bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of the dipalmitoyl species of diacyl glycerophosphocholine by rabbit alveolar macrophages
Authors: Nakagawa Yasuhito , Waku Keizo 
Published: November 2006

AbstractThe distribution of radioactivity among the molecular species of diacyl glycerophosphocholine of rabbit alveolar macrophages was determined after incubation with [3H]glycerol and 1‐[14C]palmitoyl‐sn‐glycero‐3‐phosphocholine. The highest percentage of radioactivity of [3H]glycerol was found in the dipalmitoyl species (35% of the total) followed by the 1‐palmitoyl‐2‐linoleoyl (23.6%) and 1‐stearoyl‐2‐linoleoyl plus 1‐palmitoyl‐2‐oleoyl species (19.7%) during the first 30 min incubation. The radioactivity of the dipalmitoyl species reached a maximum at 120 min incubation and decreased thereafter, although the radioactivities of other molecular species still increased. In contrast to the [3H]glycerol labeling, only 4% of the total radioactivity in diacyl glycerophosphocholine derived from 1‐[14C]palmitoyl glycerophosphocholine was found in the dipalmitoyl species; 80% of the radioactivity was located in the 1‐palmitoyl‐2‐arachidonoyl species at 10 min incubation. The present results indicate that the dipalmitoyl species of diacyl glycerophosphocholine are synthesized predominantly via a de novo pathway and not the deacylation‐reacylation pathway in rabbit alveolar macrophages.
Subcellular distribution of dietary β‐carotene in chick liver
Authors: Mayne Susan Taylor , Parker Robert S. 
Published: November 2006

AbstractStudies were conducted examining the subcellular distribution of β‐carotene (BC), α‐tocopherol (E) and retinol (A) in livers of control and BC‐fed male White Leghorn chicks. Chicks were fed Cornell B chick starter diet with or without the addition of 0.5 g BC/kg diet. A first study involved liver fractionation by differential centrifugation in 0.25 M sucrose followed by high performance liquid chromatographic (HPLC) analyses of all fractions for quantitation of BC, E and A. A second study employed both intravenous injection of Triton WR‐1339 four days prior to sacrifice and centrifugation in 1.0 M sucrose to separate mitochondria from lysosomes more efficiently. Fraction purity was assessed by marker enzyme analyses. Results showed that (i) chick liver accumulated BC; (ii) BC‐fed chicks had higher concentrations of BC in all fractions relative to controls, and (iii) the mitochondrial fraction contained the highest concentration of BC, followed by lysosomes, microsomes and nuclei, respectively. Plasma BC increased more than fivefold in BC‐fed chicks. Dietary BC increased A and E levels in liver and in the mitochondrial and lysosomal fractions while the plasma E level was decreased. Plasma A changed little with BC feeding. While dietary BC had no effect on fatty acid composition of subcellular fractions, the increase in E resulted in a large increase in the molar ratio of E to polyunsaturated fatty acids. The incorporation of BC and increased amounts of E into cellular mebranes presumably would result in increased resistance to peroxidative damage.
A method for isolation of milk fat globules
Authors: Patton Stuarf , Huston Gail E. 
Published: November 2006

AbstractThe traditional procedure for isolating milk fat globules involves repeated cycles of centrifuging to obtain globules and redispersion of them in fresh buffer to eliminate other milk components. We have evaluated a simpler, less manipulative method whereby globules are centrifuged out of the milk and through an overlying buffer layer. Human milk samples ranging from 0.1 to 35 ml were centrifuged at 1500×g for 20 min after deposition under a suitable quantity of buffer. This yielded purified globules, in less time, which could be dispersed more satisfactorily than those by the traditional procedure. Protein, phospholipid and cholesterol contents of globules by the two methods were quite similar. A lower protein content (10.4 vs 13.2 mg/g of lipid) was characteristic of globules prepared by the multiple wash method. However, large differences could not be seen in gel electrophoresis patterns of the proteins. By using plastic centrifuge tubes, tube freezing and cleavage just below the globule layer enables clean separation of globule and nonglobule phases for analysis of milk component distributions. Macro (5 to 35 ml of sample) and micro (200 μl or less) versions of the method are described. Limited trials showed that the method can be applied satisfactorily to cow's and goat's milks, but for highly pure globules a deeper buffer column than that used with human milk is required because of their much higher casein content.
Two geometrical isomers of linoleic acid: Improved total syntheses
Authors: Ofsuki Tetsuo , Brooker Robert F. , Funk Max O. 
Published: November 2006

AbstractThe total syntheses of 9(Z),12(E)‐ and 9(E),12(Z)‐octadecadienoic acids have been carried out. A useful intermediate in both syntheses, 8‐bromo‐octanoic acid, recently has become available from commercial sources. This compound has been used to expedite the preparation of these isomers. The remaining carbon atoms were derived from propargyl alcohol along with either 1‐heptyne or acetylene and 1‐bromopentane. Because the overall yield for each sequence was roughly 15% and there were no extraordinary reaction conditions in any of the synthetic steps, the compounds could be prepared readily in multiple gram quantities. The syntheses of the two compounds were supported by data from a variety of spectroscopic techniques.
Mammary transfer and metabolism in the rat of halogenated fatty acids of halogenated olive oil
Authors: Conacher H. B. S. , Chadha R. K. , Lawrence J. F. , Charbonneau S. M. , Bryce F. 
Published: November 2006

AbstractTo assess possible incorporation of halogenated fatty acids into the neonate via the milk, a 4‐day study was carried out in which lactating Wistar rats were orally dosed with either brominated olive oil (BOO) (0.6 g/kg body wt/day) or chlorinated olive oil (COO) (0.4 g/kg body wt/day) for the first 4 days. On days 1–5 inclusive 2 pups per litter were sacrificed and the stomach curd and livers analyzed for halogenated fatty acids by gas liquid chromatography (GLC). On day 5 all dams also were sacrificed and their livers and adipose tissue similarly analyzed. With BOO, brominated fatty acids (bfa) accumulated in both the milk lipids and neonate liver lipids, and appeared to plateau on day 4 at levels of 2% and 5% respectively. In contrast to the BOO in which approximately 100% of the bfa was dibromostearis (DBS), the milk bfa comprised 79% (DBS), 9% dibromopalmitic (DBP) and 12% dibromomyristic (DBM) acids, suggesting maternal metabolism to the shorter chain brominated acids. In the neonate liver lipids the bfa composition was 47% (DBS), 12% (DBP) and 41% (DBM), suggesting either further metabolism in the neonate and/or preferential accumulation of the shorter chain brominated acids. The analysis of maternal tissue indicated very low bfa residues, contrary to previous studies in non‐lactating rats. Similar results were obtained with COO.
Fatty acid and squalene compositions of mediterraneanCentrophorus SPP egg and liver oils in relation to age
Authors: Peyronel D. , Artaud J. , Iatrides M. C. , Rancurel P. , Chevalier J. L. 
Published: November 2006

AbstractThe liver oil content of seven MediterraneanCentrophorus spp. were studied together with the oil of one unfertilized egg and one yolk bag. The relative weight of the liver ranges from 15 to 29% of total body weight; 63 to 89% of the liver weight is oil. Squalene, the major component (49–89% in oil) of the unsaponifiable fraction, is directly quantified by GLC following TLC separation. The squalene level increases with the age of the animals. More than 50 fatty acid species were identified. Among them, the most abundant are: 16∶0 (22–27%), 18∶1ω9 (21–36%) and 22∶6ω3 (2–18%). The level of ω3‐fatty acids, essential in the fishes, shows a maximum in the egg (26%), decreases to a minimum in the young (5%) and stabilizes to an intermediate level in the adult (12%).
The distribution of serum high density lipoprotein subfractions in non‐human primates
Authors: Nelson Charles A. , Greer William E. , Morris Manford D. 
Published: November 2006

AbstractThe ultracentrifugal flotation patterns in 1.2 g/ml solvent and ultracentrifugal gradient distribution of high density lipoproteins (HDL) from the primates‐human, apes and monkeys‐were determined, with emphasis on the gorilla species of apes and rhesus monkeys. Diets for non‐human primates were commercial chow, which is low in cholesterol. Molecular weights and protein, cholesterol, phospholipid and triglyceride compositions of various density fractions were determined on human, gorilla and rhesus HDL. The HDL2/HDL3 ratio was determined from the two peaks observed upon flotation in high salt in the analytical ultracentrifuge. The HDL2 of all three species of apes‐gorillas (Gorilla gorilla), chimpanzees (Pan troglodytes) and orangutans (Pongo pygmaeus)—was always greater than HDL3, while that of all six species of Old World monkeys‐Rhesus (Macaca mulatta), sooty mangabeys (Cercocebus atys), cynomolgus (Macaca fascicularis), stumptails, (Macaca arctoides) patas (Erythrocebus patas) and African greens (Cercopithecus aethiops)—was less. In addition, the HDL3 concentration in five gorillas was about 15 mg/dl as cholesterol while the HDL2 concentration was 92 mg/dl, much lower and higher, respectively, than humans. HDL2 of gorillas was similar in density and molecular weight to that of humans. The distribution of densities in gorilla HDL was predominantly in HDL2, while rhesus HDL usually, but not always, was unimodal, having a density distribution similar in heterogeneity to human HDL3, but somewhat less dense (peaking at 1.109 vs 1.129 g/ml). The molecular weight of rhesus HDL was about the same as human HDL3 in all three density subfractions and at the peak density. Likewise, the chemical compositions were similar for the subfractions 1.10–1.125 and>1.125 g/ml for rhesus HDL and human HDL3. Consequently most but not all chow‐fed rhesus HDL was very similar to human HDL3, but lighter in density.
Milk fat structure of a patient with type 1 hyperlipidemia
Authors: Myher J. J. , Kuksis A. , Steiner G. 
Published: November 2006

AbstractStructural analyses were performed on milk fat samples obtained 3–10 days postpartum from a lactating patient with primary Type 1 hyperlipidemia. The milk triacylglycerols contained 3–7% C10, 14–21% C12, 20–30% C14, 22–26% C16 and 20–30% C18 (largely oleic) acids. Gas liquid chromatographic (GLC) analyses of the X‐1,3‐ and X‐1,2‐diacylglycerols on polar siloxane columns showed a markedly non‐random association of acyl chains. Stereospecific analyses indicated that the short chain length fatty acids were confined essentially to the sn‐3‐position of the triacylglycerol molecule. Furthermore, these acids were largely absent from the phosphatidylcholines and the endogenous sn‐1,2‐diacylglycerols of the milk fat. It is concluded that the short chain fatty acids are incorporated into the milk triacylglycerols during the final stage of biosynthesis via the phosphatidic acid pathway, and that the overall fatty acid distribution is consistent with the 1‐random 2‐random 3‐random hypothesis.
Studies of triacyglycerol structure of very low density lipoproteins of normolipemic subjects and patients with type III and type IV hyperlipoproteinemia
Authors: Myher J. J. , Kuksis A. , Breckenridge W. C. , Little J. A. 
Published: November 2006

AbstractThe triacylglycerols of very low density lipoproteins (VLDL‐TG) were analyzed in samples from normal subjects and patients with Frederickson’s Type III and Type IV hyperlipoproteinemia. VLDL were obtained by conventional ultracentrifugation, and the triacylglycerols were isolated by thin‐layer chromatography (TLC). Representative sn‐1,2(2,3)‐ and sn‐1,3‐diacylglycerols were generated by Grignard degradation of the triacylglycerols, and were resolved by TLC on borate‐treated silica gel. The molecular association of the fatty acids in the diacylglycerol moieties was determined by gasliquid chromatography with mass spectrometry (GC/MS) of the tertiary‐butyldimethylsilyl ethers. The positional distribution of the fatty acids was established by the Brockerhoff stereospecific analysis. The results showed a marked asymmetry in the distribution of the fatty acids in all samples, with the saturated acids predominantly in the sn‐1‐position and the unsaturated fatty acids distributed about equally between the sn‐2‐ and sn‐3‐positions. In all instances, the molecular species composition of the sn‐1,2‐, sn‐2,3‐ and sn‐1,3‐diacylglycerols was found to be similar to that calculated for 1‐random 2‐random 3‐random distribution of triacylglycerols. There were marked differences in the quantitative composition of the molecular species of the VLDL‐TG between normal subjects and patients, but these discrepancies were attributed to differences in the fatty acid composition of the samples.
Purification of lysosomal cholesteryl ester hydrolase from rat liver by preparative isoelectric focusing
Authors: Klemets Rabbe , Lundberg Bo 
Published: November 2006

AbstractIon‐exchange chromatography and preparative isoelectric focusing (PIEF) were compared to produce a stable rat liver lysosomal cholesteryl ester hydrolase of high specific activity. The PIEF purification method proved to be more rapid and easier to perform. PIEF purification involved the following steps: i) osmotic shock of the lysosome fraction, ii) (NH4)2 SO4 precipitation (10–70%, w/v), iii) Sepharose CL‐6B gel filtration, and iv) PIEF. The enzyme was purified 60–120‐fold with a yield of 2–4%. The activity of the purified enzyme was best restored by stabilizing with a 0.5% (w/v) albumin solution. The purified enzyme produced one major band on SDS‐polyacrylamide gel electrophoresis having a MW of 58,500 daltons. Gel filtration showed a MW of 58,000 daltons. The optimum pH of the enzyme was 4.5, and the isoelectric point was 6.0–6.2. The specific activity of hydrolysis of cholesteryl oleate and triolein increased by similar rates during purification.
Dihomo‐γ‐linolenic acid reverses hypertension induced in rats by diets rich in saturated fat
Authors: Hassall Cedric H. , Kirtland Stephen J. 
Published: November 2006

AbstractThis study has shown that hypertension induced in rats by a diet rich in saturated fat (16% coconut oil, 4% palmitic acid by weight) is reversed by the addition of the essential fatty acid, dihomo‐γ‐linolenic acid (DHLA), at 5.0% but not at 0.5% of dietary energy. This potent effect of DHLA has been attributed to modulation of prostaglandin biosynthesis.
Brominated fatty acid distribution in tissues and fluids of rats fed brominated vegetable oils
Authors: Lawrence James F. , Chadha Rajinder K. , Iverson Frank , McGuire Peter , Conacher Henry B. S. 
Published: November 2006

AbstractRats dosed orally for four days with 0.24 g/kg body weight per day of brominated olive oil (BOO) or brominated sesame oil (BSO) were found to accumulate dibromostearic (DBS) acid (from BOO) and DBS and tetrabromosteric (TBS) acids (from BSO) in the liver, heart and adipose tissue. The metabolites, dibromopalmitic, and dibromomyristic acids (from BOO and BSO), as well as their tetrabromo‐analogues (from BSO) were found as determined by gas chromatography with halogen specific detection and confirmed by gas chromatography‐mass spectrometry. Blood contained no DBS, TBS or metabolites. However, inorganic bromide was observed in both blood and urine while none was observed in the feces. The latter contained significant quantities of both DBS and TBS but showed the absence of the four brominated metabolites.
Incorporation of arachidonic acid and eicosapentaenoic acid into phospholipids by polymorphonuclear leukocytes in vitro
Authors: Tou Jen‐Sie 
Published: November 2006

AbstractThe present study demonstrated that the patterns of the incorporation of [1‐14C] arachidonic acid and [1‐14C] eicosapentaenoic acid into individual phospholipids by polymorphonuclear leukocytes were similar. However, human leukocytes exhibited higher activity than guinea pig periotoneal leukocytes in the formation of arachidonoyl‐ and eicosapentaenoyl‐phosphatidic acid. Cells from both origins showed a decrease of label in phosphatidylcholine accompanied by an increase of label in phosphatidylethanolamine after a longer period (30–120 min) of incubation, suggesting that part of the arachidonoyl or eicosapentaenoyl moiety in phosphatidylethanolamine may be derived from that of phosphatidylcholine. The observed difference between human cells and elicited cells in the time‐course of the incorporation of both fatty acids into phosphatidylcholine and phosphatidylethanolamine appears to be due to different contents of the diacyl and ether‐linked class compositions of these phospholipids in cells from different origins. Both labeled fatty acids were incorporated more rapidly into the diacyl‐linked class, but were retained to a greater extent in alkylacyl‐phosphatidyl‐choline and alkenylacyl‐phosphatidylethanolamine. The data suggest that, in addition to alkylacyl‐phosphatidylcholine and phosphatidylinositol, alkenylacyl‐phosphatidylethanolamine may be an important endogenous source of arachidonic acid and eicosapentaenoic acid in stimulated human leukocytes.
Studies on peroxidized lipids. V. Formation and characterization of 1,4‐dihydropyridine‐3,5‐dicarbaldehydes as model of fluorescent components in lipofuscin
Authors: Kikugawa K. , Ido Y. 
Published: November 2006

AbstractWe investigated fluorescence properties of 1,4‐dihydropyridine‐3,5‐dicarbaldehydes and their formation in mild reaction of primary amines and malonaldehyde, in order to clarify the role of malonaldehyde in the formation of fluorescent components of lipofuscin. The compounds exhibited fluorescence with excitation maxima at 375–405 nm and emission maxima at 435–465 nm, which was similar to those of lipofuscin and the fluorescent substances derived from the reaction of oxidized fatty acids with primary amines. Fluorescence of the compounds was greatly affected in acidic medium and little influenced in alkaline medium or by the metal chelator. The compounds lost fluorescence by treatment with sodium borohydride. They were inert to thiobarbituric acid reaction. Some of the fluorescence properties of the compounds were different from those of lipofuscin and the related fluorescent substances. Mild reaction of methylamine with pure malonaldehyde gave a single fluorescent compound, 1,4‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarbaldehyde (Ia), and the reaction with the acid hydrolysate of tetramethoxypropane gave Ia and 1‐methyl‐4‐(dimethoxyethyl)‐1,4‐dihydropyridine‐3,5‐dicarbaldehyde (IIa), the latter being produced from the impurity in the hydrolysate. These reactions produced a non‐fluorescent Schiff base, a 1∶1‐adduct of methylamine and malonaldehyde (IIIa), as a major product. It looks unlikely that malonaldehyde is the only product of lipid oxidation that produces fluorescent components in lipofuscin complex.
Alteration and recovery of bleeding times, platelet aggregation and fatty acid composition of individual phospholipids in platelets of human subjects receiving a supplement of cod‐liver oil
Authors: Ahmed Ahmed A. , Holub Bruce J. 
Published: November 2006

AbstractThe effect of supplementation with cod‐liver oil containing eicosapentaenoic acid (EPA), 20∶5ω3, on bleeding times, thrombin‐induced platelet aggregation, platelet protein, platelet cholesterol, and the level and fatty acid composition of individual phospholipids in the platelets of human subjects was determined. Measurement of these parameters was conducted before the subjects received the supplement (day 0), after they received the supplement for 14 days (day 14), and 14 days after the supplement was terminated (day 28) so as to monitor recovery. The mean bleeding times exhibited a marked increase (by 81%) with supplementation and returned to near basal (day 0) values within 14 days after the supplement was terminated. Cod‐liver oil supplementation significantly reduced thrombin‐induced platelet aggregation with a partial recovery being exhibited by day 28. The content of phospholipid, cholesterol and protein (μg/109 platelets) was not significantly different (P>0.05) when isolated from the subjects at day 0, 14 and 28, as neither were the composition of individual phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI) and sphingomyelin (SPH)] given as % of total phospholipid. However, the fatty acid compositions of all platelet phospholipids were altered significantly by the fish oil supplement. In PC, EPA rose from 0.3 to 2.9% of total fatty acids and docosahexaenoate from 0.7 to 1.8% concomitant with a drop in arachidonate (from 14.1 to 9.6%) and linoleate (from 10.2 to 7.9%); these levels approached basal levels 14 days after supplementation was terminated. The highest percentage of EPA with supplementation was found in PE (4.3%), while the arachidonate fell from 38.8 to 30.5%, with low percentages of EPA occurring in PS (0.7%) and PI (0.5%). The level of 24∶1 in SPH increased significantly (from 17.8 to 24.8) with supplementation and reverted to basal values by day 28. These results suggest a close relationship of the observed fatty acid changes in individual platelet phospholipids to the altered hematological parameters and platelet‐vessel wall interactions produced by cod‐liver oil supplementation.
Analysis of molluscan sterols: Colorimetric methods
Authors: Swift Mary L. 
Published: November 2006

AbstractThe wide variety of sterols normally found in extracts of bivalve molluscs leads to high variability in analytical data obtained with colorimetric (chole)sterol methods. Total sterol levels in oyster (Crassostrea virginica) extracts were determined using the Liebermann‐Burchard reagent, an acid‐FeCl3 reagent and a cholesterol oxidase procedure. The data from the latter two agreed to within 5.4% and yielded about 30% higher estimates of sterol content than the Liebermann‐Burchard test. Gas‐liquid chromatographic data also are compared.Several pure sterols, selected because of their presence in oyster sterol fractions or because of their structural similarities to such sterols, were examined using each of the three procedures. Sterols, differing from cholesterol only with regard to the side chain, reacted 80–102% as well as cholesterol with the acid‐FeCl3 reagent and cholesterol oxidase. The Liebermann‐Burchard reaction was more specific for cholesterol. The colorimetric cholesterol oxidase method is recommended for the estimation of total molluscan sterol content.
Squalene isolation by HPLC and quantitative comparison by HPLC and GLC
Authors: Sulpice J. C. , Férézou J. 
Published: November 2006

AbstractA new procedure is described for isolating and measuring squalene in plasma and in several organs of the rat. The unsaponifiable material was fractionated by normal phase HPLC on a silica gel column using a mobile phase consisting of hexane/propanol‐2/water. The eluate was monitored at 215 nm. The squalene in the hydrocarbon fraction thus collected was than quantified on an analytical column eluted with hexane. Squalene concentrations ranging from 3 to 200 μg per ml of plasma or per g of fresh tissue were accurately measured. The results obtained agree with those of the squalene assays carried out by gas chromatography on a packed or capillary column.