bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of barley FA hydroperoxide lyase are modulated by salts and detergents
Authors: Koeduka Takao , Stumpe Michael , Kajiwara Tadahiko , Feussner Ivo 
Published: November 2006

AbstractThe cDNA from barley coding FA hydroperoxide lyase (HPL) was cloned. A recombinant protein derived from the cDNA was expressed in Escherichia coli as an active enzyme. Thus far, there have been no reports on HPL in monocotyledonous plants. The recombinant protein was shown to be most active to linolenic acid 13‐hydroperoxide, followed by linoleic acid 13‐hydroperoxide. 9‐Hydroperoxides of the FA could not be substrates for the recombinant HPL. The activity was dramatically enhanced in the presence of a detergent and/or a salt in the reaction mixture. At the same time, the kinetics of the reaction, including inactivation and the Vmax value of the HPL, were also greatly modulated, depending on the concentration of a monovalent cation and/or a detergent in the reaction mixture. These results suggest that these effectors induced a conformational change in barley HPL, resulting in an improvement in substrate binding and in enzyme activity.
Programming of initial steps in bile acid synthesis by breat‐feeding vs. Formula‐feeding in the baboon
Authors: Mott Glen E. , Jackson Evelyn M. , Klein Marissa L. , Shan Hui , Pang Jihai , Wilson William K. , McMahan C. Alex 
Published: November 2006

AbstractWe tested the hypothesis that breast‐vs. formula‐feeding differentially affects the enzymatic activity of three sterol hydroxylases critical in the initial steps of bile acid formation. Thirty baboons were either breast‐fed or formula‐fed for the first 14 wk of life before weaning to baboon chow. At 14 and 34 wk of age, liver biopsies were assayed for cholesterol 7α‐hydroxylase (CYP7A1), 27‐hydroxycholesterol‐7α‐hydroxylase (CYP7B1), and cholesterol 27‐hydroxylase (CYP27A1). We also determined the kinetics of 3H‐27‐hydroxycholesterol (27‐OHC) turnover in vivo at both ages. At 14 wk of age, hepatic CYP7A1 activity was low but sevenfold higher among formula‐fed vs. breast‐fed baboons. By 34 wk, CYP7A1 activity had increased nearly 10‐fold in both infant diet groups, and the sevenfold difference in CYP7A1 between previously breast‐and formula‐fed animals persisted. There were no differences in CYP7B1 activities between infant diet groups at either 14 or 34 wk of age although the activity increased in both groups by about 50% from 14 to 34 wk. CYP27A1 activity also increased between 14 and 34 wk of age, and, compared with CYP7A1, relatively small differences in CYP27A1 activity due to infant diet were observed at each age. Plasma 27‐OHC turnover had a half‐time of 2–4 min. We had previously reported that after weaning, the total bile acid synthesis rate was higher among baboons that were formula‐fed than among breast‐fed animals. The present results suggest that this difference is most likely due to significantly higher CYP7A1 activity among formula‐fed vs. breast‐fed animals.
Comparative health effects of margarines fortified with plant sterols and stanols on a rat model for hemorrhagic stroke
Authors: Ratnayake W. M. N. , Plouffe L. , L'Abbé M. R. , Trick K. , Mueller R. , Hayward S. 
Published: November 2006

AbstractThere is increased acceptance of fortifying habitual foods with plant sterols and their saturated derivatives, stanols, at levels that are considered safe. These sterols and stanols are recognized as potentially effective dietary components for lowering plasma total and LDL cholesterol. Our previous studies have shown that daily consumption of plant sterols promotes strokes and shortens the life span of stroke‐prone spontaneously hypertensive (SHRSP) rats. These studies question the safety of plant sterol additives. The present study was performed to determine whether a large intake of plant stanols would cause nutritional effects similar to those seen with plant sterols in SHRSP rats. Young SHRSP rats (aged 26–29 d) were fed semipurified diets containing commercial margarines fortified with either plant stanols (1.1 g/100 g diet) or plant sterols (1.4 g/100 g diet). A reference group of SHRSP rats was fed a soybean oil diet (0.02 g plant sterols/100 g diet and no plant stanols). Compared to soybean oil, both plant stanol and plant sterol margarines significantly (P<0.05) reduced the life span of SHRSP rats. At the initial stages of feeding, there was no difference in the survival rates between the two margarine groups, but after approximately 50 d of feeding, the plant stanol group had a slightly, but significantly (P<0.05), lower survival rate. Blood and tissue (plasma, red blood cells, liver, and kidney) concentrations of plant sterols in the plant sterol margarine group were three to four times higher than the corresponding tissue concentrations of plant stanols in the plant stanol group. The deformability of red blood cells and the platelet count of SHRSP rats fed, the plant sterol margarine were significantly (P<0.05) lower than those of the plant stanol margarine and soybean oil groups at the end of the study. These parameters did not differ between the soybean oil and plant stanol margarine groups. These results suggest that, at the levels tested in the present study, plant stanols provoke hemorrhagic stroke in SHRSP rats to a slightly greater extent than plant sterols. The results also suggest that the mechanism by which plant stanols shorten the life span of SHRSP rat might differ from that of plant sterols.
Maternal dietary FA modulate the long‐chain n−3 PUFA status of chick cardiac tissue
Authors: Ajuyah A. O. , Cherian G. , Wang Y. , Sunwoo H. , Sim J. S. 
Published: November 2006

AbstractThe effect that egg yolk or maternal n−3 FA have on the cardiac tissue long‐chain n−3 FA status of chicks during growth was investigated. Fggs with low, medium, and high levels of n−3 PUFA were obtained by feeding breeder hens a wheat/soybean meal‐based diet containing 5% sunflower oil (Low n−3), 2.5% sunflower oil plus 2.5% fish oil (Medium n−3), or 5% fish oil (High n−3). The chicks hatched from Low, Medium, and High n−3 eggs were fed a diet containing 18∶3n−3, but devoid of long‐chain n−3 FA. The FA composition of cardiac tissue was determined on days 0, 14, 28, and 42. At day 0, the cardiac FA reflected maternal diet. With time, the level of all the long‐chain n−3 FA decreased compared with day 0, and this was true especially by day 14. These data show that dietary 18∶3n−3 fed to the chicks did not sustain high levels of EPA and DHA in cardiac tissue, despite the high content of long‐chain n−3 FA in the maternal diet. At days 0 and 14, the chicks hatched from High and Medium n−3 eggs had higher 20∶5n−3, 22∶5n−3, and 22∶6n−3 contents with a concomitant reduction in 20∶4n−6 in the cardiac tissue compared with the Low n−3 egg group. Cardiac tissue of birds hatched from Medium n−3 eggs retained higher levels of 20∶5n−3 up to day 42 of growth when compared with other treatments (P<0.05). None of the treatments was effective in maintaining DHA levels after day 14 of growth.
Linoleate diol synthase of the rice blast fungus Magnaporthe grisea
Authors: Cristea Mirela , Osbourn Anne E. , Oliw Ernst H. 
Published: November 2006

AbstractMycelia of two strains of Magnaporthe grisea, Guy 11 and TH3, were incubated with linoleic acid, and the metabolites were isolated and identified by GC‐MS and LC‐MS. The two main metabolites were identified as 8‐hydroxylinoleic and 7,8‐dihydroxylinoleic acids, and the former was further oxidized by n−2 and by n−3 hydroxylation to 8,16‐ and 8,17‐dihydroxylinoleic acids. Lipoxygenase metabolites of linoleic acid could not be detected. The sequence of the genome of M. grisea has been released from the Whitehead Institute; it contains a gene with close homology to the linoleate diol synthase gene of the take‐all fungus Gaeumannomyces graminis. Both genes appear to have the same organization, with four exons and three short introns, and the intron‐exon borders were determined by reverse‐transcription PCR and sequencing. The linoleate diol synthase precursor of G. graminis consists of 978 amino acids, whereas the putative diol synthase precursor of M. grisea contains 987 amino acids. The diol synthases of G. graminis and M. grisea can be aligned with 65% identical and 78% positive amino acid residues, and catalytically important amino acid residues were conserved.
Synthesis of novel tri‐ and tetrasubstituted C18 furan fatty esters
Authors: Lie Ken Jie Marcel S. F. , Lau Maureen M. L. , Lam Corey N. W. 
Published: November 2006

AbstractA methylene‐interrupted C18 keto‐acetylenic fatty ester (methyl 12‐oxo‐9‐octadecynoate) was obtained from methyl ricinoleate by bromination‐dehydrobromination followed by oxidation. Reaction of methyl 12‐oxo‐9‐octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl‐allyl bromide furnished methyl 8‐[5‐hexyl‐3‐allyl‐furan‐2‐yl]‐octanoate (1, 56%) or methyl 8‐[5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl]‐octanoate (2, 55%). Reaction of methyl 12‐oxo‐11‐chloro‐or 11‐fluoro‐9‐octadeyynoate (prepared from methyl santalbate‐methyl 11‐E‐9‐octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8‐(4‐fluoro‐5‐hexyl‐furan‐2‐yl)‐octanoate (3, 50%) or methyl 8‐(4‐fluoro‐5‐hexyl‐furan‐2‐yl)‐octanoate (4, 50%), respectively. And when methyl 12‐oxo‐11‐chloro‐ or 11‐fluoro‐9‐octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl‐allyl bromide, the reaction yielded tetrasubstituted C18 furan derivatives, viz, methyl 8‐(3‐allyl‐4‐chloro‐5‐hexyl‐furan‐2‐yl)‐octanoate (5, 54%), methyl 8‐[4‐chloro‐5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl)‐octanoate (6, 54%), methyl 8‐(3‐allyl‐4‐fluoro‐5‐hexyl‐furan‐2‐yl]‐octanoate (7, 10%), and methyl 8‐[4‐fluoro‐5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl]‐octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the 13C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.
Purification and characterization of an extracellular lipase from Geotrichum marinum
Authors: Huang Youliang , Locy Robert , Weete John D. 
Published: November 2006

AbstractAn extracellular lipase (EC 3.1.1.3) from Geotrichum marimum was purified 76‐fold with 46% recovery using Octyl Sepharose 4 Fast Flow and Bio‐Gel A 1.5 m chromatography. The purified enzyme showed a prominent band on SDS‐PAGE and a single band on native PAGE based on the activity staining. The molecular mass of the lipase was estimated to be 62 kDa using SDSPAGE and Bio‐Gel A chromatography, indicating that the lipase likely functions as a monomer. The pl of the lipase was determined to be 4.54. The apparent Vmax and Km were 1000 μmol/min/mg protein and 11.5 mM, respectively, using olive oil emulsified with taurocholic acid as substrate. The lipase demonstrated a pH optimum at pH 8.0 and a temperature optimum at 40°C. At 6 mM, Na+, K+, Ca2+, and Mg2+ stimulated activity, but Na+, and K+ at 500 mM and Fe2+ and Mn2+ at 6 mM reduced lipase activity. The anionic surfactant, taurocholic acid, and the zwitterionic surfactant, 3‐[(3‐cholamidopropyl)dimethylammonio]‐1‐propanesulfonate, enhanced the activity at 0.1 mM. Other anionic surfactants such as SDS and sodium dioctyl sulfosuccinate, the cationic surfactants methylbenzethonium bromide and cetyltriethylammonium bromide, and the nonionic surfactants Tween‐20 and Triton X‐100 inhibited the lipase activity to different extents. The lipase was found to have a preference for TG containing cis double bonds in their FA side chains, and the reaction rate increased with an increasing number of double bonds in the side chain. The lipase had a preference for ester bonds at the sn‐1 and sn‐3 positions over the ester bond at the sn‐2 position.
Regulation of diacylglycerol acyltransferase in developing seeds of castor
Authors: He Xiaohua , Chen Grace Q. , Lin Jiann‐Tsyh , McKeon Thomas A. 
Published: November 2006

AbstractWe have previously reported the cloning of castor diacylglycerol acyltransferase (RcDGAT) based on its homology to other plant type 1 diacylglycerol acyltransferases (DGATs). To elucidate the physiological role of the RcDGAT, we have investigated the regulation of RcDGAT expression in developing seeds of castor. The RcDGAT transcript appeared at 12 d after pollination (DAP), reached the highest level at 26 DAP, and declined rapidly after that. However, the RcDGAT protein started to accumulate at 26 DAP, reached its peak at 47 DAP, then remained at this high level until 54 DAP. The significant difference between the expression of mRNA and protein indicates that gene expression of RcDGAT in maturing castor seeds is controlled at the posttranscriptional level. We found that DGAT activity measured in microsomal membranes isolated from seed at different stages of development was parallel to RcDGAT protein level, suggesting DGAT activity is mainly a function of the level of RcDGAT protein. We monitored the triacylglycerol (TG) composition and content during seed development. Compared with the overall rate of TG accumulation, DGAT activity appeared coincidently with the onset of lipid accumulation at 26 DAP; the highest DGAT activity occurred during the rapid phase of lipid accumulation at 40 DAP; and a decline in DGAT activity coincided with a decline in the accumulation rate of TG after 40 DAP. The ricinoleate‐containing TG content was very low (only about 7%) in oil extracted from seeds before 19 DAP; however it increased up to about 77% of the oil at 26 DAP. The relative amount of triricinolein in oil at 26 DAP was 53 times higher than that at 19 DAP, and it was about 76% of the amount present in oil from mature castor seeds. The close correlation between profiles of RcDGAT activity and oil accumulation confirms the role of RcDGAT in castor oil biosynthesis.
Biomimetic oxidation of unactivated carbons in steroids by a model of cytochrome P‐450, oxorutheniumporphyrinate complex
Authors: Iida Takashi , Ogawa Shoujiro , Miyata Shouhei , Goto Takaaki , Mano Nariyasu , Goto Junichi , Nambara Toshio 
Published: November 2006

AbstractBiomimetic oxidation of unactivated carbons for structurally different steroids was studied with a model of cytochrome P‐450, oxorutheniumporphyrinate complex, which is generatedin situby 2,6‐dichloropyridineN‐oxide as an oxygen donor and (5,10,15,20‐tetramesitylporphyrinate) ruthenium(II) carbonyl complex and HBr as catalysts. The O‐insertion positions depended significantly on specific structural features of the substrates to give novel and remote‐oxygenated steroids in one step. The electrophilic oxorutheniumporphyrinate attacked predominantly allylic and benzylic β‐carbons adjacent to a π‐bond and/or less hindered, electron‐richtert‐methine carbons in the substrates to give regio‐ and stereoselectively the corresponding oxo and/or hydroxy derivatives.
Interaction between ferric ions, phospholipid hydroperoxides, and the lipid phosphate moiety at physiological pH
Authors: Morrill Gene A. , Kostellow Adele , Resnick Lawrence M. , Gupta Raj K. 
Published: November 2006

AbstractIron‐catalyzed lipid peroxidation was examined using 1H NMR in a biphasic aqueous‐chloroform system. At physiological pH (7.4), mole ratios of phospholipids/Fe3+ as low as 1300∶1 catalyzed the rapid disappearance of endogenous lipid hydroperoxides with a loss of two of the four double bonds in PC containing palmitic (16∶0) and arachidonic (20∶4) acids in the sn‐1 and sn‐2 positions, respectively. The predominant phospholipid products after 1 h at 20°C were a 9‐carbon monounsaturated carbonyl and a phospholipid with an 11‐carbon Δ5,8 FA in the sn‐2 position. PC with linoleic acid (18∶2) in the sn‐2 position lost one double bond and formed a phospholipid with a 9‐carbon FA. Cardiolipin (linoleic acid‐rich) also lost about 40% of its double bonds. No detectable loss was seen for PC containing oleic acid (18∶1) or neutral lipids with PUFA. At arachidonyl PC/Fe3+ ratios less than 20∶1, significant broadening of the choline methyl proton peak was evident, indicating that Fe3+ may form a complex with the adjacent phosphate group and that the complex involves both the phosphate and the hydroperoxide adjacent to the Δ11 double bond. The results demonstrate that, at physiological pH, Fe3+‐catalyzed peroxidation in polyunsaturated phospholipids occurs selectively adjacent to specific double bonds (Δ9 or Δ11). These PC‐derived products have been shown to activate components of the inflammatory system. This suggests that the episodic release of ferric ions may play a significant role in generating inflammatory mediators.
Phosphatidylcholine hydroperoxide levels in human plasma are lower than previously reported
Authors: Adachi Junko , Yoshioka Naoki , Funae Rika , Nagasaki Yasushi , Naito Takaeki , Ueno Yasuhiro 
Published: November 2006

AbstractThe quantification of PC hydroperoxide (PCOOH) in human plasma was studied by HPLC with chemiluminescence detection (HPLC‐CL). We identified for the first time the monohydroperoxide of 1‐palmitoyl‐2‐linoleoyl‐PC hydroperoxide (PC 16∶0/18∶2‐OOH) in plasma by LC‐MS and HPLC‐CL. The standard compound, PC 16∶0/18∶2‐OOH (synthetic PCOOH), as well as PCOOH from egg yolk, was used. Comparison of the PCOOH concentration in each participant's plasma as determined by use of a Finepak SIL NH2 column with 2‐propanol/methanol/water as the mobile phase (system A, the conventional method) gave a higher concentration than did an LC‐18‐DB column with methanol containing 0.01% triethylamine (system B). The mean PCOOH concentration for the 43 healthy volunteers was 55.1±30.4 pmol/mL (mean±SD) for system A and 16.3±9.9 pmol/mL for system B. Moreover, the main peak of the plasma extract appeared at a different time from that of synthetic PCOOH or egg yolk PCOOH in system A, whereas in system B plasma sample retention time practically corresponded to that of standard PCOOH. These findings confirm that the PCOOH plasma concentration is not so high as previously reported.
Umbelliferone aminoalkyl derivatives as inhibitors of oxidosqualene cyclases from Saccharomyces cerevisiae, Tripanosoma cruzi, and Pneumocystis carinii
Authors: Oliaro‐Bosso Simonetta , Viola Franca , Matsuda Seiichi , Cravotto Giancarlo , Tagliapietra Silvia , Balliano Gianni 
Published: November 2006

AbstractA series of umbelliferone aminoalkyl derivatives, previously studied as inhibitors of squalene‐hopene cyclase, were tested as inhibitors of yeast (Saccharomyces cerevisiae) oxidosqualene cyclase (OSC) and OSC from Trypanosoma cruzi and Pneumocystis carinii expressed in yeast. Enzymes from these pathogens were included in this study to provide a preliminary screening for antiparasitic activity. Tests were carried out both on cell homogenates incubated with radiolabeled oxidosqualene and on spheroplasts incubated with radiolabeled acetate. Derivatives bearing a methylallylamino group were the most effective on all of the three enzymes. The P. carinii enzyme was the most susceptible to the action of the inhibitors, with IC50 values for almost all of them ranging from 0.1 to 1μM. The T. cruzi enzyme was appreciably inhibited (IC50 4–5 μM) only by derivatives bearing a methylallylaminoalkyl flexible chain. Results identify a particularly promising new family of OSC inhibitors, for the development of novel antiparasitic agents.
A new glucoceramide from the watermelon begonia, Pellionia repens
Authors: Luo Yinggang , Liu Yan , Qi Huayi , Zhang Guolin 
Published: November 2006

AbstractA new glucoceramide named pellioniareside (1) was isolated from the aqueous ethanolic extract of whole plants of Pellionia repens, together with lupeol (2), uracil (3), (22E,20S,24R)‐5α,8α‐epidioxyergosta‐6,22‐dien‐3‐β‐ol (4), and daucosterol (5). The structure and relative configurations of pellioniareside were identified as (2S,3S,4R,6E,8E)‐1‐O‐β‐d‐glucopyranosyl‐2‐[(2R)‐2‐hydroxytetracosanoylamino]‐1,3,4‐octadecanetriol‐6,8‐diene by analysis of spectral data and by chemical evidence.
Immunomodulation by polyunsaturated fatty acids: Impact on T‐cell signaling
Authors: Stulnig Thomas M. , Zeyda Maximilian 
Published: November 2006

AbstractIn recent years the potential application of the immunomodulatory effects of polyunsaturated FA (PUFA), particularly those of the n−3 series, in a variety of inflammatory disorders has been of considerable interest. However, the mechanisms underlying inhibition of T‐cell activation have so far been unclear. In this short review we summarize possible mechanisms for the modulation of immune responses by PUFA. Effects of PUFA on T‐cell signal transduction pathways and underlying molecular mechanisms are described in detail. These recent results add considerably to the understanding of mechanisms of PUFA actions, but their relevance in the in vivo situation must still be elucidated.
Myringoplasty: a comparison of bismuth iodoform paraffin paste gauze pack and tri-adcortyl ointment ear dressing
Authors: Nakhla V , Takwoingi Y M , Sinha A 
Published: November 2006

Objectives: To assess the myringoplasty graft take rate, comparing two methods of post-operative ear packing: bismuth iodoform paraffin paste (BIPP) gauze versus tri-adcortyl ointment (TAO).Methods: A retrospective study of patients who had undergone myringoplasty at our department within a three-year period was undertaken. Data, including age, site and size of perforation, grade of surgeon, surgical approach, use of post-operative ear dressings, complications, and audiometric outcome, were collected from the patient notes and analysed. The overall success rate of the operation (with success being defined as an intact tympanic membrane at six months) was noted.Results: One hundred and seventy myringoplasties were performed over the study period, but data were complete on 154 patients and these constituted the study population. Age ranged from nine to 71 years (mean age 34 years) and the mean follow-up period was seven months. Consultants performed 62 per cent of the operations, with an 85 per cent success rate, whereas trainees performed the remaining 38 per cent, with a success rate of 73 per cent (p=0.059). The overall success rate was 80 per cent; 79 per cent for BIPP and 83 per cent for TAO (p=0.55), and 87 per cent for small perforations and 75 per cent for subtotal perforations (p=0.22). There was audiometric improvement in 74 per cent of cases.Conclusion: We found no significant difference in outcome between patients packed with TAO and BIPP. Packing with TAO is therefore a suitable alternative to BIPP gauze ear dressing following myringoplasty.
Effects of Composition, Solvent, and Salt Particles on the Physicochemical Properties of Polyglycolide/Poly(lactide‐co‐glycolide) Scaffolds
Authors: Kuo Yung‐Chih , Leou Sho‐Noen 
Published: November 2006

AbstractPolyglycolide (PGA)/poly(lactide‐co‐glycolide) (PLGA) scaffolds were fabricated by a solvent casting/particulate leaching method using hexafluoroisopropanol (HFIP) or acetone for material dissolution and NaCl particles as porogen. The results revealed that the mechanical strength increased as the PGA percentage in a HFIP‐processed scaffold increased. Chemical ingredients did not substantially affect the mechanical strength of acetone‐processed scaffolds. Large NaCl particles led to weak mechanical strength, low porosity, and small specific surface area. For a fixed composition, PGA crystals in a HFIP‐processed scaffold were smaller than those in an acetone‐processed scaffold. High PGA fractions yielded partly fused PGA/PLGA scaffolds. A faster degradation rate of a scaffold could result from a higher PGA percentage, smaller NaCl particles, or the existence of chondrocytes. The combination of PGA and PLGA, which compensated each other for bioactivity, would be beneficial to cartilage regeneration.