bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of platelet‐activating factor receptor expression in human B cells and B cell lines
Authors: Nguer Cheikh M. , Treton Dominique , Rola‐Pleszczynski Marek , Mishal Zohair , Thomas Yolène , Galanaud Pierce , Richard Yolande 
Published: November 2006

AbstractWe extended our previous data regarding the modulation of human platelet‐activating factor receptor (hPAF‐R) expression on human B cell lines as well as normal B cells. First, we showed that hPAF‐R, but was absent from cell lines devoid of hPAF‐R. Second, enhanced hPAF‐R membrane expression induced in IM9 line by IL9 line by IL4 was preceeded by hPAF‐R mRNA accumulation that was detectable by 8 h and which peaked at 24 h. Similar results were observed for 10 nM platelet‐activating factor treatment, which increased hPAF‐R mRNA content up to 120% at 48 h, whereas hPAF‐R membrane expression was up‐regulated by 130%. Third, our data indicate that functional hPAF‐R are expressed on resting, as well as on activated, B cells and that B cell activation is required for maintaining hPAF‐R membrane and mRNA expression. Thus, in normal B cells, as well as in B cell lines, transcriptional regulation and/or messager stability control hPAF‐R expression.
Influence of a subinhibitory dose of antifungal atty acids fromSporothrix flocculosa on cellular lipid composition in fungi
Authors: Benyagoub M. , Willemot C. , Bélanger R. R. 
Published: November 2006

AbstractsAntifungal fatty acids produced by the biocontrol fungusSporothrix flocculosa were studied on the basis of their effect on growth and cellular lipid composition of three fungi,Cladosporium cucumerinum, Fusarium oxysporum, andS. flocculosa, whose growth was decreased by 51, 33, and 5% respectively, when exposed to 0.4 mg fatty acid per ml. The sensitivity to fatty acid antibiotics fromS. flocculosa was related to a high degree of unsaturation of phospholipid fatty acids and a low proportion of sterols. The major responses of sensitive fungi to sublethal doses of antifungal fatty acids from liquid culture ofS. flocculosa were: (i) a decrease in total lipid; (ii) an increase in the degree of fatty acid unsaturation (18∶1>18∶2 > 18∶3); (iii) an increase in free fatty acids and phosphatidic acid and a decrease in total phospholipids; and (iv) an increase in sterol/phospholipid ratio. These modifications in lipid composition led to an increase in membrane fluidity in sensitive fungi, as demonstrated by assessment of fluorescence anisotropy using liposomes and 1,6‐diphenyl‐1,3,5‐hexatriene probe. This alteration in the physical state of lipids appears to be responsible for the previously demonstrated alteration of membrane structure and function in fungi confronted toS. flocculosa.
An unusual fatty acid pattern inEranthis seed oil
Authors: Aitzetmüller K. 
Published: November 2006

AbstractThe current discussion on “renewable resources”, and the possibility of gene transfer into rapeseed, has led to many investigations into the biosynthetic pathways leading to industrially useful fatty acids. The various tribes and genera of the plant familyRanunculaceae contain a large variety of unusual fatty acids. Seed fatty acid patterns differ considerably from genus to genus and are chemotaxonomically significant indicators.Eranthis seed oil has now been found to contain a fatty acid pattern that deviates significantly from the eleven different fatty acid patterns that had been described in this plant family. The main fatty acid (up to 57%) is 13‐cis, 16‐cis‐docosadienoic acid. Other, minor fatty acids found are Δ5‐cis‐monoenoic,‐dienoic, and‐trienoic fatty acids that had already been reported to be constituents of the genus‐specific seed oil fatty acid patterns of various genera from this plant family. Capillary gas‐liquid chromatographic retention data indicate that 22:3Δ5cis, 13cis, 16cis is probably also present. Seed fatty acid chemotaxonomic evidence thus points to a different position ofEranthis within the tribes of this plant family. These findings again indicate that the plant familyRanunculaceae would be an ideal object to study fatty acid biosynthesis and phylogenetic evolution, because in other genera of this family other types of desaturation and chain elongation mechanisms predominate.
Quantitative high‐performance liquid chromatography analysis of plant phospholipids and glycolipids using light‐scattering detection
Authors: Picchioni G. A. , Watada A. E. , Whitaker B. D. 
Published: November 2006

AbstractApplication of the evaporative light‐scattering principle to quantitative high‐performance liquid chromatography (HPLC) analyses of plant membrane lipids has received little study. Light‐scattering detection response curves were generated for nine classes of plant membrane phospholipid and glycolipids. Quantitative results obtained by HPLC/light‐scattering detection and conventional lipid analytical methods (thin‐layer chromatography and lipid‐P assay) were in close agreement, confirming the reliability of HPLC/evaporative light‐scattering detection (ELSD) analyses. Only three of the nine plant lipid classes gave linear detector response functions above 10 μg injected lipid mass. This finding contradicts earlier precepts involving light‐scattering detection of lipids. At a given mass, appreciable variation in ELSD signal intensity and detection limit was found to exist among the various plant membrane lipid classes. The variation in detector response among plant lipid classes is an important consideration in achieving accurate quantitative results in plant lipid analyses.
Phosphatidylglycerol molecular species of photosynthetic membranes analyzed by high‐performance liquid chromatography: Theoretical considerations
Authors: Xu Yinong , Siegenthaler Paul‐André 
Published: November 2006

AbstractA reversed‐phase high‐performance liquid chromatography technique was developed to separate, identify, and quantify individual phsphatidylglycerol (PG) molecular species in thylakoid membranes isolated from higher plant leaves. PG was first separated by thin‐layer chromatography; then the dinitrobenzoyl derivatives of diacylglycerols produced after phospholipase C hydrolysis of PG were separated by a C18 reversed‐phase column and detected at 254 nm. A linear response of the detector was observed in the range of 0.025 to 12 nmol of PG molecular species. It was established that there was an excellent correlation (r=0.996) between the carbon and double‐bond number in the aliphatic residues and the relative retention time of dinitrobenzoyl derivatives. A new equivalent carbon number value (ECN*) which takes into consideration the number ofcis‐(nc) andtrans‐(nt) double bonds per molecular species was defined as ECN*=CN‐2nc‐nt′ where CN is the number of carbon atoms in the aliphatic residues. The logarithm of the retention time increased linearily as a function of ECN* value. However, in this type of correlation, it may happen that two molecular species of PG having distinct relative retention times has the same ECN* value. In this case, the two molecular species can be identified by the linear correlation (r=1) existing between the reciprocal of the relative retention time and the number of double bonds (0≤n≤3) in the separate 18:n/Δ3‐trans‐hexadecenoic acid [16:1(3t) and 18:n/16:0 molecular species series. The advantages of this method are good separation, short elution time, quantitative precision, and predictable retention times of PG molecular species from chloroplast membranes. The method has been used routinely to identify the ten PG molecular species of thylakoid membranes in squash, potato, lettuce, and spinach leaf: 18:3/16:1(3t), 18:3/16:0, 18:2/16:1(3t), 18:2/16:0, 18:1/16:1(3t), 18:1/16:0, 18:0/16:1(3t), 18:0/16:0, 16:0/16:1(3t), and 16:0/16:0.
Acyl‐CoA binding proteins: Multiplicity and function
Authors: Gossett Ruanna E. , Frolov Andrey A. , Roths John B. , Behnke W. David , Kier Ann B. , Schroeder Friedhelm 
Published: November 2006

AbstractThe physiological role of long‐chain fatty acyl‐CoA is thought to be primarily in intermediary metabolism of fatty acids. However, recent data show that nM to μM levels of these lipophilic molecules are potent regulators of cell functionsin vitro. Although long‐chain fatty acyl‐CoA are present at several hundred μM concentration in the cell, very little long‐chain fatty acyl‐CoA actually exists as free or unbound molecules, but rather is bound with high affinity to membrane lipids and/or proteins. Recently, there is growing awareness that cytosol contains nonenzymatic proteins also capable of binding long‐chain fatty acyl‐CoA with high affinity. Although the identity of the cytosolic long‐chain fatty acyl‐CoA binding protein(s) has been the subject of some controversy, there is growing evidence that several diverse nonenzymatic cytosolic proteins will bind long‐chain fatty acyl‐CoA. Not only does acyl‐CoA binding protein specifically bind medium and long‐chain fatty acyl‐CoA (LCFA‐CoA), but ubiquitous proteins with multiple ligand specificities such as the fatty acid binding proteins and sterol carrier protein‐2 also bind LCFA‐CoA with high affinity. The potential of these acyl‐CoA binding proteins to influence the level of free LCFA‐CoA and thereby the amount of LCFA‐CoA bound to regulatory sites in proteins and enzymes is only now being examined in detail. The purpose of this article is to explore the identity, nature, function, and pathobiology of these fascinating newly discovered long‐chain fatty acyl‐CoA binding proteins. The relative contributions of these three different protein families to LCFA‐CoA utilization and/or regulation of cellular activities are the focus of new directions in this field.
Effect of Castration and hormonal supplementation on cholesterol cholelithiasis in the male hamster
Authors: Ohshima Akira , Cohen Bertram I. , Ayyad Nariman , Mosbach Erwin H. 
Published: November 2006

AbstractThis study examined the effect of castration and dietary hormonal supplementation on cholesterol cholelithiasis in male hamsters. Animals fed a standard lithogenic diet developed cholesterol gallstones (17%) after 6 wk, while castrated hamsters did not form any stones. Addition of a synthetic androgen, methyltestosterone, to the lithogenic diet induced cholelithiasis in castrated animals (50%). The biles of normal and castrated‐hormone supplemented hamsters had cholesterol saturation indices of 1.0 and 1.1, respectively, while the bile of the castrated animals remained unsaturated (0.6). The ratio of cholic acid/chenodeoxycholic acid in bile increased after castration, but returned to normal levels following hormonal supplementation. Biliary cholesterol carriers were separated by ultracentrifugation. Animals in the stone‐forming groups (normal and castrated‐hormone treated) had a significant proportion of their biliary cholesterol in vesicles (44 and 46%, respectively); castrated hamsters had less cholesterol in vesicle form (9%). The molar ratio of cholesterol/phospholipid in vesicles was reduced after castration (0.93 vs. 0.42) and increased by hormonal supplementation (1.89). In conclusion, when compared to normal male hamsters fed a standard lithogenic diet, castration reduced the cholesterol saturation of bile, lowered the vesicular/micellar ratio in bile, and inhibited cholesterol cholelithiasis. Dietary androgen supplementation increased the lithogenicity of bile, resulting in stone formation in castrated animals.
Polyunsaturated fatty acids exert antiarrhythmic actions as free acids rather than in phospholipids
Authors: Weylandt Karsten H. , Kang Jing X. , Leaf Alexander 
Published: November 2006

AbstractPrevious studies have shown that exogenous free n‐3 polyunsaturated fatty acids (PUFA) can prevent tachyarrhythmias caused by specific agents in isolated cardiac myocytes. However, the question as to whether incorporation of the n‐3 PUFA into membrane phospholipids has the same immediate protective effects remained to be answered. To answer this question, we increased the content of n‐3 PUFA in the phospholipids of cultured neonatal rat myocytes by growing them 2–3 d in a culture to which eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in 15 μM concentration was added. Analysis of the fatty acid composition of membrane phospholipids revealed a significantly higher level of EPA and DHA (from 0.2 to 7.6% and from 1.2 to 6.5%) in cells supplemented with EPA or DHA, respectively. The responses of the myocytes grown in normal media or in media enriched with the PUFA to arrhythmogenic agents were examined after free fatty acids were removed from the medium and the cells. The arrhythmogenic agents used were the β‐adrenergic agonist isoproterenol or an elevated extracellular concentration of calcium. The results showed that there was no significant difference in the induction of tachyarrhythmias by isoproterenol or by elevated [Ca2+]o in cells grown in media enriched with PUFA, as compared with cells grown in normal media in the absence of the free PUFA. Under the conditions of this study, only the unesterified PUFA were able to protect the cardiomyocytes against induced arrhythmias. There was no antiarrhythmic effect due to an increased fraction of EPA or DHA in membrane phospholipids.
The ratio of n‐6 to n‐3 polyunsaturated fatty acids in the rat diet alters serum lipid levels and lymphocyte functions
Authors: Jeffery N. M. , Sanderson P. , Sherrington E. J. , Newsholme E. A. , Calder P. C. 
Published: November 2006

AbstractPrevious studies have reported that feeding rats diets rich in fish oils, which contain high proportions of the n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic and docosahexaenoic acids, results in lowering of blood lipid levels and suppression of lymphocyte functions testedex vivo andin vivo. The effects of other n‐3 PUFA, such as α‐linolenic acid, which is found in high proportions in linseed oil, are not as well documented. Therefore, in the present study, weanling male rats were fed for six weeks on one of five high‐fat (20% by weight) diets made by mixing together sunflower and linseed oils; the resulting blends had n‐6/n‐3 PUFA ratios of 112.5:1 (pure sunflower oil), 14.8:1, 6.5:1, 0.8:1, and 0.33:1 (pure linseed oil); the levels of all other components in the diet were identical. The final body weight and total dissectable fat were lowest in rats fed the pure linseed oil diet. Serum cholesterol, triacylglycerol and nonesterified fatty acid concentrations decreased as the n‐6/n‐3 PUFA ratio of the diet decreased. The fatty acid composition of the serum and of spleen lymphocytes was influenced by the diet fed‐there was a progressive decrease in the proportions of linoleic and arachidonic acids and a progressive increase in the proportion of α‐linolenic acid as the n‐6/n‐3 PUFA ratio of the diet decreased. Eicosapentaenoic and docosahexaenoic acids were detected in the serum but not in spleen lymphocytes. Inclusion of α‐linolenic acid in the diet resulted in significant suppression of spleen lymphocyte proliferation in response to the T‐cell mitogen concanavalin A and in spleen lymphocyte natural killer cell activity, both measuredex vivo. The localized graft vs. host response, a measure of cellmediated immunityin vivo, progressively decreased as the n‐6/n‐3 PUFA ratio of the diet decreased. Thus, this study shows that dietary α‐linolenic acid results in lowered blood lipid levels and suppressed lymphocyte functionsex vivo andin vivo. With respect to these effects, α‐linolenic acid is as potent as dietary fish oil.
Intestinal lymph absorption of butter, corn oil, cod liver oil, menhaden oil, and eicosapentaenoic and docosahexaenoic acid ethyl esters in rats
Authors: Degrace P. , Caselli C. , Rayo J. M. , Bernard A. 
Published: November 2006

AbstractAdult male rats were surgically given a drainage catheter in the main mesenteric lymph duct. After an overnight fast, five groups of rats received intragastrically, in one bolus, butter, corn oil (CO), cod liver oil (CLO), menhaden oil (MO), or ethyl esters of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids (K80). Intestinal lymph was collected in these conscious animals, each hour during the first 6 h and in a single sample for the next 18 h. The absorption peak appeared earlier after MO and CO than after CLO administration. The quantities of triglycerides recovered during the first 6 h were significantly lower after butter (91 mg) and K80 (54 mg) administration than for the other three oils. No difference was observed between the vegetable oil and the two marine oils (CO=173 mg, CLO=148 mg, MO=180 mg). The total triglyceride recovered in 24 h was highest after CLO (410 mg) and lowest with K80 (146 mg). An increase in the weight percentage of some characteristic fatty acids of the lipid mixtures was observed: oleic acid for butter, oleic and linoleic acids for CO, EPA and DHA for CLO, MO, and K80. Chylomicrons were the largest with CO, more numerous and smaller with CLO, and the smallest with K80. Results obtained illustrated the relation between gastrointestinal hydrolysis, enterocyte biochemical events, and lymph triglyceride absorption profiles as related to the composition and distribution of triglyceride fatty acids.
Alterations in cell cholesterol content modulate Ca2+‐induced tight junction assembly by MDCK cells
Authors: Stankewich Michael C. , Francis Stacy A. , Vu Quynh U. , Schneeberger Eveline E. , Lynch Robert D. 
Published: November 2006

AbstractTransepithelial electrical resistance (TER), a measure of tight junction (TJ) barrier function, develops more rapidly and reaches higher values after preincubation of MDCK cells for 24 h with 2 μM Lovastatin (lova), an inhibitor of 3‐hydroxy‐3‐methylglutaryl‐CoA reductase. While this effect was attributed to a 30% fall in cholesterol (CH), possible effects of lova on the supply of prenyl group precursors could not be excluded. In the current study, strategies were devised to examine effects on TER of agents that simultaneously lower CH and increase the flux of intermediates through the CH biosynthetic pathway. Zaragozic acid, 20 μM, an inhibitor of squalene synthase known to increase the synthesis of isoprenoids and levels of prenylated proteins, lowered cell CH by 30% after 24 h, while accelerating development of TER in the same manner as lova. TER was also enhanced, despite a 23% increase in the rate of [3H]acetate incorporation into CH, when total CH was reduced by 45% during a 2‐h incubation with 2 mM methyl β‐cyclodextrin (MBCD), an agent that stimulates CH efflux from cells. The fact that the rate of TER development was diminished when cell CH content was elevated by incubation with a complex of CH and MBCD is further evidence that this sterol modulates development of the epithelial barrier. Cell associated CH derived from the complex was similar to endogenous CH with respect to its accessibility to cholesterol oxidase. Lova's effect on TER was diminished when 5 μg/mL of CH was added to the medium during the last 11 h of incubation with lova.
Fatty acid composition of late embryonic and early postnatal rat brain
Authors: Green Pnina , Yavin Ephraim 
Published: November 2006

AbstractThe fatty acid (FA) composition and distribution in a variety of phospholipids (PL) and neutral lipids (NL) at two discrete stages during the embryonic rat brain development were investigated. Over 96% of the FA were acylated into fetal brain PL at embryonic day 17 after the peak of neuronal proliferation and at embryonic day 20, one day prior to delivery. Phosphatidylcholine constituted approximately 60% of the total PL pool, phosphatidylethanolamine (PE) 30%, phosphatidylserine (PS) 6%, and phosphatidylinositol (PI) 4%. The diacylglycerols and triacylglycerols constituted 1–2% of the fetal brain lipids. α‐Linolenic acid (18∶3n−3) and linoleic acid (18∶2n−6) were found in very low amounts in all fetal brain PL and NL. The percentage of the n−6 polyunsaturated FA, consisting of arachidonic acid (AA), 22∶4n−6 and 22∶5n−6, remained unchanged in all the fractions, except in Pl, in which the proportion of AA increased. The concentration of docosahexaenoic acid (DHA) increased with age in all the fractions, with the bulk of accumulation accounted for by its increase in PE and, to a lesser extent, in PS. This finding suggests a “DHA accretion spurt” during the last three days of pregnancy.
Costs of egg caring in the skink, Mabuya longicaudata
Authors: Huang Wen‐San 
Published: November 2006

AbstractWhy do most animal species not provide parental care to their eggs or progeny? The “cost” hypothesis suggests that parental care can reduce food intake, probable survivorship, and/or subsequent fecundity of the reproductive female, and parental care is not adaptive unless it is balanced by considerable fitness trade‐offs. Therefore, parental care would be expected to evolve most often in species in which such costs are minor or insignificant. Although parental care has been reported in more than 140 species of reptiles, few records unambiguously demonstrate the cost of parental care. In the current study, I report the “costs” of maternal activities and survivorship, as well as egg attendance times, and within‐ and between‐seasonal body size variations, of females of Mabuya longicaudata after engaging in parental care. I used those data to test whether parental care necessarily entailed large costs to mother lizards. The proportion of nests guarded decreased with time after eggs were laid, with most females remaining at the nest for at least 1 week, but then some beginning to leave. The loss of mass by females over the first week of egg guarding was on average balanced by a gain in mass during subsequent foraging bouts. The snout–vent length (SVL), body mass (BM), recapture (survival) rates, fecundity, timing of a second clutch, and clutch frequencies of females that exhibited long‐term parental care (more than 28 days; mean, 31.6 ± 2.2 days) did not significantly differ from that of females that showed short‐term parental care (9∼16 days; mean, 12.5 ± 2.3 days). Thus, my data indicate that intense parental care over a long period does not necessarily entail major energy costs for the mother in terms of SVL, BM, recapture (survival) rates, or fecundity.
Lipase‐based quantitation of triacylglycerols in cellular lipid extracts: Requirement for presence of detergent and prior separation by thin‐layer chromatography
Authors: Van Veldhoven Paul P. , Swinnen Johannes V. , Esquenet Murielle , Verhoeven Guido 
Published: November 2006

AbstractA protocol, based on the use of Pseudomonas lipase, is presented to measure quantitatively the amount of triacylglycerols in extracts from cultured cells or tissues. Since the lipase also acts on di‐ and monoacylglycerols, separation of the extracts by thin‐layer chromatography is recommended. In order to allow the lipase‐catalyzed hydrolysis to proceed efficiently, lipid extracts or eluates from silica scraping were mixed with the detergent Thesit [dodecylpoly(ethylene glycol ether)], prior to drying. After dissolution of the dried residues in water, the amount of triacylglycerols was quantified using Pseudomonas sp. lipase, glycerol kinase, glycerol‐phosphate oxidase, and peroxidase. The activity of the latter enzyme was followed either colorimetrically in the presence of 4‐aminoantipyrine and 2,4,6‐tribromo‐3‐hydroxybenzoic acid or fluorimetrically in the presence of homovanillic acid.
Ectopic Pregnancy
Authors: Kriebs Jan M. , Fahey Jenifer O. 
Published: November 2006

ABSTRACTThe incidence of ectopic pregnancy in the United States has been reported to be as high as 20 per 1000 pregnancies, a more than 4‐fold increase over the last 20 years. Clinical presentation can range from subtle, nonspecific abdominal complaints to acute onset pain or hemorrhagic bleeding. This article reviews the associated risk factors, pathophysiology, diagnosis, and management of ectopic pregnancy. Clinicians must maintain a high index of suspicion whenever women who might be pregnant have abdominal complaints.