult Alaskan Eskimos (537 male/677 female). Body weight, height, circumferences, selected skinfolds, and blood pressure were measured in all participants. Blood samples were collected under fasting conditions for the isolation of plasma. Glucose, insulin, subclasses and size of lipoproteins, triglycerides, total, and HDL cholesterol and lipoprotein (a) were measured in plasma. HbA1c was measured in total blood. Univariate and bivariate quantitative genetic analyses were conducted between HDL subclasses and size and the anthropometric and biochemical measures using the variance decomposition approach. Variation in all the analyzed traits exhibits a significant genetic component. Heritabilities ranged between 0.18 ± 0.11 for LDL2 (intermediate) and 0.89 ± 0.07 for small HDL. No common genetic effects were found on the HDL subclasses (small, intermediate, and large). Small HDL particles were genetically correlated with LDL particles and HbA1c. Negative genetic correlations were observed between intermediate and large HDL subfractions, HDL size and measures of adiposity, and LDL and parameters for glucose metabolism (HbA1, insulin). These observations confirm the presence of possible pleiotropic effects on HDL, adiposity, and cardiovascular risk factors and provide novel insight on the relationship between HDL subclasses, adiposity, and glucose regulation. Am. J. Hum. Biol., 2010. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||