bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of low casein and fish oil on hyperlipidemia and proteinuria in nephritic rats
Authors: Fujisawa Kiyohito , Yagasaki Kazumi , Funabiki Ryuhei 
Published: November 2006

AbstractThe effects of amino acid‐fortified low casein and fish oil (FO) diets on hyperlipidemia and proteinuria were studied in rats with nephrotoxic serum nephritis. After an antiserum injection, rats were maintained for 14 d on four different experimental diets: a 20% casein diet containing corn oil (CO) or FO, or an 8% casein diet supplemented with cystine plus threonine containing CO or FO. The 8% casein diets reduced urinary protein excretion in nephritic rats without inducing severe growth retardation or fatty liver compared with the basal 20% casein diets. Both the 8% casein diet and the FO diet decreased serum cholesterol, triglyceride and phospholipid levels in nephritic rats, and nonesterified fatty acid levels were decreased by FO feeding. In nephritic animals, hepatic cholesterol synthesis was decreased by the 8% casein diets compared with the 20% casein diets, and tended to be reduced by FO feeding between groups at the same casein levels. No effect of diet was observed on fatty acid synthesis among the nephritic rats. FO administration to the nephritic animals suppressed fecal steroid excretion. While lipoprotein lipase activity was unchanged among the nephritic rats, hepatic triglyceride lipase activity was reduced by either the 8% casein or FO diet. The results suggest that the hypolipidemic action of low casein diets may, at least in part, be due to reduced hepatic cholesterol synthesis and suppressed triglyceride secretion from the liver. They also suggest that the hypolipidemic action of FO may, at least in part, be due to reduced hepatic cholesterol synthesis and decreased fatty acid mobilization from peripheral adipose tissue.
Structural and functional role of lipids in yeast and mycelial forms ofCandida albicans
Authors: Goyal Sawraj , Khuller G. K. 
Published: November 2006

AbstractThe levels of total lipids, sterols and phospholipids were found to be significantly higher in the mycelial form (log phase) ofCandida albicans than in the yeast form. Increased phospholipid levels in the mycelial form were due to higher levels of phosphatidylcholine, phosphatidylserine and phosphatidylinositol. Analyses of fatty acid composition also revealed higher levels of myristic acid (40%) in the yeast form, resulting in higher levels of saturated lipids than in the mycelial form. The changes in the lipid composition were also manifested in altered thermotropic phase behavior as gel‐to‐liquid crystalline phase transitions were observed at 36 and 27°C for the lipids of the yeast and mycelial forms, respectively. These changes coincided with higher uptake rate, i.e., Km and Vmax values, for the transport of L‐proline and with a higher sensitivity of the mycelial form against antifungal drugs.
Kinetic study of quenching reactions of singlet oxygen and scavenging reactions of free radicals by α‐, β‐, λ‐ and σ‐tocopheramines in ethanol solution and micellar dispersion
Authors: Itoh Shingo , Nagaoka Shin‐ichi , Mukai Kazuo , Ikesu Satoru , Kaneko Yutaka 
Published: November 2006

AbstractQuenching reactions of singlet oxygen and scavenging reactions of free radicals by α‐, β‐, λ‐ and σ‐tocopheramines (Toc‐amines) were investigated spectrophotometrically in ethanol and Triton X‐100 micellar dispersions. The rate constants of quenching of singlet oxygen (kQ) by α‐, β‐, λ‐ and σ‐Toc‐amines increased as the total electron donating capacity of the methyl groups at the aromatic ring increased. A plot of logkQ vs. peak oxidation potential (Ep) was found to be linear and the slope was negative. Similar results were obtained for scavenging of a phenoxyl radical (PhO.). The results suggest that charge transfer plays an important role in these reactions. ThekQ values were found to be 1.30–2.57 times as large askQ for α‐tocopherol (α‐Toc). Although α‐Toc has the highest antioxidant activity among natural tocopherols and related phenols, Toc‐amines also can serve as antioxidants.
The reaction of low levels of nitrogen dioxide with methyl linoleate in the presence and absence of oxygen
Authors: Gallon Aris A. , Pryor William A. 
Published: November 2006

AbstractThe reaction of methyl linoleate with low levels of nitrogen dioxide in a carrier gas, such as helium or air, at nitrogen dioxide concentrations ranging from 2 to 228 ppm was studied and the products formed were monitored. In both aerobic and anaerobic conditions, low concentrations of nitrogen dioxide reacted with methyl linoleate predominately to form allylic products. When a 1∶1 mixture of methyl palmitate/methyl linoleate was layered over an aqueous buffer and a nitrogen dioxide stream was passed from underneath, so that the stream passed through the aqueous layer before contacting the organic layer, allylic products again predominated. In the absence of air, the allylic products consisted of allylic nitro and nitrite derivatives of linoleate, whereas in the presence of air, allylic hydroperoxides were the principal products. The findings suggest that fatty acids with doubly allylic hydrogen atoms react preferentially by a hydrogen atom abstraction reaction rather than by the addition of nitrogen dioxide to a double bond.
A31P nuclear magnetic resonance investigation of acyl group transfer from phosphatidylcholine to yield lysophosphatidylcholine in human plasma
Authors: Nouri‐Sorkhabi M. Hossein , Sullivan David R. , Roberts David C. , Kuchel Philip W. 
Published: November 2006

Abstract31P nuclear magnetic resonance (NMR) spectroscopy was used to measure the rate of acyl transfer from phosphatidylcholine (lecithin, PC) in whole plasma and in high density lipoprotein (HDL). Spectral deconvolution was used to resolve overlapping resonances in the31P NMR spectra of the phospholipids. Mean values of the acyl group transfer rates from PC in plasma and HDL were 36 μmol L−1h−1 and 19 μmol L−1h−1, respectively. The reciprocal nature of the decrease in the spectral peak intensities of PC, compared to the increase in the intensities of the lysolecithin (lysoPC) peaks, suggested a substrate/product relationship consistent with the action of lecithin:cholesterol acyltransferase (LCAT), the enzyme responsible for the esterification of free cholesterol in plasma. LCAT involvement was confirmed by measuring the cholesterol esterification rate based on the13C NMR spectra obtained on lipid extracts from plasma that had been incubated at 37°C. Within experimental error, the rate of lysoPC formation in plasma was shown to be equal to that of cholesteryl ester formation.
Garlic reduces plasma lipids by inhibiting hepatic cholesterol and triacylglycerol synthesis
Authors: Yeh Yu‐Yan , Yeh Shaw‐Mei 
Published: November 2006

AbstractPrompted by the reported hypolipidemic activity of garlic, the present study was undertaken to elucidate the mechanism(s) underlying the cholesterol‐lowering effects of garlic. Rat hepatocytes in primary culture were used to determine the short‐term effects of garlic preparations on [1‐14C]acetate and [2‐3H]glycerol incorporation into cholesterol, fatty acids and glycerol lipids. When compared with the control group, cells treated with a high concentration of garlic extracts [i.e., petroleum ether‐ (PEF), methanol‐ (MEF) and water‐extractable (WEF) fractions from fresh garlic] showed decreased rates of [1‐14C]acetate incorporation into cholesterol (by 37–64%) and into fatty acids (by 28–64%). Kyolic containingS‐allyl cysteine and organosulfur compounds inhibited cholesterogenesis in a concentration dependent manner with a maximum inhibition of 87% at 0.4 mM. At this concentration, Kyolic decreased [1‐14C]acetate incorporation into fatty acids by 67%.S‐allyl cysteine at 2.0 and 4.0 mM inhibited cholesterogenesis by 20–25%. PEF, MEF and WEF depressed the rates of [2‐3H]glycerol incorporation into triacylglycerol, diacylglycerol and phospholipids in the presence of acetate, but not in the presence of oleate. The results suggest that the hypocholesterolemic effect of garlic stems, in part, from decreased hepatic cholesterogenesis, whereas the triacylglycerol‐lowering effect appears to be due to inhibition of fatty acid synthesis. Primary hepatocyte cultures as used in the present study have been proven useful as tools for screening the anticholesterogenic properties of garlic principles.
Effect of fish oil on cancer cachexia and host liver metabolism in rats with prostate tumors
Authors: Dagnelie Pieter C. , Bell Jimmy D. , Williams Steve C. R. , Bates Timothy E. , Abel Paul D. , Foster Christopher S. 
Published: November 2006

AbstractThe aim of this study was to investigate whether tumor‐induced cachexia and aberrations in host liver metabolism, induced by the MAT‐LyLu variant of the Dunning prostate tumor, could be prevented by ω3 fatty acids from fish oil. On day 0, adult Copenhagen‐Fisher rats fed normal chowad libitum were inoculated with 106 MAT‐LyLu cells (n=14) or saline (n=9). On day 7, when tumors were palpable, four tumor‐bearing (TB) and four nontumorbearing (NTB) rats were put on isocaloric diets with 50% of total energy as fish oil. The introduction of fish oil‐enriched diets caused a reduction in energy intake to less than half of the energy intake by animals fed normal diets during days 7–14 (difference by dietary group: NTB,P<0.001; TB,P<0.001). During days 14–21, energy intake in fish oil‐fed animals returned to approximately 75% of energy intake by animals fed normal diets (difference by dietary group: NTB,P<0.003; TB,P=0.001). Carcass weight of animals on day 21, when the study was terminated, was significantly related to initial weight (P=0.05) and mean food intake during the study (P=0.01). When data were adjusted for these variables using analysis of covariance, with NTB animals on normal diets being the reference group, significant loss of carcass weight was observed in TB animals on normal diets only (mean ±SEM 58±10 g loss,P<0.001), but not in TB animals on fish oil diets (8±18 g loss,P=0.67). This positive effect of fish oil diets on carcass weight in TB animals was statistically significant (50±19 g,P<0.02), implicating that the fish oil enriched diet inhibited tumor‐induced weight loss by more than 85%. No effect of fish oil diets on tumor growth was detected. In all TB animals, regardless of diet, hepatic [Pi]/adenosine triphosphate] ratios measured by31P magnetic resonance spectroscopy (MRS)in vivo andin vitro were elevated, and absolute concentrations of phosphocholine, glycerophosphocho‐line, glycerophosphoethanolamine and glucose‐6‐phosphate as determined by31P MRSin vitro were reduced. Ultrastructural studies of liver tissue revealed increased numbers of mitochondria and increased amounts of endoplasmic reticulum in the host liver of TB animals, without differences between dietary group. In conclusion, fish oil supplementation partially inhibited MAT‐LyLu tumor‐induced cachexia, but did not prevent the majority of31P MRS‐detectable alterations in host liver metabolism.
Synthesis ofE,E‐diene hydroperoxides via photoisomerization of protected hydroperoxides
Authors: Dussault P. H. , Lee I. Q. , Eary C. T. 
Published: November 2006

AbstractA general approach toE,E‐diene hydroperoxides is described based upon photoisomerization of readily availableZ,E‐diene monoperoxyketals. Protection of aZ,E‐diene hydroperoxide as the 2‐methoxypropyl peroxyketal is followed by iodine‐mediated photoisomerization to produce a mixture enriched in theE,E isomer. After chromatographic purification, deprotection of the peroxyketal with mild acid furnishes theE,E‐diene hydroperoxide.
Effect of peroxyl radicals on lecithin/cholesterol acyltransferase activity in human plasma
Authors: Chen Chen , Loo George 
Published: November 2006

AbstractThe objective of this study was to determine whether subjecting human plasma to oxidant stress reduces the activity of lecithin/cholesterol acyltransferase (LCAT, EC 2.3.1.43). Plasma was incubated for 4h with 2.25–45 mM of 2,2′‐azobis(2‐amidinopropane)HCl (AAPH), a source of peroxyl radicals. A time‐ and concentration‐dependent reduction of LCAT activity occurred, relative to control samples incubated in the absence of AAPH. Reduction of LCAT activity was disproportionate to elevation of thiobarbituric acid‐reactive substances (TBARS) in the plasma. Added ascorbate was able to significantly prevent reduction of LCAT activity, but this effect was unrelated to blockage of TBARS formation by the antioxidant. The results suggest that LCAT activity can be down‐modulated by oxidant stress, but not necessarily by lipid peroxidation.
Kinetic analysis of cardiolipin synthase: A membrane enzyme with two glycerophospholipid substrates
Authors: Schlame Michael , Zhao Ming , Rua Diego , Haldar Dipak , Greenberg Miriam L. 
Published: November 2006

AbstractMitochondrial cardiolipin synthase catalyzes the transfer of a phosphatidyl moiety from phosphatidyl‐CMP PtdCMP) to phosphatidylglycerol (PtdGro) in the presence of specific divalent cations. The synthase was solubilized fromSaccharomyces cerevisiae mitochondria and purified about 300‐fold. The partially purified enzyme was part of a medium‐size, mixed micelle which had to bind to a foreign substrate/detergent micelle before catalysis could occur. The kinetics of cardiolipin synthase were studied by changing the molar fraction of substrate in the micelles. The enzyme obeyed Michaelis‐Menten kinetics in relation to PtdCMP with aKm of 0.03 mol%. PtdGro caused sigmoidal kinetics with a low apparent affinity. it is speculated that it was involved in docking the enzyme to the substrate/detergent micelle. Cardiolipin synthase did not catalyze isotope exchange between [14C]CMP and PtdCMP, virtually excluding a ping‐pong catalytic mechanism. Mg2+stimulated the activity by increasing the turnover number rather than the substrate affinity, a mechanism which was also found for the Co2+‐activation of rat liver cardiolipin synthase. It is concluded that a direct association of the metal ion and the enzyme forms the active cardiolipin synthase which has a very high affinity for PtdCMP and a lower affinity for PtdGro.
Synergistic induction of phospholipid metabolism by granulocyte‐macrophage colony stimulating factor and steel factor in human growth factor‐dependent cell line, M07e
Authors: Mantel C. , Luo Z. , Broxmeyer H. E. 
Published: November 2006

AbstractSteel factor (SLF), the ligand for the c‐kit protooncogene tyrosine kinase receptor, synergizes with several hematopoietic growth factors to produce greatly enhanced proliferation of normal human hematopoietic progenitor cells as well as that of the human growth factor‐dependent myeloid cell line, M07e. The mechanisms of this phenomenon remain unknown. In an attempt to understand the cellular processes relevant to this phenomenon, we examined the effects of SLF and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) on induced lipid metabolism in M07e cells. We find that both GM‐CSF and SLF induced increased phosphatidylcholine (PC) turnover rates (biosynthesis and degradation) as measured by increased [3H]‐choline labelling, with SLF being more potent stimulation. The labelling of aqueous intermediates of PC metabolism was also increased by cytokine stimulation, most notably phosphocholine. Simultaneous stimulation with GM‐CSF plus SLF resulted in a true synergistic induction of PC, lysoPC, and phosphocholine labelling. GM‐CSF and SLF each induced asymmetric labelling of various phospholipid classes as measured by incorporation of different [3H]‐fatty acids. [3H]‐myristic acid labelling of phosphatidylserine was most prominently induced (approximately 12‐fold). Cytosolic choline kinase activity was also upregulated more than twofold over control by SLF, which might contribute to the increased phosphocholine labelling. These effects may have relevance to the intracellular mechanisms of the synergistic proliferative stimulation of SLF plus GM‐CSF on M07e cells.
Plasma fatty acids and lipids in two separate, but genetically comparable, icelandic populations
Authors: Skúladóttir Gudrún V. , Gudmundsdóttir Sigrún , Ólafsson Gunnlaugur B. , Sigurdsson Stefán B. , Sigfússon Nikulás , Axelsson Jóhann 
Published: November 2006

AbstractLevels of serum lipids and lipoproteins, and the fatty acid composition of plasma phospholipids, were measured in two genetically comparable, but widely separated, populations. The 1975 mortality rates for ischemic heart disease were significantly higher in one of these populations, the Manitoban residents of pure Icelandic descent, than in the other, a rural population from Northeastern Iceland. Two study populations, Icelanders and Icelandic‐Canadians, were drawn from these larger populations. The study populations were matched for age and sex and divided into three age groups, 20–39, 40–59, and 60–69 years. In comparison to the Icelandic‐Canadians, the Icelanders exhibited significantly higher levels of total cholesterol, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol, but lower triglyceride levels. Their plasma phospholipids contained significantly lower levels of saturated fatty acids (SFA), monounsaturated fatty acids, and n−6 polyunsaturated fatty acids (PUFA); but their n−3 PUFA levels were three times as high. It was additionally found that fatty acid composition of plasma phospholipids differed among Icelanders of different ages. SFA levels were significantly lower, and n−6 PUFA levels significantly higher, in the 20–39 year group than in the 60–69 year group, possibly due to different dietary fat consumption patterns between generations. No corresponding age‐related difference in the fatty acid composition of plasma phospholipids was found in the Icelandic‐Canadian study population. As the Icelandic and Icelandic‐Canadian groups are assumed to be genetically similar, the biochemical differences between them are evidently due to environmental, probably dietary, differences. The findings indicate that n−3 PUFA may be cardioprotective in the context of an otherwise atherogenic diet.
Determination of lysine modification product ε‐N‐pyrrolylnorleucine in hydrolyzed proteins and trout muscle microsomes by micellar electrokinetic capillary chromatography
Authors: Zamora Rosario , Navarro José L. , Hidalgo Francisco J. 
Published: November 2006

Abstractε‐N‐Pyrrolylnorleucine (Pnl) is a product of the reaction between the lipid peroxidation product 4,5(E)‐epoxy‐2(E)‐heptenal (EH) and the ε‐amino group of lysine. Because Pnl might also be produced in proteins, a specific method to determine this compound in protein hydrolysates has been developed. Homoarginine, added as the internal standard, and Pnl are derivatized with diethyl ethoxymethylenemalonate and analyzed by micellar electrokinetic capillary chromatography. The method also analyzes lysine and arginine, and these analyses were useful in determining losses of these amino acids after treatment with EH. The lowest concentration of Pnl detected with acceptable reproductibility is 5 nmol/mL, and the coefficient of variation was determined from four standard curves assayed on separate days. Detector response was linear for samples containing 1.6 to 74 nmol/mL of Pnl. The assay was applied in investigations of Pnl production in bovine serum albumin (BSA) and trout muscle microsomes treated with EH. When BSA was incubated overnight with 30 mM EH, 76% of lysine residues were modified, and a part of these residues were detected as Pnl (12%). Pnl formation was also detected when trout muscle microsomes were incubated for three hours with 1 or 10 mM EH. These results show that Pnl is producedin vitro in proteins treated with the lipid peroxidation product EH, and suggest that Pnl might also be constituent ofin vivo damaged proteins by their reaction with oxidized lipids.
Plasma and lipoprotein lipid peroxidation in humans on sunflower and rapessed oil diets
Authors: Turpeinen Anu M. , Alfthan Georg , Valsta Liisa , Hietanen Eino , Salonen Jukka T. , Schunk Hanna , Nyyssönen Kristiina , Mutanen Marja 
Published: November 2006

AbstractThe effects of natural mixed diets on lipid peroxidation were investigated in humans. In the first study, 59 subjects were fed a rapeseed oil‐based diet rich in monounsaturated fatty acids (MUFA) and a sunflower oil‐based diet rich in polyunsaturated fatty acids (PUFA) in a cross‐over manner for three and a half weeks. The lipid peroxidation products in plasma were determined by measuring conjugated dienes and malondialdehyde (MDA). In a second study, plasma thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, and the susceptibility of very low density lipoprotein + low‐density lipoprotein (LDL) toin vitro oxidation were measured from subjects fed similar MUFA and PUFA diets for six week diets. No significant differences in plasma MDA or conjugated diene concentrations were found after the rapeseed oil diet or the sunflower oil diet in Study 1. In the second study, a small but significant decrease (P<0.05) in both lipid hydroperoxides and TBARS was observed in the LDL fraction after the sunflower oil diet. Thein vitro oxidation gave opposite results, showing increased oxidation after the sunflower oil diet. Despite a high intake of α‐tocopherol during the oil peroids, no increase in plasma α‐tocopherol was noticed in either study. The results suggest that moderate changes in the fatty acid composition in the Western‐type diet may be adequate to affect lipoprotein susceptibility to oxidationin vitro, but there is considerable disparity with some indices ofin vivo lipid peroxidation.
Annexin I in female rabbit reproductive organs: Varying levels in relation to maturity and pregnancy
Authors: Tsao Francis H. C. , Chen Xiaoru , Chen Xiaoming , Ts'ao Chung‐hsin 
Published: November 2006

AbstractThe level of annexin I, a 36 kDa calcium‐dependent phospholipid‐binding protein (36 kDa PLBP) in the reproductive organs of young, mature, and pregnant rabbits was determined immunologically with antibodies raised against purified rabbit lung annexin I. In the cytosolic fractions of the ovary, fallopian tube, uterus, and placenta, annexin I was the only major immunoreactive protein. The reproductive organs appeared to have higher annexin I levels than most nonreproductive organ tissues, except the lung and the spleen which were also rich in annexin I. A small amount of annexin I and a nearly equal amount of its hydrolytic product, a 33 kDa polypeptide, were detected in the amniotic fluid between 21 and 27 days gestation. Structural similarity of annexin I in the reproductive organs and in the lung was suggested by their identical isoelectric point values. Annexin I in the ovary of adult rabbits was 70% higher than that in the respective organ of immature rabbits. The uterus of pregnant rabbits had about 84% higher annexin I contents than that of the nonpregnant rabbits., The placenta had more annexin I per mg cytosolic protein than either the ovary or the uterus during pregnancy. The high concentration of annexin I in the reproductive organs may reflect specific functions of these organs in the reproductive years and during the reproductive cycle.