bluuebunny/crossref_metadata_2025 huggingface dataset:
Major fetal abnormalities associated with positive screening tests for Smith‐Lemli‐Opitz syndrome (SLOS)
Authors: Craig Wendy Y. , Haddow James E. , Palomaki Glenn E. , Roberson Marie
Published: February 2007

Objective

Determine the relationship between positive screening interpretations for Smith‐Lemli‐Opitz syndrome (SLOS) and other fetal abnormalities, to aid counseling and diagnostic activities.

Methods

An SLOS screening algorithm was incorporated into California's second‐trimester screening program for Down syndrome and open neural tube defects (ONTDs). Between 2002 and 2004, 777 088 pregnant women were given an SLOS risk interpretation, using alpha‐fetoprotein (AFP), unconjugated estriol (uE3), and human chorionic gonadotrophin (hCG) measurements. Outcomes were obtained in 98.8% of screen‐positive pregnancies.

Results

SLOS screen positives, alone or in combination with screen positives for other fetal disorders (Down syndrome, trisomy 18, ONTD), were associated with a high risk for fetal pathology. Type and frequency of chromosomal or anatomic abnormalities (or fetal death) varied according to screen‐positive combination. Among 2018 screen‐positive pregnancies, 644 fetal deaths were identified. Among the 1374 viable pregnancies, 519 were screen positive for SLOS alone; two SLOS cases and 51 other serious abnormalities were identified (14 aneuploidies; 37 anatomic). The remaining 855 were also screen positive for at least one other disorder; two SLOS cases and 327 other abnormalities were identified (180 aneuploidies; 157 anatomic).

Conclusion

For screening programs implementing the SLOS algorithm, the present data may be useful for counseling and to guide diagnostic studies. Copyright © 2007 John Wiley & Sons, Ltd.
Reasons for antidepressant prescriptions in Canada
Authors: Patten Scott B. , Esposito Eleonora , Carter Brian
Published: February 2007

Purpose

To describe reasons reported by physicians making recommendations for treatment with antidepressant medications.

Methods

Data collected by IMS Health Canada in a database called the Canadian Disease and Therapeutic Index (CDTI) were used in this analysis. CDTI data are collected from a representative sample of office‐based physicians who complete diaries in their practices during selected sampling periods. A drug recommendation is recorded each time a treatment is recommended. The data are weighted to produce national estimates of the frequency of such recommendations.

Results

The frequency of recommendations for antidepressant treatment increased between 2000 and 2004. However, there was a slight decrease in 2005. Two types of antidepressant medications, tricyclic antidepressants (TCAs) and trazodone showed distinct patterns of use. TCAs were more commonly used for non‐psychiatric indications than for psychiatric indications, especially for sleep‐ and pain‐related reasons. Trazodone was frequently recommended for sleep problems. The proportion of recommendations for depressive disorders for antidepressants as a group remained stable over the 5‐year study period.

Conclusions

About one‐third of antidepressant recommendations are for reasons other than depression. It can no longer be assumed that the frequency of antidepressant use is a measure of the frequency of pharmacological depression treatment. However, prescription data may be useful for tracking trends. Copyright © 2007 John Wiley & Sons, Ltd.
Isotactic poly(butene‐1) trigonal crystal growth in the melt
Authors: Yamashita Motoi , Hoshino Akitaka , Kato Minoru
Published: February 2007

Crystal growth of the trigonal form of isotactic poly(butene‐1) (it‐PB1) was successfully observed in the melt at atmospheric pressure. The growth rate of trigonal crystals was obtained by in situ optical microscopy. It is one hundredth that of it‐PB1 tetragonal crystals. The growth rate of trigonal crystals, as well as that of tetragonal crystals, shows supercooling dependence derived from the nucleation theory. The value of the kinetic constant K of trigonal crystals is about 3.3 times larger than that of tetragonal crystals. The value of the pre‐exponential factor G0 of trigonal crystals was found to be 41 times as large as that of tetragonal crystals. The difference between these K values can be attributed to the conformational entropy of the ethyl side groups in a nucleating stem. The discrepancy found in the values of G0 could be explained by introducing pinning and nucleation barriers, which originate from the crystal thickness δlc, which does not depend on the crystallization temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 684–697, 2007
Brownian dynamics simulation of polyelectrolyte dilute solutions: Relaxation time and elongational flow
Authors: Pamies R. , Cifre J. G. Hernández , De La Torre J. García
Published: February 2007

The authors used the bead‐and‐spring model and the Brownian dynamics simulation technique including hydrodynamic interaction to study the behavior of dilute polyelectrolyte solutions under elongational flow. First they carried out simulations to determine the longest relaxation time of a polyelectrolyte, finding that the relaxation time depends on the ionic strength of the solution. Then, they studied the coil‐stretch transition of polyelectrolyte molecules in elongational flow and determined the critical value of the elongational rate necessary in order this transition to occur. In this way, they could compute the value of the Deborah number at which coil‐stretch transition sets in for polyelectrolyte dilute solutions. Finally, they studied the power law relationship that relates the critical elongational rate with the molecular weight of the polyelectrolyte. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 714–722, 2007
Improved lower bounds on the randomized complexity of graph properties
Authors: Chakrabarti Amit , Khot Subhash
Published: February 2007

We prove a lower bound of Ω(n4/3 log 1/3n) on the randomized decision tree complexity of any nontrivial monotone n‐vertex graph property, and of any nontrivial monotone bipartite graph property with bipartitions of size n. This improves the previous best bound of Ω(n4/3) due to Hajnal (Combinatorica 11 (1991) 131–143). Our proof works by improving a graph packing lemma used in earlier work, and this improvement in turn stems from a novel probabilistic analysis. Graph packing being a well‐studied subject in its own right, our improved packing lemma and the probabilistic technique used to prove it may be of independent interest. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Understanding engagement: Science demonstrations and emotional energy
Authors: Milne Catherine , Otieno Tracey
Published: February 2007

Although beloved of some chemists and physicists, science demonstrations have been criticized for stifling inquiry and assisting teachers to maintain a power differential between themselves and students in the classroom. This interpretive study reports the unexpected positive learning outcomes for urban science students in two chemistry classes that resulted from the use of science demonstrations during a unit on gas laws. Beginning with an examination of science demonstrations as sites of interactions, researchers observed greater student engagement and positive emotional energy, more sophisticated use by students of symbol systems associated with chemistry, and a greater willingness of students to move between description of the phenomena and submicroscopic explanations. Applying sociology of emotions to analysis of classroom conversations and actions, we examine the nature of engagement and propose explanations for the positive effect of science demonstrations on the engagement, emotional energy, and learning of students. © 2007 Wiley Periodicals, Inc. Sci Ed 91:523–553, 2007
The effects of the physical environment on job performance: towards a theoretical model of workspace stress
Authors: Vischer Jacqueline C.
Published: February 2007

Studies of stress in the work environment pay little attention to features of the physical environment in which work is performed. Yet evidence is accumulating that the physical environment of work affects both job performance and job satisfaction. Contemporary research on stress in the work environment typically focuses on psychosocial factors that affect job performance, strain and employee health, and does not address the growing body of work on the environmental psychology of workspace. This paper reviews theory and research bearing on stress in the workplace and explores how current theory might be applied to the relationship between worker behaviour and physical features of the work environment. The paper proposes a theoretical model of the worker–workspace relationship in which stress and comfort play a critical part, and suggests a methodological approach on which to base future empirical studies. Copyright © 2007 John Wiley & Sons, Ltd.
Three‐dimensional sonography of prenatal skull base development
Authors: Roelfsema N. M. , Grijseels E. W. M. , Hop W. C. J. , Wladimiroff J. W.
Published: February 2007

Objective

To explore longitudinally the development of the fetal skull base using three‐dimensional (3D) sonography.

Methods

Serial 3D sonographic measurements of anterior skull base length, posterior cranial fossa length and skull base angle were made in 126 normal singleton pregnancies at 18–34 weeks of gestation. In a sub‐study of 22 pregnancies, intraobserver variability was determined. Regression analysis for repeated measurements was performed by means of the random coefficients model. Results from an earlier publication on brain volume were extended to the total patient cohort.

Results

Measurements were technically successful in 69–94% of cases. The coefficient of variation for differences between repeated tests within women was 3.5–7.6% and between repeated analyses of the same recorded volume it was 3.0–5.1%. A statistically significant gestational age‐related increase was established for both the anterior skull base length and the posterior cranial fossa length and the skull base angle showed a small but significant flexion of about 6°. A higher increment in posterior cranial fossa length relative to anterior skull base angle was established. A significant quadratic relationship could be established for both anterior skull base length (P < 0.0001) and posterior cranial fossa length (P < 0.0001) but not for skull base angle, relative to brain volume.

Conclusion

The reproducibility was acceptable for all fetal skull base measurements. The more pronounced growth in posterior cranial fossa length relative to anterior skull base length is influenced by brain growth. The small flexion of the skull base angle, however, may be caused by other factors. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Gestational‐age‐adjusted reference values for the modified myocardial performance index for evaluation of fetal left cardiac function
Authors: Hernandez‐Andrade E. , Figueroa‐Diesel H. , Kottman C. , Illanes S. , Arraztoa J. , Acosta‐Rojas R. , Gratacós E.
Published: February 2007

Objective

It has been shown that the modified myocardial performance index (Mod‐MPI) is associated with higher reproducibility than conventional MPI because it uses mitral and aortic valve ‘clicks’ to calculate each time period. We aimed to construct normal reference values for the Mod‐MPI after 19 weeks' gestation.

Methods

The Mod‐MPI was calculated in the left ventricle of 557 normal fetuses at 19–39 weeks' gestation. The isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT) and ejection time (ET) were measured using the Doppler signals (clicks) of the opening and closing of the mitral and aortic valves as landmarks. Mod‐MPI was calculated as (ICT + IRT)/ET.

Results

Throughout gestation, there was a small increase in the Mod‐MPI (at 19 weeks it was 0.35 ± 0.027 (mean ± SD); at 39 weeks, 0.37 ± 0.029; Mod‐MPI = 0.33 + 0.001× gestational age (GA) (weeks), r2 = 0.017). Of the three components, ICT remained constant, IRT increased (IRT = 0.028 + 2.52 × GA (weeks)), and ET slightly decreased (ET = 0.184 − 3.65 × GA (weeks)). Fetal heart rate (FHR) had no effect on the Mod‐MPI, but the duration of IRT, ICT and ET decreased by 13–15% when FHR increased from 130 to 160 beats per minute.

Conclusion

The GA‐adjusted reference values for the Mod‐MPI and the three time periods used for its calculation can be applied to fetal cardiac evaluation in the presence of pregnancy‐associated complications. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Lubrication, single screw extrusion rates, and plasticizer structure in flexible PVC compounds
Authors: Daniels Paul H.
Published: February 2007

It is well‐established that changes in plasticizer structure affect (among other things) the melting temperatures, melt viscosities, and lubrication of flexible PVC compounds. In turn, these properties affect the extrudability of the compounds. The current study looks at the effects of plasticizer structure on lubrication, melt viscosities, extrusion rates, stock temperatures, and shear rates of PVC compounds in a single screw extrusion process. J. VINYL ADDIT. TECHNOL., 13:22–25, 2007. © 2007 Society of Plastics Engineers.
Plasticization effect of lignin in some highly filled vinyl formulations
Authors: Feldman D. , Banu D. , El‐Aghoury A.
Published: February 2007

The present study evaluates the impact of partially replacing (vinyl chloride)‐(vinyl acetate) (VC‐VAc) copolymer with lignin (L) in a vinyl flooring formulation. Lignin is a natural polymer resulting in huge quantities from wood delignification in the pulp and paper industry. An organsolv lignin, Alcell lignin (AL), was utilized. Also examined is the impact of replacing the common diethylhexyl phthalate (DOP) with plasticizers having chemical compositions different from those of DOP, i.e., diethylene glycol dibenzoate (2–45), tricresyl phosphate (Lindol®), and phenol alkylsulphonic ester (Mesamoll®). The reason for using other plasticizers is the suspicion that during the service life of vinyl flooring, the attack of fungi and microorganisms leads to the degradation of DOP and to the release of some volatile organic compounds (VOC). For the same reason, in the new flooring formulations, the VC‐VAc copolymer was partially replaced with L. Besides its other functions in wood, L imparts resistance to the attack of most microorganisms. The efficiency in plasticizing AL was also taken into consideration in choosing the above‐mentioned plasticizers. The influence of the new plasticizers, their concentration, and the influence of the partial replacement of VC‐VAc copolymer with AL on the mechanical and thermal properties of the new formulations are discussed. Laboratory data indicated that at a level of 20 parts VC‐VAc copolymer reduction and 5 parts plasticizer reduction, some of the obtained VC‐VAc‐AL blends compare very favorably with VC‐VAc copolymer control plasticized with 35 phr of DOP, the formulation of choice in vinyl flooring materials. J. VINYL ADDIT. TECHNOL., 13:14–21, 2007. © 2007 Society of Plastics Engineers.
Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 42 Ableitung und Simulation des Kristallfeld‐Aufspaltungsmusters von Tris(bis(trimethylsilyl)amido)ytterbium(III)
Authors: Jank Stefan , Reddmann Hauke , Apostolidis Christos , Amberger Hanns‐Dieter
Published: February 2007

Electronic Structures of Highly Symmetrical Compounds of f Elements. 42 Derivation and Simulation of the Crystal Field Splitting Pattern of Tris(bis(trimethylsilyl)amido)ytterbium(III)

Tris(bis(trimethylsilyl)amido)ytterbium(III), (Yb(btmsa)3 (1)) was grown as a single crystal of the size 6×2×2 mm. The unpolarized absorption and luminescence as well as the σ and π absorption spectra of this crystal were recorded at room and low temperatures. The observed polarization properties as well as identificational calculations allowed the separation of zero‐phonon‐ and phonon‐assisted transitions of comparable intensities. The thus derived crystal field splitting pattern could be simulated by fitting the free parameters of a phenomenological Hamiltonian. In order to assign the coupling vibrations, FIR/MIR‐ and unpolarized Raman spectra of 1 as well as polarized Raman spectra of Y(btmsa)3 (2) were recorded and compared with previously assigned ones of MeGa(btmsa)2 and H(btmsa).
Crystal Growth and Structure Refinement of K4Ge9
Authors: Ponou Simeon , Fässler Thomas F.
Published: February 2007

Deep‐red moisture and air sensitive single crystals of K4Ge9 were obtained by reacting GeO2 and elemental Ge with metallic W and K at high temperature in a niobium ampoule. The crystal structure of the compound was determined by single crystal X‐ray diffraction experiments. K4Ge9 crystallizes in a polar space group R3c (No. 161), Z = 4 with a = 21.208(1) and c = 25.096(2) Å. The compound contains discrete Ge94− Wade's nido‐clusters which are packed according to a hierarchical atom‐to‐cluster replacement of the Cr3Si prototype and are separated by K+ cations. Two independent [Ge9]4− clusters A (at Cr positions) and B (at Si positions) are found with a ratio A:B = 3:1. The B‐type cluster satisfactorily represents orientational disorder around the three‐fold axis.
Crystal Structure Investigation of RE–Ni–Zn Ternary Compounds (RE = La, Ce, Tb)
Authors: Solokha P. , De Negri S. , Saccone A. , Pavlyuk V. , Tedenac J.‐C.
Published: February 2007

The RENiZn (RE = La, Tb), RE2Ni2Zn (RE = La, Ce, Tb) and La3Ni3Zn ternary compounds were synthesized by two methods: by heating in a resistance furnace evacuated quartz ampoules containing Al2O3‐crucibles with element pieces and by induction melting in sealed Ta crucibles with subsequent annealing at 400 °C. Scanning electron microscopy (SEM) coupled with energy dispersive X‐ray spectroscopy (EDXS) was used for examining microstructure and phase composition of some of the alloys. The crystal structures for all the investigated phases were solved or confirmed on single crystal data by applying the direct methods refined by a standard least square procedure: LaNiZn – str. type ZrNiAl, hexagonal, $P{\bar 6}{\rm 2}m$, hP9, a = 0.7285(1), c = 0.3938(1) nm, wR2 = 0.0534, 257 F2 values, 14 variables; a = 0.7044(1), c = 0.3782(1) nm, wR2 = 0.0447, 236 F2 values, 14 variables for TbNiZn; La2Ni2Zn – str. type Pr2Ni2Al, orthorhombic, Immm, oI10, a = 0.4381(1), b = 0.5459(1) c = 0.8605(2) nm, wR2 = 0.0824, 223 F2 values, 13 variables; a = 0.4365(1), b = 0.5430(1) c = 0.8279(2) nm, wR2 = 0.0635, 209 F2 values, 13 variables for Ce2Ni2Zn; a = 0.4209(1), b = 0.5366(1) c = 0.8165 (1) nm, wR2 = 0.0757, 200 F2 values, 13 variables for Tb2Ni2Zn; La3Ni3Zn – str. type Y3Co3Ga, orthorhombic, Cmcm, oS28, a = 0.4276(1), b = 1.0310(2) c = 1.3636(3) nm, wR2 = 0.0859, 579 F2 values, 26 variables. The structural peculiarities of these compounds and their relations are discussed.
Structures and Spectroscopy of some Adducts of Coinage Metal(I) Cyanides with ‘Tetrahedral’‐Unidentate‐N‐Bases
Authors: Bowmaker Graham A. , Pettinari Claudio , Skelton Brian W. , Somers Neil , Vigar Nicholas A. , White Allan H.
Published: February 2007

Crystallization of copper(I) cyanide from piperidine (‘pip’) solution yields an adduct of CuCN : pip (3 : 4) ratio, as established by a single crystal X‐ray structure determination, which also shows the complex to have a single‐stranded ···Cu(CN)Cu(CN)···spine (C,N scrambled), one‐third of the copper atoms carrying a pair of pip ligands, the others only one. Crystallization of silver(I) cyanide from piperidine (‘pip’) or cyclohexylamine (‘CyNH2’) solutions yields adducts of the unusual AgX : unidentate‐N‐base (1 : 2) stoichiometry. The CyNH2 adduct is, unusually for cyanide complexes of this type, mononuclear with a trigonal planar silver atom, [(NC)Ag(H2NCy)2], the AgCN component lying along the intersection of two crystallographic mirror planes which bisect and relate the H2NCy ligands (Ag‐C, N 2.067(3), 2.335(2) Å; N‐Ag‐N, C 80·80(6), 139.60(4)°). In the pip adduct, the immediate silver atom environment is also three‐coordinate (Ag‐C; N, N 2.080(1); 2.288, 2.443(1) Å; N‐Ag‐N 88·34(4), N‐Ag‐C 144.47(4), 125.07(4), (Σ357.9°) perturbed toward two‐coordination, but the silver atom environment geometry is further perturbed from planarity by the parallel approach of an inversion‐related molecule (Ag···C′ 2.926(1) Å (Ag···Ag′ 3.1842(2)°) forming a loose, albeit still discrete, dimer. Key features in the IR spectra of the above compounds and of AgCN : pip (1 : 1) and CuCN : CyNH2 (2 : 3) are assigned and discussed in terms of the structures or of proposed structures in the case of the latter two adducts. The structure of [ClAg(pip)3], adventitiously obtained, is also described (Ag‐Cl 2.471(3); Ag‐N 2.147(13), 2.188(7) (x2) Å; Cl‐Ag‐N 96.1(3), 98.5(2), N‐Ag‐N 116.3(2) (x2), 122.1(3)°).
Earth Alkaline Tetrathiosquarates: Syntheses and Crystal Structures of MgC4S4 · 6 H2O and CaC4S4 · 4 H2O
Authors: Beck Johannes , Ben‐Amer Younis
Published: February 2007

Concentrated aqueous solutions of magnesium chloride and calcium nitrate, respectively, allow on addition of the potassium salt of tetrathiosquarate, K2C4S4 · H2O, the isolation of the earth alkaline salts MgC4S4 · 6 H2O (1) and CaC4S4 · 4 H2O (2) as orange and red crystals. The crystal structure determinations (1: monoclinic, C2/c, a = 17.2280(7), b = 5.9185(2), c = 13.1480(4) Å, β = 104.730(3)°, Z = 4; 2: monoclinic, P21/m, a = 7.8515(3), b = 12.7705(5), c = 10.6010(4) Å, β = 93.228(2)°, Z = 4) show the presence of C4S42− ions with almost undistorted D4h symmetry having average C–C and C–S bond lengths of 1.451Å and 1.659Å for 1and 1.451Å and 1.655Å for 2. The structure of 1 contains discrete, octahedral [Mg(H2O)6]2+ complexes. Several O–H····O and O–H····S bridges with H····O and H····S distances of less than 2.50Å connect cations and anions. The structure of 2 is built of concatenated, edge‐sharing Ca(H2O)6S2 polyhedra. The Ca2+ ions have the coordination number eight, C4S42− act as a chelating ligands towards Ca2+ with Ca–S distances of 3.14Å. The infrared and Raman spectra show bands typical for the molecular building units of the two compounds.
Crystal Structure of the New Cobalt Tellurite Chloride Co5Te4O11Cl4
Authors: Becker Richard , Johnsson Mats , Berger Helmuth
Published: February 2007

The crystal structure of the new compound Co5Te4O11Cl4 is described. It crystallizes in the triclinic system, space group P‐1 with the unit cell parameters a = 822.26(8) pm, b = 1029.7(1) pm, c = 1031.1(1) pm, α = 110.80(1)°, β = 97.950(9)°, γ = 98.260(9)° and Z = 2. The structure is layered along the bc–plane and built by [CoO5Cl], [CoO4Cl2] and [CoO4Cl] polyhedra sandwiched by [TeO3E] and [TeO4E] polyhedra. The layers can be regarded as infinite molecules without any net charge and only weak van der Waals forces connect them to each other. The halides and the lone‐pair, E, of TeIV protrude from the layers.
Synthesis, Characterization, and Crystal Structure of the New Schiff‐Bases derived from 1,2,4‐Triazole and the Structure of [(PPh3)2Cu(AMTT)]NO3·EtOH (AMTT = 4‐Amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione)
Authors: Heshmatpour Felora , Ghassemzadeh Mitra , Semsarha Maryam , Neumüller Bernhard
Published: February 2007

The reactions of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT, L1) with 2‐thiophen carbaldehyde, salicylaldehyde and 2‐nitrobenzaldehyde in methanol led to the corresponding Schiff‐bases (L1a‐c). The reaction of L1 with [(PPh3)2Cu]NO3 in ethanol gave the ionic complex [(PPh3)2Cu(L1)]NO3·EtOH (2) All compounds were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for L1a at 20 °C: space group P21/n with a = 439.6(2), b = 2074.0(9), c = 1112.8(4) pm, β = 93.51(3)°, Z = 4, R1 = 0.0406, L1b at −80 °C: space group P21/n with a = 1268.9(2), b = 739.3(1), c = 1272.5(1) pm, β = 117.97(1)°, Z = 4, R1 = 0.0361, L1c at −80 °C: space group P21/n with a = 847.8(1), b = 1502.9(2), c = 981.5(2) pm, β = 110.34(1)°, Z = 4, R1 = 0.0376 and for 2 at −80 °C: space group $\rm P{\bar1}$ with a = 1247.8(1), b = 1270.3(1), c = 1387.5(1) pm, α = 84.32(1)°, β = 84.71(1)°, γ = 63.12(1)°, Z = 2, R1 = 0.0539.
Syntheses, Spectral, Thermal and Structural Characterization of 2‐Phenyl‐2‐(1‐hydroxyiminoethyl)‐1,2,3,4‐tetrahydroquinazoline and Its Novel Nickel(II) Complex
Authors: Çolak Alper Tolga , Taş Murat , İrez Gazi , Yeşilel Okan Zafer , Büyükgüngör Orhan
Published: February 2007

The 2‐phenyl‐2‐(1‐hydroxyiminoethyl)‐1,2,3,4‐tetrahydroquinazoline (HL) and its NiII complex have been prepared and characterized by spectral method (FT‐IR, NMR (13C and 1H), UV‐vis.), elemental analysis, magnetic susceptibility and thermal analysis (TG, DTA) techniques. The crystal structures of HL and NiII complex were also determined by the single crystal X‐ray diffraction. The HL and NiII complex crystallizes in the monoclinic and triclinic, space groups P21/c and $P{\bar 1}$, respectively. The complex was occurred by the elimination of 1 mole of 2‐aminobenzylamine from the 2 moles of the HL after the ring opening reaction by the NiII attack. Crystallographic study reveal that NiII atom has a square planer geometry being coordinated by four nitrogen atoms of HL. Two thermal processes of the HL and NiII complex can occur in TG and DTA curves.
Pseudohalogeno Complexes of Sterically Hindered Tripyrrinatopalladium (TrpyPd) Fragments
Authors: Bröring Martin , Prikhodovski Serguei , Brandt Carsten D. , Cónsul Tejero Esther
Published: February 2007

Eight new pseudohalogeno complexes of sterically hindered TrpyPd fragments 4–11 have been prepared by salt metathesis in one step from known trifluoroacetates TrpyPdOAcF 1–3, using sodium salts of N3, NCO, NCS, NCSe, dicyanamide (dca) and tricyanomethanide (tcm) anions. Despite the propensity of the co‐ligands to bind to two or more metal centres in a bridging coordination mode all new complexes have been shown by NMR spectroscopy to be essentially monomeric in solution. X‐ray diffraction studies performed on TrpyPdNCS(6), TrpyPddca(8), TrpyPddca(9), and TrpyPdtcm(10) revealed the presence of two different conformers in the solid state, one with a helically distorted Trpy backbone for 6 and 10, and one with an almost planar tripyrrole but a tetrahedral distortion of the PdII coordination, a so‐called pseudoplanar form, for 8 and 9. Interestingly the helical forms are also detected by unusual wavenumbers for the νCN stretching bands in their IR spectra. The reason for the occurrence of two different conformers in the solid state appears to be the crystal packing which depends mainly on the shape of the anionic co‐ligand and on the presense of alkyl groups on the TrpyPd fragment.
Elevated levels of nonesterified fatty acids in the myocardium of alloxan diabetic rats
Authors: Chattopadhyay Jyotiprakas , Thompson Ed W. , Schmid Harald H. O.
Published: February 2007

Myocardial nonesterified fatty acids (NEFA) increase markedly within the first two days after the induction of insulin‐dependent diabetes mellitus in rats by intravenous injection of alloxan. After initial variability, NEFA levels in diabetic hearets remain constant at approximately 450 nmol/g tissue (16 nmol/gmmol lipid P), which is about three times higher than that in control hearts. Nonesterified linoleic acid is significantly increased in diabetic heart whereas both arachidonic and docosahexaenoic acids are decreased compared to controls.
Modification of phospholipid polar head group with monomethylethanolamine and dimethylethanolamine decreases cholesteryl ester and triacylglycerol synthesis in cultured human fibroblasts
Authors: Maziere Cecile , Auclair Martine , Mora Liliana , Maziere Jean‐Claude
Published: February 2007

Modification of the phospholipid polar head group was achieved by supplementation of the growth medium of cultured human fibroblasts with the choline analogues monomethylethanolamine (ME) or dimethylethanolamine (DE) at a concentration of 80–200 μg/mL for 48 hr. The maximum concentration of phosphatidylmonomethylethanolamine (PME) or phosphatidyldimethylethanolemine (PDE) reached without affecting the phospholipid/protein ratio was about 45% of total phospholipids. Incorporation of oleic acid into cholesteryl esters and triacylglycerols was markedly inhibited after supplementation with ME or DE, and accounted for 60% and 40% of controls, respectively, at 200 μg/mL, whereas incorporation into phospholipids was not affected. AcylCoA:cholesterol acyltransferase (ACAT) and diacylglycerol acyltransferase (DGAT) activities measured on cell‐free extracts appeared to be decreased also by phospholipid polar head group modification, whereas the overall phospholipid acyltransferase activity remained unchanged. The intracellular content of cholesteryl esters and triacylglycerols, determined by the isotopic equilibrium method with radioactive cholesterol and glycerol, was found to be diminished to 50–60% and 40–50% of controls, respectively, after supplementation with the choline analogues. The study showed that modification of the phospholipid polar head group affects the activity of membrane‐bound enzymes involved in the metabolism of neutral lipids.
Effect of dietary fat on the lipid composition and utilization of short‐chain fatty acids by rat colonocytes
Authors: Awad Atif B. , Ferger Sandra L. , Fink Carol S.
Published: February 2007

The objective of the present studies was to examine the effect of dietary fat on the lipid composition of rat colonocytes and their utilization of short‐chain fatty acids (SCFA). Rats were fed 14% beef fat, fish oil or safflower oil plus 2% corn oil in a semi‐synthetic base diet for 4 wk. Colonocytes were isolated and their lipid composition was examined. Feeding beef fat and fish oil resulted in an increase in monounsaturated fatty acids and a reduction in ω‐6 fatty acids. Feeding fish oil resulted in an enrichment with ω‐3 fatty acids. These was no dietary influence on the amount of either cholesterol or phospholipids of colonocytes. Fish oil feeding resulted in significant increase in colonocyte free fatty acids (FFA) as compared to other diets. Dietary fat was found to have no effect on SCFA utilization by colonocytes. Colonocytes were found to utilize SCFA in the order of butyrate ≥acetate ≥propionate. The presence of acetate and propionate in the medium had no effect on the rate of butyrate utilization.
Contrasting effects of water‐soluble and water‐insoluble dietary fibers on bile acid conjugation and taurine metabolism in the rat
Authors: Ide Takashi , Horii Masaharu , Yamamoto Tadashi , Kawashima Kenji
Published: February 2007

The effect of the type of dietary fiber on the bile acid and taurine metabolism was examined in rats. Diets containing 10% of various water‐soluble fibers (citrus pectin, konjak mannan, guar gum) as compared to a fiber‐free diet increased biliary excretion of total bile acids. In contrast, water‐insoluble dietary fibers (cellulose, corn bran, chitin; 10% in the diets) as well as cholestyramine (5% in the diet) considerably, decreased bile acid excretion. Water‐soluble dietary fibermediated increases in bile acid excretion were totally attributable to increases in glycine‐conjugates. Thus, these fibers greatly increased by the bile acid glycine‐to‐taurine ratio (G/T). Excretio of glycine conjugates decreased more than that of taurine conjugates in rats fed various water‐insoluble dietary fibers. As a results, G/T in rats fed water‐insoluble fibers was significantly lowered as compared to G/T in animals fed a fiber‐free diet. Cholestyramine did not affect the G/T ratio of bile acids. Fecal bile acid excretion and the activities of hepatic cholesterol 7α‐hydroxylase (EC 1.14.13.17) in rats fed various water‐soluble dietary fibers approximately doubled as compared to the respective values for rats fed a fiber‐free diet. Whereas cholestyramine greatly increased these parameters, water‐insoluble fibers did not significantly affect them. Various water‐soluble fibers decreased hepatic concentration and urinary excretion of taurine as well as the activity of hepatic cysteine dioxygenase (EC 1.13.11.20). In contrast, water‐insoluble fibers considerably increased hepatic taurine concentrations and enzyme activities. The parameters for taurine metabolism were unaffected by cholestyramine. It was suggested that the types of dietary fiber affected hepatic taurine synthesis and thus modified bile acid glycine/taurine ratios.
Effect of dietary fat on phospholipid class distribution and fatty acid composition in rat fat cell plasma membrane
Authors: Khuu Thi‐Dinh K. L. , Demarne Y. , Nicolas C. , Lhuillery C.
Published: February 2007

The effect of dietary fats on phospholipid class distribution and fatty acid composition was studied in rat fat cell plasma membrane. Three groups of male Wistar weanling rats were fed for 8 wk three diets differing in the amount and nature of the fats: 1.5% sunflower oil (low fat control; LFC), 10% sunflower oil (high fat, unsaturated; HFU), 1.5% sunflower oil+8.5% cocoa butter (high fat, saturated; HFS). Plasma membranes were prepared from epididymal adipocytes. The amount and type of dietary fat significantly altered membrane phospholipid distribution. Phospholipid content was lowered with HFU as compared to LFC or HFS diets, but no changes were observed for cholesterol. Phosphatidylinositol (PI) and phosphatidylserine (PS) were less affected by dietary changes than were other phospholipid classes. Major changes were detected for phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin (SM) contents. No large changes in PC and PE fatty acid compositions were observed between the LFC and HFS groups, but the HFU diet induced several changes. Correlations with plasma membrane 5′‐nucleotidase activities are discussed.
Lipoprotein lipase as a new tool in steryl ester analysis
Authors: Fischer Christine , Höll Wolfgang
Published: February 2007

A new method for the quantitative hydrolysis of steryl esters is described. Using lipoprotein lipase (triacylglycero‐protein acylhydrolase, EC 3.1.1.34), steryl esters are cleaved to yield free sterols and fatty acids. In comparison to alkaline hydrolysis, the method is more gentle, more accurate and less laborious. Quantification of the hydrolysis products was done with capillary gas chromatography. The practicability of the method is demonstrated for authentic steryl esters and steryl esters as they occur in needles of Scots pine (Pinus sylvestris L.).
Existence of cholinephosphotransferase in mitochondria and microsomes of liver and lung of guinea pig and rat
Authors: Ghosh Sukla , Mukherjee Shyamali , Das Salil K.
Published: February 2007

We reported earlier on the occurrence of cholinephosphotransferase in the mitochondria of guinea pig lung. In order to determine whether organ and/or species specificities exist in regard to the cholinephosphotransferase activity in mitochondria, we have compared the subcellular distribution of the enzyme in the liver and lungs of rats and guinea pigs. Even though the activity of the enzyme was higher in microsomes than it was in mitochondria, the mitochondrial activity was authentic in both tissues of both species. The authenticity of mitochondrial activity was established by marker enzyme studies and ultrastructural examination of mitochondrial preparations.
The Na+K+ATPase activity in cultured human fibroblasts with an elevated phospholipid triene: tetraene ratio
Authors: Karmiol Soverin , Bettger William J.
Published: February 2007

Human skin fibroblasts were cultured at low density for 11 days in MCDB 110, 0.4% fetal bovine serum, a mitogen mixture, and were supplemented with 18∶2n−6 or 18∶1n−9 as a fatty acid‐albumin complex. The cells cultured with the 18∶2n−6 supplement had a 20∶3n−9/20∶4n−6 ratio of 0.29±0.07; the 18∶1n−9 supplemented cells had a ratio of 1.51±0.27. There was less than 4% difference in total growth of the cell population under the two culture conditions. The cells supplemented with 18∶2n−9 had similar levels of protein/cell, K+/mg cell protein and functional Na+K+ATPase activity.
Isolation of a guanine‐malondialdehyde adduct from rat and human urine
Authors: Hadley M. , Draper H. H.
Published: February 2007

A 1∶1 adduct of guanine with malondialdehyde (MDA) was isolated from rat and human urine. This compound was shown to be identical to a synthetic adduct prepared according to the procedure of Setoet al. (Bull. Chem. Soc. Jpn. 58, 3431–3435, 1985). The UV, NMR and other characteristics of the compound were consistent with the tricyclic pyrimidinopurine structure proposed by these investigators. Its endogenous origin is indicated by its presence in the urine of rats fed an MDA‐free diet, and by the observation that its excretion increased following iron or carbon tetrachloride administration. It may serve as a marker for nucleic acid modification caused by lipid peroxidationin vivo.
Biochemical and functional abnormalities in hypercholesterolemic rabbit platelets
Authors: Dalal K. B. , Ebbe S. , Mazoyer E. , Carpenter D. , Yee T.
Published: February 2007

This study was designed to elucidate changes in rabbit platelet lipids induced by a cholesterol rich diet and to explore the possible correlation of these lipid changes with platelet abnormalities. Pronounced biochemical alterations were observed when serum cholesterol levels of 700–1000 mg% were reached. Hypercholesterolemic (HC) platelets contained 37% more neutral lipids and 16% less phospholipids than the controls. Lysolecithin, cholesterol esters and phosphatidylinositol (PI) levels were increased in HC platelets, and the levels of phosphatidylcholine (PC) were decreased. The cholesterol/phospholipid molar ratio of lipidemic platelets increased from 0.55±0.011 to 0.89±0.016 (P<0.01) in eight weeks. HC platelets had 90% more arachidonic acid (AA) in the PI than normal platelets. No significant changes in AA of PC were observed.

Platelet function was monitored by the uptake and release of [14C]serotonin in platelet rich plasma (PRP), using varying concentrations of collagen as an aggregating agent. The uptake of [14C]serotonin in HC and normal platelets ranged from 78–94%. The percent of [14C]serotonin released from normal and HC platelets was proportional to the concentration of collagen. However, lipidemic platelets were hyperreactive to low concentrations of collagen. Incorporation of 50 μM acetylsalicylic acid into the aggregating medium suppressed the release of [14C]serotonin in normal PRP by more than 90%, but had only a partial effect on lipidemic PRP.
Synergism between penicillin G and the antimicrobial ether lipid,rac‐1‐dodecylglycerol, acting below its critical micelle concentration
Authors: Ved H. S. , Gustow Evan , Pieringer Ronald A.
Published: February 2007

rac‐1‐Dodecylglycerol (DDG) and penicillin G (Pen G) act synergistically to dramatically lower the minimum inhibitory concentration (MIC) of each other in four Gram‐positive bacteria studied. At one‐half its MIC, DDG ether lowered the MIC of Pen G 10‐ to 80‐fold. Under the same conditions, Pen G lowered the MIC of DDG 4‐ to 7.5‐fold.

The critical micelle concentration of DDG was determined to be 7.93 mg/ml (0.0305 mM), which is approximately two‐fold greater than the minimum inhibitory concentration of DDG determined in the presence of a protein‐free chemically defined medium. This finding suggests that DDG is not killing bacteria through its detergent action. Pen G also did not alter the critical micelle concentration of DDG, which indicates that the synergism between these two agents is not related to micelle formation.
Sphingolipid metabolism in the regulation of bioactive molecules
Authors: Luberto Chiara , Hannun Yusuf A.
Published: February 2007

Conclusions

In conclusion, the study of signaling and cell regulation through ceramide has now evolved to the biochemical level by focusing on specific enzymes of ceramide metabolism. A general hypothesis can be presented whereby individual enzymes of ceramide metabolism serve as input points in the regulation of ceramide levels (Scheme 1). For example, activation of SMases or ceramide synthase would elevate ceramide levels and activate ceramide‐induced responses. On the other hand, activation of enzymes of ceramide degradation or incorporation such as ceramidases or SM synthase decreases and attenuates ceramide levels. Also, as an important corollary, some of these enzymes may play an additional fundamental role in interconverting lipid signals. For example, SM synthase has the capacity of interconverting a ceramide signal into a DAG signal, whereas ceramidases can transform a ceramide signal into a sphingosine or sphingosine‐phosphate signal. This area of research promises great future insight into important areas of cell studies.
Fatty acids, antioxidants, and coronary heart disease from an epidemiological perspective
Authors: Kromhout D.
Published: February 2007

Oxidized low density lipoproteins (LDL) play a major role in the development of atherosclerosis. Saturated fatty acids, especially fatty acids with 12–16 carbon atoms, are the most important determinants of the LDL cholesterol level. The LDL lipoprotein fraction can be oxidized by, e.g., smoking. Oxidative damage of LDL lipoproteins can be prevented by nutritive, e.g., vitamin E, and nonnutritive antioxidants, e.g., flavonoids. It can therefore be hypothesized that fatty acids and antioxidants are important determinants of coronary heart disease (CHD). There is a large body of evidence from prospective studies that LDL cholesterol‐lowering is associated with a lower CHD risk. The evidence for a protective effect of antioxidants on CHD risk is much weaker and is most promising for vitamin E and flavonoids. The Seven Countries Study showed that at the population level saturated fat, cigarette smoking, and flavonoids are important determinants of long‐term CHD mortality. These results suggest that a diet low in saturated fat and rich in antioxidants in combination with no smoking is associated with low CHD risk.
The effect of palmitic acid on lipoprotein cholesterol levels and endogenous cholesterol synthesis in hyperlipidemic subjects
Authors: Clandinin M. T. , Cook S. L. , Konrad S. D. , Goh Y. K. , French M. A.
Published: February 2007

The present study assesses the effect of high vs. low palmitic acid intakes on plasma lipoprotein cholesterol levels and on rates for endogenous synthesis of cholesterol in healthy and hyperlipidemic subjects. Four diets were formulated to provide combinations of 16:0 at two levels of 18:2n‐6. Subjects received each diet treatment for 21 d, followed by washout periods of 21 d. On day 21 of each diet treatment, a fasting blood sample was drawn for lipoprotein determination and to provide a measure of the background level of deuterium. A priming dose of deuterium was consumed and a second blood sample obtained 24 h after the first sample. Isotope ratio mass spectrometry was used to determine the incorporation of deuterium into the newly synthesized cholesterol molecule, and fractional synthetic rates were calculated. Serum total cholesterol and low density lipoprotein‐cholesterol was not significantly affected by the high level of 16:0 when diets also contained a high level of 18:2n‐6. There was no effect of dietary 16:0 on high density liproprotein‐cholesterol at either the high or low levels of intake. The results indicate that 16:0 has no effect on serum lipoprotein profiles in the presence of recommended intakes for 18:2n‐6.
Regulation of the biosynthesis of 22:5n‐6 and 22:6n‐3: A complex intracellular process
Authors: Sprecher Howard , Chen Qi , Yin Feng Qin
Published: February 2007

Both 22:4n‐6 and 22:5n‐3 are synthesized from n‐6 and n‐3 fatty acid precursors in the endoplasmic reticulum. The synthesis of both 22:5n‐6 and 22:6n‐3 requires that 22:4n‐6 and 22:5n‐3 are metabolized, respectively, to 24:5n‐6 and 24:6n‐3 in the endoplasmic reticulum. These two 24‐carbon acids must then move to peroxisomes for partial degradation followed by the movement of 22:5n‐6 and 22:6n‐3 back to the endoplasmic reticulum for use as substrates in membrane lipid biosynthesis. Clearly an understanding of the control of intracellular fatty acid movement as well as of the reactions carried out by microsomes, peroxisomes, and mitochondria are all required in order to understand not only what regulates the biosynthesis of 22:5n‐6 and 22:6n‐3 but also why most tissue lipids selectively accumulate 22:6n‐3.
Cellular fatty acid transport in heart and skeletal muscle as facilitated by proteins
Authors: Luiken J. J. F. P. , Schaap F. G. , van Nieuwenhoven F. A. , van der Vusse G. J. , Bonen A. , Glatz J. F. C.
Published: February 2007

Despite the importance of long‐chain fatty acids (FA) as fuels for heart and skeletal muscles, the mechanism of their cellular uptake has not yet been clarified. There is dispute as to whether FA are taken up by the muscle cellsvia passive diffusion and/or carrier‐mediated transport. Kinetic studies of FA uptake by cardiac myocytes and the use of membrane protein‐modifying agents have suggested the bulk of FA uptake is due to a protein component. Three membrane‐associated FA‐binding proteins were proposed to play a role in FA uptake, a 40‐kDa plasma membrane FA‐binding protein (FABPpm), an 88‐kDa FA translocase (FAT/CD36), and a 60‐kDa FA transport protein (FATP). In cardiac and skeletal myocytes the intracellular carrier for FA is cytoplasmic heart‐type FA‐binding protein (H‐FABP), which likely transports FA from the sarcolemma to their intracellular sites of metabolism. A scenario is discussed in which FABPpm, FAT/CD36, and H‐FABP, probably assisted by an albumin‐binding protein, cooperate in the translocation of FA across the sarcolemma.
A hypothesis to explain the reduced blood levels of docosahexaenoic acid in inherited retinal degenerations caused by mutations in genes encoding retina‐specific proteins
Authors: Anderson Robert E. , Maude Maureen B. , Alvarez Richard A. , Acland Gregory , Aguirre Gustavo D.
Published: February 2007

Some humans and animals with inherited retinal degenerations (RD) have lower blood levels of docosahexaenoic acid (22:6n‐3) than controls. As a result of recent studies, clearly the low blood 22:6n‐3 phenotype is found in multiple RD phenotypes and no mutation thus far identified in humans or animals is involved in lipid metabolism. Therefore, it seems reasonable to suggest that the primary defect is not in 22:6n‐3 metabolism, but rather in some common convergent pathway that ultimately leads to the reduction of blood and tissue 22:6n‐3 levels. One possibility is that the different mutations produce a metabolic stress that provokes structural and biochemical adaptive changes in photoreceptor cells and their rod outer segments. If the stress is oxidant, the retina could downregulate 22:6n‐3 and upregulate antioxidant defenses. How such a stress could lead to changes in blood levels of 22:6n‐3 is not obvious. However, the consistent finding of the 22:6n‐3 phenotype in many different retinal degeneration genotypes suggests that some form of communication exists between the retina and other tissues that serves to reduce blood levels of 22:6n‐3.
Dietary 18:3n‐3 and 22:6n‐3 as sources of 22:6n‐3 accretion in neonatal baboon brain and associated organs
Authors: Su H. ‐M. , Bernardo L. , Mirmiran M. , Ma X. ‐H. , Nathanielsz P. W. , Brenna J. T.
Published: February 2007

The bioequivalence of dietary linolenic acid (LNA) and docosahexaenoic acid (DHA) for brain DHA accretion was measured in neonatal baboons at 4–6 wk of age using stable isotope tracers. Neonates consumed a conventional U.S. term‐infant formula devoid of long chain polyunsaturates and with an n‐6/n‐3 ratio of about 10:1. At 4 wk of age, neonates were dosed with either13C LNA or13C DHA. At 6 wk of age, neonate brain, retina, and other organs were harvested for fatty acid and isotopic analyses. The relative accretion of labeled DHA was 7‐fold greater as a percentage of dose for the DHA‐dosed animals compared to the LNA‐dosed animals. The baboon is an omnivore that regularly consumes meat and insects; its plasma lipid profile responds similarly to humans in response to changes in feeding and living habits. These observations suggest that the baboon is a suitable model for human unsaturated fatty acid studies.