bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biosynthesis of lipids by bovine meibomian glands
Authors: Kolattukudy P. E. , Rogers Linda M. , Nicolaides Nicholas 
Published: November 2006

AbstractIsolated bovine meibomian glands incorporated exogenous [1‐14C] acetate into lipids. Thin layer chromatographic analysis of the lipids showed that wax esters and sterol esters contained 61% of the total label. Radio gas liquid chromatographic analysis of the acid and alcohol moieties of both ester fractions showed the label was distributed equally between the two portions of the ester in both cases. Cholesterol and 5‐α‐cholest‐7‐en‐3β‐ol were the major labeled sterols, and anteiso‐C25, anteiso‐C27 and anteiso‐C23 were the most highly labeled alcohols. The major labeled fatty acids in the wax esters were anteiso‐C15,n‐C16, anteiso‐C17 andn‐C18∶1, whereas anteiso‐C25 and anteiso‐C27 were the major labeled acids in the sterol esters. The diester region with 6% of the total label contained labeled fatty acids and fatty alcohols each with anteiso‐C25 as the major component and ω‐hydroxy acids in whichn‐C32∶1 was the major labeled component. The trigly ceride fraction which contained 8% of the total lipids was composed of labeled fatty acids similar to those found in both sterol and wax ester fractions. Chromatographic analyses of the labeled lipids derived from exogenous labeled isoleucine showed that anteiso‐branched products were preferentially labeled. The labeled triglyceride fraction derived from [U‐14C] isoleucine also contained esterified C15, C13, C11, C9, C7 and possibly shorter anteisobranched acids.
Decreased phosphatidylcholine in the lung fluid of patients with sarcoidosis
Authors: Baughman Robert P. , Strohofer Susan , Dohn Michael 
Published: November 2006

AbstractSurfactant decreases the immune response of lymphocytes. Pulmonary sarcoidosis is a disease characterized by an increased number and activity of lymphocytes in the lung. We measured the lipids and lymphocytes retrieved from the lung by bronchoalveolar lavage. Thirteen patients with active pulmonary sarcoidosis had a significantly higher percentage of lymphocytes (18±21%, mean ± standard error of the mean) than 10 control subjects (4±1.9%, p<0.01). Using an external marker, we found the absolute amount of disaturated phosphatidylcholine to be higher in the control group (174±17.4 μg/ml lung fluid) than in the sarcoid group (91±1.9 μg/ml of lung fluid, p<0.002).
New natural 2‐acetoxy fatty acids using chemical ionization and electron impact mass spectrometry
Authors: Ayanoglu Eser , Kurtz Kara , Kornprobst J. M. , Djerassi Carl 
Published: November 2006

AbstractThe phospholipids of the spongePolymastia gleneni contain saturated long chain (C22–30)‐acetoxy fatty acids. Their structures were assigned based on chromatographic and spectrometric data as well as comparison with a synthetic sample. The use of capillary gas chromatography combined with chemical ionization and electron impact mass spectrometry was instrumental in the eludication of structures, since only a very small amount of crude lipids was available.
Influence of dietary cholesterol on the relative synthesis of hepatic glycerides and molecular classes of 1,2‐diglycerides and phospholipids in the gerbil in vivo
Authors: Andersen D. B. , Holub B. J. 
Published: November 2006

AbstractThe influence of dietary cholesterol on the relative rates of synthesis of hepatic lipids in the male Mongolian gerbil,Meriones unguiculatus, was studied. The semi‐purified starch‐based diet used lard as the dietary fat and was fed with or without a 0.5% (by wt.) cholesterol supplement. Each animal received 300 μCi [2‐3H]‐glycerol i.p. after 3 or 7 days on the dietary regimens. Relative rates of [2‐3H]‐glycerol incorporation into the major hepatic glycerides in vivo was not affected significantly by dietary cholesterol (0.5% level), suggesting that alteration in the relative biosynthesis of these lipids could not readily account for the higher triglyceride (TG) to phospholipid (PL) mass ratio in liver with cholesterol feeding. However, there was evidence for an increased formation of 1,2‐diglyceride (1,2‐DG). The complement of molecular species of hepatic 1,2‐DG, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) formed de novo, as measured using isotopic glycerol, was not influenced greatly by dietary cholesterol, although lower mean rates of synthesis of tetraenoic relative to dienoic species of phospholipids were indicated in cholesterol‐fed gerbils.
Red pigment‐forming substances from autoxidized linolenate: Identification of prostaglandin‐like substances
Authors: Nakamura Takashi 
Published: November 2006

AbstractThe chemical structures of lipid degradation products capable of reacting with amino acids and forming red pigments were investigated. The red pigment‐forming substances (RPS's) derived from autoxidized linolenate in triglyceride of linseed oil were purified successively by gel chromatography on Sephadex LH‐20, column chromatography and TLC on Silica gel 60, and HPLC on μ‐Porasil. Consequently, three types of RPS's were isolated.IR spectra of RPS's were similar, except for slight differences in the fingerprint region (1300—650 cm−1). These substances included the OH group (3500 cm−1 region), conjugated aldehyde (νC=0 1688 cm−1, νC=C 1635 cm−1) and ketone (νC=0 1740 cm−1) in their molecules. RPS's were analyzed by GLC and GC‐MS after derivatization with dimethylhydrazine and/or trimethylsilyl reagents, before and after the reduction with NaBH4 and/or hydrogenation with PtO2. The fragmentation patterns indicated the presence of an ethyl group in addition to the functional groups described above, and the molecular formula was estimated to be C10H14O3. Further elucidation of the structures was obtained by13C‐ and1H‐NMR analyses, and evidence was obtained for the presence of a hydroxypentanone ring, a PG‐like structure. The sequence of the protons on the ring carbons was unequivocally deduced from the double resonance experiments.All the data taken together suggested that the RPS's were the stereoisomer of 3‐(2‐ethyl‐5‐hydroxy‐3‐oxo) cyclopentanyl‐2‐propenal.
Relationship between platelet cyclooxygenase pathway and plasma malondialdehyde‐like material
Authors: Violi F. , Ghiselli A. , Alessandri C. , Iuliano L. , Cordova C. , Baslano F. 
Published: November 2006

AbstractThrombin‐induced platelet malondialdehyde (MDA) formation and plasma malondialdehyde‐like material (MDA‐LM) were evaluated in 12 healthy subjects before and after 1 and 7 days from aspirin (1 g) ingestion. 24 hr after aspirin administration, platelet MDA was almost abolished while MDA‐LM showed a 23% decrease. Platelet MDA and plasma MDA‐LM returned to baseline values 7 days after aspirin ingestion. These data suggest that platelet cyclooxygenase pathway affects only in part plasma MDA‐LM. The evaluation of plasma MDA‐LM before and after aspirin could be useful for evaluating in vivo platelet cyclooxygenase activation.
Increased arachidonate incorporation in perfused heart phospholipids from vitamin E‐deficient rats
Authors: Chan Alvin C. , Fragiskos Bill , Douglas Cheryl E. , Choy Patrick C. 
Published: November 2006

AbstractWhen perfused with exogenous arachidonic acid (AA), the rat heart incorporates this eicosanoid precursor into the phospholipids. The incorporation of AA into phosphatidylcholine was 6‐fold higher than the incorporation of AA into phosphatidylethanolamine When vitamin E‐deficient rat hearts were perfused with AA, there was a marked increase in incorporation of AA into both phosphatidylcholine and phosphatidylethanolamine compared to rats fed with a vitamin E supplemented diet. The result of this study suggests that vitamin E has a regulatory role in phospholipid biosynthesis in the mammalian heart.
Gamma linolenic acid attenuates cardiovascular responses to stress in borderline hypertensive rats
Authors: Mills David E. , Summers Maureen R. , Ward Ron P. 
Published: November 2006

AbstractThe purpose of the present study was to investigate the effects of gamma linolenic acid (GLA) on cardiovascular responses to psychosocial stress (isolation) and to pressor hormones in the genetically borderline hypertensive rat (SHR×WKY). Adult male SHR×WKY were divided into two groups following five weeks of group housing. One group (GLA) received eight weeks constant flow osmotic pumps releasing 0.04 mg GLA in olive oil/kg‐hr, while the second group received dummy pumps (DUM). One week following pump implantation, each group was divided into two subgroups and exposed to a four‐week experimental period of either continued group housing (no stress) or isolation (stress). A two‐week recovery period of group housing followed the experimental period. Blood pressure and heart rate were determined weekly by the tail cuff technique. At the end of the recovery period, animals in the no stress condition were anesthetized and received an arterial cannula for NOR and ANG infusion and direct BP recording. Then the responses to an ED50 of NOR and ANG were determined. All animals were then killed for determination of heart weight and adrenal weight. All groups had mean control period systolic BP values ranging from 143–146 mm Hg. In the no stress condition, neither GLA nor DUM altered BP over the course of the study. However, BP increased in the DUM group durign all four weeks of the isolation period vs the control period (p<0.01), whereas BP increased only in week 1 in the GLA group (p<0.05). Heart rate increased during stress in the DUM group (p<0.05), but not in the GLA group. Vascular reactivity to NOR was unaffected by GLA administration. In contrast, GLA increased the duration of the pressor response to ANG (p<0.01), but tended to decrease the magnitude of the pressor response (p<0.09) vs DUM. GLA had no effect on heart weight/body weight ratio. Adrenal weight/body weight ratio was lower in the DUM/no stress group than all other treatment groups.These data indicate that GLA administration attenuates the cardiovascular responses to chronic stress in animals with a genetic predisposition to hypertension, in the absence of an effect on resting BP. They also demonstrate a limitation of GLA effect, in mature animals, to epigenetic pressor factors. Furthermore, GLA action may involve an alteration of the cardiovascular responses to ANG, but not NOR. These findings suggest that GLA may be useful in preventing the neurogenic triggering of hypertension by chronic stress in genetically stress‐sensitive animals.
Sex allocation in the polydomous leaf‐cutting antAcromyrmexbalzani
Authors: Ichinose Katsuya , Forti Luis C. , Pretto Denis R. , Nachman Gösta , Boomsma Jacobus J. 
Published: November 2006

AbstractLogistic regression analysis was used to analyse sex allocation in a population of the leaf‐cutting antAcromyrmexbalzanioccurring in a pasture in southern Brazil. The field sample consisted of 151 fungus‐garden chambers (18 queenright and 133 queenless), belonging to 50 nests with three vertically stacked chambers per nest on average. Taking nest chamber as the unit of analysis, seven predictor variables were considered: sampling date, chamber depth, chamber volume, weight of fungus garden, presence of a queen, number of large workers, and number of small to medium workers. The population‐level numerical proportion of females was 0.548 and the inferred proportional energetic investment in females 0.672. The former was not significantly different from 0.5 (P=0.168), but the latter was (P=0.0003). The proportional investment in females per fungus garden increased with the number of large workers present (P=0.0002) and decreased with the dry weight of the fungus garden (P=0.012). This implies that resource acquisition through foraging is likely to be a major proximate determinant of sex allocation. The negative correlation between female bias and fungus garden weight might be due to developing adult females requiring more food than males, but this hypothesis could not be confirmed by direct statistical evidence.
Oxidative effects of animal‐originated porphyrins and riboflavin on cholesterol oxidation in an aqueous model system
Authors: Kim Jong‐Seung , Chung Myung‐Sub , Shin Hyo‐Sun 
Published: November 2006

AbstractThis study was executed to investigate effects of animal‐originated porphyrins and riboflavin on cholesterol oxidation in aqueous model systems. Changes of headspace oxygen contents, cholesterol, and cholesterol oxide products (COP) in the model systems were measured by gas chromatography during storage under light. As concentration of protoporphyrin increased, contents of headspace oxygen decreased and COP increased. The same trend as that of protoporphyrin occurred with riboflavin in terms of contents of headspace oxygen, but production of COP was the highest at 5 ppm riboflavin. As concentrations of hemoglobin and myoglobin increased, headspace oxygen content and COP production were not changed significantly. Consequently, protoporphyrin could be the most active catalyst on the cholesterol oxidation in the aqueous system, but myoglobin and hemoglobin did not accelerate cholesterol oxidation.
Simplified measurement of virgin olive oil color by application of the characteristic vector method
Authors: Moyano María José , Ayala Fernando , Echávarri J. Federico , Alba José , Negueruela A. Ignacio , Heredia Francisco J. 
Published: November 2006

AbstractThere are several simplified methods to measure the color of virgin olive oils. However, their reliability is questionable, as they provide errors that sometimes can be considerable. A new method to calculate color coordinates and objective chromatic parameters in the color region of these olive oils is proposed with the aim of overcoming these objections. The method is a simplification of the original method proposed by the Commission Internationale de l'Eclairage (CIE), based on the measurement of the complete visible spectrum, from 380 to 770 nm. The characteristic vector analysis provides new equations to calculate tristimulus values as functions of these transmittance values based on a reconstruction of oil transmission spectra measuring from three to six wavelengths. The results show that color differences exist between the color coordinates of the experimental samples and those obtained by means of the proposed method. For more than 90% of the samples, the difference was smaller than three CIELAB units when equations based on four or more wavelengths were used.
Dietary diacylglycerol prevents high‐fat diet‐induced lipid accumulation in rat liver and abdominal adipose tissue
Authors: Meng Xianghe , Zou Dongya , Shi Zhongping , Duan Zouying , Mao Zhonggui 
Published: November 2006

AbstractThe inhibitory effects of 1,3‐diacylglycerol (DAG) on diet‐induced lipid accumulation in liver and abdominal adipose tissue of rats were investigated in the present study. Male Sprague‐Dawley rats were given free access to diets containing 7 wt% TAG (low TAG), 20 wt% TAG (high TAG), or 20 wt% DAG (high DAG), respectively, for 8 wk. The body weight of rats in the 20% high‐TAG group increased significantly, and the weights of their abdominal adipose tissue and liver also showed a significant increase compared with rats in the low‐TAG group. However, the high‐DAG diet resulted in both a significant reduction in body weight gain (with a decrease of 70.5%) and an increase in the ratio of abdominal fat to body weight (by 127%) compared with the high‐TAG diet. As well, the liver TAG and serum TAG levels of the high‐DAG group were significantly lower than those of the high‐IAG group. These effects were associated with up‐regulation of acyl‐CoA carnitine acyltransferase (ACAT) and down‐regulation of acyl‐CoA DAG acyltransferase (DGAT) in the liver. However, no significant difference was observed in the activities of alanine aminotransferase and aspartate aminotransferase among the groups (P>0.05). The present results indicate that dietary DAG reduced fat accumulation in viscera and body, and these effects may be involved with up‐regulation of ACAT and down‐regulation of DGAT in the liver.
Hexane elimination from soybean oil by continuous packed tower processing with supercritical CO2
Authors: Reverchon E. , Poletto M. , Osséo L. Sesti , Somma M. 
Published: November 2006

AbstractHexane elimination is the most energy‐consuming step in the industrial extraction of soybean oil. It utilizes three sets of equipment: two evaporation stages in series followed by a stripper at a pressure of about 0.07 bar. The final hexane residue in the oil is about 1000 ppm. We propose an alternative to the present process for hexane elimination, based on the extraction of the soybean oil/hexane mixture with supercritical CO2 in a continuous countercurrent packed tower. In this work, we tested a soybean oil/hexane mixture feed containing 10% by weight of hexane. Various pressures and temperatures of the column were tested to reduce hexane residue in the oil. The extraction process was demonstrated to be very effective for hexane separation. Indeed, at the bottom of the column we recovered soybean oil containing quantities of hexane as low as 20 ppm when we operated at 120 bar, 40°C. The effect of process parameters is also discussed.
Comparative study of the extraction and measurement of cottonseed free fatty acids
Authors: Wan Peter J. , Dowd Michael K. 
Published: November 2006

AbstractCrude oil was extracted from cottonseed by three different methods to study the influence of extraction technique on the free fatty acid (FFA) concentration. Extraction procedures that recovered more oil had higher levels of FFA. In addition, the highest concentration of FFA was found in oil recovered by Soxhlet reextraction of a meal initially defatted by a room‐temperature extraction process. The FFA concentrations of oils recovered by Soxhlet extraction were highly correlated with the FFA concentration of oils recovered by the other extraction methods studied (R2>0.96). Titration of oil and gas chromatography of silylated oil were compared as methods to determine FFA concentration. The methods compared well (R2=0.998) with the titration method, giving ∼5% higher values for FFA than the chromatography method. Half of this difference appeared to be due to the oleic acid approximation used in the titration approach. The other half of the difference is likely due to the detection of other acidic components in crude oil.
Discrimination of edible oil products and quantitative determination of their iodine value by Fourier transform near‐infrared spectroscopy
Authors: Li Hui , van de Voort F. R. , Ismail A. A. , Sedman J. , Cox R. , Simard C. , Buijs H. 
Published: November 2006

AbstractThis work demonstrates the application of partial least squares (PLS) analysis as a discriminant as well as a quantitative tool in the analysis of edible fats and oils by Fourier transform near‐infrared (FT‐NIR) spectroscopy. Edible fats and oils provided by a processor were used to calibrate a FT‐NIR spectrometer to discriminate between four oil formulations and to determine iodine value (IV). Samples were premelted and analyzed in gass vials maintained at 75°C to ensure that the samples remained liquid. PLS calibrations for the prediction of IV were derived for each oil type by using a subset of the samples provided as the PLS training set. For each oil formulation (type), discrimination criteria were established based on the IV range, spectral residual, and PLS factor scores output from the PLS calibration model. It was found that all four oil types could be clearly differentiated from each other, and all the validation samples, including a set of blind validation samples provided by the processor, were correctly classified. The PLS‐predicted IV for the validation samples were in good agreement with the gas chromatography IV values provided by the processor. Comparable predictive accuracy was obtained from a calibration derived by combining samples of all four oil types in the training set as well as a global IV calibration supplied by the instrument manufacturer. The results of this study demonstrate that by combining the rapid and convenient analytical capabilties of FT‐NIR spectroscopy with the discriminant and predictive power of PLS, one can both identify oil type, as well as predict IV with a high degree of confidence. These combined capabilities provide processors with better control over their process.
Adhesive properties of soy proteins modified by urea and guanidine hydrochloride
Authors: Huang Weining , Sun Xiuzhi 
Published: November 2006

AbstractAn investigation was conducted on the adhesive and water‐resistance properties of soy protein isolates that were modified by varying solutions of urea (1, 3, 5, and 8 M) or guanidine hydrochloride (GH) (0.5, 1, and 3 M) and applied on walnut, cherry, and pine plywoods. Soy proteins modified by 1 and 3 M urea showed greater shear strengths than did unmodified protein. The 3 M urea modification gave soy protein the highest shear strength. Soy proteins modified with 0.5 and 1 M GH gave greater shear strengths than did the unmodified protein. The 1 M GH‐modified soy protein gave the highest shear strength. Compared to the unmodified protein, the modified proteins also exhibited higher shear strengths after incubating with two cycles of alternating relative humidity, zero delamination, and higher remaining shear strengths after three cycles water soaking and drying. These results indicate that soy proteins modified with urea and GH enhance water resistance as well as adhesive strength. Secondary structures of globule proteins may enhance adhesion strength, and the exposure of hydrophobic amino acids may enhance water resistance. Proteins modified by 3 M urea or 1 M GH may have higher content of secondary structure and more exposed hydrophobic amino acids, compared with other modifications or unmodified proteins.
Determination of peroxide value by fourier transform near‐infrared spectroscopy
Authors: Li Hui , van de Voort F. R. , Ismail A. A. , Cox R. 
Published: November 2006

AbstractA Fourier transform‐near infrared (FT‐NIR) method originally designed to determine the peroxide value (PV) of triacylglycerols at levels of 10–100 PV was improved upon to allow for the analysis of PV between 0 and 10 PV, a range of interest to the edible oil industry. The FT‐NIR method uses convenient disposable glass vials for sample handling, and PV is determined by spectroscopically measuring the conversion of triphenylphosphine (TPP) to triphenylphosphine oxide (TPPO) when reacted with hydroperoxides. A partial‐leastsquares calibration was developed for 8 mm o.d. vials by preparing randomized mixtures of TPP and TPPO in a zero‐PV oil. The method was validated with samples prepared by gravimetric dilution of oxidized oil with a zero‐PV oil. It was shown that the American Oil Chemists’ Society primary reference method was quite reproducible (±0.5 PV), but relatively insensitive to PV differences at lower (0–2) PV. The FT‐NIR method on the other hand was shown to be more accurate overall in tracking PV, but slightly less reproducible (0.9 PV) due to working close to the limit of detection. The sensitivity and reproducibility of the FT‐NIR method could be improved upon through the use of larger‐diameter vials combined with a detector having a wider dynamic range. The proposed FT‐NIR PV method is simple to calibrate and implement and can be automated to allow for routine quality control analysis of edible fats and oils.