Lipid total

Figure 5 Electron density distributions along the bilayer normal from an MD simulation of a fully hydrated liquid crystalline phase DPPC bilayer. (a) Total, lipid, and water contributions (b) contributions of lipid components in the interfacial region.

A molecular variation of plasma membrane has been reported by Puccia et al. Reduction of total lipids (XL) content and significant variations of triglyceride (TG) and phospholipids (PL) fractions were observed as a consequence of exposure of C. intestinalis ovaries to TBTCl solutions. In particular, an evident TG decrease and a PL increase were observed, which probably provoked an increment in membrane fluidity, because of the high concentration of long chain fatty acids and, as a consequence, PL. This could be a cell-adaptive standing mechanism toward the pollutants, as observed in Saccharomyces cerevisiae. Also the increase in the content of the polyunsaturated fatty acids (PUPA), important in the synthesis of compounds such as prostaglandin which are present in the ovary in a stress situation, was probably a consequence of a defense mechanism to the stress provoked by the presence of TBTCl. 

Bligh, E.G. and E)yer, W.J. 1959 A rapid method of total lipid extraction and purification. Canadian Journal of Biochemical Physiology 37 911-917. 

Glycosphingolipids (GSLs) (neutral GSLs, gangliosides, and complex species, including the ABO blood group substances) constitute about 5-10% of the total lipid. 

Total Lipids mg/100 ml Replicates Washed with Bloors Rgt. Replicates (not washed) Difference of Means... 

Lipid Screening. The problems of lipid analysis in the newborn is difficult because of the fact that most methods for analysis for lipids require substantial amounts of serum, yet a total lipid determination is very important in various types of disease. This problem can be solved by thin-layer chromatography (59). Figure 38 shows a typical pattern obtained when an extract 7rom 10 microliters of serum is subjected to thin-layer chromatography. If these specimens are scanned, and an internal standard is run, one can obtain a rough approximation of the distribution of the various lipids in the serum. This is shown in Figure 39, in which a normal specimen is run in an adult. 

Exposures of 10 weeks (5 days/week) to 2,500 mg/kg/day trichloroethylene in com oil by gavage resulted in altered myelin thickness in the rat mental nerve, a branch of the trigeminal nerve (Barret et al. 1991). Effects of similar exposures on the rat trigeminal nerve included decreased fiber diameter and altered fatty acid composition in total lipid extracts, indicative of demyelination (Barret et al. 1992). Stronger effects were seen with the trichloroethylene decomposition product dichloroacetylene. 

The new lipid occurred only in the plasma hpids of newborns and was not present in membrane hpids of red cell membranes or platelets. Total lipids were extracted from plasma and from red blood cell membranes and platelets. A total lipid profile was obtained by a three-directional PLC using silica gel plates and was developed consecutively in the following solvent mixtures (1) chloroform-methanol-concen-trated ammonium hydroxide (65 25 5, v/v), (2) chloroform-acetone-methanol-ace-tic acid-water (50 20 10 15 5, v/v), and (3) hexane-diethyl ether-acetic acid (80 20 1, v/v). Each spot was scraped off the plate a known amount of methyl heptadecanoate was added, followed by methylation and analysis by GC/MS. The accmate characterization of the new lipid was realized using NMR technique. 

After the extrachon of total lipids from four different genotypes of flax seed (Linum usitassimum) differing markedly in their acyl composihon, PTLC was used for the isolahon of different lipid classes in the neutral lipid frachon [69]. Application of planar chromatographic methods, including PTLC, in the separahon of food lipids has been reviewed with 40 references by Olsson [70]. The polar lipid fraction of niger seed (Guizotia abyssinica Cass.) collected from different regions of Ethiopia could be separated by PTLC on silica gel [71]. 

The plasma concentration of LP(a) has been measured in patients with RA and significantly increased levels have been reported (Rantapaa-Dahlqvist et al., 1991). Whilst the plasma concentration of cholesterol is lower in patients with RA than in normal controls the concentration of LP(a) is increased, whether or not the concentration is corrected for total lipids. Rantapaa-Dahlqvist et al. (1991) surest that LP(a) may be an important cause of coronary heart disease in patients with RA. 

Gn Pig (NS) 11 d 1 hr/d 20 M (decreased cerebral hemisphere and brain stem total lipids and phospholipids) ... 

Haider SS, Hasan M. 1984. Neurochemical changes by inhalation of environmental pollutants sulfur dioxide and hydrogen sulfide Degradation of total lipids, elevation of lipid peroxidation and enzyme activity in discrete regions of the guinea pig brain and spinal cord. Ind Health 22 23-31. 

Haider SS, Hasan M, Islam F. 1980. Effect of air pollutant hydrogen sulfide on the levels of total lipids, phospholipids cholesterol in different regions of the guinea pig brain. Indian J Exp Biol 18 418-420. 

Tulasi SJ, Reddy PUM, Rao JV. 1992. Accumulation of lead and effects on total lipids and lipid derivatives in the freshwater fish Anabas testudineus (Bioch). Ecotoxicol Environ Safety 23 33-38. 

FIGURE 10.12 The mole ratio of carotenoid/phospholipid and carotenoid/total lipid (phospholipid + cholesterol) in raft domain (detergent-resistant membrane, DRM) and bulk domain (detergent-soluble membrane, DSM) isolated from membranes made of raft-forming mixture (equimolar ternary mixture of dioleoyl-PC (DOPC)/sphingomyelin/cholesterol) with 1 mol% lutein (LUT), zeaxanthin (ZEA), P-cryptoxanthin (P-CXT), or P-carotene (P-CAR). 

Most commonly, the lipid metabolism pathology is manifest as hyperlipemia (elevated concentration of lipids in blood) and tissue lipidoses (excessive lipid de-position in tissues). Normally, the lipid contents in the blood plasma are total lipids, 4-8 g/litre triglycerides, 0.5-2.1 mmol/litre total phospholipids, 2.0-3.5 mmol/litre total cholesterol, 4.0-8.0 mmol/litre (esterified cholesterol accounts for 2/3 of total cholesterol). 

Proulx [30] summarized the published lipid compositions of BBM isolated from epithelial cells from pig, rabbit, mouse and rat small intestines. Table 3.1 shows the lipid make-up for the rat, averaged from five reported studies [30], On a molar basis, cholesterol accounts for about 50% of the total lipid content (37% on a weight basis). Thus, the cholesterol content in BBM is higher than that found in kidney epithelial (MDCK) and brain endothelial cells (Table 3.1). Slightly different BBM lipid distribution was reported by Alcorn et al. [31] here, the outer (luminal) leaflet of the BBM was seen to be rich in sphingomyelin content, while the inner leaflet (cytosol) was rich in PE and PC. Apical (brush border) and basolateral lipids are different in epithelia. The basolateral membrane content (not reported by... 

Solvent extraction of the total lipid extracts from ceramic sherds and charred surface residues Isolation of DAGs and TAGs on silica solid phase cartridges Formation of lithiated adducts from the TAG fraction by addition of 2% lithium chloride in methanol... 

Extraction is usually performed in a solvent such as dichloromethane (DCM), chloroform, methanol, or a mixture of them, to obtain the so-called total lipid extracts (TLEs). 

Figure 14.10 GC profiles of total lipid extracts of archaeological bones showing the wide spread survival of lipids, in particular cholesterol and its derivatives...

The correct ratio of lipid constituents is important to form stable liposomes. For instance, a reliable liposomal composition for encapsulating aqueous substances may contain molar ratios of lecithin cholesterol negatively charged phospholipid (e.g., phosphatidyl glycerol (PG)) of 0.9 1 0.1. A composition that is typical when an activated phosphatidylethanolamine (PE) derivative is included may contain molar ratios of phosphatidylcholine (PC) cholesterol PG derivatized PE of 8 10 1 1. Another typical composition using a maleimide derivative of PE without PG is PC male-imide-PE cholesterol of 85 15 50 (Friede et al., 1993). In general, to maintain membrane stability, the PE derivative should not exceed a concentration ratio of about l-10mol PE per lOOmol of total lipid. 

Biotinylation may be done before or after liposome formation, but having a stock supply of biotin-modified PE is an advantage, since it can then be used to test a number of liposomal recipes. In addition, only a very small percent of the total lipid should be biotinylated to prevent avidin-induced aggregation in the absence of antigen. It is difficult to control precisely... 

Prepare a biotinylated liposome construct by first dissolving in chloroform, the lipids DMPC cholesterol dicetylphosphate (Sigma) at mole ratios of 5 4 1, and adding to this solution 0.1 mol percent B-PE. Larger mole ratios of B-PE to total lipid may result in nonspecific aggregation of liposomes in the presence of avidin. Maintain all lipids under an inert atmosphere to prevent oxidation. 

Prepare a liposome suspension, containing PE, at a total-lipid concentration of 5mg/ml in 0.1M sodium phosphate, 0.15M NaCl, pH 6.8. Maintain all lipid-containing solutions under an inert gas atmosphere. Degas all buffers and bubble them with nitrogen or argon prior to use. 

Dissolve the protein or peptide to be conjugated at a concentration of lOmg/ml in 0.5M sodium carbonate, pH 9.5. Mix the activated liposome suspension with the polypeptide solution at the desired molar ratio to effect the conjugation. Mixing the equivalent of 4 mg of protein per mg of total lipid usually results in acceptable conjugates. 

Periodate-oxidize a liposome suspension containing glycolipid components according to Section 2 (this chapter). Adjust the concentration of total lipid to about 5mg/ml. 

Recently, a quantitative electrospray ionization/mass spectrometry method (ESI/MS) has been developed to analyze the molecular profile, or hpidome of different lipid classes in very small samples. In this method, total lipid extracts from tissues or cultured cells can be directly analyzed. By manipulating the ionization method, the mass spectrographs of polar or even non-polar lipids can be obtained [8]. This method and the use of lipid arrays allow precise and quantitative identification of the lipid profile of a given tissue, and map functional changes that occur. 

Protein and lipid figures in percentage dry weight all others in percentage total lipid weight. Tlasinalogens are primarily ethanolamine phosphatides. 

The data in Table 4-1 indicate that myelin accounts for much of the total lipid of white matter, and that the lipid composition of gray matter is quite different from that of myelin. The composition of brain myelin from all mammalian species studied is very much the same. There are, however, some species differences for example, myelin of rat has less sphingomyelin than does that of bovine or human (Table 4-1). Although not shown in the table, there are also regional variations for example, myelin isolated from the spinal cord has a higher lipid-to-protein ratio than brain myelin from the same species. 

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