bluuebunny/crossref_metadata_2025 huggingface dataset:
Sterol galactosides and sterol esters of the cotton bud
Authors: Thompson A. C. , Henson R. D. , Gueldner R. C. , Hedin P. A.
Published: November 2006

About 60% of the total sterols in the cotton bud appeared in the free state; the esterified sterol glycosides contained about 50% saturated fatty acids, largely palmitic acid; the principal unsaturated fatty acid was linolenic acid. β‐Sitosterol was the major sterol in all classes of sterol derivatives. The sugar moiety of the esterified sterol glycosides and the sterol glycoside was galactose. Efforts are continuing to evaluate the minor sterols of cotton buds, some of which appear to be hydroxylated ecdysones, and to study their relationship to the development of the Boll weevil,Anthonomus grandis Boheman.
The GLC and TLC resolution of diastereoisomeric polyhydroxystearates and assignment of configurations
Authors: Wood Randall , Bever E. L. , Snyder Fred
Published: November 2006

Trifluoroacetate (TFA) derivatives of methyl 12‐hydroxystearate, methyl ricinoleate, five positional isomers of methylthreo‐ anderythro‐dihydroxystearate, four diastereoisomeric methyl 9,10–12‐trihydroxystearates, and four racemic diastereoisomeric methyl 9,10–12,13‐tetrahydroxystearates were prepared and analyzed by gas‐liquid chromatography (GLC). The isomericthreo‐ anderythro‐dihydroxystearates that had not previously been resolved by GLC were separated. Excellent resolution of the diastereoisomeric pairs of methylthreo‐ anderythro‐9,10–12‐triand and methylerythro, erythro‐ andthreo, threo‐9,10–12,13‐tetrahydroxystearates was obtained by GLC of their TFA derivatives. Analyses of these high‐molecular‐weight compounds were carried out on polar and nonpolar packed columns used routinely for methyl ester analysis.

The various methyl mono‐, di‐, tri‐, and tetrahydroxysterate esters were also analyzed by thin‐layer chromatography (TLC) on Silica Gel G adsorbent layers and on Silica Gel G impregnated with sodium arsenite.

Relative and absolute configurations were assigned to the various diastereoisomeric tri‐ and tetrahydroxysterates based on information obtained from GLC, TLC, synthetic ratios, and molecular‐models.

A micro hydroxylation method that gives quantitative yields ofthreo‐ anderythro‐dihydroxy acids from various concentrations of C18 monoene geometrical isomers was developed. Subsequent GLC analysis of the isomeric methyl dihydroxy TFA derivatives allows the quantitative determination of double‐bond configuration on small samples without expensive or specialized equipment.
Synthesis of cholesterol and total lipid by male and female rats fed beef tallow or corn oil
Authors: Dupont Jacqueline
Published: November 2006

Male and female weanling rats were fed diets containing 2 or 42% of calories as corn oil or 40% as beef tallow plus 2% as corn oil until they were 12 or 18 weeks of age. Incorporation of C14‐acetate into lipids of serum and liver and concentration of lipids in serum, liver, and carcass at the end of these periods were determined.

Net synthesis of noncholesterol lipid was repressed by changing the diet from 2% to 42% of calories from either dietary fat in both sexes and at both ages. Cholesterol net synthesis was enhanced 29‐fold in males and 22‐fold in females fed 42% corn oil compared to 2% corn oil to the age of 12 weeks. It was enhanced only 2.6‐fold for males and 3.4‐fold for females by 40% beef tallow plus 2% corn oil. At 18 weeks of age cholesterol synthesis in males fed 42% corn oil was 7.3 and in females 9.1 times the value for those fed 2% corn oil. At this age the values for rats fed 40% beef tallow plus 2% corn oil were 1.2 and 3.7 times those for 2% corn oil fed rats of the respective sexes.
Fatty acid oxidation in relation to cholesterol biosynthesis in rats
Authors: Dupont Jacqueline
Published: November 2006

Groups of male and female rats were fed diets containing (calorie basis) 2% corn oil (low‐fat, LF), 42% corn oil (CO) or 2% corn oil plus 40% beef tallow (BT) for 2 weeks. Then rats of each sex and diet group were given an intraperitoneal injection of14C‐acetate,‐ stearate‐ oleate or linoleate. Acetate incorporation into cholesterol and rate of oxidation of each fatty acid were determined. Specific activity of cholesterol was higher in females than males, higher with 40% lipid in the diet than with 2% corn oil and higher for CO than BT. Linoleate was oxidized more rapidly than oleate which exceeded stearate. An index of dietary lipid oxidation was computed based on fatty acid oxidation rate, per cent of each fatty acid in the diet and per cent of lipid calories in the diet. Serum cholesterol‐14C was found to be proportional to dietary lipid oxidation index.
Thin‐layer chromatographic separation of dimethylphosphatidates derived from lecithins
Authors: Wurster C. F. , Copenhaver J. H.
Published: November 2006

The separation of lecithin derivatives based on their fatty acid substituents has been investigated. Several synthetic and natural lecithins were converted to their corresponding dimethylphosphatidates by hydrolysis with phospholipase D (phosphatidylcholine phospholipase D (phosphatidylcholine phosphatidohydrolase, EC 3.1.4.4) and methylation of the resulting phosphatidic acids with diazomethane. These dimethylphosphatidates were separated into fractions by reversed‐phase thin‐layer chromatography. Separations were dependent on the total number of methylene groups and double bonds in the two fatty acid chains. Fractionated dimethylphosphatidates were extracted from the plates and fatty acids were determined.
The total synthesis of dilinoleoylphosphatidylserine and its activity in blood clotting systems
Authors: Turner D. L. , Silver M. J. , Baczynski E.
Published: November 2006

A total synthesis ofdl‐phosphatidyl‐(dilinoleoyl)‐l‐serine was achieved by the acylation of the barium salt of the phthalimidomethyl ester of glycerophosphoryl‐n‐anisyloxycarbonyl‐l‐serine. The dilinoleoyl intermediate was treated with hydrazine to remove the phthalimidomethyl group and with hydrogen chloride to remove the anisyloxycarbonyl protecting group. The resulting phosphatidylserine was purified by Rouser's methods, solubilized, and tested for biological activity in the antithromboplastin, recalcification, and Hicks‐Pitney tests. It was found to have about the same anticoagulant activity as beef brain phosphatidylserine and hence was more active than the less unsaturated phosphatidylserine synthesized earlier.
Quantitative and qualitative analyses of isolated lipid droplets from interstitial cells in renal papillae from various species
Authors: Bojesen Inge
Published: November 2006

The lipid droplets of renal papillae homogenates from four different species were obtained by ultracentrifugation. Ca. 80–98% of the lipids (triglycerides, phospholipids, free fatty acids, and cholesterol esters) consist of triglycerides. The triglycerides were fractionated by argentation thin layer chromatography and each fraction characterized by gas liquid chromatography. No fraction contained any unique triglyceride. The fatty acid composition of the total triglycerides, as analyzed by gas liquid chromatography and ozonolysis, differed markedly from the fatty acid composition of the corresponding plasma triglycerides. The papillary triglycerides were characterized by higher concentrations of stearic acid, arachidic acid, and polyunsaturated acids with 20 or more carbon atoms. Particularly interesting was the presence in the lipid droplets of docosa‐7,10,13,16‐tetraenoic acid. This acid has been shown to be a major component in the cholesterol ester fraction of rat and canine adrenal lipids. In the papillary triglycerides, this acid accounted for 7%, 15%, and more than 20% of the total fatty acids in the dog, rat, and rabbit, respectively. The pig differs from these three species in having only ca. 1% of this acid. These observations suggest that the interstitial cells produce these triglycerides. This production could occur either by a transacylation from phospholipids and cholesterol esters and by a de novo synthesis from locally produced fatty acids. The possibility that the triglyceride production may be involved in a control of the prostaglandin production of the renal medulla is discussed.
Changes in in vivo metabolism of bile acids in rat after treatment with phenobarbital
Authors: Cronholm Tomas , Einarsson Kurt , Gustafsson Jan‐Åke
Published: November 2006

The influence of phenobarbital on pool size and turnover of bile acids in rats have been investigated by administration of [24‐14C] cholic acid and tritium labeled chenodeoxycholic acid. Phenobarbital treated rats had a smaller cholic acid pool compared to control rats (6.08±2.09 mg and 23.60±7.66 mg, respectively). The pool size of chenodeoxycholic acid, plus its metabolites (α‐ and β‐muricholic acids), was of the same magnitude in the two groups of animals. Also the daily production of cholic acid was decreased in phenobarbital treated rats compared to control rats (2.12±0.46 mg and 7.24±1.66 mg, respectively). No significant difference was observed between the synthesis of chenodeoxycholic acid in the two groups of animals.
Simplified procedure for preparation of35S‐labeled brain sulfatide
Authors: Fluharty Arvan L. , Davis Marsha L. , Kihara Hayato , Kritchevsky Gene
Published: November 2006

A simplified procedure for the preparation of35S‐labeled brain cerebroside sulfates has been developed. The labeled sulfatides are synthesized in vivo after intracerebral administration of inorganic35S‐sulfate in developing rats. The animals are sacrificed three days later and brain homogenates extracted with chloroform‐methanol. The extract is subjected to mild alkaline treatment and washed with water. The organic phase is chromatographed on triethylaminoethyl‐cellulose from which sulfatides are eluted with chloroform‐methanol containing potassium acetate. Radioactive fractions are pooled, concentrated, and potassium acetate removed by dialysis against water. Alternatively, salts are removed by passing radioactive fractions through Sephadex G‐25. After evaporating to near dryness, the radioactive cerebroside sulfates are dissolved in a small volume of chloroform‐methanol and stored at −20 C. The35S‐sulfatides are essentially free of lipid contaminants, and 97% of the radio‐activity corresponds with sulfatides on chromatographic analysis.
Lipid composition of normal and hypertrophic bovine thyroids
Authors: Lagrou A. , Dierick W. , Christophe A. , Verdonk G.
Published: November 2006

The phospholipid content of bovine thyroid tissue amounts to 70% of total lipid. Triglycerides and cholesterol are the main neutral lipids. Only trace amounts of free fatty acid and esterified cholesterol are found, while two not yet identified components also are present. The distribution of lipid phosphorus in the different phospholipid classes is as follows: phosphatidyl choline, 43.0%; phosphatidyl ethanolamine, 25.2%; phosphatidyl serine, 5.6%; phosphatidyl inositol, 6.5%; sphingomyelin, 14.0%; cardiolipin, 2.8%; lysophosphatidyl choline, <1%; and phosphatidic acid, <1%. The phosphatidyl ethanolamines are rich in plasmalogens. The fatty acid patterns in the different lipid classes are reported. The essential differences between normal and hypertrophic bovine thyroid tissue are higher water content and lower triglyceride and sphingomyelin values for hypertrophic tissue.
Biosynthesis of triglycerides in freshly secreted milk from goats
Authors: Christie W. W.
Published: November 2006

It has been confirmed that freshly secreted milk from goats contains triglyceride synthetase activity which is not stimulated by addition of the usual range of cofactors, e.g. coenzyme A, adenosine 5′‐triphosphate, Magnesium ions or α‐glycerophosphate. On the other hand, free glycerol did stimulate the reaction, although only low levels of glycerol‐kinase could be detected. The products were principally, triglycerides, diglycerides, and phosphatidic acid, i.e. those expected of the phosphatidic acid pathway of triglyceride biosynthesis together with some phosphatidyl choline and phosphatidyl ethanolamine. In addition, some of the enzymes of the monoglyceride pathway appeared to be present since 2‐O‐alkylglycerols, in particular, were converted to monoacyl‐monoalkyl glycerols together with trace amounts of diacyl alkyl‐glycerols. The milk incorporated a wide variety of isotopically labeled fatty acids into lipids at widely differing rates (18∶2 at 10 times the rate of 18∶0, for example) and stereospecific analysis confirmed that fatty acids entered all three positions of the sn‐triacyl glycerols according to quite specific patterns. Stearic acid was desaturated rapidly to oleic acid, and virtually all the 18∶1 formed was esterified (to all three positions in the triglycerides also). Freshly secreted milk is a potentially useful alternative to tissue obtained surgically as a source of mammary triglyceride biosynthetic enzymes for the study of milk fat biosynthesis in vitro.
Lipid changes during life cycle of marine copepod,Euchaeta japonica marukawa
Authors: Lee Richard F. , Nevenzel Judd C. , Lewis A. G.
Published: November 2006

All stages from egg to adult of the North Pacific copepod,Euchaeta japonica contained wax esters in their lipid stores, while triglycerides were important only in the eggs, early naupliar stages, and adults. The large lipid reserves of the eggs were wax esters and triglycerides (58% and 19% of the lipid, respectively), both of which were used rapidly during the early stages of development. Wax esters continued to decrease after triglycerides had been utilized completely for energy. The slow metabolism of lipid during starvation indicated that lipid stores in adult females may be conserved for egg production. The dominant alcohols of the wax esters of all stages were tetradecanol (24–42% of the total) and hexadecanol (25–65%). Only minor amounts of polyunsaturated alcohols were observed. There was, however, a high proportion of polyunsaturation in the wax ester fatty acids, even though octadecenoic was generally predominant (16–46% of the total wax ester fatty acids). The polyunsaturation of the wax esters fatty acids and the presence of 21∶6 hydrocarbon suggest phytoplankton in the diet of adults and in the younger stages. Cholesterol was the main sterol, but there were minor amounts of desmosterol (1–12% of the total sterols) present. The latter sterol has not been found previously in copepods, although reported from Cirripedia and Decapoda.
Lipid peroxidation in chronic ethanol treated rats: In vitro uncoupling of peroxidation from reduced nicotine adenosine dinucleotide phosphate oxidation
Authors: Koes Mary , Ward Tom , Pennington Sam
Published: November 2006

Chronic ethanol treated rats were found to have enhanced ethanol metabolism and to metabolize ethanol in vivo in the presence of an inhibitor of alcohol dehydrogenase. In vitro studies of the hepatic microsomal system thought to the responsible for this activity showed it to be markedly induced. Lipid peroxidation also was enhanced in the ethanol treated animals. The lipid peroxidation was shown to be uncoupled from the microsomal nicotinamide adenine dinucleotide phosphate, reduced form, oxidase activity by a low concentration of azide.
Properties of palmityl‐CoA: L‐α‐glycerolphosphate acyl transferase from bovine mammary microsomes
Authors: Gross M. J. , Kinsella J. E.
Published: November 2006

Palmityl‐coenzyme A: L‐α‐glycerolphosphate acyltransferase is the most active acyltransferase of bovine mammary microsomes, with a specific activity ranging from 8–20 nmoles min−1 mg−1 protein. Corresponding acylation rates of 2.2, 1.4, 2.1, and 0.6 nmoles min−1 mg−1 were obtained for myristyl‐, stearyl‐, oleyl‐ and linoleyl‐coenzyme A, respectively. Optimum pH of palmityltransferase was 7.7, and activity was not affected by buffer molarity in range 25–150 mM. Inhibitory effects of palmityl‐coenzyme A (10 μM/0.1 mg microsomal protein) was relieved by bovine serum albumin. Sonication magnesium and ethylenediaminetetraacetic acid enhanced activity. Delipidation of microsomes reduced activity by 84%; restoration of extracted lipids achieved 70% of original activity. Apparent Km and Vmax values of 4.1 and 260 μM and 9.5 and 8.2 nmole min−1 mg−1 were determined for palmityl‐coenzyme A and D,L‐α‐glycerolphosphate, respectively, using untreated microsomes. The enzyme was stable as lyophilized microsomes when stored at −30 C. Phosphatidic acid was the major product and marked quantities of diglycerides were formed, especially when microsomal protein was increased.
Complex formation and reversible oxygenation of free fatty acids
Authors: Campbell I. M. , Caton R. B. , Crozier D. N.
Published: November 2006

Combined manometric and spectrophotometric studies reveal that prior to true oxidation unsaturated fatty acids undergo an oxygenation which is reversible in response to changes in oxygen pressure. The oxygenation seems to result from the oxygen molecule having a specific affinity for pairs of olefinic bonds.
Composition ofCelastrus orbiculatus seed oil
Authors: Miller Roger W. , Smith C. R. , Weisleder D. , Kleiman R. , Rohwedder W. K.
Published: November 2006

The seed oil ofCelastrus orbiculatus (family Celastraceae) was reinvestigated to determine whether the benzoic acid that it contains is esterified with glycerol. Unlike acetic acid, benzoic acid is not incorporated in glycerides of this oil but, instead, is esterified with two sesquiterpenoid triols of the empirical formula C15H26O4.trans‐Cinnamic acid also is esterified with these triols. Acetic acid is a component of these nonglyceride esters, as well as of the triglycerides. We found no evidence for the occurrence of formic acid in this oil. By countercurrent fractionation, we found that this oil contains 8% “ordinary” triglycerides, 59% mono‐acetotriglycerides, and 33% nonglyceride substances.
Stereospecific analysis of human plasma triglycerides
Authors: Parijs J. , De Weerdt G. A. , Beke R. , Barbier F.
Published: November 2006

Brockerhoff‐type procedures were used to determine the amounts of each fatty acid at each position of plasma triglycerides from normal and hyperlipemic humans. Statistically significant differences between both groups are found for the 2 and 3 positions.
Convenient apparatus for extraction of tissue lipids
Authors: Walker Brian L.
Published: November 2006

An all glass apparatus has been designed for rapid, convenient extraction of lipids from small samples of tissue. Samples are handled in vacuo or under nitrogen atmosphere throughout the extraction procedure.
Characterization and metabolism of free fatty alcohols fromEscherichia coli
Authors: Naccarato William F. , Gelman Rose A. , Kawalek Joseph C. , Gilbertson John R.
Published: November 2006

Free fatty acohols have been established as lipid components ofE. coli K‐12. Using combined gas liquid chromatography‐mass spectrometry, the major alcohols in aerobically grown cells were identified as 1‐tetradecanol (18%), 1‐hexadecanol (28%), 1‐octadecanol (14%), and 2‐pentadecanol (27%). Small amounts of 1‐hexadecenol (3%), 2‐tridecanol (8%), and 2‐tetradecanol (1.5%) were also detected. Analysis of anaerobically grown cells has shown a selective decrease of the secondary alcohols. 2‐Pentadecanol was present as only 7% of the total alcohol fraction, and only traces of 2‐tridecanol and 2‐tetradecanol were found. The major alcohols in anaerobic cells were 1‐tetradecanol, 1‐pentadecanol, 1‐hexadecenol and 1‐hexadecanol. The above observations strongly suggest two pathways for the synthesis of fatty alcohols inE. coli. One pathway synthesizes the primary alcohols and does not require molecular oxygen, and a separate pathway synthesizes the secondary alcohols and has a requirement for molecular oxygen.
Lipids ofEchinococcus granulosus protoscolices
Authors: Vessal Mahmood , Zekavat S. Yahya , Mohammadzadeh‐K Ali A.
Published: November 2006

The fatty acid composition of the triglyceride and the total phospholipid fractions of ovine liverEchinococcus granulosus protoscolices was determined by gas chromatography and compared with that of the healthy and Echinococcus infected livers. The chain length of the major saturated fatty acids identified in both the host tissues and the parasite ranged from 12–22 carbons. Oleic and linoleic acids were the only detectable unsaturated fatty acids identified in protoscolices and the liver samples. Comparison of the amounts of the fatty acids from the three different sources mentioned above by analysis of variance and the contrast method of Scheffe, revealed a significant decrease in the level of oleic acid in triglyceride fraction of the infected livers compared with normals. Thinlayer chromatography of the polar lipid fraction of the protoscolices resulted in tentative identification of lysolecithin, sphingomyelin, lecithin, phosphatidyl inositol, sulfatides, cerebrosides, cephalins and cholesterol.
Mass spectra of tocopherols
Authors: Scheppele Stuart E. , Mitchum Ronald K. , Rudolph Charles J. , Kinneberg Keith F. , Odell George V.
Published: November 2006

The mass spectra of α‐, β‐ and γ‐tocopherols (I) are characterized by the absence of numerous fragmentation processes. Ion intensities, but not the reaction pathways, are strongly dependent on temperature. Principal fragment ions are formed (a) by cleavage through the nonaromatic portion of the chromanol ring both with and without hydrogen transfer and (b) via loss of the isoprenoid side chain. For (a) occurring with hydrogen transfer, ion‐kinetic energies favor a tropylium ion structure for the daughter ion. Loss of ketene from the molecular ions of α‐ and β‐tocopherol acetates producing the molecular ion of the corresponding tocopherol is the dominant process.
Radical addition of linoleic hydroperoxides to α‐tocopherol or the analogous hydroxychroman
Authors: Gardner H. W. , Eskins K. , Grams G. W. , Inglett G. E.
Published: November 2006

Either linoleic acid hydroperoxide (LOOH) or methyl linoleate hydroperoxide react anaerobically with either α‐tocopherol (TOH) or its model compound‐2,2,5,7,8‐pentamethyl‐6‐hydroxychroman (COH)‐to form principally an addition compound of the two reactants. The reaction can be catalyzed either by 1.28 X 10−5 M Fe(III) or by proflavin (0.01%) sensitized by visible light. The presence of air in the reaction terminates the addition, and quinones become the major products from TOH or its model compound. The addition compound synthesized from COH and LOOH (a 4.9∶1 ratio of 13‐hydroperoxy‐cis‐9,trans‐12‐octadecadienoic acid and 9‐hydroperoxy‐trans‐10,cis‐12‐octadecadienoic acid) was used to solve structural details of the bridging function. Three isomers of the addition compound (methyl esterified) were isolated and identified as methyl 11‐(2,2,5,7,8‐pentamethyl‐6‐oxychroman)‐cis‐12,13‐epoxy‐trans‐9‐octadecenoate; methyl 11‐(2,2,5,7,8‐pentamethyl‐6‐oxychroman)‐trans‐12,13‐epoxy‐trans‐9‐octadecenoate; and methyl 11‐(2,2,5,7,8‐pentamethyl‐6‐oxychroman)‐cis‐9,10‐epoxy‐trans‐12‐octadecenoate in order of decreasing abundance. The mechanism appears to be free radical addition brought about by the catalytic formation of alkoxy radicals from the hydroperoxide and chromanoxy radicals from TOH or its model.
Cuticular lipids of insects: V. Cuticular wax esters of secondary alcohols from the grasshoppersMelanoplus packardii andMelanoplus sanguinipes
Authors: Blomquist Gary J. , Soliday Charles L. , Byers Barbara A. , Brakke Joyce W. , Jackson Larry L.
Published: November 2006

Wax esters of secondary alcohols constitute 18–20% of the cuticular lipid extract ofMelanoplus packardii and 26–31% of the cuticular lipids ofMelanoplus sanguinipes. The total number of carbons in the wax esters range from 37–54 with 41 predominating in both species. The fatty acids ofM. packardii wax esters are 16∶0, 18∶0, 14∶0, 20∶0 and 12∶0 in decreasing quantity. The fatty acids ofM. sanguinipes wax esters are 18∶0, 20∶0, 16∶0 22∶0, 14∶0, 19∶0 and 17∶0 in decreasing quantity. The secondary alcohols from the wax esters ofM. packardii are C25, C23 and C27 in decreasing quantity, and the secondary alcohols of theM. sanguinipes are C23, C25, C21, C27, C24, C22 and C26 in decreasing quantity. Each secondary alcohol consists of two to four isomers with the hydroxyl group located near the center of the chain.
Chemical composition of the wax secreted by a scale insect (Ceroplastes pseudoceriferus Green)
Authors: Tamaki Yoshio
Published: November 2006

The wax material in the secretion of a scale insect,Ceroplastes pseudoceriferus Green was analyzed chemically with special interest to the composition of higher fatty acids and higher alcohols. The wax consists of 34.2% fatty acids, 27.1% unsaponifiable matter and 29.5% resin acids. The fatty acids were found to be a complex mixture of 15 normal acids ranging from C8 to C32. Of these, octacosanoic, triacontanoic and dotriacontanoic acids comprise over 30% of the wax. Presence of relatively large amount of unsaturated fatty acids of the C18 series (2.8% of the wax) is of particular interest.

From the unsaponifiable fraction, only one saturated straight chain aleohol, bexacosanol, was detected (2.7% of the original wax). The other unsaponifiable matter was considered to be cyclic or branched carbon chain, and consisted of at least 12 to 20 compounds. The resin acid fraction was also found to be a complex mixture of at least 13 to 14 components.
Lipoprotein synthesis. I. rat plasma lipoprotein composition and synthesis from radioactive precursors
Authors: Trams Eberhard G. , Brown Elise Ann , Lauter Carl J.
Published: November 2006

The in vivo synthesis of rat plasma lipoproteins was studied by the use of isotopic protein and lipid precursors. Labelled amino acids, palmitic acid and tripalmitin were administered by stomach tube and the radioactivity in the plasma lipoproteins was determined following preparative ultracentrifugal isolation at densities of 1.006, 1.019, 1.063 and 1.21 g/ml.

In response to triglyceride feeding, amino acid composition of the high density lipoprotein changed little, but in the low density lipoproteins proportionality in the amino acid pattern was changed as reflected by increases and decreases in certain amino acids.

Isotopic amino acids were not incorporated in proportion to the relative abundance with which they occurred in the lipoproteins. Triglyceride feeding markedly stimulated isotope utilization, especially in the low density fractions. Methionine, though only present in small amounts, was extensively utilized and it is suggested that this amino acid may play a significant role in the synthesis of lipoproteins, other than the role of a methyl donor for phosphatidylcholine.
Effect of isoessential fatty acid lipids from animal and plant sources on cholesterol levels in mature male rats
Authors: Elson C. E. , Dugan L. R. , Brafzler L. J. , Pearson A. M.
Published: November 2006

Isopolyunsaturated lipids isolated from plant and animal sources were included in the diets of mature male rats. Liver and blood serum cholesterol lowering effects were noted only in the lipid from the vegetable source. The authors suggest that the cholesterol lowering effect of vegetable oils is associated with the generally betaunsaturated triglycerides found therein.
Metabolism of alpha‐alkoxy glyceryl monoethers in rat liver, in vivo and in vitro
Authors: Snyder Fred , Pfleger Raymond C.
Published: November 2006

An investigation of the metabolism of14C and3H labeled α‐isomers of C16 and C18 alkoxy monoethers, administered intravenously and added to liver slices, showed extensive cleavage of the ether bond in rat liver. Approximately 99% cleavage of the C16∶0 ether bond and approximately 94% cleavage of the C18∶0 ether bond occurred in rat liver within 6 hours after intravenous injection. With doubly labeled chimyl alcohol (3H and14C), acetylation and subsequent acetolysis demonstrated that less than 0.92% of the phosphatides and less than 1.52% of total lipid radioactivity were in the form of alkoxy ethers. Long‐chain fatty alcohols and fatty acids were the principal products of the ether cleavage in the liver. The relative rate of14C incorporation from chimyl alcohol and batyl alcohol into triglycerides and phospholipids, respectively, demonstrates that the palmitic (from chimyl alcohol) and stearic (from batyl alcohol) acids formed after cleavage enter the free fatty acid pool. The liver contained most of the radioactive label in the lecithin and cephalin of the microsomal fraction. Incubation of the labeled batyl or chimyl alcohols with liver slices resulted in the same products as in the in vivo experiments. Less than 1.4% of the C16 and C18 alkoxy ethers was oxidized to14CO2 during a 3‐hour incubation. In view of the extensive cleavage of the ether bond by liver, the hemopoietic and radioprotective activities reported for the alkoxy ethers should be reevaluated in terms of their metabolic products.
Interconversion of fatty aldehydes and dimethyl acetals at low temperatures
Authors: Mahadevan V. , Viswanathan C. V. , Lundberg W. O.
Published: November 2006

Facile procedures are described for nearly quantitative conversion of saturated and unsaturated fatty aldehydes to their dimethyl acetals, and vice versa, at low temperatures. The methods are based on the chemical behavior of aldehydes and dimethyl acetals in 100% sulfuric acid. Under the experimental conditions described, no side reactions seemed to occur. The purity of the aldehydes and dimethyl acetals was ascertained by thin‐layer chromatography, infrared spectra and other techniques.
Thermal reactions of methyl linoleate. II. The structure of aromatic C18 methyl esters
Authors: Michael William R.
Published: November 2006

This second report describes the characterization of C18 aromatic esters from the heated linoleate and the independent synthesis of two of them. The esters were isolated by a combination of molecular distillation, urea adduction, column chromatography, and gas chromatography. They were characterized by infrared, ultraviolet, NMR, and mass spectroscopy. The analytical data for the isolated esters were compared with the data for the synthetic esters, methyl 11‐(2′‐methylphenyl) undecanoate, methyl 7‐(2′‐pentylphenyl) heptanoate, and methyl 8‐(2′‐butylphenyl) octanoate. The latter two compounds were found to be components of the aromatic fraction isolated from heated linoleate, and their synthesis is deseribed in detail.
Human umbilical cord blood serum can replace fetal bovine serum in the culture of mesenchymal stem cells
Authors: Shetty P. , Bharucha K. , Tanavde V.
Published: November 2006

The potential of mesenchymal stem cells (MSC) to differentiate into different cell types has opened up the possibility of using these cells clinically to treat a variety of disorders. In this study we describe the use of human umbilical cord blood serum (CBS) as a replacement for fetal bovine serum (FBS) for culturing MSC from different sources. MSC from human and swine bone marrow and human umbilical cord blood were cultured in the presence of DMEM/F12 containing either FBS or CBS. Human MSC cultured in presence of FBS or CBS showed typical fibroblast‐like morphology, which is characteristic of MSC. 99% of the cells cultured in FBS had a CD73+/CD105+/CD45− phenotype compared to 96% of cells cultured in CBS. Cells cultured in CBS had a significantly higher cell count as compared to cells cultured in FBS. Swine Bone Marrow MSC cultured in the presence of FBS and CBS were morphologically and phenotypically similar. Human umbilical cord blood serum supports the growth of MSC. While no significant differences were observed in the MSC numbers in swine cells cultured in the presence of FBS or CBS, human cells showed a greater proliferation potential in the presence of CBS as compared to FBS. Therefore, CBS can be used as an effective substitute to FBS for developing clinically useful protocols for culturing MSC.
Medroxyprogesterone and tamoxifen augment anti‐proliferative efficacy and reduce mitochondria‐toxicity of epirubicin in FM3A tumor cells in vitro
Authors: Altinoz Meric A. , Bilir Ayhan , Gedikoglu Gunduz , Ozcan Emin , Oktem Gulperi , Muslumanoglu Mahmut
Published: November 2006

We have shown that low doses of medroxyprogesterone acetate (MPA‐ 2.6 μM) and tamoxifen (TAM‐ 270 nM) could augment the effectiveness of epirubicin in breast tumor cells. In this study, we monitored early cell kinetics (24–96 h plating and S‐phase) and mitochondrial morphology during chemo‐endocrine treatments to delineate the epirubicin sensitizing mechanism. S‐phase fractions with radioactive thymidine uptake, plating efficacy, and transmission electron microscopic analysis were taken for 24‐h periods until the 7th day after drug treatments. Despite strongly enhancing the clonogenic killing, both MPA and TAM did not affect epirubicin induced early cytotoxicity. Instead, they augmented the S‐phase inhibition, which was even more pronounced for TAM. Epirubicin induced prominent swelling and crista damage of mitochondria and fragmentation of nuclei. Mitochondria were a normal size during a combination of epirubicin with either MPA‐ or tamoxifen treatment, despite the persistence of chromatin fragmentation and strong synergism on the clonogenic killing of breast tumor cells. Low dosage endocrine agent‐induced anthracycline sensitization may be independent of mitochondrial toxicity. Further studies would be worthwhile, since the uncoupling of mitochondrial toxicity from the anti‐neoplastic effect may also mean obviated cardiac toxicity in clinic.
Social phobia, fear of negative evaluation and harm avoidance
Authors: Faytout M. , Tignol J. , Swendsen J. , Grabot D. , Aouizerate B. , Lépine J.P.
Published: November 2006

This naturalistic, prospective investigation examined the role of fear of negative evaluation and the personality trait of harm avoidance in the anxiety levels of treated social phobia patients. One hundred and fifty-seven patients with DSM-IV social phobia were assessed before starting treatment and were then followed for up to two years. As expected, greater fear of negative evaluation and higher scores of harm avoidance were associated with greater anxiety at the 6 month follow-up, and harm avoidance remained a significant predictor at 24 months. However, no evidence was found for an interaction between the personality and cognitive variables examined. The findings are discussed in terms of the relative independence of these factors, as well as their potential implications for the treatment of this disorder.
Deep senescent human fibroblasts show diminished DNA damage foci but retain checkpoint capacity to oxidative stress
Authors: Chen Jian-Hua , Ozanne Susan E.
Published: November 2006

Critically shortened telomeres trigger a DNA damage response in replicatively senescent cells. Here we report that while DNA damage foci can be detected in newly senescent cells, these foci eventually diminished in deep senescent cells. However, DNA checkpoint signalling and repair machinery in response to oxidative stress remain uncompromised in these deep senescent cells. Activation of p53 by oxidative stress is unaffected despite a marked decrease in expression of platelet‐derived growth factor α‐receptor. These findings suggest that cellular senescence is not a static process hence care must be taken in the selection of biomarkers of senescence in studies of ageing.
Extracellular heat shock protein 70 mediates heat stress‐induced epidermal growth factor receptor transactivation in A431 carcinoma cells
Authors: Evdonin Anton L. , Guzhova Irina V. , Margulis Boris A. , Medvedeva Natalia D.
Published: November 2006

The initial steps of heat stress in A431 cells were previously characterized by ligand‐independent EGFR transactivation via an unknown mechanism and concomitant secretion of Hsp70. In this work we demonstrate that the depletion of Hsp70 from the conditioned medium of heated cells abolishes EGFR transactivation indicating that secreted Hsp70 is essential for EGFR transactivation during heat shock. This notion is supported by the findings that purified Hsp70 can induce EGFR transactivation and the activation of EGFR‐dependent signaling pathways. Both heat stress and pure Hsp70 stimulate activation of TLR2/4 and their association with EGFR. These results suggest that the secreted Hsp70 mediates the cross‐communication of TLR and EGFR signaling systems in A431 cells.
Pyrrolysine analogues as substrates for pyrrolysyl‐tRNA synthetase
Authors: Polycarpo Carla R. , Herring Stephanie , Bérubé Amélie , Wood John L. , Söll Dieter , Ambrogelly Alexandre
Published: November 2006

In certain methanogenic archaea a new amino acid, pyrrolysine (Pyl), is inserted at in‐frame UAG codons in the mRNAs of some methyltransferases. Pyl is directly acylated onto a suppressor tRNAPyl by pyrrolysyl‐tRNA synthetase (PylRS). Due to the lack of a readily available Pyl source, we looked for structural analogues that could be aminoacylated by PylRS onto tRNAPyl. We report here the in vitro aminoacylation of tRNAPyl by PylRS with two Pyl analogues: N‐ε‐d‐prolyl‐l‐lysine (d‐prolyl‐lysine) and N‐ε‐cyclopentyloxycarbonyl‐l‐lysine (Cyc). Escherichia coli, transformed with the tRNAPyl and PylRS genes, suppressed a lacZ amber mutant dependent on the presence of d‐prolyl‐lysine or Cyc in the medium, implying that the E. coli translation machinery is able to use Cyc‐tRNAPyl and d‐prolyl‐lysine‐tRNAPyl as substrates during protein synthesis. Furthermore, the formation of active β‐galactosidase shows that a specialized mRNA motif is not essential for stop‐codon recoding, unlike for selenocysteine incorporation.
ATP binding site in the plant ADP‐glucose pyrophosphorylase large subunit
Authors: Hwang Seon-Kap , Hamada Shigeki , Okita Thomas W.
Published: November 2006

The ATP binding region in the catalytically inactive large subunit (LS) of the potato tuber ADP‐glucose pyrophosphorylase was identified and investigated. Mutations at the ATP binding significantly affected not only the apparent affinities for ATP and Glc‐1‐P, and catalytic rate but also in many instances, sensitivity to 3‐phosphoglycerate. The catalytic rates of the LS mutant enzymes correlated most strongly with changes in the affinity toward ATP, a relationship substantiated by photoaffinity labeling studies with azido‐ATP analog. These results indicate that the LS, although catalytically defective, interacts cooperatively with the catalytic small subunit in binding substrates and effectors and, in turn, influencing net catalysis.
The cell membrane‐shielding function of eicosapentaenoic acid for Escherichia coli against exogenously added hydrogen peroxide
Authors: Nishida Takanori , Orikasa Yoshitake , Watanabe Kazuo , Okuyama Hidetoshi
Published: November 2006

The colony‐forming ability of catalase‐deficient Escherichia coli mutant genetically modified to produce eicosapentaenoic acid (EPA) showed less decrease than in a control strain producing no EPA, when treated with 0.3 mM hydrogen peroxide (H2O2) under non‐growth conditions. H2O2‐induced protein carbonylation was enhanced in cells lacking EPA. The amount of fatty acids was decreased more significantly for cells lacking EPA than for those producing EPA. Much lower intracellular concentrations of H2O2 were detected for cells with EPA than those lacking EPA. These results suggest that cellular EPA can directly protect cells against oxidative damage by shielding the entry of exogenously added H2O2.
Holocene occurrence ofLophodermium piceae, a black spruce needle endophyte and possible paleoindicator of boreal forest health
Authors: Jasinski J.P. Paul , Payette Serge
Published: November 2006

Holocene occurrences of conifer needle endophytes have not previously been reported. We report the fossil remains ofLophodermium piceae(Fckl.) Hoehn., a fungal endophyte of black spruce (Picea mariana(Mill.) B.S.P.) needles, in macrofossils dating back to 8000 cal yr BP. Spruce budworm head capsules andL. piceaeremains were found preceding charcoal layers delineating the transformation of four spruce−moss forest sites to spruce−lichen woodland. AsL. piceaeis found solely on senescent needles, its increased presence during these transformation periods likely indicates that the forests were in decline due to the spruce budworm (Choristoneura fumiferana(Clem.)) when they burned. Future paleoecological studies incorporating needle fungi observations could be used to investigate the historical occurrence of tree disease and the role of fungi in forest health and decline.
The large‐scale freshwater cycle of the Arctic
Authors: Serreze Mark C. , Barrett Andrew P. , Slater Andrew G. , Woodgate Rebecca A. , Aagaard Knut , Lammers Richard B. , Steele Michael , Moritz Richard , Meredith Michael , Lee Craig M.
Published: November 2006

This paper synthesizes our understanding of the Arctic's large‐scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA‐40 reanalysis and land surface and ice‐ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (∼8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (∼8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ∼84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability.
Evaluation of aerosol distribution and optical depth in the Geophysical Fluid Dynamics Laboratory coupled model CM2.1 for present climate
Authors: Ginoux Paul , Horowitz Larry W. , Ramaswamy V. , Geogdzhayev Igor V. , Holben Brent N. , Stenchikov Georgiy , Tie Xuexi
Published: November 2006

This study evaluates the strengths and weaknesses of aerosol distributions and optical depths that are used to force the GFDL coupled climate model CM2.1. The concentrations of sulfate, organic carbon, black carbon, and dust are simulated using the MOZART model (Horowitz, 2006), while sea‐salt concentrations are obtained from a previous study by Haywood et al. (1999). These aerosol distributions and precalculated relative‐humidity‐dependent specific extinction are utilized in the CM2.1 radiative scheme to calculate the aerosol optical depth. Our evaluation of the mean values (1996–2000) of simulated aerosols is based on comparisons with long‐term mean climatological data from ground‐based and remote sensing observations as well as previous modeling studies. Overall, the predicted concentrations of aerosol are within a factor 2 of the observed values and have a tendency to be overestimated. Comparison with satellite data shows an agreement within 10% of global mean optical depth. This agreement masks regional differences of opposite signs in the optical depth. Essentially, the excessive optical depth from sulfate aerosols compensates for the underestimated contribution from organic and sea‐salt aerosols. The largest discrepancies are over the northeastern United States (predicted optical depths are too high) and over biomass burning regions and southern oceans (predicted optical depths are too low). This analysis indicates that the aerosol properties are very sensitive to humidity, and major improvements could be achieved by properly taking into account their hygroscopic growth together with corresponding modifications of their optical properties.
Past, present, and future concentrations of tropospheric ozone and aerosols: Methodology, ozone evaluation, and sensitivity to aerosol wet removal
Authors: Horowitz Larry W.
Published: November 2006

Tropospheric ozone and aerosols are radiatively important trace species, whose concentrations have increased dramatically since preindustrial times and are projected to continue to change in the future. The evolution of ozone and aerosol concentrations from 1860 to 2100 is simulated on the basis of estimated historical emissions and four different future emission scenarios (Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A2, A1B, B1, and A1FI). The simulations suggest that the tropospheric burden of ozone has increased by 50% and sulfate and carbonaceous aerosol burdens have increased by factors of 3 and 6, respectively, since preindustrial times. Projected ozone changes over the next century range from −6% to +43%, depending on the emissions scenario. Sulfate concentrations are projected to increase for the next several decades but then to decrease by 2100 to 4–45% below their 2000 values. Simulated ozone concentrations agree well with present‐day observations and recent trends. Preindustrial surface concentrations of ozone are shown to be sensitive to the assumed anthropogenic and biomass burning emissions, but in all cases they overestimate the few available measurements from that era. Simulated tropospheric burdens of aerosols are sensitive by up to a factor of 2 to assumptions about the rate of aerosol wet deposition in the model. The concentrations of ozone and aerosols produced by this study are provided as climate‐forcing agents in the Geophysical Fluid Dynamics Laboratory coupled climate model to estimate their effects on climate. The aerosol distributions from this study and the resulting optical depths are evaluated in a companion paper by P. Ginoux et al. (2006).
Copula‐based geostatistical models for groundwater quality parameters
Authors: Bárdossy András
Published: November 2006

Groundwater quality parameters exhibit considerable spatial variability. Geostatistical methods including the assessment of variograms are usually used to characterize this variability. Copulas offer an interesting opportunity to describe dependence structures for multivariate distributions. Bivariate empirical copulas can be used as an alternative to variograms and covariance functions for the description of the spatial variability. Rank correlations of these copulas express the strength of the dependence independently of the marginal distributions and thus offer an alternative to the variograms. Empirical copulas for four quality parameters, chloride, sulfate, pH, and nitrate, obtained from a large‐scale groundwater quality measurement network in Baden‐Württemberg (Germany) are calculated. They indicate that the spatial dependence structure of the investigated parameters is not Gaussian. Two theoretical copula‐based models are presented in this paper: a Gaussian and a non‐Gaussian. Bootstrap‐based statistical tests using stochastic simulation of the multivariate distributions are used to investigate the appropriateness of the models. According to the test results the Gaussian copula is rejected for most of the parameters while the non‐Gaussian alternative is not rejected in most cases.