Tg Fraction Research Articles

The effect of dietary fish oil supplement upon the content of dihomo-gammalinolenic acid in human plasma phospholipids

Patients (n = 23) with definite or classical rheumatoid arthritis were given 18 g/day fish oil in gelatin capsules which provided 3.2 g/day EPA and 2.0 g/day DHA. The treatment period was 12 weeks followed by a 4 week washout period. Fish oil supplementation to the diet resulted in a substantial increase in the content of EPA and DHA in each of the plasma fractions examined (PL, TG, and CE). Little change was seen in the AA level of the TG and CE fractions but a modest decrease in AA was seen in PL. However the intake of fish oil caused a significant depression in the content of DGLA in the PL (p<0.005) and CE (p<0.01) fractions relative to baseline values. All changes had reverted to near baseline levels 4 weeks after dietary intervention. Since DGLA is the precursor of PGE 1, which has been shown to be anti-inflammatory, our findings suggest that the anti-inflammatory effects of fish oil consumption could be mitigated by an associated reduction in DGLA.

Changes in Lipid Biosynthesis During Development of the House Cricket, Acheta domesticus (Orthoptera: Gryllidae)

The incorporation of [I-14·e] acetate into lipid was monitored during the final three stadia of male and female house crickets, Acheta domesticus (L.). Large fluctuations in lipid bio-synthesis –total lipid synthesis and the synthesis of various classes of lipid were observed for males and females during development. All three stadia showed low levels of radiolabel incorporation near ecdysis. Peak incorporation occurred at midstadium. All lipid classes examined (triacylglycerol [TG], phospholipid [PL], hydrocarbon [HC], diacylglycerol, alcohol, and free fatty acid) showed similar patterns. No differences in lipid biosynthesis were observed between male and female nymphs. However, adult females showed a distinct peak of [1·14. C] acetate incorporation into total lipid and into the TG fraction 2–3 d after ecdysis. This peak corresponded to the initiation of vitellogenesis. Males showed a more gradual increase in lipid biosynthesis through day 7. Near ecdysis, the relative distribution of radioactivity showed that the radio labeled acetate was incorporated into HC and PL in a higher proportion than it was into TG. By day 2, about 70% of the lipid synthesized was incorporated into TG by males and females. In general, the large changes in lipid synthesis correlate closely with the physiological needs of the insect associated with its development.

Separation and Immunological Characterization of Membrane Fractions from Barley Roots

Tonoplast and plasma membranes (PM) were isolated from barley roots (Hordeum vulgare L. cv California Mariout 72) using sucrose step gradients. The isolation procedure yielded sufficient quantities of PM and tonoplast vesicles that were sealed and of the right orientation to measure ATP-dependent proton transport in vitro. The proteins of the endoplasmic reticulum, tonoplast-plus-Golgi membrane (TG) and PM fractions were separated on sodium dodecyl sulfate gels, and immunoblots were used to test for cross-contamination between the fractions. Proteins that cross-reacted with antibodies to the PM ATPase from corn roots and Neurospora were greatly enriched in the PM fraction, as were proteins that cross-reacted with monoclonal antibodies to an arabinogalactan protein from the PM of tobacco cells. Proteins that cross-reacted with antibodies to the 58- and 72-kilodalton subunits of the tonoplast ATPase of red beet storage tissue were greatly enriched in the TG fraction. The results with immunoblots and enzyme assays indicated that there was little cross-contamination between the tonoplast and PM vesicles. The molecular weights and isoelectric points of the PM ATPase and the tonoplast ATPase subunits were also determined using immunoblots of two-dimensional gels of the PM and TG proteins.

Fatty acid composition of acylglycerol and free fatty acid fractions of fat body, haemolymph and muscle lipids in tenebrio molitor l. (Coleoptera Tenebri-Onidae) larvae

The fatty acid compositions of lipid classes in non-esterified fatty acid and in acylglyceroi fractions of Tenebrio molitor L. (Coleoptera: Tenebrionidae) larvae were identified in fat bcdy, haemolymph and muscle by Gas-T iquid Chromatography. The identified 18 fatty acids had sıraight, mostly odd numbered carbon chains wîth C numbers ranging fi’om 14 tc 22. Some of the n3 and n6 members of polyenoics were also separated. Quantitative and some gualitative differences wçre observed in fatty aCid compositions between the lipid classes of the same tissue and between a given lipid fraction of ali tissues. The main saturated fatty acid was C 16:0 in all the lipid classes. Ali the other salurates, namely C 14:0, C 17:0, C 18:0 and C 20:0, were also e isted in various proportions. In FFA fractions C 18:0 was distinctively hıgher than in acylglycerol fractions. High nnsaturation was observed primarily as a resnlt of high proportions of C 18: 1 an .l C 20:4 n3 in 1,2-JÜGj TG and FFA fractions and in MG and 1,3-DG fractions respectively.

Occurrence and metabolism of arachidonic acid in the housefly, Musca domestica (L.)

Gas-liquid chromatography (GLC) on polar, non-polar and capillary columns and chemical ionization-gas chromatography-mass spectrometry (CI-GC-MS) were used to verify the presence of arachidonic acid (20:4) and eicosatrienoic acid (20:3, n-6) at low levels in adult male and female houseflies. The phospholipid (PL) fraction contained the highest amounts of these fatty acids. An analysis of the distribution of radiolabelled 20:4, 20:3 (n-6), oleic acid (18:1) and palmitic acid (16:0) when injected into the insect showed that a large proportion of the radioactivity from 20:4 was incorporated into the PL fraction, whereas the radioactivity from the other fatty acids was recovered at higher levels in the free fatty acid and triacylglycerol fractions. When [ 3H]20:4 was injected into the haemolymph it was rapidly sequestered into the PL fraction. Over 80% of the recovered radiolabel from 20:4 was found in PL, 10 min after injection. Approximately one-half of the [ 3H]20:4 in the PL was recovered in phosphatidylethanolamine (PE), the major PL of the housefly. Liberation of the acyl moiety from the 2 position by phospholipase A 2 showed that over 80% of the sequestered 20:4 was in the 2-position. Radio-GLC showed that the injected [ 3H]20:4 was incorporated intact into PL. When large amounts of unlabelled 20:4 were injected into the insect or were included in the diet of adult insects prior to administration of [ 3H]20:4, then larger amounts of radioactivity were recovered in the TG and FFA fractions. These data document the presence of 20:4 in the housefly and demonstrate that injected [ 3H]20:4 was readily incorporated into PL specifically into the 2-position.

A TG study of the solvolytic breakdown of a crosslinked double base propellant

The solvolytic breakdown and dissolution of obsolete crosslinked propellants may be carried out with surprising ease with subsequent recovery of expensive constituents in high yields. An approach was adopted in which degradation was initiated in composites while they were swollen in an appropriate solvent containing additives capable of reacting with and cleaving chemical bonds located in the polymer chain. A kinetic study of the solvolysis reaction of the urethane linkages in a crosslinked double base propellant in ethanolamine solution was followed by thermogravimetry. Kinetic data were obtained using the propellant fraction reacted, which was expressed as the product of the TG fraction at 200°C and the molarity of the ethanolamine solution. First-order rate constants for the reaction were found to be higher in the mixed solvent of toluene-isopropanol compared with isopropanol probably because of their differences in swelling behavior. Activation energies for solvolysis were about 5 kcal mole −1 in toluene-isopropanol and about 8 kcal mole −1 in isopropanol. Nitroglycerin present as a plasticizer in double base propellants was extracted prior to kinetic analysis because it was found to react with the ethanolamine. The solvolytic degradation of the propellant binder with nitrocellulose was about three times as fast as the binder without nitrocellulose. A variable heating rate study showed that the binder with or without nitrocellulose had the same activation energy for thermal decomposition. Kinetic data indicates that nitrocellulose appears to catalyze the solvolytic degradation but not the thermal degradation of a crosslinked double base propellant binder.

Receptors for the third complement component on a proportion of large granular lymphocytes from human peripheral blood.

Large granular lymphocytes (LGL) are nonadherent cells with cytoplasmic azurophilic granules, avid receptors for the Fc portion of IgG, and a paranuclear localization of alpha-naphthyl acid esterase or acid phosphatase. LGL constitute the bulk of TG cells (cells with receptors for sheep erythrocytes and for IgG molecules) and null cells (non-T, non-B cells). In the present study we demonstrate that 20-33% of the circulating human LGL express receptors for the third complement component (C3R). When TG cell or null cell fractions from normal individuals or non-T cells from a patient with infantile agammaglobulinaemia (which contained almost exclusively LGL) were rosetted with erythrocytes coated with antibody and complement, a variable number of C3R-bearing cells were detected. Such cells were isolated and analysed further; the great majority of them displayed the cytochemical and ultrastructural features of LGL.

Preliminary studies on the lipid metabolism ofNeomysis integer, Involving Labelled Feeding Experiments

A series of controlled, labelled feeding experiments were carried out onNeomysis integerin order to investigate its lipid metabolism. The techniques of thin-layer chromatography, preparative column chromatography, analytical and preparative gas-liquid chromatography and low-background14C counting were used to follow the incorporation of a14Clabelled fraction from a range of diets into the animal's lipid.Neomysis integerwas found to be capable of converting dietary starch or short-chain saturated fatty acids to longchain polyunsaturated fatty acids, which were then incorporated into the TG and PL fractions.

Incorporation of [1- 14C]Palmitate into lipids and the pattern of haemolymph proteins in diapause and non-diapause larvae of the beetle Trogoderma granarium

Trogoderma granarium lipids were separated into 10 classes by thin-layer chromatography. The lipids detected were phospholipids, monoglycerides, diglycerides, sterols, free fatty acids (FFA), triglycerides, sterol esters, and hydrocarbons. [1- 14C]Palmitate is esterified rapidly into TG. After 0.5 hour a third of the total label was found in the TG fraction with a concomitant loss in the FFA. The rate of incorporation was similar in non-diapause and diapause larvae. Electropherograms from diapause and control larvae showed differences in the protein pattern which may reflect the physiological and nutritional state of the two groups of animals.