bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced triolein removal using microemulsions formulated with mixed surfactants
Authors: Tongcumpou C. , Acosta E. J. , Scamehorn J. F. , Sabatini D. A. , Yanumet N. , Chavadej S.
Published: November 2006

In previous work, a microemulsion‐based formulation approach yielded excellent laundry detergency with hydrophobic oily soils hexadecane and motor oil. In this work, the same approach is used in detergency of triolein, which is a model triglyceride, some of the most difficult oils to be removed from fabric. The linker concept was applied in formulation of the microemulsion system. Three different surfactants were used: (i) dihexyl sulfosuccinate, an ionic surfactant with a moderate hydrophile‐lipophile balance (HLB); (ii) secondary alcohol ethoxylate, a lipophilic nonionic surfactant with a very low HLB; and (iii) alkyl diphenyl oxide disulfonate (ADPODS), a hydrophilic anionic surfactant with a very high HLB. The phase behavior and interfacial tension (IFT) of the surfactant systems were determined with different concentrations of ADPODS. The results indicate that as the HLB of the system increases, a higher salinity is required to shift the phase transition from Winsor Type I to Type III to Type II. The three formulations at different salinities were used in detergency experiments to remove triolein from polyester/cotton sample fabric. The results showed that there were two peaks of maximum detergency in the range of salinity from 0.1% to 10% NaCl. The higher the hydrophilicity of the system, the higher the salinity required for maximum detergency. The results of the dynamic IFT and the detergency performance from two rinsing methods lead to the hypothesis that one of these maxima in detergency results from a spreading or wetting effect. The other maximum in detergency is believed to be related to ultralow IFT associated with oil/water middle‐phase microemulsion formation. Triolein removal exceeding 80% was attained, validating the microemulsion approach to detergency.
Preventing discoloration of squalene‐soiled cotton fabrics with antioxidants
Authors: Chi Yong‐Seung , Obendorf S. Kay
Published: November 2006

Removal of discoloration caused by aged oily soils is difficult because oily soils undergo autoxidation, which results in polymerization and formation of chromophores. Use of antioxidants and a reducing agent was investigated for their impact on appearance retention and soil removal. The effect of a reducing agent, sodium dithionite, on the removal of aged squalene from cotton fabrics was studied as a pretreatment to laundering, which enhanced the removal of squalene as well as whiteness restoration. Increases in treatment concentration and time increased color removal. However, no significant increase was found in oil removal, suggesting that the role of the reducing agent is mainly a reductive bleaching action. Thus, the color will probably reverse by oxidation over time making this approach a not‐so‐promising laundry treatment. As a method of preventing discoloration of oily soiled textile materials, antioxidants Irganox® 1010, t‐butylhydroxyanisole and α‐tocopherol were examined; they were found to be effective antioxidants for this purpose by preventing the discoloration of squalene upon aging. With Irganox® 1010, this prevention occurred without decreasing the detergency of the oil. Most importantly, these antioxidants either did not stain the substrate or showed very low levels of staining upon usage. The biggest barrier to applying antioxidants on textiles is their hydrophobic nature. A search for water‐soluble antioxidants with nonstaining and good oxidation inhibiting properties is necessary.
Characteristic properties of cutting fluid additives derived from the reaction products of hydroxyl fatty acids with some acid anhydrides
Authors: Tomoda Hideyuki , Sugimoto Yasuhiro , Tani Yumiko , Watanabe Shoji
Published: November 2006

Several adducts were prepared from the thermal reaction of hydroxyl fatty acids (ricinoleic acid oligomers, 12‐hydroxystearic acid oligomers, oleyl alcohol, dehydrated castor oil fatty acids, and dimer acid) with maleic anhydride and screened as water‐soluble cutting fluids. For example, aqueous solutions of triethanolamine salts with the products of ricinoleic acid oligomers, 12‐hydroxystearic acid dimer, and 12‐hydroxysteric acid hexamer showed good antirust properties for waterbased cutting fluids. Various half esters of hydroxyl fatty compounds with acid anhydrides were prepared. Aqueous solutions of triethanolamine salts of half esters of maleic anhydride and succinic anhydride and phthalic anhydride with hydroxyl fatty acids gave good antirust and antiwear properties for waterbased cutting fluids.
Characterization of simple and reproducible vascular stenosis model in hypercholesterolemic hamsters
Authors: Matsuno Hiroyuki , Kozawa Osamu , Niwa Masayuki , Abe Akira , Takiguchi Yoshiharu , Uematsu Toshihiko
Published: November 2006

The importance of low‐density lipoprotein (LDL) in the etiology of atherosclerosis is well recognized. We have established a reproducible stenosis model in hypercholesterolemic hamsters, and the process of arterial stenosis by thrombus or neointima was studied and compared with that in normal hamsters. The level of plasma LDL was 4.6 times higher in hamsters fed a high‐cholesterol diet than in hamsters fed normal food. Endothelial injury in right common carotid arteries was induced using a modified catheter. Arterial blood flow was monitored continuously using a Doppler flow probe. Arterial patency after the initiation of injury in high‐cholesterol hamsters was significantly changed as compared with that of normal hamsters. Neointima was observed 2 wk after the vascular injury. The neointimal area of high‐cholesterol hamsters was significantly larger than that of normal hamsters. To characterize the stenosis in hypercholesterolemic hamsters, we measured platelet aggregation, thrombin time, activated partial thromboplastin time, and proliferating smooth muscle cells (SMC) in vitro and in vivo. The half‐maximal inhibitory concentration value for platelet aggregation induced by thrombin or collagen, the DNA synthesis stimulated by plateletderived growth factor (PDGF)‐BB, and 5‐bromo‐2‐deoxy‐uridine labeling indices (proliferating index of SMC in vivo) in high‐cholesterol hamsters were each significantly higher than the comparable value from normal hamsters. However, specific binding of PDGF‐BB in SMC was not different between the two types of hamsters. Furthermore, we investigated the inhibitory effects of probucol or losartan on neointima formation using this model. Probucol, but not losartan, significantly reduced the neointimal area in hypercholesterolemic hamsters. These findings indicated that high levels of plasma LDL strongly contributed to the development of thrombus and neointima formation via both up‐regulation of platelet aggregation and the enhancement of SMC proliferation. This stenosis model may be useful for the investigation of hypercholesterolemia‐associated cardiovascular diseases.
A novel sphingophosphonolipid head group 1‐hydroxy‐2‐aminoethyl phosphonate in Bdellovibrio stolpii
Authors: Watanabe Yoko , Nakajima Masaharu , Hoshino Tsutomu , Jayasimhulu Koda , Brooks Elwood E. , Kaneshiro Edna S.
Published: November 2006

Members of the bacterial genus Bdellovibrio include strains that are free‐living whereas others are known to invade and parasitize larger Gram‐negative bacteria. The bacterium can synthesize several sphingophospholipid compounds including those with phosphoryl bonds as well as phosphonyl bonds. In the present study, the dominant sphingophosphonolipid component was isolated by column chromatography, and the long‐chain bases, fatty acids, and polar head groups were identified by thin‐layer and gas‐liquid chromatographic procedures. The definitive structural identity of the sphingolipid was established by nuclear magnetic resonance and mass spectrometry of hydrolysis products and the intact compound. The compound was identified as N‐2′‐hydroxypentadecanoyl‐2‐amino‐3,4‐dihydroxyheptadecan‐1‐phosphono‐(1‐hydroxy‐2‐aminoethane).
Interaction of CETP inhibitory peptide and lipoprotein substrates in cholesteryl ester transfer assay: Relationship between association properties and inhibitory activities
Authors: Cho Kyung‐Hyun , Lee Ju‐Young , Choi Myung‐Sook , Bok Song‐Hae , Park Yong Bok
Published: November 2006

In a previous study, CETP inhibitory peptide (3 kDa) was isolated from hog plasma. The peptide, synthesized chemically according to the amino acid sequence of the 3‐kDa peptide (designated P28), showed CETP inhibitory activity both in vitro and in vivo [Cho et al. (1998) Biochim. Biophys. Acta 1391, 133–144]. We report herein further unique features of P28 when it was associated with the cholesteryl ester (CE)‐donor and‐acceptor lipoproteins. Lipoprotein substrates with P28 present in both HDL (as a CE‐donor) and LDL (as a CE‐acceptor) served as poor substrates, with CE‐transfer activity decreased up to 60% compared to normal substrates without P28. P28 was found to be located in HDL fractions of hog plasma and showed the same electromobility as that visualized by PAGE on 7% polyacrylamide gel under nondenaturing conditions. Addition of apolipoprotein A‐1 (apoA‐1) or apoB antibody to a normal CE‐transfer mixture did not alter CE‐transfer activity. However, addition of apoA‐1 or −B antibody to a CETP‐inhibition mixture decreased the inhibitory activity of P28 by ca. 20%. Western blot analysis revealed that P28 was associated only with human and hog HDL among several lipoproteins purified from human, hog, and rabbit. CFTP‐inhibition assays with various lipoprotein substrates revealed that P28 exhibited substrate‐specific inhibitory activity. The inhibitory activity of P28 was highly dependent on the type of lipoprotein substrate (whether CE‐donor or‐acceptor); P28 inhibited CE transfer from HDL to LDL, but it did not inhibit CE transfer from HDL to HDL.
Correlation between fatty acyl composition in neutral and polar lipids and enzyme activities from various tissues of calcium‐deficient rats
Authors: Marra Carlos A. , Rimoldi Omar , de Alaniz María J. T.
Published: November 2006

In this study we investigated the changes induced by feeding rats a calcium‐deficient diet (0.5 g Ca/kg diet) during 65 d after weaning. Phospholipase A2, acyl‐Co synthetase and FA Δ9‐, Δ6‐, and Δ5‐desaturase activities were also determined. Calcium deficiency evoked a general alteration in the quality and proportion of the FA chains acylated to neutral and polar lipids from liver, lungs, spleen, brain, kidneys, fat, articular cartilage, erythrocyte ghosts, and plasmas, characterized by an increment of saturated FA and a significant depletion of polyunsaturated acids derived from linoleate and α‐linolenate. Several interlipid and lipid/protein relationships were also modified in microsomes from calcium‐deprived rats, with a concomitant reduction in the rotational mobility of the probe diphenylhexatriene. Phospholipase A2 and acyl‐CoA synthetase activities were also decreased and increased, respectively, in some tissues from calcium‐deficient rats, whereas Δ9‐, Δ6‐ and Δ5‐desaturases were significantly depressed. We conclude that changes in tissue fatty acyl composition evoked by calcium deprivation are due to alterations in the acylation/deacylation cycles via inhibition of the phospholipase A2. These changes were reflected in the physicochemical properties of the membranes, which in turn inhibits desaturase activities. A possible failure in the transcriptional rate for desaturase‐mRNA was also discussed.
Endothelial vasodilatory function is predicted by circulating apolipoprotein B and HDL in healthy humans
Authors: Steer Peter , Hulthe Johannes , Millgård Jonas , Sarabi Dennis M. , Basu Samar , Vessby Bengt , Lind Lars
Published: November 2006

Endothelium‐dependent vasodilation (EDV), LDL particle size, and antibodies against oxidized LDL (oxLDLab) have been shown to be related to the development of atherosclerosis and cardiovascular disease. In this study, we investigated whether LDL particle size, oxLDLab, apolipoproteins, and lipoproteins are related to endothelial vasodilatory function in a population sample of 58 apparently healthy subjects aged 20 to 69 yr. EDV and endothelium‐independent vasodilation (EIDV) were studied in the forearm during local administration of methacholine chloride (2 and 4 μg/min) or sodium nitroprusside (5 and 10 μg/min). Forearm blood flow was determined with venous occlusion plethysmography. In multiple stepwise regression analyses, neither oxLDLab nor small LDL particles were significantly predictive of endothelial vasodilatory function. Instead, a high level of apolipoprotein B (apoB) was an independent predictor of both attenuated EDV and EIDV (r=−0.43, P<0.01, and r=−0.34, P<0.05, respectively). HDL cholesterol, on the other hand, was the only lipid variable that was significantly related to the EDV to EIDV ratio, an index of endothelial vasodilatory function (r=0.35, P<0.01). The inverse associations between apoB and both EDV and EIDV indicate that apoB might be an early marker of structural vascular changes in healthy subjects, whereas HDL seems to be more specifically related to endothelial vasodilatory function.
The role of cytochrome P450 in the regulation of cholesterol biosynthesis
Authors: Gibbons Geoffrey F.
Published: November 2006

A ubiquitously expressed member of the cytochrome P450 superfamily, CYP51, encodes lanosterol 14α‐demethylase, the first step in the conversion of lanosterol into cholesterol in mammals. The biosynthetic intermediates of lanosterol 14α‐demethylation are oxysterols, which inhibit HMG‐CoA reductase and sterol synthesis in mammalian cells in vitro. These oxysterols (5α‐lanos‐8‐en‐3β,32‐diol and 3β‐hydroxy‐5α‐lanost‐8‐en‐32‐al) are efficiently converted into cholesterol in vitro and are generally considered to be natural cholesterol precursors. When added to hepatocytes in high concentrations, besides their conversion into cholesterol, they are also rapidly metabolized into more polar sterols and into steryl esters. The 15α‐ and 15β‐hydroxy epimers of 5α‐lanost‐8‐en‐3β‐ol are also rapidly metabolized into more polar sterols and steryl esters but are not converted efficiently into cholesterol. Polar sterol formation from all these oxysterols is dependent on an active form of cytochrome P450. Oxysterols are potent regulators of the activities of transcription factors of the sterol regulatory element‐binding protein family and of liver X‐receptor α. It is proposed that the rapid, cytochrome P450‐dependent metabolism of naturally occurring regulatory oxysterols provides a route for their deactivation so that they become incapable of affecting gene transcription. Inhibition of cytochrome P450 by the drug ketoconazole prevents the inactivation of such oxysterols, leading to a prolonged suppression of hepatic HMG‐CoA reductase in vivo and in vitro.
Studies toward the synthesis of the shark repellent pavoninin‐5
Authors: Williams John R. , Chai Deping , Gong Hua , Zhao Wei , Wright Dominic
Published: November 2006

Sharks are the most dangerous predators of people in the sea, resulting in people being mauled and killed each year. A shark repellent could help to diminish this danger. The aglycone of the shark repellent pavoninin‐5, (25R)‐cholest‐5‐en‐3β,15α,26‐triol (5a), was synthesized from diosgenin (9). Removing mercury from the Clemmensen reduction of 9 gave a higher yield of (25R)‐cholest‐5‐en‐3β,16β,26‐triol, 10a, and was also more environmentally friendly. Attempted methods for the transposition of the C‐16β hydroxyl to the 15α position are described. A successful method for this transposition via the 15α‐hydroxy‐16‐ketone, 8a, using the Barton deoxygenation reaction on the 16‐alcohol 14b, is reported.
Microtubular integrity differentially modifies the saturated and unsaturated fatty acid metabolism in cultured hep G2 human hepatoma cells
Authors: Marra Carlos A. , de Alaniz María J. T.
Published: November 2006

The influence of cytoskeleton integrity on the metabolism of saturated and unsaturated FA was studied in surface cultures and cell suspensions of human Hep G2 hepatoma cells. We found that colchicine (COL), nocodazol, and vinblastin produced a significant inhibition in the incorporation of labeled saturated FA, whereas incorporation of the unsaturated FA remained unaltered. These microtubule‐disrupting drugs also diminished Δ9‐, Δ5‐, and Δ6‐desaturase capacities. The effects produced by COL were dose (0–50 μM) and time (0–300 min) dependent, and were antagonized by stabilizing agents (phalloidin and DMSO). Dihydrocytochalasin B (20μM) was tested as a microfilament‐disrupting drug and produced no changes in either the incorporation of [14C]FA or the desaturase conversion of the substrates. We hypothesized that the interactions between cytoskeleton and membrane proteins such as FA desaturases may explain the functional organization, facilitating both substrate channeling and regulation of unsaturated FA biosynthesis.
Use of a 13C tracer to investigate lutein as a ligand for plasma transthyretin in humans
Authors: Chen Liwei , Collins Xixuan Hu , Tabatabai Louisa B. , White Wendy S.
Published: November 2006

The selective accumulation of lutein in the macula of the human retina is likely to be mediated by specific transport and/or binding proteins. Our objective was to determine whether transthyretin (TTR) is a plasma transport protein for lutein. We used a biosynthetic 13C‐lutein tracer and GC‐combustion interfaced‐isotope ratio MS to gain the requisite sensitivity to detect the minute amounts of lutein expected as a physiological ligand for TTR. Subjects (n=4) each ingested 1 mg of 13C‐lutein daily for 3 d and donated blood 24 h after the final dose. For three subjects, the plasma TTR‐retinol‐binding protein (RBP) complex was partially purified by anion‐exchange (diethylaminoethyl, DEAE) chromatography and then dissociated by hydrophobic‐interaction chromatography to yield the TTR component. For subject 4, the initial DEAE purification step was omitted and total plsma TTR (RBP‐bound and free) was isolated by hydrophobic‐interaction chromatography. In each case, the crude TTR fractions were then purified to homogeneity by RBP‐sepharose affinity chromatography. Pure TTR was extracted with chloroform, and unlabeled lutein was added to the extract as a carrier. The mean 13C/12C ratio (expressed in delta notation, δ13C) of the lutein fraction isolated from the plasma TTR extracts of the four subjects was −30.53±3.29‰. The δ13C value of the unlabeled lutein carrier was −30.97±0.27‰. Thus, no 13C enrichment was detected in association with TTR. We conclude that lutein is not associated with TTR in human plasma after being ingested in physiological amounts.
1H and 13C NMR characterization and stereochemical assignments of bile acids in aqueous media
Authors: Ijare Omkar B. , Somashekar B. S. , Jadegoud Y. , Nagana Gowda G. A.
Published: November 2006

The unconjugated bile acids cholic acid, deoxycholic acid, and chenodeoxycholic acid; their glycine and taurine conjugated glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid; and a taurine conjugated ursodeoxycholic acid, tauroursodeoxycholic acid, were characterized through 1H and 13C NMR in aqueous media under the physiological pH region (7.4±0.1). Assignments of 1H and 13C signals of all the bile acids were made using a combination of several one‐ and two‐dimensional, homonuclear (1H−1H) and heteronuclear (1H−13C) correlations as well as spectral editing NMR methods. Stereochemical assignment of the five‐membered ring of the bile acids is reported here for the first time. The complete characterization of various bile acids in aqueous media presented here may have implications in the study of the pathophysiology of biliary diseases through human biliary fluids using NMR spectroscopy.
Lipid malabsorption persists after weaning in rats whose dams were given GLP‐2 and dexamethasone
Authors: Iordache Claudiu , Drozdowski Laurie A. , Clandinin M. Tom , Wild Gary , Todd Zoe , Thomson Alan B. R.
Published: November 2006

Glucagon‐like peptide‐2 (GLP‐2) enhances intestinal growth and absorption in mature animals, and glucocorticosteroids (GC) increase the sugar and lipid uptake in adult animals. However, the role of GC and GLP‐2 in the ontogeny of lipid absorption is unknown. We hypothesized that GLP‐2 and the GC dexamethasone (DEX), when administrated to rat dams during pregnancy and lactation, would enhance lipid uptake in the off‐spring. Rat dams were treated in the last 10 d of pregnancy and during lactation with GLP‐2 [0.1 μg/g/d subcutaneous (sc)], DEX (0.128 μg/g/d sc), GLP‐2+DEX, or a placebo. Sucklings were sacrificed at 19–21 d of age, and weanlings were sacrificed 4 wk later. Lipid uptake was assessed using an in vitro ring uptake method. Although DEX and GLP‐2+DEX increased the jejunal mass, the jejunal lipid uptake was unchanged. In contrast, GLP‐2, DEX, and GLP‐2+DEX reduced the ileal lipid uptake in suckling and weanling rats. This reduction was not due to alterations in intestinal morphology or to changes in fatty acid‐binding protein abundance, but it was partially explained by an increase in the effective resistance of the intestinal unstirred water layer. In sucklings, DEX dramatically reduced the jejunal lipid uptake to levels similar to those seen in weanlings, such that the normal ontogenic decline in lipid uptake was not observed. Giving dams GLP‐2 or DEX during pregnancy and lactation reduced lipid uptake in the offspring, and this persisted for at least 1 mon. The impact this may have on the nutritional well‐being of the animal in later life is unknown.
Effect of dietary n−6 and n−3 polyunsaturated fatty acids on peroxidizability of lipoproteins in steers
Authors: Scislowski Valérie , Bauchart Dominique , Gruffat Dominique , Laplaud Paul‐Michel , Durand Denys
Published: November 2006

The susceptibility of major plasma lipoproteins to lipoperoxidation was studied in relation to the FA composition of their neutral and polar lipids in steers given PUFA‐rich diets. Two trials used, respectively, 18 (“sunflower” experiment, S) or 24 (“linseed” experiment, L) crossbred Salers x Charolais steers. Each involved three dietary treatments over a 70‐d period: a control diet (CS or CL diets) consisting of hay and concentrate, or the same diet supplemented with oilseeds (4% diet dry matter) fed either as seeds (SS or LS diets) or continuously infused into the duodenum (ISO or ILO diets). Compared with control diets, ISO and ILO treatments tended to decrease the resistance time of LDL and HDL classes to peroxidation, mainly owing to the enrichment of their polar and neutral lipids with PUFA. With diets SS and LS, sensitivity of major lipoprotein classes (LDL, light and heavy HDL) was not affected because ruminal hydrogenation of dietary PUFA decreased their incorporation into lipoparticles. ISO and ILO treatments induced a more important production of conjugated dienes and hydroperoxides generated by peroxidation in the three lipoprotein classes due to the higher amounts of PUFA esterified in lipids of the core and the hydrophilic envelope of particles. The production of malondialdehyde (MDA) increased in steers fed linseed supplements, indicating that MDA production did not occur with linoleic acid provided by sunflower oil supplements. Thus, plasma peroxidation of PUFA generates toxic products in steers fed diets supplemented with PUFA and can be deleterious for the health of the animal during long‐term treatment.
Supplementation with a pine bark extract rich in polyphenols increases plasma antioxidant capacity and alters the plasma lipoprotein profile
Authors: Devaraj Sridevi , Vega‐López Sonia , Kaul Nalini , Schönlau Frank , Rohdewald Peter , Jialal Ishwarlal
Published: November 2006

Pycnogenol® (PYC), an extract of French maritime pine bark (Pinus pinaster), is a potent antioxidant with potential health benefits. Its bioavailabilty has previously been shown by urinary excretion studies of constituents and metabolites of PYC. The aim of this study was to test the effect of PYC supplementation on measures of oxidative stress and the lipid profile in humans. Twenty‐five healthy subjects received PYC (150 mg/d) for 6 wk. Fasting blood was collected at baseline, after 3 and 6 wk of supplementation, and again after a 4‐wk washout period. After 6 wk of supplementation with PYC, a significant increase in plasma polyphenol levels was detectable, which was reversed after the 4‐wk washout phase. The antioxidant effect of PYC was demonstrated by a significant increase in oxygen radical absorbance capacity (ORAC) in plasma throughout the supplementation period (P<0.05). The ORAC value returned to baseline after the 4‐wk washout period. Moreover, in addition to its antioxidant effects, PYC significantly reduced LDL‐cholesterol levels and increased HDL‐cholesterol levels in plasma of two‐thirds of the subjects. While the LDL changes reversed during washout, the HDL increase did not. There was no significant difference in LDL oxidizability or plasma lipid peroxides following PYC supplementation. Hence, following oral supplementation in humans, PYC significantly increases antioxidant capacity of plasma, as determined by ORAC, and exerts favorable effects on the lipid profile.
EPA, but not DHA, decreases mean platelet volume in normal subjects
Authors: Park Yongsoon , Harris William
Published: November 2006

The first indication of platelet activation is an increase in mean platelet volume (MPV). n−3 FA are known to inhibit platelet function and to reduce the risk for coronary heart disease. The purpose of this study was to determine the effects of FPA and DHA on MPV. Healthy subjects received olive oil placebo for 4 wk and then were randomly assigned to receive 4g of ethyl esters of either safflower oil (n=11), EPA (n=10), or DHA (n=12) for 4 wk. At the end of placebo run‐in and treatment periods, MPV (fL; mean±SEM) and platelet count (PLT‐CT; 103/μL blood) were measured in the basal state and after ex vivo stimulation with collagen (10 μg/mL), cold (4°C), and heat (37°C). Unlike DHA, EPA lowered MPV as compared with safflower oil (7.2±0.1 vs. 7.5±0.1 fL; P<0.05) and raised PLT‐CT (211±18 vs. 192±18 103/μL; P<0.05) in the fasting state. Collagen and cold significantly increased MPV whereas heat lowered MPV regardless of treatment. All stimuli decreased PLT‐CT. EPA significantly increased platelet EPA (0.2±0.1 vs. 3.3±0.4%) and docosapentaenoic acid (DPA; 2.2±0.3 vs. 2.9±0.3%) concentrations, but not DHA. DHA treatment significantly increased DHA (1.4±0.2 vs. 4.1±0.5%) and DPA (2.0±0.4 vs. 3.0±0.4%) concentrations, but not EPA. In conclusion, EPA, but not DHA, reduces platelet activation, an early step in platelet aggregation.
Alterations of the lipid profile after 7.5 years of low‐dose antioxidant supplementation in the SU.VI.MAX study
Authors: Hercberg Serge , Bertrais Sandrine , Czernichow Sébastien , Noisette Nathalie , Galan Pilar , Jaouen Adèle , Tichet Jean , Briancon Serge , Favier Alain , Mennen Louise , Roussel Anne‐Marie
Published: November 2006

Antioxidant micronutrients have been reported to be associated with an improvement in the blood profile, but the results are not consistent. The aim of the present study was to assess the effects of antioxidant supplementation on changes in the serum lipid profile of adult participants in the SU.VI.MAX study. French adults (n=12,741∶7,713 females aged 35–60 yr, and 5,028 males aged 45–60 yr) received daily antioxidant supplementation (120 mg vitamin C, 30 mg vitamin E, 6 mg β‐carotene, 100 μg selenium, and 20 mg zinc) or a matching placebo. Median follow‐up time was 7.5 yr. After 7.5 yr, no effect of supplementation on total cholesterol was observed in men or women after adjusting for baseline total cholesterol levels and lipid‐lowering medications. The prevalence of hypercholesterolemia (≥6.5 mmol/L) showed a trend toward being higher in women who received supplements compared with those who received the placebo (P=0.06). In both sexes, the group receiving supplements exhibited higher mean serum TG concentrations than did the placebo group (P=0.06 in men; P=0.05 in women). The prevalence of hypertriglyceridemia (≥2.3 mmol/L) was also significantly higher in men who received supplements (P=0.03), but not in women. Our results suggest than long‐term daily supplementation with low doses of β‐carotene, vitamins C and E, selenium, and zinc does not result in an improved lipid profile and could even adversely affect some blood lipids, possibly with a higher risk of hyperlipidemia in women.
Metal‐lon stimulation and inhibition of lysophospholipase D which generates bioactive lysophosphatidic acid in rat plasma
Authors: Tokumura Akira , Miyake Maki , Yoshimoto Osamu , Shimizu Mayumi , Fukuzawa Kenji
Published: November 2006

We found that lysophospholipase D (LPLD) in rat plasma prefers unsaturated to saturated lysophosphatidylcholines as substrates, generating a biologically active lipid, lysophosphatidic acid, but it does not hydrolyze diacyl‐phospholipids. In this study, this LPLD required a metal ion for activity, Co2+ being the most effective, followed in order by Zn2+, Mn2+, and Ni2+. This metal‐ion‐stimulated LPLD with unique substrate specificity, which has not been described previously, was susceptible to thiol‐blocking reagents and serine esterase inhibitors, but not to a histidine‐modifying reagent. Consistent with results using thiol‐modifying agents, short‐chain fatty aldehydes, secondary products of lipid peroxidation, were found to inhibit LPLD. Addition of dibutylhydroxytoluene or butylhydroxyanisole to the plasma increased the activity of this enzyme, probably in a manner independent of its antioxidant activity, since another antioxidant, propyl gallate, was rather inhibitory. These results suggest that rat plasma contains an active LPLD that differs in some properties from other members of the known phospholipase D family detected in animal tissues and body fluids.
Lipid and fatty acid composition of different fractions from rat urinary transitional epithelium
Authors: Calderon Reyna O. , Glocker Monica , Eynard Aldo R.
Published: November 2006

The phospholipid composition of rat urinary transitional epithelium (TE) and the fatty acid composition of microsomal, mitochondrial, cytosolic, and plasma membrane (PM) subcellular fractions were investigated. PM marker enzymes and electron microscopy analysis were used to characterize the PM fraction, which showed a distinctive lipid composition compared to the general profile of PM from different sources. The levels of cholesterol and sphingomyelin were not enriched in the PM fraction; on the other hand, the increased amounts of glycosphingolipids and phosphatidylserine, and the decreased level of phosphatidylcholine followed the general features of a PM profile. This differential PM lipid composition may reflect the unique morphology of this mammal TE, consisting of concave plaques with an asymmetrical membrane unit. The distribution of the double bond across the PM indicated a higher unsaturation of the inner relative to the outer part of the PM hemileaflet. In addition, the presence of 20∶3n−9 nonessential fatty acid in a normal TE may represent a characteristic fatty acid metabolism of this epithelium.
Obesity as a risk factor for certain types of cancer
Authors: Carroll K. K.
Published: November 2006

Summary and Conclusions

In conclusion, obesity has been associated with increased risk for a number of different types of cancer. The evidence has been most consistent for endometrial cancer, breast cancer in postmenopausal women, and renal cell cancer. More variable results have been reported for colorectal, prostate and pancreatic cancer.

Possible mechanisms by which obesity may influence cancer risk include alteration in hormonal patterns, including sex hormones and insulin, and factors such as the distribution of body fat and changes in adiposity at different ages. The increasing prevalence of obesity in many parts of the world emphasizes the importance of learning more about the relationship between obesity and cancer and the mechanisms involved in their interaction.
Surface pressure‐dependent cross‐modulation of sphingomyelinase and phospholipase A2 in monolayers
Authors: Fanani María Laura , Maggio Bruno
Published: November 2006

We investigated the ways in which phospholipase A2 and sphingomyelinase are mutually modulated at lipid interfaces. The activity of one enzyme is affected by its own reaction products and by substrates and products of the other enzyme; all this depends differently on the lateral surface pressure. Ceramide inhibits both the sphingomyelinase activity rate and the extent of degradation, and decreases the lag time at all surface pressures. Dilauroyl‐ and dipalmitoylphosphatidyl‐choline, the substrates of phospholipase A2 (PLA2), do not affect sphingomyelinase activity. The products of PLA2, palmitic acid and lysopalmitoylphosphatidylcholine, strongly enhance and shift to high surface pressures the activity optimum and the cut‐off point of sphingomyelinase. Palmitic acid also shifts to high surface pressures the cut‐off point of PLA2 activity. Sphingomyelin strongly inhibits PLA2 at surface pressures above 5 mN/m, while ceramide shifts the cut‐off point and the activity optimum to high surface pressures. The sphingolipids increase the lag time of PLA2 at low surface pressures. Both phosphohydrolytic pathways involve different levels of control on precatalytic steps and on the rate of activity that appear independent on specific alterations of molecular packing and surface potential. The mutual lipid‐mediated interfacial modulation between both phosphohydrolytic pathways indicates that phospholipid degradation may be self‐amplified or dampened depending on subtle changes of surface pressure and composition.
Low density lipoprotein of synovial fluid in inflammatory joint disease is mildly oxidized
Authors: James M. J. , van Reyk D. , Rye K. A. , Dean R. T. , Cleland L. G. , Barter P. J. , Jessup W.
Published: November 2006

Oxidatively modified low density lipoprotein (LDL) has many biological activities which could contribute to the pathology of the atherosclerotic lesion. Because atherosclerosis has an inflammatory component, there has been much interest in the extent to which LDL could be oxidatively modified in vivo by inflammation. The present study examined LDL present in an accessible inflammatory site, the inflamed synovial joint, for evidence of compositional change and oxidative modification. LDL was isolated from knee joint synovial fluid (SF) from subjects with inflammatory arthropathies and also from matched plasma samples. SF and plasma LDL had similar free cholesterol and α‐tocopherol content, but SF LDL had a lower content of esterified cholesterol. On electrophoresis, SF LDL was slightly more electronegative than LDL from matched plasma samples, but the changes were much less than those resulting from Cu2+‐treatment of LDL. Oxidized cholesterol was not detected in any samples, but cholesterol ester hydroperoxide levels were greater in SF than in plasma LDL. When samples from three subjects were incubated with macrophages, the SF LDL did not cause significant loading of the cells with cholesterol or cholesterol esters, in contrast to the situation with acetylated LDL. Overall, the SF LDL displayed evidence of slightly increased oxidation by comparison with matched plasma samples. Despite their isolation from an environment with active inflammation, changes were modest compared with those resulting from Cu2+ treatment. Thus, extensive LDL oxidation is not a necessary correlate of location in a chronic inflammatory site, even though it is characteristic of atherosclerotic lesions.
Lipid peroxidation of isolated chylomicrons and oxidative status in plasma after intake of highly purified eicosapentaenoic or docosahexaenoic acids
Authors: Hansen John‐Bjarne , Berge Rolf K. , Nordøy Arne , Bønaa Kaare H.
Published: November 2006

Fourteen healthy male volunteers were given two separate high‐saturated‐fat meals with and without the addition of 4 g highly purified ethyl esters of either eicosapentaenoic acid (EPA) (95% pure, n=7) or docosahexaenoic acid (DHA) (90% pure, n=7) supplied as 1‐g capsules each containing 3.4 mg vitamin F. The chylomicrons were isolated 6 h after the meals, at peak concentrations of n−3 fatty acids (FA). Addition of n−3 FA with the meal caused a 10.4‐fold increase in the concentration of n−3 FA in chylomicrons compared to the saturated fat meal without addition of n−3 FA. After the saturated‐fat meal, the concentration of thiobarbituric acid‐reactive substances (TBARS) was 327.6±34.6 nmol/mmol triacylglycerol (TAG), which increased to 1015.8±212.0 nmol/mmol TAG (P<0.0001, n=14) after EPA and DHA were added to the meal. There was no significant correlation between the concentrations of TBARS and vitamin E in the chylomicrons collected 6 h after the test meal. The present findings demonstrate an immediate increase in chylomicron peroxidation ex vivo provided by intake of highly purified n−3 FA. The capsular content of vitamin E was absorbed into chylomicrons, but the amount of vitamin E was apparently not sufficient to protect chylomicrons against lipid peroxidation ex vivo. Daily intake of 4 g n−3 FA either as EPA or DHA for 5 wk did not change the plasma concentration of TBARS. Although not significantly different between groups, DHA supplementation decreased total glutathione in plasma (P<0.05) and EPA supplementation increased plasma concentration of vitamin E (P<0.05). The other lipid‐soluble and polar antioxidants in plasma remained unchanged during 5 wk of intervention with highly purified n−3 FA.
Human SIRT1: A potential biomarker for tumorigenesis?
Authors: Lim Chang‐Su
Published: November 2006

Accumulating body of evidence reveals that hSIRT1, an NAD+‐dependent protein deacetylase, is involved in regulating numerous biological processes. Therefore cellular functions of hSIRT1 are highly pleiotropic. The integrated hypothetical mechanisms of hSIRT1 action contributing to regulating cellular senescence and longevity have been proposed. Based on recent evidence, I propose that hSIRT1 is a potential biomarker for tumorigenesis.
Industry Watch
Authors: DALE ROBERT
Published: November 2006

The last six months have seen a number of interesting announcements and products in the commercial language technology arena. Here are some that caught my eye, and which you might find interesting too.
Influence of present day and glacial surface conditions on the Antarctic Oscillation/Southern Annular Mode
Authors: Justino Flávio , Peltier W. Richard
Published: November 2006

Based upon coupled climate simulations driven by present day and glacial boundary conditions, we demonstrate that the internal variability associated with the pronounced south polar climate anomalies that characterized the glacial climate regime was largely confined to the winter season. In particular, the intensity and spatial structure of the Antarctic Oscillation/Southern Annular Mode is found to display a strong seasonal cycle. In the summer season, we demonstrate that this mode of internal climate variability is extremely robust in response to a change from modern to glacial conditions in that it seems not to depend upon the latitudinal position of the baroclinic zone nor on the strength of the mean atmospheric zonal circulation. In winter, however, and under glacial conditions, this mode is characterized by a significantly modified atmospheric circulation that differs dramatically in terms of its internal variability from that characteristic of modern conditions
Areal estimation of intensity and frequency of summertime precipitation over a midlatitude region
Authors: Kursinski Ana L. , Zeng Xubin
Published: November 2006

Spatially averaged precipitation characteristics derived from observations are needed to evaluate climate model generated precipitation intensity and frequency. In this study, observations from gauges and radar datasets are used to address three issues that are related to the areal estimation of intensity and frequency of summertime precipitation over the state of Ohio, USA. First, spatial averages of intensity and frequency from point precipitation are found to be very sensitive to the averaging method (i.e., spatial averaging followed by temporal averaging versus temporal followed by spatial averaging), particularly at lower precipitation thresholds. Second, approximately 30 gauges are found to be necessary to construct average intensity for a typical climate model grid, which is much higher than the gauge number required for average precipitation amount. Finally, the fractional area receiving rainfall is found to have a fairly linear relation with the precipitation amount averaged over the grid, but the slope differs between the gauge and radar data.
Electrical structure beneath the northern MELT line on the East Pacific Rise at 15°45′S
Authors: Baba Kiyoshi , Tarits Pascal , Chave Alan D. , Evans Rob L. , Hirth Greg , Mackie Randall L.
Published: November 2006

The electrical structure of the upper mantle beneath the East Pacific Rise (EPR) at 15°45′S is imaged by inverting seafloor magnetotelluric data obtained during the Mantle ELectromagnetic and Tomography (MELT) experiment. The electrical conductivity model shows no evidence for a conductive region immediately beneath the ridge, in contrast to the model previously obtained beneath the EPR at 17°S. This observation can be explained by differences in current melt production along the ridge, consistent with other observations. The mantle to the east of the ridge at 60 –100 km depth is anisotropic, with higher conductivity in the spreading direction compared to the along‐strike direction, similar to the 17°S region. The high conductivity in the spreading direction can be explained by a hydrated mantle with strain‐induced lattice preferred orientation of olivine or by partial melt preferentially connected in the spreading direction.
Seismic anisotropy of the upper crust in southeastern Poland—effect of the compressional deformation at the EEC margin: Results of CELEBRATION 2000 seismic data inversion
Authors: Środa P.
Published: November 2006

Analysis of the data from CELEBRATION 2000 experiment in southeastern Poland revealed azimuthal variation of the Vp velocity, unlikely to be caused by crustal inhomogeneity. This is explained by upper crustal seismic anisotropy and was analysed by the anisotropic delay‐time inversion. The result, indicating 8–10% anisotropy, fits to the geology of the area, where tightly folded metapelitic rocks are abundant. The fast velocity axis direction of 115° (WNW‐ESE) coincides well with the azimuths of outcropping folds axes and other deformational structures. In order to assess the credibility of the result, synthetic tests have been performed. The traveltimes calculated for isotropic models were inverted, to check if an artificial anisotropy will be generated. The tests indicate that realistic isotropic velocity inhomogeneities can only account for a fraction of observed traveltime variations, and that the anisotropy cannot be an artifact resulting from the inhomogeneous crust.
Neutral density response to the solar flares of October and November, 2003
Authors: Sutton E. K. , Forbes J. M. , Nerem R. S. , Woods T. N.
Published: November 2006

In this paper we report the first measurements of the thermosphere neutral density response to a solar EUV flare. Two X17 flares are considered: The first on 28 October, 2003, and the second on 4 November, 2003. The density measurements are provided by accelerometers on the GRACE and CHAMP satellites near 490 km and 400 km, respectively. X‐ray fluxes are provided by GOES‐12, and EUV fluxes by the SEE instrument on TIMED. The thermosphere density increases associated with the first flare are about 50–60% at low to mid‐latitudes. The time to peak response is 72 ± 47 minutes with respect to the peak EUV flux emitted by the flare, while the recovery to prior quiescent levels takes nearly 12 hours with an approximate decay time constant of 8 hours. The response to the second flare is about 35–45% with similar response and recovery times. The above density enhancements correspond to exosphere temperature increases of about 125–175 K and 100–125 K, respectively. These results provide new opportunities for the testing and validation of models over time scales similar to those of basic mechanisms governing the thermosphere response, such as thermal conduction, radiative cooling, and restoration of diffusive equilibrium.
Association of substorm chorus events with drift echoes
Authors: Abel G. A. , Freeman M. P. , Smith A. J. , Reeves G. D.
Published: November 2006

Over recent years, substorm chorus events (SCEs) have been proposed as a useful indicator of substorm onset. The events are regularly seen in the data from the VELOX (VLF/ELF Logger Experiment) instrument at Halley, Antarctica, which has provided over a decade of near continuous observations. SCEs are generally thought to be excited by the injection of electrons near midnight as they gradient‐curvature drift toward dawn. On close one‐to‐one inspection of SCEs seen at Halley and energetic electron signatures seen with the LANL geostationary spacecraft, we have found that many events are associated with the drift echo of the injected electrons rather than the initial injection. In this paper we present some example events as well as the relative statistics. We find that approximately 1/4 of SCEs where a clear signature can be seen in the LANL data are associated with drift echoes rather than the initial substorm injection. We argue that rather than being a direct signature of substorm onset, SCEs are a signature of enhanced electron fluxes in the chorus generation region, which are often, but not exclusively, associated with substorm injections.
Comparison of kinetic theory predictions with experimental results for a vibrated three-dimensional granular bed
Authors: Viswanathan H. , Wildman R. D. , Huntley J. M. , Martin T. W.
Published: November 2006

The three-dimensional conservation equations relating energy and momentum transfer in a vibrated three-dimensional granular bed have been solved numerically by the finite element method. Two closures based on granular kinetic theory were used: one, the standard Fourier law relating heat flux to temperature gradient and the other, including an additional concentration gradient term. Each prediction of the two-dimensional axisymmetric granular temperature and packing fraction fields was compared against a one-dimensional model and three-dimensional experimental results, acquired using the technique of positron emission particle tracking. Both closures resulted in solutions that were in reasonable agreement with the experimental results, but it was found that differences between the predictions of each of the closures were relatively small in comparison to the anisotropy of the experimentally determined temperature distribution.