bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical and physiological studies of certain ticks (Ixodoidea): Isolation and partial identification of a new fatty acid in eggs ofDermacentor andersoni Stiles (Ixodidae)
Authors: Shimi Ibrahim R. , Maroun Nabila A. , Kamel Mamdouh Y. , Ragheb Hemmat H. , Badran Mohga M. 
Published: November 2006

AbstractGas liquid chromatographic analysis of the fatty acid methyl esters from eggs ofDermacentor andersoni Stiles (Ixodidae) revealed the presence of significant quantities (15% total fatty acids) of an unidentified component with a retention time between C18∶3−C22∶0 fatty acids. Smaller amounts of the unidentified component (ca. 5% total fatty acid) also were detected in host rabbit serum. Purified, the unidentified component's methyl ester collected from the tick eggs by preparative gas liquid chromatography was partially identified and characterized by chemical and spectroscopic analyses. The evidence suggests that the unidentified component is a methyl branched C15 tricarboxylic acid containing two vicinal carboxylic acid groups. Biosynthesis of the unidentified component by the tick is under investigation.
Gas chromatographic resolution of homologous monoacyl and monoalkylglycerols
Authors: Myher J. J. , Kuksis A. 
Published: November 2006

AbstractHomologous series of 1 and 2 monoacyl and monoalkyl‐sn‐glycerols with 0–6 double bonds were resolved by gas liquid chromatography as the trimethylsilyl ethers and acetates using ethylene glycolsuccinate siloxane, cyanopropylphenylsiloxane, and methylsiloxane liquid phases. The trimethylsilyl ethers gave effective separation of positional isomers and saturated and unsaturated derivatives of acylglycerols on both ethylene glycolsuccinate siloxane and cyanopropylphenylsiloxane, columns. The corresponding acetyl esters were eluted on the basis of unsaturation, but positional isomers overlapped. The ethylene glycol‐succinate siloxane and cyanopropylphenylsiloxane columns resolved the positional isomers and saturated and unsaturated species of the alkylglycerols when chromatographed as the acetates, while the corresponding trimethylsilyl ethers were separated on the basis of unsaturation only. On methylsiloxane columns essentially complete overlapping was observed among the positional isomers within each acyl and alkylglycerol series when chromatographed as the acetates. There was an effective resolution of the positional isomers of the acylglycerols as the trimethylsilyl ethers on methylsiloxane. From methylsiloxane, the alkenylglycerols were eluted earlier than the alkylglycerols of corresponding carbon numbers. These species were not separated on conventional ethylene glycol‐succinate siloxane or cyanopropylphenylsiloxane columns.
Biosynthesis of monoacyl‐sn‐glycerol 3‐phosphate by rabbit heart mitochondria: Positional specificity differing from liver enzyme
Authors: Liu M. S. , Brooks P. J. , Kako K. Joe 
Published: November 2006

AbstractRabbit heart mitochondria synthesize comparably more monoacyl‐than diacylglycerol 3‐phosphate as compared to heart microsomes. Since the fatty acid specificity of the biosynthesis by cardiac enzymes differs from that by hepatic enzymes, the positional specificity of monoacylglycerol 3‐phosphate formation by mitochondria was investigated by using a method utilizing lysosomal phosphatidate phosphohydrolase and borate‐impregnated thin layer chromatography. Contrary to the results of studies with liver particulates, ca. one‐third of palmitate was found at position 2 of the glycerol moiety and the remainder at position 1, whereas one‐third of oleate was bound at position 1. Only a slight, asymmetric distribution was observed with linoleate as the acyl donor. Thus, our study indicates that preferential acylation of individual fatty acids during the formation of monoacylglycerol 3‐phosphate is not as distinct in the heart mitochondria as in the liver mitochondria and microsomes.
Obligatory role of bile for the intestinal absorption of vitamin E
Authors: Gallo‐Torres Hugo E. 
Published: November 2006

AbstractNormal, white female rats subjected to cannulation of the abdominal thoracic duct have been utilized for a study on the essentiality of biliary and pancreatic secretions for the intestinal absorption of vitamin E. In all animals the thoracic duct lymph was collected. Some rats had the enterohepatic circulation undisturbed and in others bile or pancreatic juice or both were drained to the exterior by appropriate catheters in the common bile duct. On the first postoperative day, the animals received intragastrically an emulsion containing protein, carbohydrate, monoolein, 2 mg ofd,l‐α‐tocopheryl acetate plus 50 μC ofd,l‐α‐tocopheryl‐1’,2’‐3H‐acetate. The appearance of radioactive α‐tocopherol and its derivatives was determined in lymph, hourly, after emulsion administration. The obligatory role of bile in intestinal absorption ofd,l‐α‐tocopheryl‐1’,2’‐3H‐acetate has been established. Pancreatic juice seems to be necessary for the hydrolysis of the vitamin E acetate ester. The simultaneous infusion of bile and pancreatic juice promotes absorption of about 10% of the administered dose into the lymph. A chromatographic separation of the radioactive vitamin E fractions revealed that most of the vitamin E, which is actively transfered from the intestinal lumen to the lymph, is nonesterified. An oxidation product of α‐tocopherol, presumably itsp‐quinone, appears in small amounts in the lymph, but almost no labeled α‐tocopheryl acetate could be detected under these experimental conditions.
Binding of long chain fatty acids to β‐lactoglobulin
Authors: Spector Arthur A. , Fletcher John E. 
Published: November 2006

Abstractβ‐lactoglobulin (BLG), a bovine milk protein that is available commercially in crystalline form, binds long chain free fatty acids (FFA). The binding data were analyzed with a model containing one primary FFA binding site and a large number of weak secondary binding sites. At 37C and pH 7.4, the apparent association constant for binding of FFA to the primary site was of the order of 105 M−1 and that for binding to the secondary sites was approximately 103 M−1. The strength of binding was: palmitate > stearate > oleate > laurate. The affinity of BLG for palmitate increased as the pH of the incubation medium was raised from 6.5 to 8.7 and decreased as the ionic strength of the medium was raised. Palmitate binding was decreased in the presence of 6 M urea and when the protein either was exposed to elevated temperature or was acetylated prior to incubation. BLG took up methyl palmitate, cetyl alcohol, hexadecane and cholesterol to a lesser extent than FFA. Binding of FFA to BLG was associated with a small increase in the intensity of the fluorescent emission of the protein at 333 mμ. BLG can serve as an FFA acceptor or carrier in biological experiments. FFA released from adipose tissue during in vitro incubation was taken up by BLG. Net transfer of fatty acid to the incubation medium ceased when the molar ratio of FFA to BLG exceeded 1.1.14C‐1‐Palmitate bound to BLG was taken up by Ehrlich ascites tumor cells in vitro. At a given palmitate‐protein molar ratio, much more labeled fatty acid was taken up by these cells from media containing BLG than from those containing bovine albumin, apparently because FFA is bound less firmly to BLG than to albumin.
Isolation and structural determination of the C20 and C22 unsaturated fatty acids of rapeseed oil
Authors: Haeffner E. W. 
Published: November 2006

AbstractPolyunsaturated C20 and C22 fatty acids, which seldom are found in the triglycerides of higher plants, were isolated from rapeseed oil and their structures fully characterized. Pure 20∶2 and 20∶3 were identified as all‐cis Δ‐11,14 and all‐cis Δ‐11,14,17. Pure 22∶2 and 22∶3 were characterized as all‐cis Δ‐13,16 and all‐cis Δ‐13,16,19. Trienoic acids were found in very small amounts. Reinvestigation of the 20∶1 acid showed that it is a mixture of 75%cis Δ‐11 and 25%cis Δ‐13, whereas the 22∶1 is thecis Δ‐13 isomer only. Evidence is also given for the presence of a 24∶1 acid.
Spectrophotometric determination of molar amounts of glycosphingolipids and ceramide by hydrolysis and reaction with trinitrobenzenesulfonic acid
Authors: Yamamoto Akira , Rouser George 
Published: November 2006

AbstractThree spectrophotometric procedures for determination of chromatographically separated glycosphingolipids (cerebroside, sulfatide, ganglioside) are described and compared. Hydrolysis to release long chain base followed by reaction of the amino group with trinitrobenezene sulfonic acid (TNBS) and measurement at 340 mμ was shown to give values in good agreement with those obtained by reaction of the carbohydrate moiety with α‐naphthol or anthrone and measurement at 550 and 625 mμ respectively. The TNBS method is also applicable to ceramide.
Synthesis of phospholipids and phospholipid fatty acids by isolated perfused rat lung
Authors: Wang M. C. , Meng H. C. 
Published: November 2006

AbstractSynthesis of phospholipids and phospholipid fatty acids in isolated perfused rat lung was studied. The perfusion fluid was a Krebs‐Ringer bicarbonate buffer containing a14C labeled substrate. It was found that 1‐14C‐acetate, 1‐14C‐laurate, 1‐14C‐palmitate, 1‐14C‐stearate, 1‐14C‐oleate, or U‐14C‐D‐glucose was incorporated into tissue lipids in the isolated perfused lung at a rate geeater than that in incubated minced tissue. However, the patterns of the newly synthesized lipids from these two systems were similar. In 1 hr of perfusion, 6.8, 3, 14.5, 7.5, 7, and 2% of the initial14C‐radioactivity of 1‐14C‐acetate, 1‐14C‐laurate, 1‐14C‐palmitate, 1‐14C‐stearate, 1‐14C‐oleate, and U‐14C‐D‐glucose, respectively, were incorporated into phospholipids. Phospholipid fatty acids accounted for 95–96% total phospholipids‐14C when14C‐substrates, other than glucose, were used. For glucose, only 20% phospholipids‐14C was in phospholipid fatty acids. More than 80% phospholipid fatty acids‐14C was in palmitic acid when 1‐14C‐acetate and U‐14C‐D‐glucose were used, while 37, 61, 80, and 94% phospholipid fatty acid‐14C from 1‐14C‐laurate, 1‐14C‐sterate, 1‐14C‐oleate, and 1‐14C‐palmitate, respectively were recovered in the original form of the fatty acid used. The newly synthesized phospholipid fatty acid (13–24%) from 1‐14C‐laurate, 1‐14C‐stearate, and 1‐14C‐oleate was palmitic, and 10% of phospholipid fatty acid from 1‐14C‐stearate was in oleic acid. Hydrolysis by phospholipase A showed that14C from perfused substrates was esterified to both α and β positions of phospholipids. It was found that positional selectivity of phospholipid fatty acids was determined by chain length, degree of unsaturation, and source of fatty acid.
Differential trypsin effect upon (1‐14C) acetate incorporation into choline and ethanolamine glycerophosphatides of rat brain and liver
Authors: Cohen Steven R. , Bernsohn Joseph 
Published: November 2006

AbstractPreincubation of rat brain and liver slices in a medium (5% glucose, 5% fructose, 1% albumin, 1% trypsin, 10 mM phosphate buffer pH 6.0) used to pretreat brain tissue for the separation of cell types was found to uncouple the incorporation of (1‐14C) acetate into ethanolamine phosphoglycerides from that of the choline phosphoglycerides. Incorporation into ethanolamine phosphoglycerides was stimulated in both brain (330%) and liver (780%) slices, while the incorporation of (1‐14C) acetate into choline phosphoglycerides was reduced for both brain (71%) and liver (63%) slices, compared to control values from nonpreincubated material. With (1‐14C) linolenic acid as a precursor, no significant differences were found in incorporation into ethanolamine phosphoglycerides and choline phosphoglycerides.
Quantitation of phosphatidyl N‐methyl and N,N‐dimethyl aminoethanol in liver and lung of N‐methylaminoethanol fed rats
Authors: Katyal S. L. , Lombardi B. 
Published: November 2006

AbstractA diet supplemented with N‐methylaminoethanol was fed to rats, and liver and lung phospholipids were resolved by a two dimensional thin layere chromatographic method affording the separation of phosphatidyl N‐methylaminoethanol and phosphatidyl N,N‐dimethylaminoethanol, as well as of the major phosphatides. Significant amounts of phosphatidyl N‐methylaminoethanol and phosphatidyl N,N‐dimethylaminoethanol accumulated within 24 hr in liver and lung. The fatty acid composition of liver phosphatidyl N‐methylaminoethanol and phosphatidyl N,N‐dimethylaminoethanol was determined. Stearic, arachidonic, and docosahexaenoic acids were the predominant fatty acids of these phosphatides. After injection of (Me‐14C)methionine, only phosphatidyl N,N‐dimethylaminoethanol and phosphatidylcholine became heavily labeled in both liver and lung. These findings indicate that N‐methylaminoethanol is incorporated into phosphatidyl N‐methylaminoethanol, and the latter is methylated to phosphatidyl N,N‐dimethylaminoethanol and phosphatidylcholine.
Formation of palmitate esters of monohydric short chain alcohols by swine arterial subcellular fractions
Authors: Morin Robert J. , Ihrig Thomas 
Published: November 2006

AbstractAlcohols of 1–5 carbon chain length were esterified with palmitic acid and palmitoyl CoA substrates by swine aortic cytosol, mitochondrial, and microsomal fractions. Esterification of the palmitic acid substrate with ethanol was enhanced by the addition of adenosine 5′‐triphosphate and CoA to the mitochondrial and microsomal fractions. The rate of esterification of ethanol was most rapid in the microsomal fraction and with the palmitoyl CoA substrate. Esterification was linearly related to time of incubation, was optimal at pH 6.8, and could be inactivated by heating at 90 C. Esterification was inactivated by ethanol concentrations above 0.8 M and by lower concentrations of the other alcohols. Rates of esterification were highest with n‐propanol and lowest with tert‐butanol and the pentanols. The formation of cholesteryl esters by the aortic microsomes was inhibited by ethanol and was inversely related to the rate of ethyl palmitate formation.
New drugs affecting lipid metabolism
Authors: Kritchevsky David 
Published: November 2006

AbstractThe search for an ideal hypolipidemic agent still is underway. A relatively large number of the newer hypolipemic agents are related to ethyl p‐chlorophenoxyisobutyrate—among them are compounds with the trivial names or designations of SU 13,437; Sah 42‐348; halofenate, treloxinate, S‐8527, and two valeric acid derivatives. Other lipopenic agents, whose modes of action are described, are linoleic acid amides, Colestipol, antidiabetic agents, bis (hydroxyethylthio) 1,10‐decane, pyridinol carbamate, and some nicotinic acid derivatives.
Effect of (−)‐hydroxycitrate upon the accumulation of lipid in the rat: I. Lipogenesis
Authors: Sullivan Ann C. , Triscari Joseph , Hamilton James G. , Miller O. Neal , Wheatley Victor R. 
Published: November 2006

AbstractThe purpose of these investigations was to ascertain the effect of (−)‐hydroxycitrate on the accumulation of lipid in the meal fed rat by examining the rates of lipogenesis after acute and chronic treatment. Oral administration of (−)‐hydroxycitrate depressed significantly the in vivo lipogenic rates in a dose‐dependent manner in the liver, adipose tissue, and small intestine. The hepatic inhibition was significant for the 8 hr period, when control animals demonstrated elevated rates of lipid synthesis. The kinetics of this reduction of in vivo hepatic lipogenesis were identical after acute or chronic administration of (−)‐hydroxycitrate. However, in vitro rates of lipogenesis were elevated after chronic administration of (−)‐hydroxycitrate for 30 days. Rats receiving (−)‐hydroxycitrate consumed less food than the untreated controls; however, this decreased caloric intake was not responsible for the drug induced depression of hepatic lipogenesis, as shown by studies using pair fed rats.
Effects of dietary cholesterol upon bile acid metabolism in guinea pig
Authors: Lansma Heleni , Ostwald Rosemarie 
Published: November 2006

AbstractCholesterol fed guinea pigs develop a hemolytic anemia accompanied by high cholesterol concentrations in the liver, plasma, and red cells. We have studied the bile acid metabolism of guinea pigs fed a diet with or without cholesterol in a search for the factor(s) which prevent adequate control of their body cholesterol pool and, therefore, its pathological consequences. The results show that in the cholesterol fed guinea pig the synthesis (and excretion) of bile acids was at least three times greater than in controls. This is the result of a doubling of the fractional turnover rate and a smaller increase in the pool size. The major increase of the bile acid pool was in the liver. The main bile acid in gall bladder bile and small intestines was chenodeoxycholic acid, with smaller amounts of 7‐ketolithocholic and ursodeoxycholic acids. In the caecum, large intestines, and feces, the major bile acid was lithocholic acid.
Enzymic synthesis of ethanolamine plasmalogens through ethanolaminephosphotransferase activity in neurons and glial cells of rabbit in vitro
Authors: Binaglia L. , Roberti R. , Goracci G. , Francescangeli E. , Porcellati G. 
Published: November 2006

AbstractThe de novo synthesis of ethanolamine plasmalogen in isolated neuronal and glial cells from adult rabbit brain cortex was investigated in vitro, using labeled cytidine‐5′‐diphosphate ethanolamine as lipid precursor. The neuronal cell enriched fraction was found to possess a twofold ethanolaminephosphotransferase activity (EC 2.7.8.1), as compared to the glial fraction. The neuronal/glial ratio was similar both in the absence and in the presence of saturating alkenylacyl glycerol. Under the most favorable conditions, rates of 31 nmoles and 16 nmoles ethanolamine plasmalogen/mg protein/30 min were obtained for neurons and glia, respectively. Several kinetic properties of the phosphotransferase were found to be similar both in neurons and glia, e.g., Km of cytidine‐5′‐diphosphate ethanolamine, pH optimum, need for divalent cations; the Km value for alkenylacyl glycerol was twofold higher in glia (4 mM) than in neurons (2 mM). The neuronal/glial ratio for the phosphatidylethanolamine synthesizing activity was 2, 4.5, and 6 on using diacyl glycerols prepared from ox heart, ox brain, and soybean, respectively. It is concluded that the cytidine‐dependent system for ethanolamine plasmalogen and phosphatidylethanolamine synthesis is concentrated prevalently in the neuronal cells, as compared to glia.
Unusual composition of sterols in a phytophagous insect, Mexican bean beetle reared on soybean plants
Authors: Svoboda J. A. , Thompson M. J. , Elden T. C. , Robbins W. E. 
Published: November 2006

AbstractThree saturated sterols, cholestanol, campestanol, and stigmastanol, constituted 54, 72, and 77% of the total sterols of the egg, prepupa, and adult, respectively, of the Mexican bean beetle,Epilachna varivestis (Mulsant), reared on soybean plants. Lathosterol (7‐cholesten‐3β‐ol), possibly formed from cholestanol in this insect, constituted 12, 16, and 11.8% of the total sterols isolated from egg, prepupa, and adult, respectively. None of these sterols have been isolated and identified previously as components of the sterols of a phytophagous insect reared on a natural host plant. Cholesterol, a major sterol of most plant feeding insects studied thus far, comprised less than 5% of the total sterols in any of the stages examined. The unique composition of the sterols in this insect in relation to the sterol composition of the host plant is compared to dietary sterol utilization and metabolism in other phytophagous insects.
Studies on phospholipids with particular reference to cardiolipin of rat heart after feeding rapeseed oil
Authors: Blomstrand Rolf , Svensson Lennart 
Published: November 2006

AbstractThe influence of dietary rapeseed oil on the lipid classes and fatty acid pattern of rat heart homogenate and mitochondria has been investigated after feeding a diet with 9.8% by wt erucic acid for 10 days and 1.4% and 2.6% erucic acid for 28 days. The rats treated with 9.8% erucic acid showed a significant increase in the triglycerides of the heart mitochondria. This tendency was much less pronounced in rats treated with 1.4 and 2.6% erucic acid, respectively. In all experiments, the triglycerides of the heart mitochondria showed a high content of erucic acid. The fatty acids of phosphatidylcholine, phosphatidylethanolamine, and cardiolipin were all influenced by the dietary rapeseed oil, but the erucic acid seemed to have a specific affinity to cardiolipin. Cardiolipin of rat heart mitochondria was isolated and identified with gas chromatography and mass spectrometry. The isolated cardiolipin was found to contain 12% erucic acid after feeding 9.8% erucic acid as rapeseed oil for 10 days. Similar results were obtained after feeding glyceryl trierucate for 5 days to rats. The incorporation of erucic acid into cardiolipin was followed by a corresponding decrease of linoleic acid. This observation is of great interest because the molecular structure of fatty acids in lipid molecules has a profound influence on the packing of these molecules in a bilayer. Since cardiolipin is a component of the inner membrane of mitochondria its high affinity for erucic acid might influence the normal function of the inner membrane of heart mitochondria.
Metabolic effects following medium chain triglycerides load in dogs: IV. Influence of administration of methylene blue
Authors: Bach A. , Metais P. , Guisard D. , Debry D. 
Published: November 2006

AbstractThe perfusion of 1 g/kg of medium chain triglycerides in 1 hr in the dog causes an increase in triglycerides, nonesterified fatty acids, and ketone bodies in the plasma. Hyperinsulinemia and hypoglycemia are observed at the same time. Simultaneous perfusion of fat and a hydrogen acceptor, such as methylene blue, does not modify the triglycerides, nonesterified fatty acids, and total ketone bodies variations. On the other hand, the dye modified the redox state of the liver, the consequence of which is an increase in glycemia, despite high concentrations of insulin.
Bile acid metabolism in mammals: VII. Studies on sex differences in deoxycholic acid metabolism in isolated perfused rat liver
Authors: Fisher M. M. , Price V. M. , Magnusson R. J. , Yousef I. M. 
Published: November 2006

AbstractThe hepatic metabolism of deoxycholic acid was studied using the isolated perfused rat liver technique. In 20 perfusions, 10 involving the livers of male rats and 10 involving the livers of female rats, 30 μmoles deoxycholic acid was added to the perfusion medium. In 10 perfusions, 5 male and 5 female, 1 μmole deoxycholic acid was added to the perfusion medium. In 10 of the high dose studies and in the 10 low dose studies, 1 μCi deoxycholic acid‐C‐24‐C14 also was added. The deoxycholic acid was added to 100 ml perfusion medium after 2 hr of baseline perfusion, and the studies were continued another 3 hr. Biliary bile acids were analyzed by combined thin layer and gas chromatography, and the radioactivity content of the perfusion medium and liver was documented. Although there was no sex difference in total bile acid secretion in the high dose studies, there were sex differences in the bile acid secretion rate and in the quantitative secretion of individual bile acids. The biliary secretion of deoxycholic acid and cholic acid was immediate in the female studies and delayed in the male, and the amounts of cholic acid and sulfated deoxycholyl‐taurine secreted were considerably greater in the male studies. In the low dose studies the isolated perfused liver of the female rat converted more deoxycholic acid to cholyl‐taurine than did that of the male rat. There are sex differences in the hepatic metabolism of deoxycholic acid. In contrast to those found in the case of chenodeoxycholic acid, these sex differences are not impressive when physiological amounts of deoxycholic acid are presented to the liver.