Plasma lipids, analysis

Wang GQ, DiPietro M, Roeder K et al. Cladistic analysis of human apolipoprotein a4 polymorphisms in relation to quantitative plasma lipid risk factors of coronary heart disease. Ann Hum Genet. 2003, 67 107-124. 

Apolipoprotein C-II can also be isolated from VLDL or HDL (H20, L5, N3). It contains 78 residues (J3) and has been shown by Chou-Fasman analysis to bind phospholipids (M26, M40), with three predicted helical sequences (M26). ApoC-II has attracted a great deal of attention because it activates one of the most important enzymes in plasma lipid metabolism, lipoprotein lipase, responsible for the hydrolysis of triglyceride in chylomicrons and VLDL. Sparrow and Gotto have summarized a number of studies on structure-function relationships (S52). These, taken together, indicate that there are separate functional domains in apoC-II, in that lipoprotein lipase activation is mediated by residues 55-78 and phospholipid binding by... 

Lipid analysis revealed low plasma cholesterol. A fasting lipid profile showed total cholesterol was 1 mmol/L (normal is 3.5-5.0 mmol/L). On fractionation, HDL was found to be normal while LDL was undetectable. Postprandial electrophoresis of plasma lipoproteins demonstrated the presence of HDL, but absence of chylomicrons, VLDL, and LDL. Plasma levels of apolipoprotein B (apoB) were well below the sensitivity of the test used for their measurement... 

Whitsel EA, Boyko EJ, Matsumoto AM, Anawalt BD, Siscovick DS. Intramuscular testosterone esters and plasma lipids in hypogonadal men a meta-analysis. Am J Med 2001 lll(4) 261-9. 

Schiller, J., Arnhold, J., Glander, H.-J. and Arnold, K., Lipid analysis of human spermatozoa and seminal plasma by MALDI-TOE mass spectrometry and NMR spectroscopy-effects of freezing and thawing, Chem Phys Lipids, 106 (2000) 145-156. 

Fatty acids affect CHD risk, in part, via effects on plasma lipids and lipoproteins. A meta-analysis of 60 controlled trials (Mensink et al., 2003) reported that saturated and trans fatty acids increase low-density lipoprotein cholesterol (LDL-C), whereas unsaturated fatty acids decrease LDL-C. Saturated fatty acids, MUFA, and PUFA all increase high-density lipoprotein cholesterol (HDL-C), whereas trans fatty acids do not. Both MUFA and PUFA decrease the TC to HDL-C ratio, whereas trans fatty acids increase it, and SFA have little effect (Fig. 20.4). 

Blood collected at each time point was allowed to remain on ice for 15 min prior to centrifugation at 1800g. Plasma was transferred to 5-ml cryogenic vials and stored at -8(PC until analyzed. Plasma lipids were extracted from duplicate 2.2-g plasma aliquots for isotope ratio analysis or from 0.25-g aliquots for HPLC quantification of retinol and /3C after addition of internal standard (retinyl acetate). Plasma aliquots were de-proteinized with 1 vol of ethanol and lipids extracted with 3 vol of hexane (Optima Grade, Fisher Scientific, Rochester, NY). 

Analysis of plasma lipids. HDL was separated by selective precipitation of veiy-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) by dextran sulphate and manganese chloride (20), and HDL cholesterol was measured by cholesterol determination of the clear supernatant fraction. Cholesterol and triglycerides were analysed by enzymic procedures (21,22). 

Data on fatty acid alterations in man have recently been reported (Horwitt and Harvey, 1962) to show that whereas the fatty acids of plasma lipids are rapidly altered to give an indication of short-term dietary effects (days), the erythrocyte fatty acids provide an estimation of what has been consumed during recent weeks or months. The depot fats from analysis of samples obtained by the syringe aspiration method of Hirsch et al. (1960) change quite slowly and give an estimate of what has accumulated during past years. 

Nonetheless, the debate over what constitutes the "ideal" fat is controversial, since it uses the term saturated fat without distinguishing individual SFA. In this sense, even a cursory analysis of some of the so-called saturated fats (e.g., palm oil, lard, tallow, butter, coconut oil) reveals that they have distinct profiles and empirically exert different metabolic effects. Accordingly, research in recent years has shifted toward elucidating the effects of specific dietary fatty acids in TAG, as opposed to specific classes of fats, on plasma lipids and lipoprotein metabolism [141]. 

Yao, H. T. and Chiang, M. T. 2006. Effect of chitosan on plasma lipids, hepatic hpid and fecal bUe acid in Hamsters. Journal of Food and Drug Analysis 14 183-189. 

See also Blood and Plasma. Clinical Analysis Glucose. Enzymes Immobilized Enzymes Enzyme-Based Electrodes Enzymes in Physiological Samples Industrial Products and Processes. Ethanol. Flow Injection Analysis Principles Detection Techniques. Food and Nutritional Analysis Alcoholic Beverages. Forensic Sciences Alcohol in Body Fluids. Immunoassays, Techniques Enzyme Immunoassays. Lipids Determination in Biological Fluids. Pesticides. Process Analysis Bioprocess Analysis. 

The translation of results from animal studies into a useful paradigm in humans has represented a major roadblock in CLA research. In many occasions, very impressive differences between groups found throughout the course of animal experimentation were diluted or absent when human intervention studies were performed. An example of these controversial results was observed when the decrease in body fat observed in humans is significantly less than that anticipated based on the results from animal studies. Terpstra conducted a meta-analysis on the effects of CLA on body composition and plasma lipids. Terpstra accounted for differences in CLA composition/intake, study design, energy intake, and initial BMI between studies to explain differential responses to CLA treatment (62). However, a classification of subjects on the basis of PPAR y and 8 polymorphisms was not considered. We propose that PPAR y and 8 polymorphisms may account for differential responses to CLA treatment. Consequently, subjects could be classified as responders or non-... 

Most of the studies providing data on CLA lipid class distribution in humans have focused on the analysis of serum or plasma lipids. Iverson et al. (10) and LLarrison et al. 

Stiibiger, G., Pittenauer, E., Belgacem, O., Rehulka, P, Widhalm, K., and Allmaier, G. 2009. Analysis of human plasma lipids and soybean lecithin by means of high-performance thin-layer ehromatography and matrix-assisted laser desorption/ionization mass speetrometry. Rapid Commun. Mass Spectrom., 23 2711-2723. 

Gas Chromatographic Analysis of the Plasma Lipides in Normal and Diabetic Subjects... 

Determination of Plasma Lipid Profiles by Automated Gas Chromatography and Computerized Data Analysis... 

Analysis of Blood Plasma Lipids Using Gas-Liquid Chromatography. Possibility of the Analysis of the Plasma Lipid Profile with the Chrom 41 Insbrument Vnitr. Lek. 22(4) 390-392 (1976) ... 

The primary diagnosis of peroxisomal disorders is made by the GC analysis of very long-chain fatty acids in plasma. Lipids have to be extracted and the analytes have to be derivatized by transesterification [9]. Historically the methyl ester formation was preferred, but alternative derivatives may be more suited for GC/MS analysis [14]. 

Kahlke and Richterich 1965) and plasma lipids of Refsum s (1946) case T. E. (Kahlke 1964 a). Methods and results were identical in both instances although a nuclear resonance spectrum was obtained only in the first case and a complete mass spectrometric analysis only in the second case. Phytanic acid was isolated by preparative gas-liquid chromatography from a mixture of fatty acid methyl esters. Traces of stearic acid were removed as the urea inclusion compound by treatment with a saturated methanolic solution of urea (Cason et al. 1953). After repeated crystallization from acetone at minus 70—80 C and drying under vacuum at minus 10 C, phytanic acid was obtained as a white crystalline powder with a melting point of minus 7—6 C. At room temperature phytanic acid is a colorless, odorless oil. The lack of hydrogen uptake with exhaustive... 

Numerous studies have dealt with the epithelium of the small intestine. Entry of fat from the bowel lumen into the mucosal cells appears to proceed as evidenced by the extreme degree of fat accumulation in these cells. Steatorrhea may result when the maximal absorptive capacity of these cells is exceeded. There is no evidence of selective absorption of certain fats, as could be shown by analysis of mucosal lipids and feces. In particular, the lowering of plasma linoleic acid concentration in a-jff-lipoproteinemia and other forms of malabsorption does not appear to be due to impairment of absorption of, essential fatty acids. After administration of diets rich in polyenoic acids Ways and Parmentier (1963) found more linoleic acid in mucosal phospholipids and triglycerides than was found with the normal diet. There was a simultaneous increase in the proportion of linoleate in plasma cholesterol esters. Linoleic acid, given for a period of three years, was absorbed to about 97 per cent (Frezal et al. 1966). Its administration resulted in a significant increase of the proportion of linoleic acid in the plasma lipid fatty acids. Normal values were reached in the triglyceride and phospholipid fractions (see table 6). 

P. A. J. Smith, and N. A. Hurley Idiopathic hyperlipemia and primary hypercholester-emic xanthomatosis. I. Clinical data and analysis of the plasma lipids. J. invest. Derm. 22, 33 (1954). 

In another example of normal-phase LC-MS analysis of human and monkey plasma lipids, a Luna Silica column (150 X 2.0 mm, 3-pm particle size) was employed with a linear gradient from mobile phase A (chloroform-methanol-ammonium hydroxide, 89.5 10 0.5) to B (chloroform-methanol-ammonium hydroxide-water, 55 39 0.5 5.5) [68]. Mass spectra were recorded in both positive-ion and negative-ion ESI modes with an MRM method. PC, SM, ceramide, and GluCer were monitored in the positive-ion mode and PE, PI, PS, PG, PA, and ganglioside M3 were measured in the negative-ion mode. A total of 153 lipid species were determined in the study. 

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