bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physicochemical characterization of psychosine by 1H nuclear magnetic resonance and electron microscopy
Authors: Orfi Laszlo , Larive Cynthia K. , LeVine Steven M. 
Published: November 2006

AbstractKrabbe's disease is an autosomal recessive disease that affects the lysosomal enzyme galactosylceramidase. The storage of one of its substrates, psychosine (β‐galactosylsphingosine), is thought to be responsible for the induction of pathological changes. Psychosine has a free amine group which is necessary for the mediation of its toxic effects. In the present study, the physicochemical properties of psychosine were investigated. Nuclear magnetic resonance (NMR) detected pH titration was used to determine that the amine group had a pKa of 7.18±0.05. Pulsed‐field gradient NMR spectroscopy was used to determine that the diffusion coefficient of 2.8 mM psychosine in D2O at pD 4.46 or 7.04 is 1.16±0.02×10−10 m2/s or 0.77±0.02×10−10 m2/s, respectively. Negative staining electron microscopy (EM) studies of acidic and neutral solutions of psychosine also were performed. At pH 4.5, spherical structures were formed, which were relatively stable between 3, 120, and 216 h following preparation; the diameter ranged from ∼14 nm at the earliest time point to ∼18 nm at the last time point. The critical micelle concentration (CMC) was 1.26 mM at pH 4.0. At pH 7.1, the structures changed from spherical structures with a diameter of 15–23 nm, at the earliest time point, to a heterogeneous population of structures ranging from spherical structures, with a diameter of only a few nm, to irregularly shaped oblong structures that had one or more dimensions exceeding 100 nm. The NMR and EM data indicate that the deprotonation of the amine group causes psychosine to form aggregates that are unstable, which prevents a determination of the CMC at a neutral pH. These data indicate that molecular interactions of psychosine at the acidic pH of the lysosome, where it is normally digested, are more orderly than those at the pH of the cytoplasm or extracellular space where psychosine goes during disease.
Growth inhibitory effects of liposome‐associated 1‐O‐octadecyl‐2‐O‐methyl‐sn‐glycero‐3‐phosphocholine
Authors: Peters Andrew C. , Ahmad Imran , Janoff Andrew S. , Pushkareva Marina Y. , Mayhew Eric 
Published: November 2006

AbstractThe growth inhibitory effects of 1‐O‐octadecyl‐2‐O‐methyl‐sn‐glycero‐3‐phosphocholine (ET‐18‐OCH3) and various liposome compositions of ET‐18‐OCH3 were compared in a standardized growth inhibition assay utilizing a diverse tumor cell line panel including cell lines expressing multidrug resistance. ET‐18‐OCH3 and ELL‐12 (4∶3∶1∶2, dioleoylphosphatidylcholine/cholesterol/dioleoylphosphatidylethanolamine‐glutaric acid/ET‐18‐OCH3), an optimal liposomal ET‐18‐OCH3 formulation, inhibited growth in the micromolar range in drug‐sensitive and‐resistant cells. In general, ET‐18‐OCH3‐liposomes were about twofold less growth inhibitory than ET‐18‐OCH3. However, the known hemolytic effects of ET‐18‐OCH3 were greatly reduced, up to 20 or more times, by liposome association. The effects of ET‐18‐OCH3 and ELL‐12 were compared in intracellular [Ca2+] modulation and DNA fragmentation assays. ET‐18‐OCH3 elicited both concentration‐ and serum‐dependent transient and permanent increases in intracellular [Ca2+]. In contrast, ELL‐12 did not modulate intracellular [Ca2+]. ET‐18‐OCH3 and ELL‐12 similarly affected DNA fragmentation, which may be indicative of apoptosis. The results suggest that, although the specific growth inhibitory effects of ET‐18‐OCH3 and ELL‐12 are similar, associating ET‐18‐OCH3 with stable well‐characterized liposomes eliminates nonspecific cell membrane‐associated lytic effects.
In vitro effect of garlic powder extract on lipid content in normal and atherosclerotic human aortic cells
Authors: Orekhov Alexander N. , Tertov Vladimir V. 
Published: November 2006

AbstractIn the present study, the mechanism of the in vitro effect of garlic powder extract (GPE) on lipid content of cultured human aortic cells was investigated. The addition of GPE abolished atherogenic blood serum‐induced accumulation of free cholesterol, triglycerides, and cholesteryl esters in smooth muscle cells derived from uninvolved (normal) intima. In cells isolated from atherosclerotic plaque, GPE lowered these lipids. GPE inhibited lipid synthesis both in normal and atherosclerotic cells. It inhibited acyl‐CoA:cholesterol acyltransferase activity that participates in the cholesteryl ester formation and stimulated cholesteryl ester hydrolase that degrades cholesteryl esters. This may explain the lipid reduction caused by GPE in atherosclerotic cells. GPE inhibited the uptake of modified low density lipoprotein and degradation of lipoprotein‐derived cholesteryl esters, thus considerably reducing the intracellular accumulation of cholesteryl esters. This suggests the mechanism responsible for the prevention of lipid accumulation in aortic cells caused by atherogenic blood serum.
Comparative hypocholesterolemic effects of six dietary oils in cholesterol‐fed rats after long‐term feeding
Authors: Fukushima Michihiro , Matsuda Takae , Yamagishi Kiichiro , Nakano Masuo 
Published: November 2006

AbstractRats (8 wk of age) fed a conventional diet were shifted to diets containing 10% Oenothera biennis Linn oil (OBLO, linoleic acid +γ‐linolenic acid) from a wild plant, evening primrose oil (EPO, linoleic acid +γ‐linolenic acid) from a cultivated plant, bio‐γ‐linolenic acid oil from mold (BIO, palmitic acid+oleic acid+linoleic acid+γ‐linolenic acid), safflower oil (linoleic acid), palm oil (PLO, palmitic acid+oleic acid+linoleic acid), or soybean oil (linoleic acid+α‐linolenic acid) with 0.5% cholesterol for 13 wk. Though there were no significant differences in the food intake among the groups, the body weight gain of the OBLO group was significantly lower than that of other groups except for the BIO and PLO groups, and that of the EPO and SPO groups were the highest among the groups. The liver weight of the OBLO group was significantly lower than that of other groups, and that of the PLO group was the highest among the groups. The serum total cholesterol and very low density lipoprotein (VLDL)+intermediate density lipoprotein (IDL)+low density lipoprotein (LDL) cholesterol concentrations of the OBLO and EPO groups were consistently lower than those in the other groups. However, those of the BIO group were higher than those in the OBLO and EPO groups. The liver cholesterol concentration of the PLO group was the highest among all groups except for the EPO group. The fecal neutral sterol and bile acid extraction of the BIO group tended to increase compared to other groups. The results of this study demonstrate that OBLO and EPO inhibit the increasing of serum total cholesterol and VLDL+IDL+LDL‐cholesterol concentrations in the presence of excess cholesterol in the diet compared with the other dietary oils.
Molecular speciation of fish sperm phospholipids: Large amounts of dipolyunsaturated phosphatidylserine
Authors: Bell M. V. , Dick J. R. , Buda Cs. 
Published: November 2006

AbstractThe molecular species compositions of the main diacyl phosphoglyceride classes and ether‐linked subclasses from sperm of three species of fish, sea bass Dicentrarchus labrax, Atlantic salmon Salmo salar and Chinook salmon Onchorhynchus tsawytscha, were determined. The phospholipids from sperm were highly unsaturated, dipolyunsaturated fatty acid (diPUFA) molecular species comprised 64.6 to 71.8% of phosphatidylserine (PS), 10.1 to 17.4% of phosphatidylethanolamine (PE), and 3.3 to 10.1% of phosphatidylcholine (PC). In sea bass sperm, di22∶6n‐3 phospholipid was the predominant diPUFA molecular species, but in both salmon species 22∶5n‐3/22∶6n‐3 was also a major constituent of PS. Phospholipids containing 22∶6n‐3 dominated in sea bass sperm with 16∶0/22∶6n‐3 as a major component of PC and PE, and 18∶0/22∶6n‐3 of PE and PS in addition to di22∶6n‐3 in the latter two classes. In contrast, both salmon species contained much more 20∶5n‐3 and less 22∶6n‐3 so that saturated/20∶5n‐3 and monounsaturated/20∶5n‐3 molecular species were more abundant than the corresponding molecules containing 22∶6n‐3. Ether‐linked lipids comprised 11.3–36.3% of choline and ethanolamine phosphoglycerides in each fish species. Molecular species containing 22∶6n‐3 were the major components of 1‐O‐alkyl‐2‐acyl‐glycerophosphocholine, especially 16∶0a/22∶6n‐3 in sea bass and 18∶1a/∶6n‐3 in the two salmon species, while in 1‐O‐alk‐1′‐enyl‐2‐acyl‐glycerophosphoethanolamine, 16∶0a/22∶6n‐3 was the major component in both salmon and 18∶0a/22∶6n‐3 in sea bass with 18∶1a/22∶6n‐3 abundant in all three species. In Atlantic salmon 1‐O‐alkyl‐2‐acylglycerophosphoethanolamine comprised 24.6% of ethanolamine glycerophospholipids which were predominantly 16∶0a/22∶6n‐3 and 18∶1a/22∶6n‐3. Phosphatidylinositol from sperm was dominated by stearoyl/C20 PUFA molecular species, in sea bass overwhelmingly 18∶0/20∶4n‐6, while in both salmon species 18∶0/20∶4n‐6 and 18∶0/20∶5n‐3 were equally abundant.
Lipids and buoyancy in Southern Ocean pteropods
Authors: Phleger Charles F. , Nichols Peter D. , Virtue Patti 
Published: November 2006

AbstractThe lipids of Clione limacina, a Southern Ocean pteropod (order Gymnosomata), contain 28% diacylglyceryl ether (DAGE) (as percentage of total lipid) whereas the pteropod Limacina helicina (order Thecosomata) lacks DAGE. The alkyl glyceryl ether diols (1‐O‐alkyl glycerols, GE) of Clione DAGE are dominated by 16∶0 (60%) and 15∶0 (21%), in contrast with deep‐sea shark liver DAGE, which is dominated by 18∶1 GE. The fatty acid profiles of Clione and Limacina are similar (28–32% polyunsaturated, 26–34% monounsaturated) as are the sterols, which include 24‐methylenecholesterol, transdehydrocholesterol, cholesterol, and desmosterol. This finding probably reflects the fact that Limacina is the major food source for Clione. Spongiobranchaea australis, another Southern Ocean pteropod (order Gymnosomata), has 0.9–1.7% DAGE, but has less lipid (3.3–4.8 mg/g lipid, wet weight) than Clione (50.8 mg/g lipid, wet weight). We propose a buoyancy role for DAGE in Clione since Limacina has bubbles for flotation which Clione lack; DAGE provides 23% more uplift than triacylglycerol at a concentration of 1.025 g/mL seawater.
Sulfoquinovosyl diacylglycerols from the alga Heterosigma carterae
Authors: Keusgen Michael , Curtis Jonathan M. , Thibault Pierre , Walter John A. , Windust Anthony , Ayer Stephen W. 
Published: November 2006

AbstractAn extract of the chloromonad Heterosigma carterae (Raphidophyceae), cultivated in natural seawater, contained a complex mixture of sulfoquinovosyl diacylglycerols. Palmitoyl (16:0), three isomers of hexadecenoyl (16:1 cis Δ9, Δ11, Δ13), and eicosapentenoyl (20:5) were found to be the main fatty acyl substituents. Exact double‐bond sites were determined by mass spectrometry analysis of the corresponding nicotinyl derivatives. Four major sulfoquinovosyl diacylglycerol components were partially purified and identified as 1–4 by interpretation of their nuclear magnetic resonance and mass spectral data. In addition, complete analysis of the H. carterae sulfoquinovosyl diacylglycerols was performed using high‐performance liquid chromatography combined with electrospray tandem mass spectrometry.
Measurement of apolipoprotein B in various cell lines: Correlation between intracellular levels and rates of secretion
Authors: Bakillah Ahmed , Zhou Zhangyin , Luchoomun Jayraz , Hussain M. Mahmood 
Published: November 2006

AbstractWe have standardized simple but sensitive enzyme‐linked immunoassays to understand a relationship between intracellular levels and secretion rates of apoB. The assays were based on commercially available antibodies and were specific to human apoB. A monoclonal antibody, 1D1, was immobilized on microtiter wells and incubated with different amounts of low density lipoproteins to obtain a standard curve. Conditioned media were added to other wells in parallel, and the amount of apoB was quantitated from a linear regression curve. To standardize conditions for the measurement of intracellular apoB, cells were homogenized and solubilized with different concentrations of taurocholate. We found that 0.5% taurocholate was sufficient to solubilize all the apoB in HepG2, Caco‐2, and McA‐RH7777 cells. Next, a standard curve was prepared in the presence of taurocholate and used to determine intracellular levels of apoB in different cell lines. The intracellular levels (pmol/mg cell protein) and the rates of secretion (pmol/mg/h) of apoB100 were positively correlated (r2=0.81, P=0.0009) in HepG2 cells. Furthermore, a positive correlation (r2=0.88, P<0.0001) was found between intracellular and secreted apoB42 in stably transfected McA‐RH7777 cells. In contrast, no correlation was observed for human apoB28 and apoB18 in stably transfected cells that were secreted either partially associated or completely unassociated with lipoproteins. These studies indicated that the rate of secretion of lipid‐associated apoB, but not the lipid‐free apoB, was tightly controlled.
The effect of dietary docosahexaenoic acid on platelet function, platelet fatty acid composition, and blood coagulation in humans
Authors: Nelson G. J. , Schmidt P. S. , Bartolini G. L. , Kelley D. S. , Kyle David 
Published: November 2006

AbstractThe effect of dietary docosahexaenoic acid (DHA) in the absence of eicosapentaenoic acid (EPA) has been studied infrequently in humans under controlled conditions. This 120‐d study followed healthy, adult male volunteers who lived in the metabolic research unit (MRU) of the Western Human Nutrition Research Center for the entire study. The basal (low‐DHA) diet consisted of natural foods (30 en% fat, 15 en% protein, and 55 en% carbohydrate), containing <50 mg/d of DHA, and met the recommended daily intake for all essential nutrients. The high‐DHA (intervention) diet was similar except that 6 g/d of DHA in the form of a triglyceride containing 40% DHA replaced an equal amount of safflower oil in the basal diet. The subjects (ages 20 to 39) were within −10 to +20% of ideal body weight, nonsmoking, and not allowed alcohol in the MRU. Their exercise level was constant, and their body weights were maintained within 2% of entry level. They were initially fed the low‐DHA diet for 30 d. On day 31, six subjects (intervention, group A) were placed on the high‐DHA diet; the other four subjects (controls, group B) remained on the low‐DHA diet. Platelet aggregation in platelet‐rich plasma was determined using ADP, collagen, and arachidonic acid. No statistical differences could be detected between the amount of agonist required to produce 50% aggregation of platelet‐rich plasma before and after the subjects consumed the high‐DHA diet. The prothrombin time, activated partial thromboplastin time, and the antithrombin‐III levels in the subjects were determined, and, again, there were no statistically significant differences in these three parameters when their values were compared before and after the subjects consumed the high‐DHA diet. In addition, the in vivo bleeding times did not show any significant difference before and after the subjects consumed the high‐DHA diet (9.4 ±3.1 min before and 8.0±3.4 min after). Platelets from the volunteers exhibited more than a threefold increase in their DHA content from 1.54±0.16 to 5.48±1.21 (wt%) during the DHA feeding period. The EPA content of the subjects’ platelets increased from 0.34±0.12 to 2.67±0.91 (wt%) during the high‐DHA diet despite the absence of EPA in the subjects’ diets. The results from this study on blood clotting parameters and in vitro platelet aggregation suggest that adding 6 g/d of dietary DHA for 90 d to a typical Western diet containing less than 50 mg/d of DHA produces no observable physiological changes in blood coagulation, platelet function, or thrombotic tendencies in healthy, adult males.
Pancreatic bile salt‐dependent lipase activity in serum of normolipidemic patients
Authors: Caillol Nathalie , Pasqualini Eric , Mas Eric , Valette Anne , Verine Alain , Lombardo Dominique 
Published: November 2006

AbstractBile salt‐dependent lipase (BSDL, E.C. 3.1.1.‐) is a digestive enzyme secreted by the pancreatic acinar cell. Once in the duodenum, the enzyme, upon activation by primary bile salts, hydrolyzes dietary lipid esters such as cholesteryl esters and lipid‐soluble vitamin esters. This enzyme is partially transferred from the duodenum or pancreas to the circulation where it has been postulated to exert a systemic action on atheromagenerating oxidized‐low density lipoprotein (LDL). In the present study, sera from 40 healthy normolipidemic volunteers were used to investigate the possible linkage between circulating BSDL, lipids, and lipoproteins. We showed, firstly that pancreatic‐like BSDL, activity can be detected in these serums. Secondly, BSDL activity increased significantly with the level of LDL‐cholesterol and was also positively linked to the serum concentration of Apo B100 and Apo A‐1. Thirdly, we also established that BSDL was associated with LDL, in part by a specific interaction with Apo B100, while no interaction was found with Apo A‐1. No linkage with other recorded parameters (triglycerides, phospholipids, and high density lipoprotein‐cholesterol) was detected. Because an increase in LDL‐cholesterol represents an important risk factor for atheroma, the concomitant increase in BSDL, which can metabolize atherogenic LDL, suggests for the first time that this circulating enzyme may exert a positive effect against atherosclerosis.
Prevention of ischemia‐induced cardiac Sudden death by n−3 polyunsaturated fatty acids in dogs
Authors: Billman George E. , Kang Jing X. , Leaf Alexander 
Published: November 2006

AbstractThe objective of this study was to obtain functional information associated with the prevention by n−3 polyunsaturated fatty acids (PUFA) of ischemia‐induced fatal cardiac ventricular arrhythmias in the intact, conscious, exercising dog. Thirteen dogs suceptible to ischemia‐induced ventricular fibrillation were prepared surgically by ligation of their anterior descending left coronary artery and placement of an inflatable cuff around their left circumflex artery. After 4 wk of recovery, exercise‐plus‐ischemia tests were performed without and then with an intravenous infusion of an emulsion of free n−3 PUFA just prior to occluding the left circumflex artery while the animals were running on a treadmill. One week later the exercise‐plus‐ischemia test was repeated but with a control infusion replacing the emulsion of n−3 PUFA. The infusion of the free n−3 PUFA in quantities of 1.0 to 10 g prevented ventricular fibrillation in 10 of the 13 dogs tested (P<0.005), apparently without esterification of the PUFA into membrane phospholipids. The antiarrhythmic effect of the n−3 PUFA was associated with slowing of the heart rate, shortening of the QT‐interval (electrical action potential duration), reduction of left ventricular systolic pressure, and prolongation of the electrocardiographic atrial‐ventricular conduction time (P‐R interval). These effects are comparable with those we have reported in studies with cultured neonatal rat cardiac myocytes.
Biliary excretion of dolichols and β‐hexosaminidase—Effect of ethanol and glucagon
Authors: Humaloja Kari , Salaspuro Mikko , Roine Risto P. 
Published: November 2006

AbstractAlcohol has been reported to increase the urinary excretion of dolichols, and urinary dolichols are suggested to be derived from the lysosomes of the renal cells. In the present study we examined the effects of alcohol and glucagon on the biliary excretion of dolichols in rats. Chronic ethanol treatment decreased both biliary dolichol and β‐hexosaminidase excretion. The absolute amount of dolichol excreted into the bile correlated highly significantly with the absolute amount of biliary β‐hexosaminidase. Our results indicate that biliary dolichols are—at least in part—derived from hepatic lysosomes. Decreased biliary dolichol output during chronic alcohol administration suggests that urinary and biliary dolichol excretions are regulated independently of each other.
Effect of curcumin and capsaicin on arachidonic acid metabolism and lysosomal enzyme secretion by rat peritoneal macrophages
Authors: Joe Bina , Lokesh B. R. 
Published: November 2006

AbstractThe inflammatory mediators secreted by macrophages play an important role in autoimmune diseases. Spice components, such as curcumin from turmeric and capsaicin from red pepper, are shown to exhibit antiinflammatory properties. The influence of these spice components on arachidonic acid metabolism and secretion of lysosomal enzymes by macrophages was investigated. Rat peritoneal macrophages preincubated with 10 μM curcumin or capsaicin for 1 h inhibited the incorporation of arachidonic acid into membrane lipids by 82 and 76%: prostaglandin E2 by 45 and 48%; leukotriene B4 by 61 and 46%, and leukotriene C4 by 34 and 48%, respectively, but did not affect the release of arachidonic acid from macrophages stimulated by phorbol myristate acetate. However, the secretion of 6‐keto PG F1α was enhanced by 40 and 29% from macrophages preincubated with 10 μM curcumin or capsaicin, respectively, as compared to those produced by control cells. Curcumin and capsaicin also inhibited the secretion of collagenase, elastase, and hyaluronidase to the maximum extent of 57, 61, 66%, and 46, 69, 67%, respectively. These results demonstrated that curcumin and capsaicin can control the release of inflammatory mediators such as eicosanoids and hydrolytic enzymes secreted by macrophages and thereby may exhibit antiinflammatory properties.
Lipid specificity and location of the sterol carrier protein‐2 fatty acid‐binding site: A fluorescence displacement and energy transfer study
Authors: Frolov Andrey , Miller Kimberly , Billheimer Jeffrey T. , Cho Tae‐Hyeon , Schroeder Friedhelm 
Published: November 2006

AbstractAlthough it was recently recognized that sterol carrier protein‐2 (SCP‐2) interacts with fatty acids, little is known regarding the specificity of SCP‐2 for long‐chain fatty acids or branched‐chain fatty‐acid‐like molecules. Likewise the location of the fatty‐acid binding site within SCP‐2 is unresolved. A fluorescent cis‐parinaric acid displacement assay was used to show that SCP‐2 optimally interacted with 14–22 carbon chain lipidic molecules: polyunsaturated fatty acids > monounsaturated, saturated > branched‐chain isoprenoids > branched‐chain phytol‐derived fatty acids. In contrast, the other major fatty‐acid binding protein in liver, fatty‐acid binding protein (L‐FABP), displayed a much narrower carbon chain preference in general: polyunsaturated fatty acids > branched‐chain phytol‐derived fatty acids > 14‐ and 16‐carbon saturated > branched‐chain isoprenoids. However, both SCP‐2 and l‐FABP displayed a very similar unsaturated fatty‐acid specificity profile. The presence and location of the SCP‐2 lipid binding site were investigated by fluorescence energy transfer. The distance between the SCP‐2 Trp50 and bound cis‐parinaric acid was determined to be 40 Å. Thus, the SCP‐2 fatty‐acid binding site appeared to be located on the opposite side of the SCP‐2 Trp50. These findings not only contribute to our understanding of the SCP‐2 ligand binding site but also provide evidence suggesting a potential role for SCP‐2 and/or L‐FABP in metabolism of branched‐chain fatty acids and isoprenoids.