bluuebunny/crossref_metadata_2025 huggingface dataset:
First determination of the incidence of the unique TOR1A gene mutation, c.907delGAG, in a Mediterranean population
Authors: Frédéric Mélissa , Lucarz Estelle , Monino Christine , Saquet Céline , Thorel Delphine , Claustres Mireille , Sylvie Tuffery‐Giraud , Gwenaelle Collod‐Béroud
Published: February 2007

The c.907delGAG mutation in the TOR1A gene (also named DYT1) is the most common cause of early‐onset primary dystonia. The mutation frequency and prevalence have so far been only estimated from rare clinical epidemiological reports in some populations. The purpose of this study was to investigate the incidence at birth of the c.907delGAG mutation in a French‐representative mixed population of newborn from South‐Eastern France. We applied an automated high‐throughput genotyping method to dried blood spot samples from 12,000 newborns registered in Hérault between 2004 and 2005. Only one allele was found to carry the mutation, which allows to determine its incidence at birth as 1/12,000 per year in this area. © 2007 Movement Disorder Society
Belly dancer's syndrome following central pontine and extrapontine myelinolysis
Authors: Roggendorf Julia , Burghaus Lothar , Liu Wei‐Chi , Weisenbach Simon , Eggers Carsten , Fink Gereon R. , Hilker Ruediger
Published: February 2007

We report on a woman with delayed‐onset of belly dancer's syndrome 5 months after central pontine and extrapontine myelinolysis (CPM/EPM) and severe hyponatriemia. This case demonstrates that basal ganglia lesions in EPM can be the underlying pathoanatomic substrate for the rarely observed belly dancer's syndrome. The sequential appearance of extrapyramidal symptoms might reflect an ongoing but ineffective or deficient remyelination process. The presence of CPM/EPM should be considered in patients with involuntary dyskinesias of the abdominal wall. © 2007 Movement Disorder Society
Exact boundary controllability for non‐autonomous quasilinear wave equations
Authors: Wang Zhiqiang
Published: February 2007

In this paper, we first show that quite different from the autonomous case, the exact boundary controllability for non‐autonomous wave equations possesses various possibilities. Then we adopt a constructive method to establish the exact boundary controllability for one‐dimensional non‐autonomous quasilinear wave equations with various types of boundary conditions. Finally, we apply the results to multi‐dimensional quasilinear wave equation with rotation invariance. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization and multilineage differentiation of embryonic stem cells derived from a buffalo parthenogenetic embryo
Authors: Sritanaudomchai Hathaitip , Pavasuthipaisit Kanok , Kitiyanant Yindee , Kupradinun Piengchai , Mitalipov Shoukhrat , Kusamran Thanit
Published: February 2007

Embryonic stem (ES) cells derived from mammalian embryos have the ability to form any terminally differentiated cell of the body. We herein describe production of parthenogenetic buffalo (Bubalus Bubalis) blastocysts and subsequent isolation of an ES cell line. Established parthenogenetic ES (PGES) cells exhibited diploid karyotype and high telomerase activity. PGES cells showed remarkable long‐term proliferative capacity providing the possibility for unlimited expansion in culture. Furthermore, these cells expressed key ES cell‐specific markers defined for primate species including stage‐specific embryonic antigen‐4 (SSEA‐4), tumor rejection antigen‐1‐81 (TRA‐1‐81), and octamer‐binding transcription factor 4 (Oct‐4). In vitro, in the absence of a feeder layer, cells readily formed embryoid bodies (EBs). When cultured for an extended period of time, EBs spontaneously differentiated into derivatives of three embryonic germ layers as detected by PCR for ectodermal (nestin, oligodendrocytes, and tubulin), mesodermal (scleraxis, α‐skeletal actin, collagen II, and osteocalcin) and endodermal markers (insulin and α‐fetoprotein). Differentiation of PGES cells toward chondrocyte lineage was directed by supplementing serum‐containing media with ascorbic acid, β‐glycerophosphate, and dexamethasone. Moreover, when PGES cells were injected into nude mice, teratomas with derivatives representing all three embryonic germ layers were produced. Our results suggest that the cell line isolated from a parthenogenetic blastocyst holds properties of ES cells, and can be used as an in vitro model to study the effects of imprinting on cell differentiation and as an a invaluable material for extensive molecular studies on imprinted genes. Mol. Reprod. Dev. 74: 1295–1302, 2007. © 2007 Wiley‐Liss, Inc.
Dynamics of lamin A/C in porcine embryos produced by nuclear transfer
Authors: Lee Kiho , Fodor William L. , Machaty Zoltan
Published: February 2007

This study was conducted to investigate the presence of lamin A/C in porcine nuclear transfer embryos and to determine whether lamin A/C can serve as a potential marker for nuclear reprogramming. First, lamin A/C was studied in oocytes and embryos produced by fertilization or parthenogenetic oocyte activation. We found that lamin A/C was present in the nuclear lamina of oocytes at the germinal vesicle stage while it was absent in mature oocytes. Lamin A/C was detected throughout preimplantation development in both in vivo‐derived and parthenogenetic embryos. Incubation of the activated oocytes in the presence of α‐amanitin (an inhibitor of RNA polymerase II), or cycloheximide (a protein synthesis inhibitor) did not perturb lamin A/C assembly, indicating that the assembly resulted from solubilized lamins dispersed in the cytoplasm. In nuclear transfer embryos, the lamin A/C signal that had previously been identified in fibroblast nuclei disappeared soon after fusion. It became detectable again after the formation of the pronucleus‐like structure, and all nuclear transfer embryos displayed lamin A/C staining during early development. Olfactory bulb progenitor cells lacked lamin A/C; however, when such cells were fused with enucleated oocytes, the newly formed nuclear envelopes stained positive for lamin A/C. These findings suggest that recipient oocytes remodel the donor nuclei using type A lamins dispersed in the ooplasm. The results also indicate that lamin A/C is present in the nuclear envelope of pig oocytes and early embryos and unlike in some other species, its presence after nuclear transfer is not an indicator of erroneous reprogramming. Mol. Reprod. Dev. 74: 1221–1227, 2007. © 2007 Wiley‐Liss, Inc.
Design and Implementation of a Novel Quench Flow Reactor for the Study of Nascent Olefin Polymerisation
Authors: Di Martino Audrey , Broyer Jean‐Pierre , Schweich Daniel , de Bellefon Claude , Weickert Guenter , McKenna Timothy F. L.
Published: February 2007

A novel stopped flow reactor system is described in the current work, along with the underlying design philosophy. While the concept of stopped flow technology is not recent, this system is the first to be designed with the objective of studying particle morphology, and to work at extremely short (40 ms) residence times. It is shown that traditional chemical engineering principles are required to properly design and operate this type of reactor, and that when correctly design, it is a very flexible tool for the study of nascent polymerisation of olefins.

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Vibration of axisymmetric composite piezoelectric shells coupled with internal fluid
Authors: Larbi W. , Deü J.‐F. , Ohayon R.
Published: February 2007

This paper presents the theoretical and finite element formulations of piezoelectric composite shells of revolution filled with compressible fluid. The originality of this work lies (i) in the development of a variational formulation for the fully coupled fluid/piezoelectric structure system, and (ii) in the finite element implementation of an inexpensive and accurate axisymmetric adaptive laminated conical shell element. Various modal results are presented in order to validate and illustrate the efficiency of the proposed fluid–structure finite element formulation. Copyright © 2007 John Wiley & Sons, Ltd.
External quality assessment of rapid prenatal detection of numerical chromosomal aberrations using molecular genetic techniques: 3 years experience
Authors: Ramsden S. C. , Mann K. , McConnell C. , Hastings R.
Published: February 2007

Objectives

Prenatal diagnosis using rapid molecular genetic techniques is now a widely used method for detecting the most prevalent chromosomal aneuploidies. The object of this work was to develop a methodology for delivering external quality assessment (EQA) appropriate to the needs of routine diagnostic testing laboratories.

Methods

We have provided three rounds of EQA using 15 different samples over 3 years. The scheme has developed to assess both the genotyping accuracy of the results and the appropriateness of the clinical reports issued to the referring clinician.

Results

Participation in the EQA scheme has increased from 9 to 27 laboratories from across Europe over the three sample distributions. All laboratories have used quantitative fluorescence‐PCR (QF‐PCR) to analyse these samples except for a sole participant in 2006 who used multiplex ligation‐dependent probe amplification (MLPA). In total 265 samples have been distributed, of which four (1.5%) were not reported due to technical failures and one (0.4%) was reported incorrectly and must be regarded as a genotyping error.

Conclusions

We have demonstrated a significant and increasing demand for EQA in the rapid detection of aneuploidies in UK and other European laboratories. Using the methodologies described, we have had a very low rate of technical failures and demonstrated a high level of genotyping accuracy. However, the quality of the clinical reports was variable and suggestions are made for improvement. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of molecular weight on shape memory behavior in polyurethane films
Authors: Chen Shaojun , Hu Jinlian , Liu Yeqiu , Liem Haiming , Zhu Yong , Meng Qinghao
Published: February 2007

Understanding the relationship between the number‐average molecular weight (Mn) and the shape memory behavior of polymers is crucial for a complete picture of their thermomechanical properties, and hence for the development of smart materials, and, in particular, in textile technology. We report here on the study of shape memory properties as a function of Mn of polymers. Shape memory polyurethanes (SMPUs) of different Mn were synthesized, with various catalyst contents or molar ratio(r = NCO/OH) in the composition. In particular, two types of SMPU, namely Tm and Tg types according to their switch temperature type, were synthesized to compare the influence of Mn on their shape memory behavior. X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, and shape memory behavior results for the SMPUs are presented. The results indicate that the melting temperature (Tm), the glass transition temperature (Tg), the crystallinity, and the crystallizability of the soft segment in SMPUs are influenced significantly by Mn, before reaching a critical limit around 200 000 g mol−1. Characterization of the shape memory effect in PU films suggests that the Tm‐type films generally show higher shape fixities than the Tg‐type films. In addition, this shape fixity decreases with increasing Mn in the Tg‐type SMPU, but the shape recovery increases with Mn in both types of SMPU. The shape recovery temperature, in contrast, decreases with Mn as suggested by the result of their thermal strain recovery. It is concluded that a higher molecular weight (Mn > 200 000 g mol−1) is a prerequisite for SMPUs to exhibit higher shape recovery at a particular temperature. Copyright © 2007 Society of Chemical Industry
SNi fragmentations of alkoxychlorocarbenes – a perspective
Authors: Moss Robert A. , Fu Xiaolin , Sauers Ronald R.
Published: February 2007

After a review of the early literature concerning SNi fragmentations of alkyl chlorosulfites and chloroformates, we present experimental and computational results for the SNi fragmentations of alkoxychlorocarbenes. Examples include cyclohexyloxychlorocarbene, 7‐norbornyloxychlorocarbene, 3‐nortricyclyloxychlorocarbene, exo‐5‐norbornenyl‐2‐oxychlorocarbene, and endo‐5‐norbornenyl‐2‐oxychlorocarbene. Computations generate a ‘family’ of closely related charge‐separated SNi structures which approximate asynchronous, polar, concerted transition states and tight, short‐lived ion pair intermediates. The precise description and behavior of these species in a given reaction depends on the identities of the alkyl group, the potential counterion, and the solvent. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing the transport properties of organic penetrants in low‐density polyethylene using free volume models
Authors: Ritums J. E. , Neway B. , Doghieri F. , Bergman G. , Gedde U. W. , Hedenqvist M. S.
Published: February 2007

Three models, two of them relying on free volume—the Cohen–Turnbull–Fujita (CTF) model and the Vrentas–Duda (VD) model, and the third being empirical using an exponential concentration dependence of the diffusivity, were applied to desorption data for a series of alkane penetrants (2,2‐dimethylbutane, cyclohexane, n‐hexane, n‐decane, and n‐tetradecane) in low‐density polyethylene. The CTF model described the desorption data very well and better than the exponential diffusion law. The VD model with the attractive feature of being based on independently determined parameters was unsuccessful in describing the desorption data. Diffusivity data indicated that the three components outside the crystal core were less accessible to n‐tetradecane than to the other penetrants. This indication was further substantiated by solubility data. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 723–734, 2007
Electrical conductivity and polarization processes in nanocomposites based on isotactic polypropylene and modified synthetic clay
Authors: Motori Antonio , Montanari Gian Carlo , Saccani Andrea , Patuelli Francesca
Published: February 2007

The direct‐current and alternating‐current electrical behavior of nanocomposites, formed by isotactic polypropylene partially modified with maleic anhydride and filled with different amounts of modified synthetic clay, has been studied; moreover, the conduction mechanisms and the relaxation processes that take place in the materials have been investigated. The nanocomposites containing small clay contents exhibit direct‐current insulating properties comparable to or even higher than those observed in the polymeric matrix. However, as the synthetic clay content increases, the ionic contribution to conductivity becomes considerable. The nanocomposites also show a slightly higher permittivity and loss factor than the host material because of the appearance of a thermally activated relaxation process in the frequency range of 10−2 to 102 Hz at the investigated temperatures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 705–713, 2007
Absence of epidermal growth factor receptor gene mutations in patients with hormone refractory prostate cancer not responding to gefitinib
Authors: Curigliano Giuseppe , Pelosi Giuseppe , De Pas Tommaso , Renne Giuseppe , De Cobelli Ottavio , Manzotti Michela , Spitaleri Gianluca , de Braud Filippo
Published: February 2007

BACKGROUND

Mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in human cancers are associated with increased sensitivity to anilinoquinazoline EGFR inhibitors. To our knowledge no data have been reported on EGFR gene mutations in hormone refractory prostate cancer (HRPC).

METHODS

Between March 2003 and December 2004, 23 patients with HRPC received 250 mg oral gefitinib daily in addition to antiandrogen plus luteinizing hormone‐releasing hormone (LH‐RH) analog for at least 2 months or until disease progression. Patients with unresected prostate cancer prospectively underwent trans‐rectal biopsy of primary tumor (before starting gefitinib treatment).

RESULTS

None of the patients demonstrated PSA or objective response to gefitinib. We sequenced exons 18–21 of the EGFR TK domain from genomic DNA isolated from 8 HRPC patients. No patient showed EGFR TK domain mutations.

CONCLUSIONS

Our results show EGFR mutations did not occur in these patients suggesting that gefitinib is unlikely to be effective in patients with tumors not harboring specific EGFR TK domain. Prostate 67: 603–604, 2007. © 2007 Wiley‐Liss, Inc.
Fusion characteristics of rigid PVC/wood‐flour composites by torque rheometry
Authors: Matuana Laurent M. , Kim Jae‐Woo
Published: February 2007

This study was aimed at examining the effects of wood flour contents, wood species (softwood vs. hardwood), and particle size on the fusion characteristics (fusion time, fusion temperature, fusion torque, and fusion energy) of rigid PVC/wood‐flour composites in a torque rheometer. Neat rigid PVC exhibited one fusion peak, whereas the addition of wood flour into the PVC matrix led to two fusion peaks. Increased wood flour content caused a significant increase in the time, temperature, and energy at which fusion between the primary particles started, thereby leading to increased fusion torque, irrespective of the wood flour species. These results implied that rigid PVC filled with wood flour must be processed at higher temperatures than neat resin. Although fusion characteristics of the composites were influenced by the wood species, a clear trend between softwood and hardwood species could not be established. However, finer particles fused more quickly and needed less energy than coarse ones. J. VINYL ADDIT. TECHNOL., 13:7–13, 2007. © 2007 Society of Plastics Engineers.
Ultrasound‐aided extrusion process for preparation of polypropylene–clay nanocomposites
Authors: Lapshin Sergey , Isayev A. I.
Published: February 2007

Two methods for the fabrication of polypropylene/clay nanocomposites using a continuous ultrasound assisted process are compared. In the first approach, a two‐stage process was implemented. The nanocomposites were prepared by using a corotating twin‐screw extruder followed by a single‐screw extruder equipped with an ultrasonic die attachment. In the second method, a single‐stage process was used. The nanocomposites were compounded by using a single‐screw extruder with mixing elements and an ultrasonic die attachment. Two regimens of feeding were realized, namely, starved and flood feeding. The gap size in the ultrasonic treatment zone was varied. Die pressure and power consumption were measured. Similarities and differences of nanocomposites obtained by these two methods are discussed on the basis of their rheological and mechanical properties and their structural characteristics. J. VINYL ADDIT. TECHNOL., 13:40–45, 2007. © 2007 Society of Plastics Engineers.
The 3D Supramolecular Compound {[Cu2(L‐val)2(4,4′‐bipy)(H2O)2](NO3)2}n (L‐val = L‐valine anion, 4,4′‐bipy = 4,4′‐bipyridine)
Authors: Lou Benyong , Huang Xiaodong , Lin Xiangchao
Published: February 2007

{[Cu2(L‐val)2(4,4′‐bipy)(H2O)2](NO3)2}n was synthesized and its crystal structure was determined by X‐ray diffraction. In the presence of 4,4′‐bipyridine, deprotoned L‐valine chelates CuII ions into coordination layers which were linked into a framework by hydrogen‐bonded chains resulting from nitrate anions and water molecules.
Synthesis, Structure and Magnetic Property of an “Adamantane” Type Tetranuclear Iron(III) Complex
Authors: Tian Jin‐Lei , Gu Wen , Yan Shi‐Ping , Liao Dai‐Zheng , Jiang Zong‐Hui
Published: February 2007

A new tetranuclear complex [Fe4L2(μ‐O)2(μ‐>OH)2](ClO4)4·H2O (1), (HL = N,N,N′,N′‐tetrakis‐[(2‐pyridyl)methyl]‐2‐hydroxypropane‐1,3‐diamine) has been synthesized and its crystal structure and magnetic properties are shown. X‐ray crystallography reveals that complex 1 contains a quadruply‐charged, tetranuclear iron(III) cation and four perchlorate anions. In 1, the Fe4O6 core is composed of a tetrahedron of iron atoms bridged by six oxygen atoms (two oxo, two hydroxo, and two alkoxo groups from L). This results in an adamantane‐type geometry with the iron atoms occupying the bridgehead positions. Susceptibility data of 1 indicate strong intramolecular antiferromagnetic coupling of high‐spin FeIII atoms.
Hydrolysis and Oxidation of a 1‐Boryl‐1‐silyl‐alkene. Molecular Structures of 9‐Hydroxy‐9‐borabicyclo[3.3.1]nonane and a Bicyclic Oxasilabora‐heptadecane B2(OSiPh2OSiPh2O)3
Authors: Wrackmeyer Bernd , Khan Ezzat , Kempe Rhett
Published: February 2007

Slow hydrolysis and oxidation of (Z)‐9‐[1‐chlorodiphenylsilyl)‐2‐phenyl‐vinyl]‐9‐borabicyclo[3.3.1]nonane (1) afforded 9‐hydroxy‐9‐borabicyclo[3.3.1]nonane (2) and the bicyclic oxasilabora‐heptadecane B2(OSiPh2OSiPh2O)3 (3), both of which could be isolated as crystalline materials and studied by X‐ray analysis. Molecules of 2 are associated in the crystal lattice by O‐H‐O bridging. The molecular structure of the diborabicyclo[5.5.5]heptadecane 3 is built by 12‐membered rings with the boron atoms in bridge head positions. The gas phase structures of 2 (2a) and of the parent 3a, B2(OSiH2OSiH2O)3, were optimized at the B3LYP/6‐311+G(d,p) level of theory.
Nickel(II) Complexes of 1‐Alkyl‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane – Synthesis and Solid‐State Structures
Authors: Mebi Charles A. , Frost Brian J.
Published: February 2007

Complexes [NiI3(mpta)2]I (1) and [NiI3(ppta)2]I (2) have been synthesized by reaction of nickel(II) halide salts with ‐1‐methyl‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane iodide (mpta+I−) and 1‐(n‐propyl)‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane bromide (ppta+Br−) respectively. The crystal structures of compounds 1 and 2 are described and are similar, with both compounds crystallizing in monoclinic space groups. The geometry about both nickel atoms is that of a trigonal bipyramid with the cationic phosphine ligands found in the axial positions and the iodide ligands arranged in the equatorial plane.
Synthesis, Molecular Structure, Optical Properties and Electrical Conductivity of Zwitterionic Ferrocenyldithiophosphonates
Authors: Karakus Mehmet , Aydogdu Yıldırım , Celik Omer , Kuzucu Veysel , Ide Semra , Hey‐Hawkins Evamarie
Published: February 2007

Ferrocenyldithiodiphosphetane [FcPS(μ‐S)]2 [Fc = Fe(η5‐C5H4)(η5‐C5H5)] reacts with the aminoethanol derivatives 1‐ethyl‐3‐pyrrolidinol and 2‐(piperazin‐1‐yl)ethanol to give the zwitterionic (O‐ethylammonium)ferrocenyldithiophosphonates $\rm [FcP(S)S(\overline{C_{4}H_{7}N}HEt)]$ (2) and $\rm [FcP(S)S(OC_{2}H_{4}\overline{NHC_{4}H_{8}N}H)]$ (3), which were fully characterized by elemental analysis, IR and NMR spectroscopy and mass spectrometry. The optical and electrical properties of 2 and 3 as well as those of the previously reported [FcP(S)S(OC2H4NHEt2)] (1) were studied. A molecular structure determination of 1 is also reported.
Atomistic Simulation Study of Calcium, Phosphate and Fluoride Ion Association to the Teleopeptide‐Tails of Collagen – Initial Steps to Biomineral Formation
Authors: Schepers Thorsten , Brickmann Jürgen , Hochrein Oliver , Zahn Dirk
Published: February 2007

The attachment of single ions to putative adsorption sites in the tails of collagen fibers is investigated by means of molecular dynamics simulations and discussed with respect to the very early steps of apatite/collagen biomineral formation. Our studies clearly demonstrate an increased flexibility of the tails of the triple‐helical collagen protein. Apart from the termini of the backbone, several side chains were also observed to be freely accessible to ion attachment from aqueous solution. The teleopeptide was systematically scanned for suitable adsorption sites for calcium, phosphate and fluoride ions. Association of these ions was then explored from potential of mean force calculations. The resulting energy profiles reveal a variety of favorable protein‐ion bonds and hint at the suitability of the collagen tails to promote apatite aggregation.
Arachidonic acid regulates the binding of human interferon in human skin fibroblasts
Authors: Menon Sree Devi , Yap W. H. , Lim Andrew , Tan Y. H.
Published: February 2007

The induction of the antiviral state in human fibroblasts by human interferon is inhibited by arachidonic acid, its analogues 5,8,11,14‐eicosatetraynoic and 5,8,11‐eicosatriynoic acids, as well as by sodium arachidonate. The fatty acids myristic or oleic acid and sodium palmitate do not inhibit the antiviral action of interferon. Experiments were conducted to investigate the mechanism by which arachidonic acid could inhibit the action of interferon. No correlation between cellular lipoxygenase activities and the inhibition of antiviral action of interferon was observed in the fatty acid treated cells. Likewise, the cyclooxygenase inhibitors indomethacin and oxyphenylbutazone do not inhibit the interferon‐induced antiviral state. Taken together, the inhibition of interferon action by arachidonates is unlikely to be mediated by cyclooxygenase or lipoxygenase‐generated intermediates, even though arachidonates are known to affect the activity of these enzymesin vitro. Measurement of interferon receptors in the fatty acid treated cells showed that arachidonic acid sodium arachidonate and its analogues decreased the number of human type I interferon receptors available for binding, and inhibited the transcription of the interferon‐induced 6–16 gene and the induction of cellular (2′–5′)‐oligoadenylate synthetase, suggesting the mechanism of inhibition is mediated at the level of the interferon receptor. The significance of the finding that arachidonic acid, a common fatty acid of cells and serum, can affect the antiviral action of interferon is discussed.
Purification of plasmalogens usingRhizopus delemar lipase andNaja naja naja phospholipase A2
Authors: Hirashima Yutaka , Farooqui Akhlaq A. , Murphy Eric J. , Horrocks Lloyd A.
Published: February 2007

Bovine heart ChoGpl (choline glycerophospholipid) and bovine brain EtnGpl (ethanolamine glycerophospholipid) contain diacyl, alkenylacyl and alkylacyl analogs. Purification of plasmalogens was achieved usingR. delemar lipase andN. naja naja phospholipase A2 digestion. TheR. delemar lipase hydrolyzes the acyl bond at the 1‐position of 1,2‐diacyl glycerophospholipids. TheN. naja naja phospholipase A2 has greater activity with diacyl and alkylacyl than with alkenylacyl glycerophospholipids. These enzymes were mainly used to remove diacyl and alkylacyl analogs respectively. When the diacyl types were removed by double incubation withR. delemar lipase, the plasmalogen content was 94.2%±0.21% (mean±S.E.M., n=4) for PlsCho (plasmenylcholine) and 94.9%±0.19% (mean±S.E.M., n=3) for PlsEtn (plasmenylethanolamine). Recoveries were 74% and 88% respectively. These partially purified plasmalogens were treated withN. naja naja phospholipase A2. Finally, 97.7%±0.24% (mean±S.E.M., n=4) and 98.8%±0.27% (mean±S.E.M., n=3) pure plasmalogens were obtained for PlsCho and PlsEtn respectively. Plasmalogens were recovered in an overall yield of 7.7%±0.7% (mean±S.E.M., n=4) and 10.2%±1.2% (mean±S.E.M., n=3) for PlsCho and PlsEtn.
Metabolism of phosphatidylinositol in plasma membranes and synaptosomes of rat cerebral cortex: A comparison between endogenous Vs exogenous substrate pools
Authors: Navidi Meena , MacQuarrie Ronald A. , Sun Grace Y.
Published: February 2007

The metabolism of phosphatidylinositols (PI) labeled with [14C]arachidonic acid within plasma membranes or synaptosomes was compared to the metabolism of PI prelabeled with [14C]arachidonic acid and added exogenously to the same membranes. Incubation of membranes containing the endogenously‐labeled PI pool in the presence of Ca2+ resulted in the release of labeled arachidonic acid, as well as a small amount of labeled diacylglycerol. Labeled arachidonic acid was effectively reutilized and returned to the membrane phospholipids in the presence of adenosine triphosphate (ATP), CoA, and lysoPI. Although Ca2+ promoted the release of labeled diacylglycerol from prelabeled plasma membranes, this amount was only 17% of the maximal release, i.e., release in the presence of deoxycholate and Ca2+. This latter condition is known to fully activate the PI‐phospholipase C, and incubation of prelabeled plasma membranes resulted in a six‐fold increase in labeled diacylglycerols. On the other hand, when exogenously labeled PI were incubated with plasma membranes in the presence of Ca2+, the labeled diacylglycerols released were 59% of that compared to the fully activated condition. The phospholipase C action was calcium‐dependent, regardless of whether exogenous or endogenous substrates were used in the incubation. In contrast to plasma membranes, intact synaptosomes had limited ability to metabolize exogenous PI even in the presence of Ca2+, although the activity of phospholipase C was similar to that in the plasma membranes when assayed in the presence of deoxycholate and Ca2+. These results suggest that discrete pools of PI are present in plasma membranes, and that the pool associated with the acyltransferase is apparently not readily accessible to hydrolysis by phospholipase C.
Analysis of north atlantic and baltic fish oil triacylglycerols by high‐performance liquid chromatography with a silver ion column
Authors: Laakso Paivi , Christie William W. , Pettersen Jan
Published: February 2007

Triacylglycerols from Atlantic herring (Clupea harengus), sandeel (Ammodytes sp.) and Baltic herring (Clupea harengus membras) have been fractionated by silver ion high‐performance liquid chromatography. An ion exchange column loaded with silver ions was the stationary phase, and a gradient in the mobile phase from 1,2‐dichloroethane/dichloromethane (1∶1, v/v) to acetone and then to acetone/acetonitrile (2∶1, v/v) was used to effect the separation with light‐scattering (i.e., mass) detection. Fractions were collected via a streamsplitter, and fatty acid methyl esters were prepared by transesterification in the presence of an internal standard for identification and quantification by gas liquid chromatography. Triacylglycerols were separated according to the number of double bonds in the fatty acyl residues. Resolution was excellent at first, when the least unsaturated molecules eluted (trisaturated to dimonoene‐monodiene fractions). Base‐line resolution could no longer be achieved when molecules containing trienoic or more highly‐unsaturated fatty acids began to elute because of overlapping components. Nonetheless, some valuable separations of species containing two saturated and/or monoenoic fatty acids and one polyenoic fatty acid were achieved. Double bond indices (average number of double bonds in each triacylglycerol molecule) were calculated to estimate the separations possible. Fractions containing at least 11–14 double bonds per molecule were obtained.
Lability of red blood cell membranes to lipid peroxidation: Application to humans fed polyunsaturated lipids
Authors: Fraga Cesar G. , Tappel A. L. , Leibovitz Brian E. , Kuypers Franz , Chiu Daniel , Iacono James M. , Kelley Darshan S.
Published: February 2007

Red blood cell membranes (RBCM) were used to estimate human red blood cell lability to lipid peroxidationin vitro. RBCM were prepared from blood collected from humans fed diets with either 3 or 15% polyunsaturated fatty acids for 80 days. RBCM were isolated by centrifugation, and oxidative stress was induced byin vitro incubation with 0.1 or 0.5 mM tert‐butyl hydroperoxide (t‐BOOH) in the presence of 0.5 mg added hemoglobin. Lipid Peroxidation was evaluated by measurement of thiobarbituric acid‐reactive substances (TBARS). Lipid peroxidation correlated with the protein content of RBCM in both noninduced and t‐BOOH‐induced lipid peroxidation systems. TBARS production was dependent on the amount of t‐BOOH added to the RBCM. The production of TBARS by RBCM incubated with 0.5 mM t‐BOOH was correlated with the arachidonic acid content in the red blood cells (RBC) from which RBCM were prepared. The methodology developed was useful for comparative estimations of the lability of RBCM to lipid peroxidation.
Solubilization and partial purification of cholinephosphotransferase in hamster tissues
Authors: O Kar‐min , Choy Patrick C.
Published: February 2007

CDP choline:1,2‐diacylglycerol cholinephosphotransferase (EC 2.7.8.2) is located on the cytoplasmic side of the endoplasmic reticulum, and catalyzes the final step in the synthesis of phosphatidylcholine via the CDP choline pathway. The enzyme was solubilized from hamster liver microsomes by 3% Triton QS‐15, and partially purified by DEAE‐Sepharose chromatography and Sepharose 6B chromatography. The microsomal and partially purified enzymes displayed similar pH profile, and both showed absolute requirement for Mg++ or other divalent cations. The Km values of CDP choline were similar between microsomal and partially purified enzyme, whereas the Km value for diacylglycerol was substantially lowered when the enzyme was partially purified. Hamster heart cholinephosphotransferase was not solubilized by Triton QS‐15.
Lipids in vascular function
Authors: Sellmayer Alois , Hrboticky Nina , Weber Peter C.
Published: February 2007

Physiological and pathological vascular responses depend on the action of numerous intercellular mediators, ranging from hormones to gases like nitric oxide, proteins, and lipids. The last group consists not only of the different types of lipoproteins, but also includes a broad array of other lipophilic signaling molecules such as fatty acids, eicosanoids, phospholipids and their derivatives, sphingolipids and isoprenoids. Due to space limitations, it is impossible to discuss all the vascular effects of lipophilic mediators or compounds. Therefore, we will focus on one of the most important lipid‐mediated diseases, atherosclerosis. Lipoproteins and especially their native or oxidized lipid compounds affect vascular function in many different ways, and these effects do not only modulate atherogenesis but are of paramount physiological and pathophysiological importance in other diseases, such as inflammation, tumor metastasis, or normal wound healing.
Dietary fatty acids and coronary heart disease
Authors: Nordøy Arne
Published: February 2007

The effects of dietary fats have been established in epidemiological and intervention studies and through relationship to risk factors for development of coronary heart disease (CHD). During a period where the impressive effects of hydroxymethylglutaryl‐CoA reductase inhibitors on the mortality of CHD dominate the medical journals, it is important to realize the major effects of dietary fatty acids on a series of events included in the multifactorial disorder of CHD.
Administration of docosahexaenoic acid influences behavior and plasma catecholamine levels at times of psychological stress
Authors: Hamazaki Tomohito , Sawazaki Shigeki , Nagasawa Tetsuro , Nagao Yoko , Kanagawa Yuko , Yazawa Kazunaga
Published: February 2007

The purpose of the present research was to clarify the effect of docosahexaenoic acid (DHA) intake on behavior and plasma catecholamines (CA). In Study 1, 42 students took either DHA‐rich oil capsules containing 1.5–1.8 g DHA/d or control oil capsules containing 97% soybean oil plus 3% of another fish oil for 3 mon in a double‐blind fashion. They took a psychological test (PF Study) at the start and end of the study. This study started at the end of summer vacation and ended just before the final exams. In the control group, external aggression (aggression against others) in PF Study was significantly increased at the end of the study as compared with that measured at the start (+8.9%), whereas it was not significantly changed in the DHA group (−1.0%). In a similar double‐blind study (Study 2), we measured external aggression under nonstressful conditions. External aggression slightly decreased in the control group, whereas there were no significant changes in the DHA group. In Study 3 with 14 students, plasma CA were measured at the start and end of capsule administration period of 2 mon. Subjects were under continuous stress of the final exams that lasted throughout the whole study period. The ratio of plasma epinephrine to norepinephrine concentrations was significantly increased in the DHA group (78%), whereas it stayed at the same level in the control group. In Study 4, mice were fed either DHA‐deficient diet or ‐sufficient diet for 4 wk, and their rearing frequency (an anxiety index) was measured. In the DHA‐sufficient group, the rearing frequency was significantly less than in the other group. These effects of DHA intake may be applied to people in an attempt to ameliorate stress‐related diseases.
n‐3 fatty acids in the prevention of cardiac arrhythmias
Authors: Leaf Alexander , Kang Jing X. , Xiao Yong‐Fu , Billman George E.
Published: February 2007

In animals and probably in humans n‐3 polyunsaturated fatty acids (PUFA) are antiarrhythmic. A report follows on the recent studies of the antiarrhythmic actions of PUFA. The PUFA stabilize the electrical activity of isolated cardiac myocytes by inhibiting sarcolemmal ion channels, so that a stronger electrical stimulus is required to elicit an action potential and the relative refractory period is markedly prolonged. This appears at present to be the probable major antiarrhythmic mechanism of PUFA.
Rats with low levels of brain docosahexaenoic acid show impaired performance in olfactory‐based and spatial learning tasks
Authors: Greiner Rebecca Sheaff , Moriguchi Toru , Hutton Ana , Slotnick Burton M. , Salem Norman
Published: February 2007

Studies were carried out to determine if decreased levels of central nervous system docosahexaenoic acid (DHA), a result of consuming an n‐3‐deficient diet, had an effect on learning‐ and memory‐related behaviors in adult male rats. Females were reared on an n‐3‐deficient or n‐3‐adequate diet beginning at 21 d of life. Their male pups, the F2 generation, were weaned to the diet of the dam and tested at 9–12 wk of age. An olfactory‐based discrimination and Morris water maze task were used to assess performance. Whole brain was collected after the behavioral experiments and central nervous system fatty acid content was analyzed in olfactory bulb total lipid extracts. F2 generation male rats consuming the n‐3‐deficient diet had an 82% decrease in DHA compared to rats consuming the n‐3‐adequate diet. The n‐3‐deficient animals made significantly more total errors in a 7‐problem, 2‐odor discrimination task compared to the n‐3‐adequate group. Furthermore, the escape latency in the Morris water maze task was significantly longer for the n‐3‐deficient rats compared to the n‐3‐adequate rats. These results indicate that rats with decreased DHA levels in the central nervous system perform poorer in these tasks compared to rats with higher DHA levels and suggest the presence of learning deficits in these animals.
Regulation of cellular 15‐lipoxygenase activity on pretranslational, translational, and posttranslational levels
Authors: Kühn Hartmut , Heydeck Dagmar , Brinckman Roland , Trebus Frank
Published: February 2007

In mammalian cells, enzymatic lipid peroxidation catalyzed by 12/15‐lipoxygenases is regulated by pretranslational, translational, and posttranslational processes. In rabbits, rats, and mice induction of experimental anemia leads to a systemic up‐regulation of 12/15‐lipoxygenases expression. In addition, interleukins‐4 and ‐13 were identified as strong up‐regulators of this enzyme in human and murine monocyte/macrophages and in the lung carcinoma cell line A549, and the interleukin‐4(13) cell surface receptor as well as the signal transducer and activator of transcription 6 (STATG) appears to be involved in the signal transduction cascade. On the level of translation, 15‐lipoxygenase synthesis is blocked by the binding of regulatory proteins to a characteristic gurnine‐cytosine‐rich repetitive element in the 3′‐untranslated region of the rabbit 15‐lipoxygenase mRNA, and the formation of such 15‐lipoxygenase mRNA/protein complexes was identified as molecular reason for the translational inactivity of the 15‐lipoxygenase mRNA in immature red blood cells. However, proteolytic breakdown of the regulatory proteins which were recently identified as hnRNP K and hnRNP E1 overcomes translational inhibition during later stages of reticulocyte maturation. For maximal intracellular activity, 12/15‐lipoxygenases require a rise in cytosolic calcium concentration inducing a translocation of the enzyme from the cytosol to cellular membranes as well as small amounts of preformed hydroperoxides which act as essential activators of the enzymes. 12/15‐Lipoxygenases undergo irreversible suicide inactivation during fatty acid oxygenation, and this process may be considered an element of down‐regulation of enzyme activity. Suicide inactivation and proteolytic breakdown may contribute to the disappearance of functional 12/15‐lipoxygenase at later stages of erythropoiesis.
New products from the agri‐food industry: The return of n‐3 fatty acids into the food supply
Authors: Simopoulos Artemis P.
Published: February 2007

The meat from animals and fish in the wild, chicken eggs produced under complete natural conditions, and wild plants contain higher amounts of n‐3 fatty acids compared to domesticated or cultivated ones. The composition of meats, fish, and eggs is dependent on animal feed. Fish‐meal, flax, and n‐3 from algae in animal feeds increase the n‐3 fatty acid content of egg yolks and lead to the availability of n‐3 fatty acidenriched eggs in the marketplace. Research is ongoing for the production of n‐3 fatty acid‐enriched products from poultry, beef, lamb, pork, milk, bakery products, etc. In the case of n‐3 fatty acid‐enriched eggs, the egg under complete natural conditions (Greek or Ampelistra egg) can serve as a guide for proper composition. Otherwise, the amount of n‐3 fatty acids is determined by the organoleptic properties of the products. It is essential in the process of returning the n‐3 fatty acids into the food supply that the balance of n‐6/n‐3 fatty acids in the diet that existed during evolution is maintained. Clinical investigations confirm the importance of n‐3 fatty acids for normal function during growth and development and in the modulation of chronic diseases. The availability of n‐3 fatty acid‐enriched products should lead to improvements in the food supply. Pregnant and lactating women and infants should benefit since their diet is deficient in n‐3 fatty acids, especially for the vegetarians among them. Studies with n‐3‐enriched eggs lower cholesterol levels, platelet aggregation, and blood pressure. Since cardiovascular disease, hypertension, and autoimmune, allergic, and neurological disorders appear to respond to n‐3 fatty acid supplementation, a diet balanced in n‐3 and n‐6 fatty acids consistent with the diet during human evolution should decrease or delay their manifestation.
Intestinal absorption of unconjugated dihydroxy bile acids: Non‐mediation by the carrier system involved in long chain fatty acid absorption
Authors: Stremmel Wolfgang , Hofmann Alan F.
Published: February 2007

Experiments were performed using isolated mucosal cells from the rat jejunum or using the perfused jejunum in the anesthetized rat to test whether lipophilic unconjugated dihydroxy bile acids are absorbed from the proximal small intestine via the same carrier mechanism involved in the uptake of long chain fatty acids. With isolated jejunal mucosal cells, the cellular uptake rate of deoxycholic acid or chenodeoxycholic acid increased linearly with time, showed no evidence of saturation, and was not decreased by the presence of a monospecific antibody to the membrane fatty acid binding protein. In contrast, oleate uptake was saturable, was inhibited by the same antibody, but was not affected by the presence of chenodeoxycholic acid or deoxycholic acid. Bile acid uptake by isolated enterocytes occurred at one‐eighth the rate of fatty acid uptake if expressed in relation to total solute concentration; if expressed in relation to monomeric concentration, initial bile acid uptake was four orders of magnitude slower than fatty acid uptake. In the isolated perfused jejunal segment, chenodeoxycholic acid and deoxycholic acid uptake was not influenced by the presence of the antibody to membrane fatty acid binding protein, whereas absorption of oleate was inhibited by more than 70%. These experiments indicate that absorption of unconjugated lipophilic dihydroxy bile acids in the rodent jejunum does not involve the carrier mediated uptake mechanism involved in the absorption of long chain fatty acids—the mechanism is likely to be passive nonionic diffusion.
The uptake of (R,R,R)α‐tocopherol by human endothelial cells in culture
Authors: Chan Alvin C. , Tran Khai
Published: February 2007

Endothelial cells from human umbilical cord vein in culture incorporate physiological and pharmacological amounts of (R,R,R)α‐tocopherol in a time‐dependent and dose‐dependent manner. Incorporated tocopherol was found to associate predominantly with membrane fractions of the cell. When expressed on the basis of organelle protein, the highest amount of tocopherol was found in plasma membrane, and decreasing amounts in mitochondria, endoplasmic reticulum and cytosol. With the relatively wide range of tocopherol concentrations used in these studies (23.2–92.8 μM), there was no apparent toxicity on the cells as judged by unaltered cell numbers and cell viability. When the cells were enriched with tocopherol and cell tocopherol levels were monitored in tocopherol‐free medium, there was a rapid phase of tocopherol disappearance, which was followed by a slower phase. The half‐time for the disappearance of incorporated tocopherol was found to be approximately 65±8.6 hr (mean±SD, n=3). The results of this study clearly show that human endothelial cells in culture are a feasible model for the study of vitamin E uptake. The cell culture model could potentially be used to study other fat‐soluble vitamins and essential nutrients.
Effects of dietary fish oil on biliary phospholipids and prostaglandin synthesis in the cholesterol‐fed pairie dog
Authors: Booker Michael L. , Scott Thayer E. , La Morte Wayne W.
Published: February 2007

Cholesterol gallstone formation in the prairie dog is accompanied by an increase in the percentage of biliaryphospholipids containing arachidonic acid, and an increase in gallbladder prostaglandin (PG) synthesis, but the pathogenetic significance of these changes is unclear. Dietary supplementation with eicosapentaenoic acid (EPA), an omega‐3 fatty acid which is commonly found in fish oil, decreases prostaglandin synthesis in some tissues by replacing arachidonic acid, and by competitively inhibiting prostaglandin synthesis. We studied the effect of dietary fish oil on gallbladder PG synthesis, and the relative abundance of various molecular species of phosphatidylcholines and phosphatidylethanolamines in bile and gallbladder epithelium in the cholesterol‐fed prairie dog. Prairie dogs were maintained for 4 weeks on one of four diets: i) control, ii) cholesterol‐supplemented (0.34%), iii) menhaden oil (50 g/kg chow), or iv) cholesterol plus menhaden oil. Supplementation with menhaden oil resulted in a replacement of arachidonic and linoleic acids with EPA and docosahexaenoic acids in the phospholipids of bile and gallbladder mucosa. In cholesterol‐fed animals, supplementation with menhaden oil prevented increased gallbladder PG synthesis. Menhaden oil also reduced the incidence of cholesterol monohydrate crystals among cholesterol‐fed animals (9/20 with cholesterol plus menhaden oil vs 21/22 with cholesterol alone), but the improvement could not clearly be attributed to decreased PG synthesis since supplementation with menhaden oil also increased the total phospholipid concentration in bile, and decreased the degree of cholesterol saturation. These results demonstrate that dietary supplementation with omega‐3 fatty acids significantly influences biliary phospholipids, and decreases the incidence of cholesterol monohydrate crystal formation in this animal model.