bluuebunny/crossref_metadata_2025 huggingface dataset:
Peroxisome proliferator‐activated receptor α is not the exclusive mediator of the effects of dietary cyclic FA in mice
Authors: Bretillon Lionel , Alexson Stefan E. H. , Joffre Florent , Pasquis Bruno , Sébédio Jean‐Louis
Published: November 2006

Cyclic FA monomers (CFAM) formed during heating of α‐linolenic acid have been reported to interfere in hepatic metabolism in a putatively peroxisome proliferator‐activated receptor α (PPARα)‐dependent manner. In the present work, CFAM (0.5% of the diet) were administered for 3 wk to wild‐type and PPARα‐null mice of both genders to elucidate the role of PPARα in mediating the effects of CFAM on the activity of acyl‐CoA oxidase (ACO) and ω‐laurate hydroxylase (CYP4A), the regulation of which is known to be dependent on the PPARα. Dietary CFAM enhanced CYP4A activity threefold in male and female wild‐type mice. This effect was abolished in PPARα‐null mice. A twofold induction of ACO activity was found in wild‐type female mice fed CFAM; however, no effect was seen in males. In wild‐type animals, (ω‐1)‐laurate hydroxylase (CYP2E1) activity, the expression of which has not been shown to be PPARα dependent, was not affected by the CFAM diet. In contrast, stearoyl‐CoA desaturase activity was reduced in wild‐type mice. CFAM feeding reduced the activities of ACO, CYP2E1, and stearoyl‐CoA desaturase and caused accumulation of lipids in the livers of female PPARα‐null mice. These data show that CFAM apparently activate gene expression via the PPARα and have profound effects on lipid homeostasis, exacerbating the disturbances preexisting in mice lacking functional PPARα. Although the data emphasize the importance of PPARα in the metabolism of the CFAM, these results show that PPARα is not the exclusive mediator of the effects of CFAM in lipid metabolism in mice.
Ligand‐binding domain of farnesoid X receptor (FXR) had the highest sensitivity and activity among FXR variants in a fluorescence‐based assay
Authors: Cho Kyung‐Hyun , Park Ji‐Young , Han Jang‐Il , Jeong Tae‐Sook
Published: November 2006

The farnesoid X receptor (FXR, NR1H4) has been recognized as an attractive therapeutic target because it is a nuclear hormone receptor that controls the expression level of cholesterol‐7α‐hydroxylase, which in turn regulates bile acid production and cholesterol excretion. To compare receptor activity between each domain and the full‐length protein, human FXR cDNA was cloned from a human liver cDNA library. Three human FXR cDNA, designated FXR20, FXR33, and FXR53 cDNA, were subcloned and ligated into a pET28a expression vector. Each protein was expressed in Escherichia coli (BL21) and purified by nickel‐nitrilotriacetic acid column chromatography. Approximately 5 mg of FXR33 (1–182 amino acids deleted from FXR, 37 kDa) and 2 mg of FXR53 (the full‐length protein of FXR, 59 kDa) was purified from 1 L of Luria‐Bertani culture, achieving at least 90% purity. The coactivator recruitment assay for FXR activation was carried out with the three variants of the FXR protein by using dissociation‐enhanced lanthanide fluoroimmunoassay‐europium‐N1‐labeled anti‐His antibody. From an optimized assay, a saturated hyperbolic fluorescence signal curve was produced when 250 nM of FXR33 and 100 nM of steroid receptor coactivator‐1 peptide, a coactivator of FXR consisting of 26 amino acids, were used with a concentration dependence on chenodeoxycholic acid (from 0 to 200 μM). The ligand‐binding domain of FXR (FXR33) was the most suitable protein for studying the activation of FXR with a fluorescence‐based assay, because it showed better structural stability than either the full length of FXR (FXR53) or the DNA‐binding domain of FXR (FXR20).
Genes regulated by arachidonic and oleic acids in Raji cells
Authors: Verlengia Rozangela , Gorjão Renata , Kanunfre Carla Cristine , Bordin Silvana , de Lima Thais Martins , Newsholme Philip , Curi Rui
Published: November 2006

FA are known to modulate immune function in conditions such as arthritis and lupus erythematosus. The effects of arachidonic (AA) and oleic acids (OA) on function and pleiotropic gene expression of Raji cells were investigated. The following parameters were evaluated: cytotoxicity as assessed by loss of membrane integrity and DNA fragmentation; proliferation as measured by [14C]thymidine incorporation; production of interleukin (IL)‐10, interferon (INF)‐γ, and tumor necrosis factor (TNF)‐α; and expression of pleiotropic genes by a macroarray technique (83 genes in total). AA was more toxic to Raji cells than OA. Both FA promoted an increase in Raji cell proliferation at 75 μM, whereas OA at high concentrations (200 μM) decreased proliferation. AA reduced the production of IL‐10, TNF‐α, and INF‐γ. On the other hand, OA provoked an increase of INF‐γ production but did not affect the production of IL‐10 and TNF‐α. The proportions of genes with altered expression were 27% for AA and 35% for OA. The FA affected the expression of genes clustered as: cytokines, signal transduction pathways, transcription factors, cell cycle, defense and repair, apoptosis, DNA synthesis, cell adhesion, cytoskeleton, and hormone receptors. The most remarkable changes were observed in the genes of signal transduction pathways. These results led us to conclude that the effect of these FA on B‐lymphocytes includes regulation of gene expression. Thus, diets enriched with fat containing OA or AA may affect B lymphocyte function in vivo.
Two distinct pathways for the formation of hydroxy FA from linoleic acid by lactic acid bacteria
Authors: Kishimoto Noriaki , Yamamoto Izumi , Toraishi Kazuki , Yoshioka Satiko , Saito Kenji , Masuda Hideki , Fujita Tokio
Published: November 2006

Twenty‐three of 86 strains of lactic acid bacteria transformed linoleic acid into hydroxy FA. Two distinct conversion pathways were in operation. Two strains of Lactobacillus acidophilus and a strain of Pediococcus pentosaceus produced 13(S)‐hydroxy‐9‐octadecenoic acid [13(S)‐OH 18∶1] and 10,13‐dihydroxyoctadecanoic acid (10,13‐OH 18∶0) as main and minor products, respectively, whereas 13 strains, including L. casei subsp. casei, L. paracasei subsp, paracasei, L. rhamnosus, L. lactis subsp. cremoris, and Streptococcus salivarius subsp. thermophilus produced 10‐hydroxy‐12‐octadecenoic acid (10‐OH 18∶1). Seven strains of L. plantanum converted linoleic acid to 10‐hydroxyoctadecanoic acid (10‐OH 18∶0) through 10‐OH 18∶1 Linoleic acid at 2 g/L was converted by L. acidophilus LFO13951T to 1.3 g of 13(S)‐OH 18∶1 and 0.09 g of 10,13‐OH 18∶0 in 7 d. Lactobacillus paracasei subsp. paracasei JCM 1111 produced 10‐OH 18∶1 in 91% yield, and L. plantarum JCM 8341, 10‐OH 18∶0 in 59% yield from linoleic acid (2 g/L) under optimal conditions. To our knowledge, this is the first report on the production of 13(S)‐OH 18∶1 by lactic acid bacteria other than ruminal bacteria, and of 10,13‐OH 18∶0 by any bacteria.
Regiospecific analysis by ethanolysis of oil with immobilized Candida antarctica lipase
Authors: Shimada Yuji , Ogawa Jun , Watanabe Yomi , Nagao Toshihiro , Kawashima Akiko , Kobayashi Takashi , Shimizu Sakayu
Published: November 2006

A mixture of oil/ethanol (1∶3, w/w) was shaken at 30°C with 4% immobilized Candida antarctica lipase by weight of the reaction mixture. The reaction regiospecifically converted FA at the 1‐ and 3‐positions to FA ethyl esters, and the lipase acted on C14−C24 FA to a similar degree. The content of 2‐MAG reached a maximum after 4 h; the content was 28–29 mol% based on the total amount of FA in the reaction mixture at 59–69% ethanolysis. Only 2‐MAG were present in the reaction mixture during the first 4 h, and 1(3)‐MAG were detected after 7 h. After removal of ethanol from the 4‐h reaction mixture by evaporation, 2‐MAG were fractionated by silica gel column chromatography. The contents of FA in the 2‐MAG obtained by ethanolysis of several oils coincided well with FA compositions at the 2‐position, which was analyzed by Grignard degradation. It was shown that ethanolysis of oil with C. antarctica lipase can be applied to analysis of FA composition at the 2‐position in TAG.
Modulation of renal injury in pcy mice by dietary fat containing n−3 fatty acids depends on the level and type of fat
Authors: Sankaran Deepa , Lu Jing , Bankovic‐Calic Neda , Ogborn Malcolm R. , Aukema Harold M.
Published: November 2006

Low‐fat diets and diets containing n−3 fatty acids (FA) slow the progression of renal injury in the male Han:Sprague‐Dawley (SPRD)‐cy rat model of polycystic kidney disease. To determine whether these dietary fat effects are similar in females and in another model of renal cystic disease, in this study we used both male and female pcy mice to examine the effects of fat level and type on disease progression. Adult pcy mice were fed 4, 10, or 20 g soybean oil/100 g diet for 130 d in study 1. In study 2, weanling pcy mice were fed high or low levels of fat rich in 18∶2n−6 (corn oil, CO) 18∶3n−3 (flaxseed oil/CO 4∶1 g/g, FO), or 22∶6n−3 (algal oil/CO 4∶1 g/g, DO) for 8 wk. In adult pcy mice, low‐compared with high‐fat diets lowered kidney weights (2.4±0.2 vs. 3.1±0.2 g/100 g body weight, P=0.006) and serum urea nitrogen (SUN) (9.6±0.6 vs. 11.9±0.6 mmol/L, P=0.009), whereas in young pcy mice it reduced renal fibrosis volumes (0.44±0.04 vs. 0.62±0.04 mL/kg body weight, P<0.0001). FO feeding in young pcy mice mitigated the detrimental effects of high fat on fibrosis while not altering kidney size, function, and oxidative damage when compared with the CO‐fed mice. In contrast, DO‐compared with CO‐fed mice had higher kidney weights (2.64±0.07 vs. 2.24±0.08 g/100 g body weight, P=0.005), SUN (9.4±0.57 vs. 7.0±0.62 nmol/L, P<0.0001), and cyst volumes (7.9±0.28 vs. 6.2±0.30 mL/kg body weight, P<0.0001) and similar levels of oxidative damage and fibrosis. The FA compositions of the diets were reflected in the kidneys: 18∶2n−6, 18∶3n−3, and 22∶6n−3 were the highest in the CO, FO, and DO diets, respectively. Dietary effects on kidney disease progression were similar in males and females. A low‐fat diet slows progression of renal injury in male and female pcy mice, consistent with findings in the male Han:SPRD‐cy rat. Dietary fat type also influenced renal injury, with flaxseed oil diets rich in 18∶3n−3 slowing early fibrosis progression compared with diets rich in 18∶2n−6 or in 22∶6n−3.
Influences of dietary n−3 long‐chain PUFA on body concentrations of 20∶5n−3, 22∶5n−3, and 22∶6n−3 in the larvae of a marine teleost fish from Australian waters, the striped trumpeter (Latris lineata)
Authors: Bransden M. P. , Dunstan G. A. , Battaglene S. C. , Cobcroft J. M. , Morehead D. T. , Kolkovski S. , Nichols P. D.
Published: November 2006

We determined the effect of dietary long‐chain (≥C20) PUFA (LC‐PUFA), 20∶5n−3 and 22∶6n−3, on larval striped trumpeter (Latris lineata) biochemistry through early development and during live feeding with rotifers (Brachionus plicatilis). Rotifers were enriched using seven experimental emulsions formulated with increasing concentrations of n−3 LC‐PUFA, mainly 20∶5n−3 and 22∶6n−3. Enriched rotifer n−3 LC‐PUFA concentrations ranged from 10–30 mg/g dry matter. Enriched rotifers were fed to striped trumpeter larvae from 5 to 18 d post‐hatch (dph) in a short‐term experiment to minimize gross deficiency symptoms such as poor survival that could confound results. No relationships were observed between larval growth or survival with dietary n−3 LC‐PUFA at 18 dph. The larval FA profiles generally reflected those of the rotifer diet, and significant positive regressions were observed between most dietary and larval FA at 10, 14, and 18 dph. The major exception observed was an inverse relationship between dietary and larval 22∶5n−3. The presence of 22∶5n−3 in elevated amounts when dietary 22∶5n−3. The presence of 22∶5n−3 in elevated amounts when dietary 22∶6n−3 was depressed suggests that elongation of 20∶5n−3 may be occurring in an attempt to raise body concentrations of 22∶6n−3. We hypothesize that accumulation of 22∶5n−3 might be an early indicator of 22∶6n−3 deficiency in larval fish that precedes a reduction in growth or survival. A possible role of 22∶5n−3 as a biochemical surrogate for 22∶6n−3 is discussed.
Replacement of dietary fish oil with increasing levels of linseed oil: Modification of flesh fatty acid compositions in Atlantic salmon (Salmo salar) using a fish oil finishing diet
Authors: Bell J. Gordon , Henderson R. James , Tocher Douglas R. , Sargent John R.
Published: November 2006

Five groups of salmon, of initial mean weight 127±3 g, were fed increasing levels of dietary linseed oil (LO) in a regression design. The control diet contained capelin oil (FO) only, and the same oil was blended with LO to provide the experimental diets. After an initial period of 40 wk, all groups were switched to a finishing diet containing only FO for a further 24 wk. Growth and flesh lipid contents were not affected by dietary treatment. The FA compositions of flesh total lipids were linearly correlated with dietary FA compositions (r2=0.88–1.00, P<0.0001). LO included at 50% of added dietary lipids reduced flesh DHA and EPA (20∶5n−3) concentrations to 65 and 58%, respectively, of the concentrations in fish fed FO. Feeding 100% LO reduced flesh DHA and EPA concentrations to 38 and 30%, respectively, of the values in fish fed FO. Differences between diet and flesh FA concentrations showed that 16∶0, 18∶1n−9, and especially DHA were preferentially retained in flesh, whereas 18∶2n−6, 18∶3n−3, and 22∶1n−11 were selected against and presumably utilized for energy. In fish previously fed 50 and 100% LO, feeding a finishing diet containing FO for 16 wk restored flesh DHA and EPA concentrations, to ≈80% of the values in fish fed FO throughout. Flesh DHA and EPA concentrations in fish fed up to 50% LO were above recommended intake values for humans for these EFA. This study suggests that LO can be used as a substitute for FO in seawater salmon feeds and that any reductions in DHA and EPA can be largely overcome with a finishing diethigh in FO before harvest.
Identification of minor fatty acids and various nonmethylene‐interrupted diene isomers in mantle, muscle, and viscera of the marine bivalve Megangulus zyonoensis
Authors: Kawashima H. , Ohnishi M.
Published: November 2006

To clarify the occurrence of nonmethylene‐interrupted (NMI) FA in the marine bivalve Megangulus zyonoensis, methyl esters of unsaturated FA were fractionated according to the degree of their unsaturation by using argentation TLC. Their structures were elucidated by using GC‐MS of their FAME and 2‐alkenyl‐4,4‐dimethyloxazoline derivatives. Seventy‐two unsaturated FA, including the novel 7,15–21 and 20∶4n−1, were identified. The unusual tetraenoic acids 20∶4n−4, 20∶4n−1, 21∶4n−6, and 21∶4n−5 were found in M. zyonoensis. This bivalve was extremely rich in the positional isomers of 19∶1, 20∶2, and 20∶3. The distribution of NMI and positional isomers of unusual FA in the bivalve tissues was also discussed.
Determining the relative amounts of positional isomers in complex mixtures of triglycerides using reversed‐phase high‐performance liquid chromatography‐tandem mass spectrometry
Authors: Malone Michael , Evans Jason J.
Published: November 2006

A reversed‐phase HPLC‐tandem mass spectrometry (RP‐HPLC‐MS‐MS) method was refined for the positional analysis of complex mixtures of TAG. This method has the advantages of speed, ease of automation, and specificity over traditional digestion‐based methods for the positional analysis of TAG. Collision‐induced dissociation (CID) of ammoniated TAG in an ion‐trap mass spectrometer produced spectra that were dependent on the FA position. Dominant DAG fragments were formed from the loss of a FA moiety from the ammoniated TAG species. The loss of FA in the outer positions was favored over their loss in the central position. The combination of RP‐HPLC and CID produced spectra that were free of the isotope effects that can complicate spectral interpretation in existing methods. The combination also provided selectivity based on the chromatographic fractionation of TAG, in addition to the selectivity inherent in the CID process. Proof‐of‐concept experiments were performed with binary mixtures of TAG from the SOS/SSO, OSO/OOS, and the PSO/POS/SPO positional isomer systems (where S is 18∶0, stearic acid; O is 18∶1 (cis‐9), oleic acid; and P is 16∶0, palmitic acid). Plots of fractional DAG fragment intensities vs. fractional composition of the binary mixtures were linear. These plots were used to determine the fractional composition of each of these isomeric systems in a variety of vegetable oils and animal fats. Current limitations, future developments, and applications of this method are discussed.
An efficient and novel method for the synthesis of cardiolipin and its analogs
Authors: Lin Zhen , Ahmad Moghis U. , Ali Shoukath M. , Ahmad Imran
Published: November 2006

A novel synthetic method has been developed for cardiolipin and its analog via a chlorophosphoramidite coupling reaction followed by oxidation. The reagent, N,N‐diisopropylmethylphosphoramidic chloride, couples effectively with 1,2‐O‐dimyristoyl‐sn‐glycerol in the presence of an amidite activator to form a phosphoamidite intermediate, which then reacts with 2‐O‐benzylglycerol in the presence of a basic catalyst followed by in situ oxidation to give the corresponding protected cardiolipin. Deprotection of the protecting groups provides tetramyristoyl cardiolipin in good overall yield of 60%. The synthetic method is applicable to large‐scale synthesis of cardiolipin and various analogs with or without unsaturation for liposomal drug delivery.
Comparison of the lymphatic transport of radiolabeled 1,3‐dioleoylglycerol and trioleoylglycerol in rats
Authors: Yanagita Teruyoshi , Ikeda Ikuo , Wang Yu‐ming , Nakagiri Hideaki
Published: November 2006

It has been reported that, compared with TAG, DAG suppresses postprandial hypertriacylglycerolemia and reduces visceral fat levels in experimental animals and humans. To clarify the mechanism responsible for these beneficial effects, we compared the lymphatic transport of 1,3‐DAG, a major isomer of DAG, and TAG in rats. Male SD rats, after insertion of a cannula into the thoracic duct, were given 1,3‐di[1‐14C]oleoylglycerol or tri[1‐14C]oleoylglycerol via a stomach tube. The 24‐h receovery of the radioactivity from 1,3‐di[14C]oleoylglycerol in the lymph was slightly but significantly lower than that from tri[14C]oleoylglycerol (81.3±1.0 vs. 86.5±1.2%, respectively). However, in the first 1‐h interval after administration, the recovery of radioactivity from 1,3‐dioleoylglycerol was almost half of that from trioleoylglycerol (17.5±2.0 vs. 31.1±1.4%). The amount of TAG and phospholipids secreted into the lymph was significantly lower 1 h after the administration of 1,3‐dioleoylglycerol compared with that after the administration of trioleoylglycerol. More than 90% of the radioactivity recovered in the lymph in the first 3 h was distributed in the TAG fraction for both 1,3‐dioleoylglycerol and trioleoylglycerol. These results suggest that slower lymphatic transport of 1,3‐DAG compared with TAG could be a factor in the suppression of postprandial hypertriacylglycerolemia. The possibility that the slower lymphatic transport of DAG contributes to the antiobesity action observed in the feeding of 1,3‐DAG cannot be excluded.
Alteration of 20∶5n−3 and 22∶6n−3 fat contents and liver peroxisomal activities in fenofibrate‐treated rainbow trout
Authors: Du Zhen‐yu , Demizieux Laurent , Degrace Pascal , Gresti Joseph , Moindrot Bastien , Liu Yong‐jian , Tian Li‐xia , Cao Jun‐ming , Clouet Pierre
Published: November 2006

Fish easily accumulate n−3 PUFA of exogenous origin, but the underlying mechanisms are not well established in the whole animal. This study was undertaken to investigate whether this feature was physiologically associated with mitochondrial and peroxisomal capacities that differentially affect FA oxidation. For this purpose, peroxisomal FA oxidation was increased by treating rainbow trout with fenofibrate, which strongly stimulates the peroxisome proliferator‐activated receptor‐α in rodents. Diets containing EPA and DHA, with or without fenofibrate added, were administered to male trout for 12 d. After treatment, neither liver hypertrophy nor accumulation of fat was apparent within the liver and muscle cells. However, fenofibrate treatment decreased the contents of EPA and DHA in the liver, white muscle, and intraperitoneal fat tissue, which represented (per whole body) at least 280 mg less than in controls. Carnitine‐dependent palmitate oxidation rates, expressed per gram of liver, were slightly increased by fenofibrate when measured from tissue homogenates and were unchanged when calculated from isolated mitochondria, relative to control fish. The treatment altered neither carnitine palmitoyltransferase I activity rates, expressed per gram of liver, nor the sensitivity of the enzyme to malonyl‐CoA inhibition, but did increase the malonyl‐CoA content (+45%). Meanwhile, fenofibrate increased (by about 30%) the peroxisome‐related activities, i.e, catalase, carnitine‐independent palmitate oxidation, acyl‐CoA oxidase, and the peroxisomal FA‐oxidizing system, relative to the control group. The data strongly suggest that the induction of peroxisomal activities, some of which being able to oxidize very long chain FA, was responsible for the lower contents of EPA and DHA in the body lipids of fenofibrate‐treated trout.
Effects of EPA and DHA on proliferation, cytokine production, and gene expression in Raji cells
Authors: Verlengia Rozangela , Gorjão Renata , Kanunfre Carla Cristine , Bordin Silvana , de Lima Thais Martins , Martins Edgair Fernandes , Newsholme Philip , Curi Rui
Published: November 2006

The effects of EPA and DHA on the function and gene expression of a B‐lymphocyte cell line (Raji) were investigated. Proliferation; production of interleukin‐10 (IL‐10), tumor necrosis factor (TNF)‐α, and interferon (INF)‐γ; and expression of pleiotropic genes were evaluated. Cell proliferation was increased in the presence of 12.5 μM EPA (approximately twofold) and 12.5 μM DHA (approximately 1.5‐fold). EPA and DHA (25 μM) also decreased production of the key immunoregulatory cytokines IL‐10, TNF‐α, and INF‐γ. EPA and DHA changed the expression of specific genes, but this effect was more marked for EPA (25.9% of genes investigated) compared with DHA (8.4% of genes investigated). EPA and DHA affected the expression of genes clustered as: cytokines, signal transduction, transcription, cell cycle, defense and repair, apoptosis, cell adhesion, cytoskeleton, and hormones. The most remarkable changes were observed in the genes of signal transduction and transcription. These results led us to conclude that the mechanism of DHA and EPA effects on B‐lymphocyte functions includes regulation of gene expression. Thus, the ingestion of fish oil, a rich source of EPA and DHA, may have a strong effect on B‐lymphocyte functionin vivo. However, remarkable differences were observed between DHA and EPA, demonstrating that specific effects of these FA may be responsible for the marked differences in edible oil effects on immune functionin vivoreported by others.
Astonishing diversity of natural surfactants: 1. Glycosides of fatty acids and alcohols
Authors: Dembitsky Valery M.
Published: November 2006

Alkyl and fatty acid glycosides have become of great commercial interest in general and specifically for the pharmaceutical, cosmetic, and food industries. Natural surfactants are good sources for future chemical preparation of these glycosides. This review article shows an astonishing diversity of natural surfactants that could be used in laboratories and industry. More than 250 natural surfactants, including their chemical structures and biological activities, are described in this review article.
Dietary modulation of fatty acid profiles and oxidative status of rat hepatocyte nodules: Effect of different n−6/n−3 fatty acid ratios
Authors: Abel S. , De Kock M. , Smuts C. M. , de Villiers C. , Swanevelder S. , Gelderblom W. C. A.
Published: November 2006

Male Fischer rats were fed the AIN76A diet containing varying n−6/n−3 FA ratios using sunflower oil (SFO), soybean oil (SOY), and SFO supplemented with EPA‐50 and GLA‐80 (GLA) as fat sources. Hepatocyte nodules, induced using diethylnitrosamine followed by 2‐acetylaminofluorene/partial hepatoctomy promotion, were harvested, with surrounding and respective dietary control tissues, 3 mon after partial hepatectomy. The altered growth pattern of hepatocyte nodules in rats fed SFO is associated with a distinct lipid pattern entailing an increased concentration of PE, resulting in increased levels of 20∶4n−6. In addition, there is an accumulation of 18∶1n−9 and 18∶2n−6 and a decrease in the end products of the n−3 metabolic pathway in PC, suggesting a dysfunctional Δ‐6‐desaturase enzyme. The hepatocyte nodules of the SFO‐fed rats exhibited a significantly reduced lipid peroxidation level that was associated with an increaser in the glutathione (GSH) concentration. The low n−6/n−3 FA ratio diets significantly decreased 20∶4n−6 in PC and PE phospholipid fractions with a concomitant increase in 20∶5n−3, 22∶5n−3, and 22∶6n−3. The resultant changes in the 20∶4/20∶5 FA ratio and the 20∶3n−6 FA level in the case of the GLA diet suggest a reduction of prostaglandin synthesis of the 2‐series. The GLA diet also counteracted the increased level of 20∶4n−6 in PE by equalizing the nodule/surrounding ratio. The low n−6/n−3 ratio diets significantly increased lipid peroxidation levels in hepatocyte nodules, mimicking the level in the surrounding and control tissue while GSH was decreased. An increase in n−3 FA levels and oxidative status resulted in a reduction in the number of glutathione‐S‐transferase positive foci in the liver of the GLA‐fed rats. Modulation of cancer development with low n−6/n−3 ratio diets containing specific dietary FA could be a promising tool in cancer intervention in the liver.
Rapid clearance of hexachlorobenzene from chylomicrons
Authors: Jandacek Ronald J. , Zheng Shuqin , Yang Qing , Iso Patrick
Published: November 2006

Toxic organochlorines that are present in food are lipophilic and carried by chylomicrons. We have studied the clearance of an organochlorine, hexachlorobenzene, from chylomicrons. Chylomicrons were obtained from mesenteric lymph of rats that were intraduodenally given 14C‐hexachlorobenzene and 3H‐triolein. The labeled chylomicrons were injected intravenously into recipient rats, and the clearance of isotopes was followed. Surprisingly, the hexachlorobenzene disappeared from the plasma more rapidly than the triolein. This unexpected result raises questions about the manner in which hexachlorobenzene is delivered to tissues. The tissue distribution of the hexachlorobenzene is consistent with its rapid uptake.
Separation of vitamin E (tocopherol, tocotrienol, and tocomonoenol) in palm oil
Authors: Ng Mei Han , Choo Yuen May , Ma Ah Ngan , Chuah Cheng Hock , Hashim Mohd Ali
Published: November 2006

Previous reports showed that vitamin E in palm oil consists of various isomers of tocopherols and tocotrienols [α‐tocopherol (α−T), α‐tocotrienol, γ‐tocopherol, γ‐tocotrienol, and δ‐tocotrienol), and this is normally analyzed using silica column HPLC with fluorescence detection. In this study, an HPLC‐fluorescence method using a C30 silica stationary phase was developed to separate and analyze the vitamin E isomers present in palm oil. In addition, an α‐tocomonoenol (α−T1) isomer was quantified and characterized by MS and NMR. α−T1 constitutes about 3–4% (40±5 ppm) of vitamin E in crude palm oil (CPO) and is found in the phytonutrient concentrate (350±10 ppm) from palm oil, whereas its concentration in palm fiber oil (PFO) is about 11% (430±6 ppm). The relative content of each individual vitamin E isomer before and after interesterification/transesterification of CPO to CPO methyl esters, followed by vacuum distillation of CPO methyl esters to yield the residue, remained the same except for α−T and γ−T3. Whereas α−T constitutes about 36% of the total vitamin E in CPO, it is present at a level of 10% in the phytonutrient concentrate. On the other hand, the composition of γ−T3 increases from 31% in CPO to 60% in the phytonutrient concentrate. Vitamin is present at 1160±43 ppm, and its concentrations in PFO and the phytonutrient concentrate are 4,040±41 and 13,780±65 ppm, respectively. The separation and quantification of α−T1 in palm oil will lead to more in‐depth knowledge of the occurrence of vitamin E in palm oil.
Olive oil and modulation of cell signaling in disease prevention
Authors: Wahle Klaus W. J. , Caruso Donatella , Ochoa Julio J. , Quiles Jose L.
Published: November 2006

Epidemiological studies show that populations consuming a predominantly plant‐based Mediterranean‐style diet exhibit lower incidences of chronic diseases than those eating a northern European or North American diet. This observation has been attributed to the greater consumption of fruits and vegetables and the lower consumption of animal products, particularly fat. Although total fat intake in Mediterranean populations can be higher than in other regions (ca. 40% of calories), the greater proportion is derived from olive oil and not animals. Increased olive oil consumption is implicated in a reduction in cardiovascular disease, rheumatoid arthritis, and, to a lesser extent, a variety of cancers. Olive oil intake also has been shown to modulate immune function, particularly the inflammatory processes associated with the immune system. Olive oil is a nonoxidative dietary component, and the attenuation of the in‐flammatory process it elicits could explain its beneficial effects on disease risk since oxidative and inflammatory stresses appear to be underlying factors in the etiology of these diseases in man. The antioxidant effects of olive oil are probably due to a combination of its high oleic acid content (low oxidation potential compared with linoleic acid) and its content of a variety of plant antioxidants, particularly oleuropein, hydroxytyrosol, and tyrosol. It is also possible that the high oleic acid content and a proportionate reduction in linoleic acid intake would allow a greater conversion of α‐linolenic acid (18∶3n−3) to longer‐chain n−3 PUFA, which have characteristic health benefits. Adoption of a Mediterranean diet could confer health benefits in high‐risk populations.
Functional alterations in NO, PGI2 and EDHF pathways in the aortic endothelium after myocardial infarction in rats
Authors: Csanyi Gabor , Bauer Michael , Dietl Wolfgang , Lomnicka Magdalena , Stepuro Tatiana , Podesser Bruno K. , Chlopicki Stefan
Published: November 2006

Background

Previous work on endothelial dysfunction in post‐MI heart failure has shown conflicting results.

Aim

To analyze gender related alterations in NO‐, PGI2‐ and EDHF‐dependent endothelial function in the thoracic aorta 7 and 42 days after myocardial infarction (MI).

Methods and results

MI was induced by coronary artery ligation in female and male Sprague–Dawley rats. There was no gender related difference in infarct‐size or in the impairment of fractional shortening of the left ventricle 42 days after coronary ligation. Neither acetylcholine‐induced (Ach) vasodilation nor basal PGI2 production in the aorta was modified by coronary ligation. Interestingly, 7 days after MI, basal NO production was impaired and the EDHF component of Ach‐induced vasodilation was up‐regulated, in both male and female rats. However, 42 days post‐MI, basal NO was only impaired in male rats, while EDHF was only up‐regulated in female rats.

Conclusion

MI induced impairment of functional activity of basal NO production and adaptive up‐regulation of the EDHF component of Ach‐induced relaxation. The above alterations in endothelial function in the aorta were gender‐specific at 42 days but not 7 days after MI. Some of the previously reported discrepancies in the development of endothelial dysfunction in the post‐MI period may be gender related differences.
A novel subunit of axonemal dynein conserved among lower and higher eukaryotes
Authors: Yamamoto Ryosuke , Yanagisawa Haru-aki , Yagi Toshiki , Kamiya Ritsu
Published: November 2006

To elucidate the subunit composition of axonemal inner‐arm dynein, we examined a 38 kDa protein (p38) co‐purified with a Chlamydomonas inner arm subspecies, dynein d. We found it is a novel protein conserved among a variety of organisms with motile cilia and flagella. Immunoprecipitation using specific antibody verified its association with a heavy chain, actin and a previously identified light chain (p28). Unexpectedly, mutant axonemes lacking dynein d and other dyneins retained reduced amounts of p38. This finding suggests that p38 is involved in the docking of dynein d to specific loci.
Effect of temperature on protein quality in bacterial inclusion bodies
Authors: de Groot Natalia Sánchez , Ventura Salvador
Published: November 2006

Increasing evidence indicates that protein aggregation in bacteria does not necessarily imply loss of biological activity. Here, we have investigated the effect of growth‐temperature on both the activity and stability of the inclusion bodies formed by a point‐mutant of Aβ42 Alzheimer peptide, using green fluorescent protein as a reporter. The activity in the aggregates inversely correlates with the temperature. In contrast, inclusion bodies become more stable in front of chemical denaturation and proteolysis when temperature increases. Overall, the data herein open new perspectives in protein production, while suggesting a kinetic competition between protein folding and aggregation during recombinant protein expression.
Different modulation of TRAIL‐induced apoptosis by inhibition of pro‐survival pathways in TRAIL‐sensitive and TRAIL‐resistant colon cancer cells
Authors: Vaculová Alena , Hofmanová Jiřina , Souček Karel , Kozubík Alois
Published: November 2006

Epithelial cells can be manipulated to undergo apoptosis depending on the balance between pro‐survival and apoptotic signals. We showed that TRAIL‐induced apoptosis may be differentially regulated by inhibitors of MEK ERK (U0126) or PI3K/Akt (LY294002) pathway in TRAIL‐sensitive (HT‐29) and TRAIL‐resistant (SW620) human epithelial colon cancer cells. U0126 or LY294002 significantly enhanced TRAIL‐induced apoptosis in HT–29 cells, but not in SW620 cells. We report a different regulation of the level of an anti‐apoptotic Mcl‐1 protein under MEK/ERK or PI3K/Akt pathway inhibition and suggest the mechanisms involved. A special attention was paid to the role of the ERK1/2, Akt, and glycogen synthase kinase 3β.
The mechanism of graft transmission of sense and antisense gene silencing in tomato plants
Authors: Shaharuddin Noor A. , Han Yuanhuai , Li Hongying , Grierson Don
Published: November 2006

We investigated the effect of target mRNA level on grafting‐transmitted gene silencing in tomato plants by using a strong ACC oxidase 1 (ACO1) silencer as the stock and transgenic ACO1 overexpressers as scions. Manifestation of graft transmission of sense gene silencing required a high initial level of target mRNA in the scion. A relatively high level of siRNA, similar to that in the strong ACO1 silencer, was also detected in the silencing‐susceptible strong ACO1 overexpressers prior to grafting. After grafting the silencing signal from the stock enhanced the level of the siRNAs in the scion and the ACO1 mRNA level was reduced dramatically. Using stock and scions producing different siRNAs we provided evidence that the transmissible silencing signal does not correspond to the bulk siRNAs in the stock. We also showed, contrary to a previous report, that antisense silencing was graft‐transmissible but it took longer to manifest itself. The delay in graft transmission from antisense‐silenced plants could be attributed to the difference in the nature or strength of the signal or the mechanism of its amplification, but is further evidence of mechanistic similarities between sense and antisense silencing.
RECENT DEVELOPMENTS. THE ELABORATION OF A LEGAL FRAMEWORK FOR THE PROTECTION OF INTERNALLY DISPLACED PERSONS IN AFRICA
Authors: BEYANI CHALOKA
Published: November 2006

The aim of this article is to draw on contemporary developments relating to the elaboration of a binding legal framework for the treatment of internally displaced persons in Africa. By definition, internally displaced persons are “persons or groups of persons who have been forced or obliged to flee or to leave their homes or places of habitual residence, in particular as a result of, or in order to avoid the effects of armed conflict, situations of generalized violence, violations of human rights or natural or human-made disasters, and who have not crossed an internationally recognized State border”.
Measuring ecosystem response in a rapidly changing environment: the Latitudinal Gradient Project
Authors: Howard-Williams C. , Peterson D. , Lyons W.B. , Cattaneo-Vietti R. , Gordon S.
Published: November 2006

In the face of climate variability and change, science in Antarctica needs to address increasingly complex questions. Individual small studies are being replaced by multinational and multidisciplinary research programmes. The Latitudinal Gradient Project (LGP) is one such approach that combines a series of smaller studies under a single broad hypothesis to provide information that uses a gradient in latitude as a surrogate for environmental gradients, particularly climate. In this way latitudinal differences can be used to indicate climate change differences. The Key Questions for the LGP were developed via national workshops in Italy, New Zealand, and the USA and via two international workshops at SCAR conferences. Science and logistics are currently jointly shared by New Zealand, Italy and the USA, and cover marine and inland ecosystem studies along the Victoria Land coast from 72° to 78°S with plans for extensions to 85°S. The LGP forms part of the SCAR Programme Evolution and Biodiversity in Antarctica. This Special Issue summarizes some of the work in the first three years of the LGP (2002–2005), between McMurdo Sound and Cape Hallett, to form a basis for future comparative studies as the research shifts along the latitudinal span in the next decade.
Co-variation in soil biodiversity and biogeochemistry in northern and southern Victoria Land, Antarctica
Authors: Barrett J.E. , Virginia R.A. , Wall D.H. , Cary S.C. , Adams B.J. , Hacker A.L. , Aislabie J.M.
Published: November 2006

Data from six sites in Victoria Land (72–77°S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties showthe influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific sites in northern and southern Victoria Land, as was the distribution of nematode and tardigrade species. Variation in soil metazoan communities was related to differences in soil organic matter, while bacterial diversity and community structure were not strongly correlated with any single soil property. There were no apparent correlations between metazoan and bacterial diversity, suggesting that controls over distribution and habitat suitability are different for bacterial and metazoan communities. Our results imply that top-down controls over bacterial diversity mediated by their metazoan consumers are not significant determinants of bacterial community structure and biomass in these ecosystems.
A network for monitoring terrestrial ecosystems along a latitudinal gradient in Continental Antarctica
Authors: Cannone Nicoletta
Published: November 2006

A network for monitoring change in the vegetation communities to assess the impact of future climate changes was established in Victoria Land (Continental Antarctica) in 2002 and 2003. The network is within the framework of the SCAR project RiSCC (Regional Sensitivity to Climate Change in Antarctic terrestrial and limnetic ecosystems), and in cooperation with LGP (Latitudinal Gradient Project) assessing how ecosystem biodiversity and structure may change with latitude and with climate change. The network is composed of 19 permanent plots at nine sites along a latitudinal gradient from Apostrophe Island (73°30′S, 167°50′E) to Granite Harbour (77°00′S, 162°26′E), with a main coastal transect and three subtransects inland from the coast. The sites are representative of the most frequent environmental conditions and the most widespread communities occurring in Continental Antarctica and in Victoria Land. The selected communities show different ecological requirements and have different potential sensitivities to climate change. The vegetation of each plot was described using the RiSCC research protocol, developed originally in the Maritime Antarctic and here adapted, for plot size, to Continental Antarctica. This paper characterizes the vegetation at the sites as the starting point of the long term monitoring.
Comparison of the microalgal community within fast ice at two sites along the Ross Sea coast, Antarctica
Authors: Ryan K.G. , Hegseth E.N. , Martin A. , Davy S.K. , O'Toole R. , Ralph P.J. , McMinn A. , Thorn C.J.
Published: November 2006

Diverse microbial communities survive within the sea ice matrix and are integral to the energy base of the Southern Ocean. Here we describe initial findings of a four season survey (between 1999–2004) of community structure and biomass of microalgae within the sea ice and in the underlying water column at Cape Evans and Cape Hallett, in the Ross Sea, Antarctica as part of the Latitudinal Gradient Project. At Cape Evans, bottom-ice chlorophyll a levels ranged from 4.4 to 173 mg Chl a m−2. Dominant species were Nitzschia stellata, N. lecointei, and Entomoneis kjellmanii, while the proportion of Berkeleya adeliensis increased steadily during spring. Despite being obtained later in the season, the Cape Hallett data show considerably lower standing stocks of chlorophyll ranging from 0.11 to 36.8 mg Chl a m−2. This difference was attributed to a strong current, which may have ablated much of the bottom ice biomass and provided biomass to the water below. This loss of algae from the bottom of the ice may explain why the ice community contributed only 2% of the standing stock in the total water column. Dominant species at Cape Hallett were Nitzschia stellata, Fragilariopsis curta and Cylindrotheca closterium. The low biomass at Cape Hallett and the prevalence of smaller-celled diatoms in the bottom ice community indicate that the ice here is more typical of pack ice than fast ice. Further data will allow us to quantify and model the extent to which ice-driven dynamics control the structure and function of the sea ice ecosystem and to assess its resilience to changing sea ice conditions.
Diversity and distribution of mollusc assemblages on the Victoria Land coast and the Balleny Islands, Ross Sea, Antarctica
Authors: Schiaparelli Stefano , Lörz Anne-Nina , Cattaneo-Vietti Riccardo
Published: November 2006

In 2004 as part of the joint Latitudinal Gradient Project in the Ross Sea, cruises of RV Tangaroa and RV Italica along the Victoria Land coast and the Balleny Islands collected 142 species of mollusc (four Polyplacophora, 99 Gastropoda, 37 Bivalvia and two Scaphopoda). About 20% of these species represent new records for the Ross Sea quadrant. The species richness was found to be higher at 71–72°S (Cape Hallett–Cape Adare) and lower at 74–75°S (Terra Nova Bay–Cape Russell) using Shannon-Wiener's H', Pielou's J' and Simpson's λ indices, as well as by using species richness estimators (e.g. ICE, Chao 2, Jack 2). The Balleny Islands (65–67°S), though not exhaustively sampled, show diversity values comparable to those of Terra Nova Bay–Cape Russell. These islands, located in the main Antarctic Coastal Current, appear to represent a crossroads in the Southern Ocean, with mollusc and other invertebrate species present, that have previously been recorded only from the Weddell Sea. The higher diversity in the Cape Hallett–Cape Adare area is not easy to interpret, but could be a result of the intense iceberg scouring off the two capes, observed from seafloor mapping, a factor that is known to enhance species diversity at the regional scale. The existence of a decreasing trend in diversity towards higher latitudes along the Victoria Land coast cannot yet be shown, due to the large gaps in sampling coverage.
Accounting for local scale variability in benthos: implications for future assessments of latitudinal trends in the coastal Ross Sea
Authors: Cummings Vonda , Thrush Simon , Norkko Alf , Andrew Neil , Hewitt Judi , Funnell Greig , Schwarz Anne-Maree
Published: November 2006

This paper is a contribution to the Latitudinal Gradient Project. It describes macro and epifaunal assemblages and habitats at three shallow water locations at the southern end of the western Ross Sea coast, and investigates relationships between faunal composition and environmental characteristics. Many variables (e.g. substrate type, sediment composition, depth, latitude, longitude) contributed to explaining the differences in community composition between locations, with latitude (a likely surrogate for broader scale factors, e.g. ice cover) one of the most important. The percentage explained by environmental characteristics was strongly scale dependent, decreasing with increasing scale of observation. As much as 66% and 75% of the variability in macrofaunal and epifaunal assemblages, respectively, was explained at the smallest scale (i.e. between transects within a location), compared to 9–18% and 11–32%, respectively, at the scale of the entire study. This relationship was also true for species richness and total abundance. This suggests that while small-scale habitat variability will not confound our ability to detect latitudinal gradients in future studies, adequately quantifying the environmental factors important in structuring these communities at larger (latitudinal) spatial scales will be important. Finally, large differences in habitat structure did not translate into large differences in the diversity of fauna, illustrating the difficulty of predicting faunal composition in the Ross Sea based on seafloor topography alone.
Exchange between populations of Adamussium colbecki (Mollusca: Bivalvia) in the Ross Sea
Authors: Guidetti Marta , Marcato Stefania , Chiantore Mariachiara , Patarnello Tomaso , Albertelli Giancarlo , Cattaneo-Vietti Riccardo
Published: November 2006

The endemic Antarctic scallop Adamussium colbecki (Mollusca: Bivalvia) represents a key species in the Ross Sea littoral benthic ecosystem, locally reaching very high densities. This species has an annual gametogenic cycle, with a summer spawning event, and a pelagic larval behaviour. This paper aims at describing population structure and genetic polymorphism (using AFLP) of the large populations inhabiting the Ross Sea (Terra Nova Bay and McMurdo Sound) in order to investigate possible genetic exchange between A. colbecki in these areas. In Terra Nova Bay, size-frequency distributions show, generally, the dominance of large individuals, although site related differences are found in the abundance of smaller size classes (less than 40 mm), suggesting that recruitment is not a regular event. All McMurdo sites are characterized by large individuals and, at least during this sampling period, recruitment is completely absent. Nuclear DNA analyses show that the largest differences are found at the largest scale (between McMurdo Sound and Terra Nova Bay), but all populations sampled, even at a smaller spatial scale, have a well-settled genetic structure, notwithstanding the pelagic larval strategy. The panmixia hypothesis has therefore to be rejected for this species.