Lipoprotein, serum

Lipoproteins, Serum, Ultracentrifugal Analysis (de Lalla and Gofman). . 1 459... 

Serum and serum proteins have diverse functions which are now reasonably well understood for the industrially important cell lines, and which can generally be substituted by non-protein alternatives. Mammalian cells typically require a source of fatty acids, which were historically supplied by serum. To supply these, serum-free media usually contain plasma lipoprotein fractions, free fatty acids complexed to serum albumin or fatty acid/phospholipid microemulsions [61]. A high-density lipoprotein serum-fraction in medium containing bovine serum albumin was used by Seamans et al. [62] to replace serum in cultures of a recombinant antibody-producing GS-NSO cell line. Further, they found that the serum-fraction could be replaced with a commercially available non-protein-aceous lipid emulsion and a pluronic F-68/cholesterol emulsion. This gave equivalent growth and productivity (100 mg L ). 

Popov, L, Lewin, G. Photochemiluminescent detection of antiradical activity. VI. Antioxidant characteristics of human blood plasma, low-density lipoprotein, serum albumin and aminoacids during in vitro oxidation. Luminescence 1999, 14 169-174. 

Uric acid, cholesterol, and lipoprotein serum concentrations have been measured in 53 patients with migraine taking topiramate and 44 age- and sex-matched controls. Topiramate significantly increased uric acid concentrations [315 ]. 

Lipoproteins. The lipid moiety of lipoproteins is quite variable both qualitatively and quantitatively. The a-lipoprotein of serum contains glyceride, phosphatide and cholesterol to about 30 -40% of the total complex. The -lipoprotein of serum contains some glyceride but the phosphatide and cholesterol account for nearly 75% of the total. 

Atherosclerosis is a degenerative disease which is characterized by cholesterol-containing thickening of arterial walls. Saturated fatty acids, high levels of cholesterol, elevated blood pressure, and elevated serum lipoprotein are well-knowm risk... 

LIPOPROTEINS. Blood plasma lipoproteins are prominent examples of the class of proteins conjugated with lipid. The plasma lipoproteins function primarily in the transport of lipids to sites of active membrane synthesis. Serum levels of low density lipoproteins (LDLs) are often used as a clinical index of susceptibility to vascular disease. 

When most lipids circulate in the body, they do so in the form of lipoprotein complexes. Simple, unesterified fatty acids are merely bound to serum albumin and other proteins in blood plasma, but phospholipids, triacylglycerols, cholesterol, and cholesterol esters are all transported in the form of lipoproteins. At various sites in the body, lipoproteins interact with specific receptors and enzymes that transfer or modify their lipid cargoes. It is now customary to classify lipoproteins according to their densities (Table 25.1). The densities are... 

Defects in Lipoprotein Metabolism Can Lead to Elevated Serum Cholesterol... 

F9 embryonal carcinoma cells have a simple set of growth supplements which are required for growth in serum-free medium insulin, transferrin, and fibronectin (Rizzino and Sato, 1978). Fibronectin is a component of the extracellular matrix and facilitates the attachment of the cells to the culture dish. In addition, high density lipoprotein (HDL) has been observed to promote the growth of F9 cells serum-free. 

Sample Collection and Enzyme Stability. Serum samples are collected with chemically clean, sterile glassware. Blood is allowed to clot at room temperature, the clot is gently separated from the test tube with an applicator stick, and the blood is centrifuged for 10 minutes at 1,000 g. If the red cells are known to contain the enzymes whose activity is being measured, as in the case of LD, even slightly hemolyzed serums must be discarded. When acid phosphatase is to be measured, the serum should be placed immediately in ice and processed as soon as possible, or it should be acidified by the addition of a small amount of sodium citrate. Anticoagulants such as EDTA, fluoride and oxalate inhibit some serum enzymes. However, heparin activates serum lipoprotein lipase. 

KAPLAN M and AVIRAM M (1999) Oxidized low density lipoprotein atherogenic and proinflammatoiy characteristics during macrophage foam cell formation. An inhibitory role for nutritional antioxidants and serum paraoxonase Clinical Chemistry Laboratory Medicine 37,111-9,1. 

Table 14.4 Serum ASAT, ALAT, creatinine, serum lipoproteins and oxidation kinetics before and after four week consumption of study breads ...

Jurgens, G., Hoff, H.F., Chisolm, G.M. and Esterbauer, H. (1987). Modification of human serum low density lipoprotein by oxidation - characterisation and pathophysiological implications. Chem. Phys. Lipids 45, 315-336. 

Esterbauer et al. (1991) have demonstrated that /3-carotene becomes an effective antioxidant after the depletion of vitamin E. Our studies of LDL isolated from matched rheumatoid serum and synovial fluid demonstrate a depletion of /8-carotene (Section 2.2.2.2). Oncley et al. (1952) stated that the progressive changes in the absorption spectra of LDL were correlated with the autooxidation of constituent fatty acids, the auto-oxidation being the most likely cause of carotenoid degradation. The observation that /3-carotene levels in synovial fluid LDL are lower than those of matched plasma LDL (Section 2.2.2) is interesting in that /3-carotene functions as the most effective antioxidant under conditions of low fOi (Burton and Traber, 1990). As discussed above (Section 2.1.3), the rheumatoid joint is both hypoxic and acidotic. We have also found that the concentration of vitamin E is markedly diminished in synovial fluid from inflamed joints when compared to matched plasma samples (Fairburn etal., 1992). This difference could not be accounted for by the lower concentrations of lipids and lipoproteins within synovial fluid. The low levels of both vitamin E and /3-carotene in rheumatoid synovial fluid are consistent with the consumption of lipid-soluble antioxidants within the arthritic joint due to their role in terminating the process of lipid peroxidation (Fairburn et al., 1992). 

There is a long-standing hypothesis that the microvasculature plays a pathological role in forms of chronic inflammatory polyarthritis, particularly RA (Rothschild and Masi, 1982). One of the proposed mechanisms of vascular damage in connective tissue disease is the direct action of a cytotoxic serum factor inducing endothelial cell damage. Blake et al. (1985) have su ested that the vascular abnormalities associated with RA may be linked to oxidized lipoproteins because they are cytotoxic to endothelial cells. 

Antibodies to very low density lipoprotein (VLDL) and LDL have been detected in the serum of patients with RA, but not control groups (Lazarevic et al., 1993). In these studies, 38% of patients with active RA tested positive for anti-VLDL/LDL antibodies whilst these autoantibodies were not detected in patients with psoriatic arthritis, osteoarthritis or healthy subjects. Lipoproteins were found in the dissociated components of circulating immune complexes in the serum of 30% of the RA patients. It was concluded that dyslipoproteinaemia in some RA patients may be due to an autoimmune component of the disease. 

Fairburn, K., Grootveld, M., Ward, R.J., Abiuka, C., Kus, M., Williams, R.B., Winyard, P.G. and Blake, D.R. (1992). Tocopherol, lipids and lipoproteins in knee-joint synovial fluid and serum from patients with inflammatory joint disease. Clin. Sci. 83, 657-664. 

Oncley, J.L., Gurd, F.R.N. and Melin, M. (1950). Preparation and properties of serum and plasma proteins XXV. Composition and properties on human serum d-lipoprotein. J. Am. Chem. Soc. 72, 458-464. 

Nishigaki, 1., Hagjhara, M., Tsunekawa, H., Maseki, M. and Yagi, K. (1981). Lipid peroxide levels of serum lipoprotein fractions of diabetic patients. Biochem. Med. 25, 373-378. 

Total cholesterol greater than 240 mg/dL (6.22 mmol/L) High-density lipoprotein less than 40 mg/dL (1.04 mmol/L) Triglycerides greater than 200 mg/dL (2.26 mmol/L) Fasting blood serum or plasma glucose... 

Metformin also has been shown to produce beneficial effects on serum lipid levels and thus has become a first-line agent for type 2 DM patients with metabolic syndrome. Triglyceride and low-density lipoprotein (LDL) cholesterol levels often are reduced by 8% to 15%, whereas high-density lipoprotein (HDL) cholesterol improves by approximately 2%. A modest weight loss of 2 to 3 kg (4.4—6.6 lb) also has been reported with metformin therapy. Metformin often is used in combination with a sulfonylurea or a thiazolidinedione for synergistic effects. 

Aro, A., Tuomilehto, J., Kostiainen, E., Uusitalo, U., Pietinen, P., Boiled coffee increases serum low density lipoprotein concentration, Metabolism, 36, 1027, 1987... 

The fate of injected liposomes is drastically altered by administration route, dose and size, lipid composition, surface modification, and encapsulated drugs. Liposomes encapsulating drugs are often administered iv, therefore, the stability of liposomes in plasma is important. When liposomes composed of PC with unsaturated fatty acyl chains are incubated in the presence of serum, an efflux of internal solute from the liposomes is observed. This increase in permeability is caused by the transfer of phospholipids to high density lipoprotein (HDL) in serum (55). To reduce the efflux of liposomal contents, cholesterol is added as a liposomal component... 

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