bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of polyoxyethylated cholesterol on fecal bile acids and nitrogen and on cholesterol balance in rats
Authors: Amorosa L. F. , Martucci C. P. , Stevenson N. R. , Khachadurian A. K. 
Published: January 2007

AbstractPolyoxyethalated cholesterol (POEC) is a water soluble derivative of cholesterol which decreases cholesterol absorption in rats without affecting body weight, fatty acid excretion, or intestinal histology. In the present study rat feces were analyzed for cholic, deoxycholic, chenodeoxycholic, muricholic and lithocholic acid following 3 months of feeding a standard or a 2% enriched cholesterol diet with or without 1.5% POEC. In rats maintained on the cholesterol free diet, POEC increased total bile acids (mg/day) by 50% from 14±3 to 21±3 (mean ±SEM) but only the increase in chenodeoxycholic acid was significant (P<0.05). The corresponding POEC effect in the 2% cholesterol diet was 31% (70±8 to 93±3, P<0.01). Fecal nitrogen and serum cholesterol did not vary among groups. Comparing these data with neutral steroid excretion previously determined showed that POEC in the cholesterolfree diet increased the negative cholesterol balance more than three‐fold (34±7vs 118±13 P<0.01). In rats fed 2% cholesterol, POEC caused a negative cholesterol balance of 222±8 compared to the control of 27±52 (P<0.01). The data indicate that POEC exerts complex effects in the intestinal tract which increase both bile acid and cholesterol excretion.
Plasma lipid profiling by liquid chromatography with chloride‐attachment mass spectrometry
Authors: Kuksis A. , Marai L. , Myher J. J. 
Published: January 2007

AbstractA sensitive high‐performance liquid chromatographic assay was developed using chloride attachment negative chemical ionization mass spectrometry for detection of glyceryl esters and ceramides, and positive chemical ionization mass spectrometry for detection of free cholesterol and cholesteryl esters in minimal quantities of plasma. The novel technique was validated by high temperature gas‐liquid chromatography with flame ionization detection. Sample preparation was achieved by phospholipase C digestion of whole plasma, total lipid extraction and derivatization of any free carboxyl and hydroxyl groups by trimethyl‐ ortert‐butyldimethyl‐chlorosilane. The lipids were separated by reverse phase HPLC with 20–90% propionitrile in acetonitrile containing 1% dichloromethane, which served as the reagent and the source of chloride. Negative chemical ionization with chloride attachment is estimated to provide about 100 times higher response for the triacylglycerols and the trimethylsilyl ortert‐butyldimethylsilyl ethers of diacylglycerols, and about 500 times higher response for the trimethylsilyl ortert‐butyldimethylsilyl ethers of ceramides than positive chemical ionization mass spectrometry. Determination of the full negative chemical ionization mass spectra showed that each glycerolipid and ceramide species yielded a single ionic species corresponding to the chloride‐attachment product of the parent ion. The cholesteryl esters and ethers failed to attach chloride and remained undetected by negative chemical ionization. However, the cholesteryl esters and ethers gave a high response for the steroid nucleus in positive chemical ionization mass spectrometry. Chloride attachment negative chemical ionization mass spectrometry is suitable for the unequivocal identification of plasma glycerolipids and ceramides in high‐performance liquid chromatography and for the quantitation of molecular species in any unresolved peaks following appropriate calibration of the instrument response.
The effect of a salmon diet on blood clotting, platelet aggregation and fatty acids in normal adult men
Authors: Nelson Gary J. , Schmidt Perla C. , Corash Laurence 
Published: January 2007

AbstractThis study was designed to measure the effect of dietary n−3 fatty acids (FA) on platelets and blood lipids. Healthy men (n=9), ages 31 to 65, were fed diets in which salmon was the source of n−3 fatty acids. They were confined in a nutrition suite at this Center for 100 days. Food intake and exercise levels were rigidly controlled. Initially they were placed on a stabilization diet for 20 days, then six men were fed the salmon diet for 40 days. The others remained on the stabilization diet. The two groups switched diets for the last 40 days of the study. Both diets were isocaloric [16% protein, 54% carbohydrate, and 30% fat by energy‐% (En%)]. The salmon diet contained 7.5% of calories from n−6 FA and 2% from n−3 FA, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in a 40∶60 ratio, while the stabilization diet contained 7.5% of calories from n−6 FA and less than 0.3% n−3 FA, mainly 18∶3n−3. The bleeding time was unaffected by the diets in this study. The prothrombin time was shortened (11.6 sec.vs. 12.6 sec., p<0.01) for the subjects consuming the salmon diet as compared to that measured after 20 days of the stabilization diet. Mean platelet volume increased significantly during the period in which the volunteers consumed the salmon diet compared to the baseline diet (p<0.01), while the mean platelet levels decreased. Platelet aggregation (PA) was measured in platelet rich plasma before, during, and after the salmon diet using collagen, ADP, arachidonic acid (AA), and thrombin agonists. The PA threshold for ADP was significantly increased for the subjects on the salmon diet (p<0.05). No change in the PA threshold was detected for collagen or thrombin. The PA threshold for AA was unchanged also, but the platelets in subjects consuming the salmon diet had a prolonged time to maximum aggregation (p<0.01) with this reagent compared to platelets from men on the stabilization diet. Plasma, red cell, and platelet total FA composition was determined by capillary GLC. While the men consumed the salmon diets, there were marked increases (3 to 10‐fold) in the EPA and DHA levels in all blood components with concomitant decreases in linoleic acid and AA levels. Thus, a salmon diet, high in n−3 FA, did not influence the bleeding times, but it decreased the sensitivity of platelets to ADP and AA, increased the mean platelet size, decreased the platelet count, and changed the FA composition of the plasma, RBC and platelet membrane lipids.
Analysis of aldehydic lipid peroxidation products by TLC/densitometry
Authors: Beckman Jeffrey K. , Morley Samuel A. , Greene Harry L. 
Published: January 2007

AbstractWe have explored the use of thin‐layer chromatography (TLC)/densitometry in both the reflectance and fluorescence mode for quantitation of specific products of lipid peroxidation. Aldehydic peroxidation products were generated by exposure of arachidonic acid to iron and ascorbic acid for 24 hr. Several methods for the quantitative analysis of peroxidation products by TLC/densitometry were compared using two different aldehydespecific derivatizing reagents, namely dinitrophenylhydrazine (DNPH) and cyclohexanedione (CHD). DNPH hydrazones of the arachidonic acid‐peroxidation products, upon TLC separation on silica gel, revealed prominent alkanal and hydroxyalkenal bands. Reverse phase high performance liquid chromatography confirmed that the primary alkanal component was hexanal, while the primary hydroxyalkenal was 4‐hydroxynonenal. Semiquantitative methods for the direct analysis of these products by TLC/densitometry were worked out based on the use of external hydrazone standards. TLC/densitometry (fluorescence mode) was used to measure CHD adducts of aldehydes by forming the derivatives in the presence of decanal (used as an internal standard) and separating the derivatives by reverse phase TLC. Hexanal‐CHD was detectable upon application of 0.5 nanomoles while 4‐hydroxynomenal showed a lower response and was detectable with 10 nanomoles. Using appropriate response factors, hexanal and 4‐hydroxynonenal were measured in the aldehyde sample from arachidonic acid and results were similar to those obtained by the DNPH method.Similar approaches were used to analyze the peroxidation products of docosahexaenoic acid (24‐hr exposure) The DHA peroxidation products contained extremely low levels of alkanals, while polar aldehydes and hydroxyalkenals were prominent. Formation of alkanals, osazones, hydroxyalkenals and phospholipid aldehydes from iron‐exposed microsomes was also demonstrated. Uses and limitations of these methods of aldehyde measurement are discussed.
A new eicosapentaenoic acid formed from arachidonic acid in the coralline red algaeBossiella orbigniana
Authors: Burgess John R. , de la Rosa Roger I. , Jacobs Robert S. , Butler Alison 
Published: January 2007

AbstractAqueous extracts of the coralline red algaeBossiella orbigniana have been shown to catalyze the enzymatic oxidation of arachidonic acid to a previously unreported ω6 eicosapentaenoic acid product. This unique fatty acid contains a conjugated tetraene with absorption maxima at 293, 306, and 321 nm, and was identified by spectral methods as 5(Z),8(Z),10(E),12(E),14(Z)‐eicosapentaenoic acid. The compound was given the trivial name bosseopentaenoic acid. Under experimental conditions, production of bosseopentaenoic acid was linear up to 2 hr and dioxygen was consumed. Bosseopentaenoic acid, along with several other conjugated tetraenes, was also present in the algae endogenously as revealed by a comparison of the ultraviolet (UV) spectra and the high‐performance liquid chromatographic (HPLC) pattern of the purified product and the organic extract ofBossiella.
Absence of sterol biosynthesis in oyster tissue culture
Authors: Holden Marcia J. , Patterson Glenn W. 
Published: January 2007

AbstractAn oyster heart tissue culture was used to investigate the ability of the American oyster (Crassostrea virginica) to synthesize sterols from [14C]acetate. Lipids were extracted from cultured oyster heart cells and no label was found in the purified fatty acid fraction, 90% of which was located in the saturated and monounsaturated fractions. Although these results cannot rule out the possibility of sterol synthesis in other oyster tissues, this and previous evidence are in support of the hypothesis that the American oyster is unable to synthesize sterols.
Guinea pig epidermis generates putative anti‐inflammatory metabolites from fish oil polyunsaturated fatty acids
Authors: Miller Craig C. , Yamaguchi Ronald Y. , Ziboh Vincent A. 
Published: January 2007

AbstractClinical studies have indicated that dietary fish oil may have therapeutic value in the treatment of psoriasis, a hyperproliferative, inflammatory skin disorder characterized by elevated LTB4. To evolve a possible mechanism for these beneficial effects, we determined the metabolic fate of fish oil derived n‐3 fatty acids in the skin. Specifically, we incubated guinea pig epidermal enzyme preparations with [3H]eicosapentaenoic acid (20∶5n−3) and [14C]docosahexaenoic acid (22∶6n−3). Analyses of the radiometabolites revealed the transformation of these n−3 fatty acids into n−6 lipoxygenase (arachidonate 15‐lipoxygenase) products: 15‐hydroxyeicosapentaenoic acid (15‐HEPE) and 17‐hydroxydocosahexaenoic acid (17‐HDHE), respectively. Since 15‐lipoxygenase products have been suggested as possible endogenous inhibitors of 5‐lipoxygenase (an enzyme which catalyzes the formation of LTB4) we tested the ability of 15‐HEPE and 17‐HDHEin vitro to inhibit the activity of the 5‐lipoxygenase. Incubations of these metabolites with enzyme preparations from rat basophilic leukemia (RBL‐1) cells demonstrated that 15‐HEPE (IC50=28 μM) and 17‐HDHE (IC50=20 μM) are respectively potent inhibitors of RBL‐I‐5‐lipoxygenase. The inhibitory potential of these fish oil metabolites provides a possible mechanism by which fish oil might act to decrease local cutaneous levels of LTB4, and thereby alleviate psoriatic symptoms.
Phorbol myristate inhanced specific incorporation of arachidonic acid into phospholipids through lysophospholipid acyltransferase in cultured smooth muscle cells
Authors: Kanzaki Tetsuto , Morisaki Nobuhiro , Saito Yasushi , Yoshida Sho 
Published: January 2007

AbstractThe effect of stimulation of phospholipase with phorbol 12‐myristate 13‐acetate and lipopolysaccharide on 1‐acyl‐glycerophospholipid acyltransferase was studied in cultured rabbit aorta smooth muscle cells. The acyltransferase in smooth muscle cells without stimulation was active on a wide range of unsaturated fatty acids and was not arachidonic acid specific. Upon increase in phospholipase activity, acyltransferase activity only with arachidonic acid as substrate increased in a time‐dependent fashion. Apparent acyltransferase activity was increased most upon increase in phospholipase activity when lysophosphatidylcholine was used as acceptor. These results suggest that arachidonic acid specific acyltransferase was induced in smooth muscle cells by increase in phospholipase activity. The role of this acyltransferase is postulated to be the specific incorporation of endogenously released arachidonic acid.
Turnover and fate of plasma free fatty acids in briefly‐fasted lymphoma‐bearing mice
Authors: Baker Nome , Gan‐Elepano Minerva , Guthrie Brenda A. , Mead James F. 
Published: January 2007

AbstractBody fat loss during tumor growth may be due to increased mobilization of adipose triglycerides. Earlier work from this laboratory suggested that (i) lymphoma‐bearing AKR mice have a circulating lipid mobilizing factor (LMF) which caused body fat loss during cancer growth; that (ii) fatty acids (FA) mobilized in these tumor‐bearing (TB) mice were not oxidized to CO2 as in starved mice that lose their body fat; and that (iii) instead, the mobilized FA were sequestered by the lymphoma. We tested these hypotheses by injecting [1‐14C]palmitate‐albumin into lymphoma‐bearing and control mice. We measured turnover of plasma FFA for 24 hr and predicted the cumulative conversion of tracer into breath14CO2 (at 85 min) in the TB mice. Plasma FFA were mobilized more slowly in briefly fasted tumor‐bearing mice than in controls with the same plasma FFA pool sizes. The fractional catabolic rate (FCR) (min−1) of plasma FFA turnover in both groups decreased during the night when the mice ate: postabsorptive controls, 1.07(±5.6%); fed controls, 0.25 (±13%); postabsorptive TB, 0.53 (±4.6%); fed TB, 0.29 (±7.3%). Virtually all of the plasma FFA irreversible disposal in TB mice was accounted for as breath14CO2 (30 to 40% I.D.), not as tumor lipids (1.1±0.22% I.D.). Thus, FFA oxidation to CO2 is the major fate of plasma FFA turnover in TB mice, and sequestration of FFA (palmitate) by tumor cells is a quantitatively minor process. The putative circulating LMF did not cause increased FFA mobilization in these lymphoma‐bearing mice in the post‐absorptive state.
Increased liver lipase activity in rats with essential fatty acid deficiency
Authors: Schoonderwoerd Kees , Hülsmann Willem C. , Jansen Hans 
Published: January 2007

AbstractLiver lipase activity was measured in EFA‐deficient rats (long‐term) and in control rats and rats fed an EFA‐deficient diet for two weeks (short‐term). Liver lipase activity was significantly enhanced by EFA deficiency, both in long‐term and short‐term experiments. The enhanced liver lipase activity could be normalized by feeding these rats normal laboratory chow for 14 days. Since during EFA deficiency prostaglandin synthesis is impaired, the possible involvement of prostaglandins in the observed changes in liver lipase actvity during EFA deficiency was studied. Administration of the prostaglandin synthesis inhibitor indomethacin (5 mg/kg body weight, i.p.) to normally fed rats for two days led to an increase of liver lipase activity. Prostaglandin E2 was found to inhibit the secretion of liver lipase activity by freshly isolated parenchymal liver cellsin vitro. These results indicate that the increase in liver lipase activity during EFA deficiency may be due to an impairment of the prostaglandin synthesis.
Synthesis and properties of Nα‐lauroyl‐L‐arginine dipeptides from collagen‐lauroyl‐L‐arginine dipeptides from collagen
Authors: Molinero J. , Julia M. R. , Erra P. , Robert M. , Infante M. R. 
Published: January 2007

AbstractIn order to obtain protein‐based amphoteric surfactants with antimicrobial properties, Nα‐lauroyl arginine dipeptides have been prepared by condensation between Nα‐lauroyl arginine and amino acids which come from a collagen hydrolysate. Some surfactant properties and the minimum inhibitory concentration against Gram positive and Gram negative bacteria have been evaluated. All types of compounds presented a surfactant‐like behavior. Furthermore, the compounds described in this paper may be considered as mild preservative or protective substances.
Gel filtration of surfactants
Authors: Nakagawa Toshio , Jizomoto Hiroaki 
Published: January 2007

AbstractA simulation technique was developed for analyzing the gel filtration chromatography of surfactants. Theoretical elution curves obtained by this technique were compared with the experimental curves for the following five systems: an ionic or a nonionic surfactant of a single component, an ionic surfactant in the presence of an electrolyte, a mixture of two nonionic surfactants, a mixture of two ionic surfactants, and a mixture of an ionic and a nonionic surfactant. In the first four systems, good agreement was found between the theoretical and experimental elution curves. A possible explanation for the disagreement in the last system is presented.
Interactions of colloidal particles with complex ions and polymers
Authors: Matijevic Egon 
Published: January 2007

AbstractThe lecture represented a review of the work done in the author's laboratory dealing with the behavior of a variety of submicronic particles in the presence of simple and complex ions, surface active agents, polyelectrolytes and polymers. Experimentally, the stability of colloidal sols, which can be readily followed by optical methods, was investigated as a function of the composition of the electrolyte environments. This approach offers a number of advantages when the evaluation of solid‐solute interactions is attempted. By selecting various colloidal sols one can study the interactions of counterions with particles of different surface properties, such as the charge density, type and concentration of stabilizing ions, degree of solvation, surface ionization, etc.
Alkali isomerization—Gas chromatography with the microreactor apparatus
Authors: Bitner E. D. , Lanser Alan C. , Dutton H. J. 
Published: January 2007

AbstractA simple and rapid method of simultaneously conjugating polyunsaturation and forming methyl esters from triglyceride oils, other esters and fatty acids has been developed by using the microreactor apparatus (MRA). These reactions occur while a mixture of tetramethylammonium hydroxide and sample of fat is being injected into a gas chromatograph from the MRA reaction chamber. The speed of this microanalysis is limited only by peak elution and peak integration times. Analyses of soybean oil and six partially hydrogenated fats have been compared with those previously obtained by the alkali isomerization spectrometric method. The amount of conjugation that occurs during the reaction is a measure of the linoleic acid in the oil. This procedure should prove useful for rapid microscale analysis of conjugatable dienes in a variety of samples, including edible fat products.
Odor and flavor responses to additives in edible oils
Authors: Evans C. D. , Moser Helen A. , List G. R. 
Published: January 2007

AbstractThe odor threshold was determined for a series of unsaturated ketones, secondary alcohols, hydrocarbons and substituted furans added to bland edible oil. Odor thresholds were taken as the point where 50% of a 15‐ to 18‐member taste panel could detect an odor difference from the control oil. These additives are oxidative products of fats, but the concentrations investigated were far below any level associated with an identifying odor or taste of the additive per se. Odor, rather than flavor, was selected as the starting basis because of greater acuity and ease of handling a large number of samples with less taster fatigue. Oil samples containing additive concentrations near the odor threshold levels were evaluated by flavor score and flavor descriptions. Taste panel members were experienced oil tasters and were allowed free choice in selecting terms to describe the flavor quality of the oil samples. The propyl and butyl members of the homologous series of vinyl ketones had the lowest odor thresholds, whereas the difference in odor threshold was small between homologs in the unsaturated alcohols and in the 2 substituted furans. Vinyl propyl ketone, vinyl propyl carbinol (1‐hexen‐3‐ol) and 2‐propyl furan had odor thresholds of 0.005, 0.5 and 6 ppm, respectively. Odor thresholds of the unsaturated hydrocarbons are markedly lower than those of the saturated isologs. The odor of nonane can be detected at 650 ppm. However, at 1000 ppm it cannot be tasted and oils containing it were scored equal to the control oil. 1‐Nonene, 1‐nonyne and other tested C‐9 unsaturated hydrocarbons, including a number of dienes, have odor thresholds of about 10 ppm. The hydrocarbons 1‐hexyne, 1‐nonyne and 1‐decyne had odor thresh‐olds of 0.2, 5 and 4 ppm, respectively.
Salmonella reservoirs in animals and feeds
Authors: Ellis Edwin M. 
Published: January 2007

AbstractSalmonellosis is an important worldwide problem involving all species of wild and domestic animals and fowl. With few exceptions serotypes are not host specific and cross infections are frequent. Carriers exist in most species including man. Probably no species is free of the disease. Animal feeds frequently contain the organisms. Transmission is most often due to ingestion of fecal‐contaminated food or water, but infection by contact is a frequent and serious problem. Control by sanitation and protection against contamination of feeds would appear to solve much of the problem. Improved serologic methods for detecting carriers are badly needed.
Humans and pets as sources of salmonellae
Authors: Galton Mildred M. 
Published: January 2007

AbstractReported non‐typhoid salmonella infections in man have increased in the United States from 723 in 1946 to 20,040 in 1966, and this may represent only 1% of the salmonella infections actually occurring. The temporary carrier state following infections in man represents an important source for the spread of infection to other persons. Pets including dogs, cats, Easter chicks and ducklings, and turtles can also be a source of human salmonella infections. Approximately 15–20% of normal household dogs may be infected with salmonellae, although documented human infections traced to dogs are rare. Pet Easter chicks and ducklings have been incriminated frequently as a source of infection in young children. More than 100 cases of salmonellosis have been traced to pet turtles. Only by the implementation of appropriate control measures attacking each one of these potential sources of infection can we hope to reduce the increasing incidence of salmonellosis in the United States.
Method for determination of combined maleic anhydride in rosin‐maleic anhydride adducts by chromatographic techniques
Authors: Stanley J. B. , Moseley P. B. 
Published: January 2007

AbstractA new analytical method for the determination of combined maleic anhydride in rosin maleic anhydride adducts has been developed. The method is based on the use of chromatographic techniques for separating the rosin acids and the rosin maleic anhydride adduct using silicic acidcelite as the adsorbent and benzene and acetone as solvents. An acid number is determined on the adduct which is used to calculate the combined maleic anhydride in the sample. Free maleic anhydride does not interfere in the analysis. Data are presented showing good agreement with the results obtained on known blends by infrared spectroscopy and chromatography.