bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaktionen des Gallium‐haltigen Heterocyclus [Me2Ga{HNC(Me)}2CCN]
Authors: Iravani Effat , Neumüller Bernhard
Published: December 2003

Die Reaktion von [Me2Ga{HNC(Me)}2CCN] (1) mit fac‐[Mo(CO)3(MeCN)3] führt nach Umkristallisieren aus TMEDA zum Mo‐Komplex fac‐[Mo(CO)3(1)(TMEDA)] (2). Unter identischen Reaktionsbedingungen kann mit fac‐[W(CO)3(MeCN)3] nur der Tetracarbonyl‐Komplex [W(CO)4(TMEDA)] (3) isoliert werden. Umsetzungen des dilithiierten 1 mit Me2SiCl2 bzw. InCl3 lösen eine Spaltung des Gerüstes von 1 aus. Gewonnen und charakterisiert werden konnten das Salz [Me2Ga(TMEDA)][Me2GaCl2] (4) bzw. der Indiumkomplex [Me2InCl(TMEDA)] (5). 2—5 wurden mit Hilfe von spektroskopischen und spektrometrischen Methoden als auch durch Röntgenstrukturanalysen beschrieben. Danach besetzt in 2 der Ligand 1 eine der facialen Positionen im Komplex durch Donierung mit dem N‐Atom der NC‐Gruppe in 1. Die Moleküle 2 sind durch ein Netzwerk von Wasserstoffbrücken‐Bindungen verknüpft. In 3 besetzt der Chelatligand TMEDA bei intramolekularer Koordination zwei benachbarte Positionen, so daß cis‐3 resultiert. Im Salz 4 sind sowohl das Kation als auch das Anion verzerrt tetraedrisch umgeben, während in 5 eine verzerrte trigonal‐bipyramidale Koordinationssphäre vorliegt, wobei der Abstand In1‐Cl1 mit 261.74(9) pm deutlich aufgeweitet ist.
Novel Derivatives of the CaIn2 Type of Structure: Yb1+xMg1—xGa4 (0 ≤ x ≤ 0.058) and YLiGa4
Authors: Fedorchuk A. , Prots Yu. , Schmidt M. , Schnelle W. , Burkhardt U. , Schwarz U. , Grin Yu.
Published: December 2003

The compounds Yb1+xMg1—xGa4 (0 ≤ x ≤ 0.058) and YLiGa4 were synthesized by direct reaction of the elements in sealed niobium crucibles. The atomic arrangement of Yb1+xMg1—xGa4 (x = 0.058) represents a new structure type (space group P6¯m2, a = 4.3979(3)Å and c = 6.9671(7)Å) as evidenced by single crystal structure analysis and can be described as an ordered variant of CaIn2. YLiGa4 is isotypic to the ytterbium compound according to X‐ray Guinier powder data (a = 4.3168(1)Å and c = 6.8716(2)Å). Measurements of the magnetic susceptibility of both compounds reveal intrinsic diamagnetic behaviour, i.e., ytterbium in the 4f14 configuration for Yb1+xMg1—xGa4 (x = 0). From electrical resistivity data both compounds can be classified as metals. The compressibility of Yb1+xMg1—xGa4 (x = 0.058) as measured in diamond anvil cells by angle‐dispersive X‐ray diffraction is compatible with a valence change of the ytterbium atoms at high‐pressures and indicates a slight anisotropy which is in accordance with the structural organisation of the gallium network. X‐ray absorption spectra of the Yb LIII edge of Yb1+xMg1—xGa4 (x = 0.058) at pressures up to 25.0 GPa show a two‐peak structure which reveals the presence of Yb in the 4f14 and 4f13 states. The amount of ytterbium in the 4f13 state increases in two steps with progressing compression. The bonding analysis by means of the electron localization function reveals the Zintl‐like character of both compounds and confirms the 4f14 state for the majority of ytterbium atoms.
Synthesis and Crystal Structure of CsCu3O2, Containing a New Type of Oxocuprate(I) Polyanion
Authors: Sofin M. , Peters E. M. , Jansen M.
Published: December 2003

CsCu3O2 was prepared via the azide route. Stoichiometric mixtures of the precursors (CsN3, Cu2O and CuO) were heated in a special regime up to 450 °C and annealed at this temperature for 50 h in silver crucibles. Single crystals have been grown by subsequent annealing of as prepared powders at 450 °C for 2000 h in silver crucibles, which were sealed in glass ampoules under dried Ar. According to the X‐ray analysis of the crystal structure (P3¯m1, Z = 1, a = 5.250(1), c = 5.442(1)Å, γ = 120°) copper is linearly coordinated by oxygen atoms. The CuO2‐dumb‐bells are connected to an infinite two‐dimensional Cu3O2‐network. CsCu3O2 is isostructural with CsCu3S2, CsAu3S2, CsAu3Se2 and RbAu3Se2.
Heteroleptic Complexes of Zirconium Acetylacetonates: Better Precursors for the Preparation of Zirconia. Structural Characterization of [(acac)2Zr{ONC(Me)py‐2}2]
Authors: Pathak Madhvesh , Bohra Rakesh , Mehrotra Ram C. , Lorenz Ingo‐Peter , Piotrowski Holger
Published: December 2003

The reactions of the heteroleptic zirconium diisopropoxide bis(acetylacetonate) in benzene solution with two equivalents of oximes, alkoxyalkanols, triphenylsilanol and trimethylsilyl acetate yield products with the formula [{MeC(O)CHC(O)Me}2ZrL2] with L = —ONC(Me)C5H4N‐2, —ONC(Me)C4H3O‐2, —OCH2CH2OR (R = Me, Et, Bun; py = pyridine, fu = furan), —OSiPh3 and —OSiMe3. Most of these derivatives are solids, but the [(acac)2Zr(OSiMe3)2] is a viscous oil. They could be purified either by recrystallization or by vacuum distillation; all of these are monomeric in boiling benzene. Their elemental analyses, molecular weight measurements and IR as well as NMR spectra were measured. The oximato complex [(acac)2Zr{ONC(Me)py‐2}2] has been shown by single crystal X‐ray crystallography to be monoclinic and mononuclear in the solid state, where zirconium has the coordination number 8; all the ligands are situated in cis‐ position and the oximato ligand binds via N and O in a dihapto (η2‐N, O) manner.
Cobalt(II) Complexes with Dicyanamide — from Binuclear Entities to Chains
Authors: Shen Wei‐Zheng , Chen Xiao‐Yan , Cheng Peng , Liao Dai‐Zheng , Yan Shi‐Ping , Jiang Zong‐Hui
Published: December 2003

One binuclear complex [Co(bpm*)2(dca)]2(ClO4)2 (1) and two 1D chain CoII complexes, {[Co(bpm)2(dca)](ClO4)}n (2) and [Co(dmf)2(dca)2]n (3), (bpm*: bis[(3, 5‐dimethyl)pyrazolyl]methane; bpm: bis(pyrazolyl)methane; dca: dicyanamide; dmf: N, N‐dimethyl formamide) have been prepared and structurally characterized. The cobalt atoms are hexa‐coordinated forming a slightly distorted octahedral coordination. Compound 1 crystallizes in the monoclinic system, space group P21/c, a = 9.849(3)Å, b = 21.944(7)Å, c = 13.814(5)Å, β = 94.824(6), Z = 4, R1 = 0.0672, wR2 = 0.1395. 1 is a binuclear complex linked by two dca ligands, and each CoII ion is coordinated by two terminal bpm* ligands. Compound 2 crystallizes in the orthorhombic system, space group Cmcm, a = 10.377(4)Å, b = 13.594(5)Å, c = 15.999(6)Å, Z = 4, R1 = 0.0609, wR2 = 0.1328. The structure of 2 can be described as a one‐dimensional zigzag chain of CoII ions bridged by one dca ligand. Each CoII ion in the chain is coordinated by two bpm ligands. Compound 3 crystallizes in the monoclinic system, space group C2, a = 13.559(15)Å, b = 7.393(8)Å, c = 8.110(9)Å, β = 112.228(15), Z = 2, R1 = 0.0260, wR2 = 0.0760. 3 has a one‐dimensional linear chain of CoII ions bridged by two dca ligands, in which each CoII ion is coordinated with two dmf molecules.
Synthese, Struktur und Eigenschaften der Komplexe [(Me2PhP)3Cl2Re≡N‐IrCl2(C5Me5)], [(Me2PhP)3Cl2Re≡N‐IrCl(COD)], [PPh4][O3Os≡N‐IrCl2(C5Me5)] und [PPh4][O3Os≡N‐IrCl(COD)] mit Nitridobrücken Re≡N‐Ir und Os≡N‐Ir
Authors: Schwarz Simon , Niquet Elke , Santos Saez Abel , Cots Pascual Montserrat , Strähle Joachim
Published: December 2003

Die heteronuklearen Zweikernkomplexe [(Me2PhP)3Cl2Re≡N‐IrCl2(C5Me5)] (1), [(Me2PhP)3Cl2Re≡N‐IrCl(COD)] (2), [PPh4][O3Os≡N‐IrCl2(C5Me5)] (3) und [PPh4][O3Os≡N‐IrCl(COD)] (4) entstehen bei der Reaktion der Nitridokomplexe [ReNCl2(PMe2Ph)3] und [OsO3N]— mit den Iridiumverbindungen [IrCl2(C5Me5)]2 und [IrCl(COD)]2 in Benzonitril. 1 kristallisiert in Form roter Kristalle der Zusammensetzung 1·C6H5CN mit der monoklinen Raumgruppe P21/c und a = 1264, 7(2); b = 1945, 3(2); c = 1835, 4(1) pm, β = 90, 35(1)°, Z = 4. Im Zweikernkomplex ist das Komplexfragment [IrCl2(C5Me5)] über eine asymmetrische Nitridobrücke Re≡N‐Ir mit dem Nitridokomplex [ReNCl2(PMe2Ph)3] verknüpft. Die Nitridobrücke ist durch einen Bindungswinkel Re‐N‐Ir von 179, 4(2)° und Abstände Re‐N = 170, 9(4) pm und Ir‐N = 203, 3(4) pm charakterisiert. 2 bildet rotbraune, trikline Kristalle mit der Raumgruppe P1¯ und a = 1076, 6(2); b = 1373, 2(2); c = 1452, 4(1) pm; α = 107, 513(8); β = 101, 843(9); γ = 110, 04(1)°, Z = 2. Die Nitridobrücke zum Komplexfragment [IrCl(COD)] weist einen Bindungswinkel Re‐N‐Ir von 173, 8(4)° und Abstände Re‐N = 170, 4(8) pm und Ir‐N = 196, 2(8) pm auf. 3 kristallisiert als monokline rote Kristalle in der Raumgruppe P21/n und a = 1449, 9(2); b = 906, 74(4); c = 2628, 9(5) pm; β = 103, 50(1)°, Z = 4. Die Nitridobrücke Os≡N‐Ir ist mit einem Bindungswinkel von 165, 0(3)° leicht abgewinkelt. Die Abstände betragen Os‐N = 168, 3(5) pm und Ir‐N = 201, 9(5) pm. 4 ergibt dunkelbraune orthorhombische Kristalle mit der Raumgruppe P212121 und a = 704, 35(2); b = 1228, 17(6); c = 3442, 0(4) pm; Z = 4. Die Abstände in der schwach abgewinkelten Nitridobrücke (Os‐N‐Ir = 161, 8(4)°) betragen Os‐N = 169, 3(7) pm und Ir‐N = 197, 8(7) pm.
Linking obesity and activity level with children's television and video game use
Authors: Vandewater Elizabeth A , Shim Mi‐suk , Caplovitz Allison G
Published: January 2004

This study examined the links between childhood obesity, activity participation and television and video game use in a nationally representative sample of children (N=2831) ages 1–12 using age‐normed body mass index (BMI) ratings. Results indicated that while television use was not related to children's weight status, video game use was. Children with higher weight status played moderate amounts of electronic games, while children with lower weight status played either very little or a lot of electronic games. Interaction analyses revealed that this curvilinear relationship applied to children under age 8 and that girls, but not boys, with higher weight status played more video games. Children ages 9–12 with lower weight status used the computer (non‐game) for moderate amounts of time, while those with higher weight status used the computer either very little or a lot. This was also true for the relationship between print use and weight status for children of all ages. Results also indicated that children with higher weight status spent more time in sedentary activities than those with lower weight status.
Attachment contexts of adolescent friendship and romance
Authors: Miller Judi Beinstein , Hoicowitz Tova
Published: January 2004

The purpose of this study was to compare memories of attachments to parents, friends, and romantic partners in relation to the maintenance of high school friendships and romantic relationships. College students recorded the length of their friendships and romantic relationships during high school and rated the quality of each. They also rated their memories of attachments to parents, friends, and partners during that time. Parental attachments were the most reliable predictor of friendship outcomes and romantic attachments the most reliable predictor of romantic outcomes, but attachments to parents, friends, and partners each predicted unique variation in maintenance of romantic relationships.
Calcium signalling during cell interactions with bacterial pathogens
Authors: Van Nhieu Guy Tran , Clair Caroline , Grompone Gianfranco , Sansonetti Philippe
Published: January 2004

Abstract The ability of a pathogenic microorganism to cause a disease is conditioned by its ability to colonise a given niche and implicates the expression of specific determinants, i.e. virulence factors, that allow the pathogen to adhere to or to invade epithelial cells. Diseases may be induced by bacteria that replicate extracellularly and alter the epithelial mucosa by producing toxins. Ca2+ signalling has been implicated in various steps of bacterial infection. Bacterial toxins can induce an increase in free cytosolic Ca2+ in host cells, itself required for the toxin‐mediated effects. Such toxins, by diffusing in the extracellular media, can act at a distance from the site of infection and have a global effect on the integrity of the epithelium by promoting the expression of pro‐inflammatory cytokines. Independent on toxins, bacteria can induce Ca2+ responses that play a role in cytoskeletal rearrangements required for cell binding or internalisation of the microorganism. In some instances, invasion of the epithelium may be followed by bacterial access to deeper tissue, dissemination to other organs, and sometimes persistence in host cells in a parasitic‐like mode. Such strategies underline the pathogen abilities to control innate defence cells such as professional phagocytes, and may implicate the diversion of Ca2+‐dependent cellular processes that normally result in killing of the ingested bacteria. Finally, bacterial pathogens can also induce the cell release of ATP, a Ca2+ agonist, that may expand bacterial cell signalling by a paracrine or autocrine route, leading to enhanced colonisation or enhanced host cell responses to the invading microorganism.
Calcium signal communication in the central nervous system
Authors: Braet Katleen , Cabooter Liesbet , Paemeleire Koen , Leybaert Luc
Published: January 2004

Abstract The communication of calcium signals between cells is known to be operative between neurons where these signals integrate intimately with electrical and chemical signal communication at synapses. Recently, it has become clear that glial cells also exchange calcium signals between each other in cultures and in brain slices. This communication pathway has received utmost attention since it is known that astrocytic calcium signals can be induced by neuronal stimulation and can be communicated back to the neurons to modulate synaptic transmission. In addition to this, cells that are generally not considered as brain cells become progressively incorporated in the picture, as astrocytic calcium signals are reported to be communicated to endothelial cells of the vessel wall and can affect smooth muscle cell tone to influence the vessel diameter and thus blood flow. We review the available evidence for calcium signal communication in the central nervous system, taking into account a basic functional unit –the brain cell tripartite‐ consisting of neurons, glial cells and vascular cells and with emphasis on glial‐vascular calcium signaling aspects.
Ca2+ signals and T lymphocytes “New mechanisms and functions in Ca2+ signalling”
Authors: Randriamampita C. , Trautmann A.
Published: January 2004

Abstract Interaction between a T cell and an antigen‐presenting cell leads to the rapid formation of an immunological synapse allowing antigen detection by the T cell and the development of an immune response. Antigen detection triggers various cellular responses including a modest but sustained T cell Ca2+ increase. In this review are discussed a series of related questions. What are the various molecular events by which a T cell Ca2+ response can be triggered in the immunological synapse by a very small amount of antigen ? How is Ca2+ released from intracellular stores and how can these stores remain empty for hours ? Through which channels does Ca2+ influx takes place, and how is Ca2+ influx coupled to Ca2+ release from intracellular stores ? What are the main immediate and indirect cellular targets of the Ca2+ increase ?
Alteration in temporal kinetics of Ca2+ signaling and control of growth and proliferation
Authors: Lipskaia Larissa , Lompré Anne‐Marie
Published: January 2004

Abstract Calcium is a ubiquitous second messenger controlling a broad range of cellular functions including growth and proliferation. Quiescent, hyperthrophic and proliferating cells have different types of calcium signal. In quiescent cells the calcium signal mostly involves elementary calcium events such as sparks and puffs, produced by localized Ca2+ release via a cluster of intracellular calcium channels, IP3 receptors and ryanodine receptors. This type of calcium signal promotes activation of the transcription factor CREB (cAMP response element binding protein) leading to cell cycle arrest in G1 phase via transactivation of p53/p21 signaling pathways. Proliferation is induced by phosphoinositide‐coupled agonists and is associated with a sustained increase in cytosolic calcium due to 1.) enhanced excitability of IP3Rs after IP3 binding; 2.) enhanced activity of store‐operated Ca2+ channels and T‐type voltage‐operated Ca2+ channels; 3.) decreased cytosolic Ca2+ removal due to inhibition of PMCA (plasma membrane Ca2+‐ATPase) and SERCA (sarco/endoplasmic reticulum Ca2+‐ATPase) calcium pumps. This type of calcium signal favors activation of the transcription factor NFAT (nuclear factor of activated T lymphocytes) that promotes hypertrophic growth and/or cell cycle progression. We suggest that the two main Ca2+‐regulated transcription factors, CREB and NFAT, exert opposite control over cell growth and/or proliferation. Therapeutic strategies based on lowering intracellular Ca2+ or targeting of Ca2+‐regulated transcription factors seems to be a promising approach to arrest growth and/or proliferation.
Yessotoxin affects fMLP‐induced cell shape changes inMytilus galloprovincialis immunocytes
Authors: Malagoli Davide , Ottaviani Enzo
Published: January 2004

Using computer‐assisted microscopic image analysis, we have found that algal yessotoxin (YTX) affects the immune response of Mytilus galloprovincialis. Indeed, YTX increases immunocyte cell motility through the involvement of both extracellular Ca2+and cAMP, but not through protein kinase A, protein kinase C or phosphoinositide 3‐kinase. Alone, however, the toxin does not induce any effect, as its action on cell motility is observed only after addition of the chemotactic substance N‐formyl‐Meth‐Leu‐Phe (fMLP). fMLP is known to induce cellular changes via both the phosphatidylinositol and cAMP pathways and, from this scenario, we can surmise that Ca2+and cAMP concentrations rise sufficiently in fMLP‐activated immunocytes to reveal YTX action. One possible explanation is that the toxin increases fMLP‐mediated cell activation by intervening in L‐type Ca2+‐channel opening through a cAMP‐dependent/PKA‐independent pathway.
Muscarinic acetylcholine receptors involved in the regulation of neural stem cell proliferation and differentiation in vitro
Authors: Zhou Chang , Wen Zhe‐xing , Shi Dong‐mei , Xie Zuo‐ping
Published: January 2004

Neural stem cells (NSCs) are currently considered powerful candidates for cell therapy in neurodegenerative disorders such as Parkinson's disease. However, it is not known when and how NSCs begin to differentiate functionally. Recent reports suggest that classical neurotransmitters such as acetylcholine (Ach) are involved in the proliferation and differentiation of neural progenitor cells, suggesting that neurotransmitters play an important regulatory role in development of the central nervous system (CNS). We have shown by calcium imaging and immunochemistry that proliferation and differentiation are enhanced by M2 muscarinic Ach receptors (mAchR) expressed on the NSC surface and on their neural progeny. Moreover, atropine, an mAchR antagonist, blocks the enhancement and inhibits the subsequent differentiation of NSCs. Further understanding of this neural‐nutrition role of Ach might elucidate fetal brain development, the brain's response to injury, and learning and memory.
Primary cilia in vertebrate corneal endothelial cells
Authors: Collin Shaun P. , Collin H. Barry
Published: January 2004

The presence of primary cilia in corneal endothelial cells of a range of species from six non‐mammalian vertebrate classes (Agnatha, Elasmobranchii, Amphibia, Teleostei, Reptilia and Aves) is examined by scanning and transmission electron microscopy. Our aim is to assess whether these non‐motile cilia protruding into the anterior chamber of the eye are a consistent phylogenetic feature of the corneal endothelium and if a quantitative comparison of their morphology is able to shed any new light on their function. The length (0.42–3.80 μm) and width (0.12–0.44 μm) of the primary cilia varied but were closely allied with previous studies in mammals. However, interspecific differences such as the presence of a terminal swelling in the Teleostei and Amphibia suggest there are functional differences. Approximately one‐third of the endothelial cells possess cilia but the extent of protrusion above the cell surface varies greatly, supporting a dynamic process of retraction and elongation. The absence of primary cilia in primitive vertebrates (Agnatha and Elasmobranchii) that possess other mechanisms to control corneal hydration suggests an osmoregulatory and/or chemosensory function.
Influence of initial fixation protocol on the appearance of primary cilia on the rabbit corneal endothelial cell apical surface as assessed by scanning electron microscopy
Authors: Doughty Michael J
Published: January 2004

The objective was to examine primary cilia at the apical surface of corneal endothelial cells after using different fixatives. Female albino rabbits (2 kg) were euthanised at 15:00 h and the corneas fixed immediately (usually with an isotonic 2% glutaraldehyde—cacodylate fixative) either after dissection, by application fixative at 4 °C, by immersion of the eyeball in fixative at room temperature (RT), or by application of an isotonic or a hypertonic (Karnovsky‐type) fixative at RT. Images at 2000× were taken from the central corneal region, and number and length of primary cilia assessed. The length was the same regardless of method (overall average of 1.67±0.70 μm), but the incidence of primary cilia was hypertonic fixative (87% of cells) >cold drop fixation (71%), >whole globe immersion (68%) >dissect then fix methods (67%) >RT drop fixation (34%). The first four methods however yielded cells with unacceptable artefacts (especially distortion). More details should be provided of the primary fixation method used.
Feline high-rise syndrome: 119 cases (1998–2001)
Authors: Vnuk D. , Pirkić B. , Matičić D. , Radišić B. , Stejskal M. , Babić T. , Kreszinger M. , Lemo N.
Published: January 2004

High-rise syndrome was diagnosed in 119 cats over a 4-year period. 59.6% of cats were younger than one year, and the average height of the fall was four stories. High-rise syndrome was more frequent during the warmer period of the year. 96.5% of the presented cats, survived after the fall. 46.2% of cats had fractured limbs; 38.5% of fractures were of the forelimb, 61.5% of the hindlimb. The tibia was fractured most often (36.4%), followed by the femur (23.6%). 78.6% of femoral fractures were distal. The mean age of patients with femoral fractures was 9.1 months, and with tibial fractures 29.2 months. Thoracic trauma was diagnosed in 33.6% of cats. Pneumothorax was diagnosed in 20% of cats, and pulmonary contusions in 13.4%. Falls from the seventh or higher stories, are associated with more severe injuries and with a higher incidence of thoracic trauma.
Thinking outside the box: Feline elimination
Authors: Neilson Jacqui
Published: January 2004

Feline elimination problems are the leading behavioral complaint of cat owners. When presented with a feline elimination problem there are three main diagnostic categories: medical problems, marking or toileting problems. It isimportant to first perform diagnostic tests to rule out and/or address underlying medical issues and all feline housesoiling patients should receive a comprehensive physical examination. When the elimination problem persists after a medical problem has either been ruled out or remedied, a behavioral diagnosis should be obtained. The primary distinction that must be made in a behavioral diagnosis is whether the cat is engaging in marking behavior or selecting a spot other than the litterbox for elimination (a toileting problem). The motivation for urine marking may be territorial behavior or anxiety/stress whereas toileting problems are often triggered by medical causes, aversions, preferences or anxiety. Marking animals should be neutered and additional treatment measures may include reducing conflict and stress in the environment. Drug therapy has been long used to help control urine marking and recent studies have furthered our knowledge about the most appropriate treatments. Treatment for toileting problems should focus on providing an attractive litterbox while reducing the attractiveness or accessibility of inappropriate target spots.
An ethical viewpoint: The role of veterinarians and behaviourists in ensuring good husbandry for cats
Authors: Neville Peter F.
Published: January 2004

Cat owners commonly consider their pets to be members of their families, and many factors contribute to a high level of owner attachment to their cats. Suppression of a cat's emotional needs in favour of the emotional requirements of the owner may produce a less satisfactory relationship for the owner, and usually for the cat as well. Owners' failure to comprehend their cat's true demands of life, and their false expectation of their ability to fulfil human psychological demands lies at the heart of many feline behaviour problems.
Pain management in cats—past, present and future. Part 2. Treatment of pain—clinical pharmacology
Authors: Robertson S.A. , Taylor P.M.
Published: January 2004

Opioids have an unjustified reputation for causing mania in cats, but with refinements in dosing they are now used successfully in this species. The mu-opioid agonists are generally considered the best analgesics. Morphine (0.1–0.3 mg/kg) is effective in a clinical setting. Methadone (up to 0.5 mg/kg) has a similar profile to morphine. Pethidine (Demerol, meperidine; 2–5 mg/kg) is a useful analgesic with a faster onset but shorter duration of action than morphine. Oxymorphone and hydromorphone (0.05–0.1 mg/kg) are widely used in the USA. These opioids are more potent (up to 10 times), and longer acting than morphine in cats. Butorphanol (0.1–0.4 mg/kg) is a mu-opioid antagonist that produces its analgesic actions through kappa agonist activity. It rapidly reaches a ceiling effect, is short acting and is a weaker analgesic than pure mu opioids. Buprenorphine (0.01–0.02 mg/kg), a partial mu-agonist, is the most popular opioid used in small animal practice in the UK, other parts of Europe, Australia and South Africa. In clinical studies it has produced better analgesia than several other opioids and appears to be highly suitable for perioperative pain management in cats. NSAIDs are also used in cats for pain management, although cats metabolise these differently from other species. With appropriate dosing, carprofen (1–4 mg/kg) and meloxicam (0.3 mg/kg) have proved highly effective with few side effects. The use of ketoprofen (2 mg/kg), tolfenamic acid (4 mg/kg) and vedaprofen (0.5 mg/kg) has been reported in cats. Other less traditional analgesics such as ketamine, medetomidine and local anaesthetics are also used for clinical pain management. The transmucosal, transdermal and epidural routes offer novel methods for administration of analgesic drugs and have considerable potential for improving techniques in feline pain management.
Feline necrotising sialometaplasia: A report of two cases
Authors: Brown P.J. , Bradshaw J.M. , Sozmen M. , Campbell R.H.
Published: January 2004

Unilateral swelling of submandibular salivary gland in two cats was diagnosed as necrotising sialometaplasia. Histological features that differentiate the disease from other salivary gland lesions, particularly neoplasia are: lobular necrosis of salivary tissue; squamous metaplasia conforming to duct and/or acinar outlines; preservation of salivary lobular morphology; and variable inflammation and granulation tissue.
Anesthetic and physiologic effects of tiletamine, zolazepam, ketamine, and xylazine combination (TKX) in feral cats undergoing surgical sterilization
Authors: Cistola Alexis M. , Golder Francis J. , Centonze Lisa A. , McKay Lindsay W. , Levy Julie K.
Published: January 2004

Tiletamine (12.5 mg), zolazepam (12.5 mg), ketamine (20 mg), and xylazine (5 mg) (TKX; 0.25 ml, IM) combination was evaluated as an anesthetic in 22 male and 67 female adult feral cats undergoing sterilization at high-volume sterilization clinics. Cats were not intubated and breathed room air. Oxygen saturation (SpO2), mean blood pressure (MBP), heart rate (HR), respiration rate (RR), and core body temperature were recorded. Yohimbine (0.25 ml, 0.5 mg, IV) was administered at the completion of surgery. TKX produced rapid onset of lateral recumbency (4±1 min) and surgical anesthesia of sufficient duration to complete surgical procedures in 92% of cats. SpO2 measured via a lingual pulse oximeter probe averaged 92±3% in male cats and 90±4% in females. SpO2 fell below 90% at least once in most cats. MBP measured by oscillometry averaged 136±30 mm Hg in males and 113±29 mm Hg in females. MBP increased at the onset of surgical stimulation suggesting incomplete anti-nociceptive properties. HR averaged 156±19 bpm, and RR averaged 18±8 bpm. Neither parameter varied between males and females or over time. Body temperature decreased significantly over time, declining to 38.0±0.8 °C at the time of reversal in males and 36.6±0.8 °C at the time of reversal in females. Time from anesthetic reversal to sternal recumbency was prolonged (72±42 min). Seven cats (8%) required an additional dose of TKX to maintain an adequate plane of anesthesia at the onset of surgery, and this was associated with significantly longer recovery times (108±24 min).
Prevalence of infectious diseases in feral cats in Northern Florida
Authors: Luria Brian J. , Levy Julie K. , Lappin Michael R. , Breitschwerdt Edward B. , Legendre Alfred M. , Hernandez Jorge A. , Gorman Shawn P. , Lee Irene T.
Published: January 2004

Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.
A retrospective analysis of feline bronchoalveolar lavage cytology and microbiology (1995–2000)
Authors: Foster S.F. , Martin P. , Braddock J.A. , Malik R.
Published: January 2004

A retrospective study of 88 bronchoalveolar lavage specimens from 80 cats presenting to the University of Sydney Veterinary Centre between 1995 and 2000 was performed. Bronchoalveolar lavage cytology and microbiology in conjunction with other diagnostic aids and patient records were used to classify cases as lower respiratory tract infections (LTRIs), LRTI revisits, feline bronchial disease, cardiac disease, neoplastic disease and multisystemic disease. Cases for which a definitive diagnosis could not be made were classified as inconclusive. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Cryptococcus neoformans, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study highlights the importance of bronchoalveolar lavage cytology and microbiology in the evaluation of feline lower respiratory tract disease.
Chondroitin sulfate of appican, the proteoglycan form of amyloid precursor protein, produced by C6 glioma cells interacts with heparin‐binding neuroregulatory factors
Authors: Umehara Yuko , Yamada Shuhei , Nishimura Shuji , Shioi Junichi , Robakis Nikolaos K. , Sugahara Kazuyuki
Published: January 2004

Appican produced by rat C6 glioma cells, the chondroitin sulfate (CS) proteoglycan form of the amyloid precursor protein, contains an E disaccharide, –GlcUA‐GalNAc(4,6‐O‐disulfate)–, in its CS chain. In this study, the appican CS chain from rat C6 glioma cells was shown to specifically bind several growth/differentiation factors including midkine (MK) and pleiotrophin (PTN). In contrast, the appican CS from SH‐SY5Y neuroblastoma cells contained no E disaccharide and showed no binding to either MK or PTN. These findings indicate that the E motif is essential in the interaction of the appican CS chain with growth/differentiation factors, and suggest that glial appican may mediate the regulation of neuronal cell adhesion and migration and/or neurite outgrowth.
PKA phosphorylation and 14‐3‐3 interaction regulate the function of neurofibromatosis type I tumor suppressor, neurofibromin
Authors: Feng Liping , Yunoue Shunji , Tokuo Hiroshi , Ozawa Tatsuya , Zhang Dongwei , Patrakitkomjorn Siriporn , Ichimura Toru , Saya Hideyuki , Araki Norie
Published: January 2004

Neurofibromin, a neurofibromatosis type I (NF1) tumor suppressor gene product, has a domain acting as a GTPase activating protein and functions in part as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation. Therefore, regulation of the function of neurofibromin is heavily involved in cell growth and differentiation. In the present study, we identified a novel cellular neurofibromin‐associating protein, 14‐3‐3, which belongs to a highly conserved family of proteins that regulate intracellular signal transduction events in all eukaryotic cells. The interaction of 14‐3‐3 is mainly directed to the C‐terminal domain (CTD) of neurofibromin, and the cAMP‐dependent protein kinase (PKA)‐dependent phosphorylation clustered on CTD‐Ser (2576, 2578, 2580, 2813) and Thr (2556) is required for the interaction. Interestingly, the increased phosphorylation and association of 14‐3‐3 negatively regulate the function of neurofibromin. These findings indicate that PKA phosphorylation followed by 14‐3‐3 protein interaction may modulate the biochemical and biological functions of neurofibromin.
Independent folding and conformational changes of the barnase module in the VL‐barnase immunofusion: calorimetric evidence
Authors: Tsybovsky Yaroslav I , Kedrov Alexey A , Martsev Sergey P
Published: January 2004

Although stability is critical for in vivo application of immunotoxins, a thermodynamic description of their folding/stability is still lacking. We applied differential scanning calorimetry (DSC) to RNase‐based immunofusion comprising barnase, cytotoxic RNase from Bacillus amyloliquefaciens, fused to the light chain variable domain (VL) of anti‐human ferritin antibody F11. By analyzing DSC curves recorded with or without preheating and addition of the barnase‐stabilizing ligand guanosine 3′‐monophosphate, we (i) assigned two well‐resolved thermal transitions to the VL and barnase modules of VL‐barnase, (ii) demonstrated independent folding of these two modules, and (iii) showed altered stability of the barnase module, which resulted from the dimeric state of VL‐barnase.
Evidence that cleavage of the precursor enzyme by autocatalysis caused secretion of multiple amylases by Aspergillus niger
Authors: Ravi-Kumar K , Venkatesh K.S , Umesh-Kumar S
Published: January 2004

The observation that a mutant strain of Aspergillus niger isolated for protease overproduction accumulated Taka‐amylase supported an earlier report that processing of the precursor amylase by protease resulted in the secretion of multiple amylases. Studies using a mutant strain revealed that such processing was not due to aspergillopepsin but to autocatalysis by an inherent protease activity of the precursor and glucoamylase. Alignment of protease sequences with glucoamylase showed regions of consensus with serine carboxypeptidase of A. niger. Thus point mutations in this region due to ultraviolet radiation apparently caused the mutant to evolve with enhanced protease activity that degraded the precursor and accumulated Taka‐amylase.
Emerging from the museum: Joseph Dawson, mineralogist, 1740–1813
Authors: PACEY A. J.
Published: January 2004

Joseph Dawson is known mainly as one of the founders of Low Moor Ironworks, near Bradford (Yorkshire). But he also had wide interests in science. Local museum collections illustrate several aspects of his work in chemistry and mineralogy. His mineral collection is particularly important because it is accompanied by a rare early catalogue in Dawson's hand. This shows how he arranged his 2206 mineral specimens according to Thomas Thomson's essentially Wernerian classification. Dawson's comments about minerals as well as about iron furnaces demonstrate a view of science in which chemistry was fundamental. Moreover, his contacts with other iron-masters and leading industrialists, as well as with mineralogists and Nonconformist ministers, show him active within several networks through which scientific ideas, attitudes and practices were disseminated.
‘Newton dépossédé!’ The British response to the Pascal forgeries of 1867
Authors: HIGGITT REBEKAH
Published: January 2004

Between 1867 and 1869 Michel Chasles presented a series of manuscripts to the Académie des sciences, which suggested that Isaac Newton's claims to original discovery were unfounded. It quickly became apparent to the majority of the academicians that the manuscripts were forgeries, but Chasles was repeatedly allowed to state his case. This essay focuses on the responses to the affair from four British men of science: David Brewster, Augustus De Morgan, Robert Grant and Thomas Archer Hirst. It asks why they felt it necessary to add their voices to this debate and examines their various strategies for refuting Chasles's evidence.
Telling stories
Authors: FYFE AILEEN , SMITH PAUL
Published: January 2004

In the beginning, there was Dava Sobel and Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time (1998). Others followed, in a veritable flood which D. P. Miller recently dubbed the ‘Sobel Effect’. Academic historians of science have been concerned by this flood, partly because people other than them are (presumably) making money out of ‘their’ subject, but also because of the ways it might affect the public perception of the history of science. Like the scientists they study, historians fear that popularizers will distort in the process of simplifying. But, knowing how difficult it has been for scientists to control the popularization of their subject, historians may not expect a great deal more success.
Aspects of nitrogen use efficiency of cauliflower I. A simulation modelling based analysis of nitrogen availability under field conditions
Authors: KAGE H. , ALT C. , STÜTZEL H.
Published: January 2004

Data from several field experiments (eight crops grown under a widely varying nitrogen supply on a loess loam soil) were used for a simulation modelling based analysis of nitrogen availability of cauliflower. The model was built out of components describing root growth, nitrate transport to the roots and the vertical nitrate transport within the soil.

Root observations obtained over 2 years indicated an increased fraction of dry matter allocated to the fine roots under N deficiency. An adopted version of a root growth model for cauliflower described the rooting data with an R2=0·75. Based upon an acceptable description of the soil water budget, vertical nitrate movement during the growth period of cauliflower was accurately described. The magnitude of this movement, however, was limited to soil depths of about 60 cm even after periods of high rainfall, because of a high soil water holding capacity. An analysis of the factors determining nitrate availability indicated that apparent mass flow was only of high importance for conditions of extremely high N supply where high amounts of nitrate nitrogen remain in the soil up to the end of the growing season. Otherwise, the dominating fraction of nitrate has to be transported to the roots by diffusion. Single root model based calculations of maximum nitrate transport to roots overestimated N availability as indicated by estimates of critical soil nitrate N that were too low. The introduction of a restricted uptake activity period of the roots was used to bridge the gap between theoretical calculations and empirical results. Scenario calculations were carried out to obtain functional relationships between N supply and residual soil nitrate levels for different soil conditions and management practices.
Variation in water use and transpiration efficiency among durum wheat genotypes grown under moisture stress and non-stress conditions
Authors: SOLOMON K. F. , LABUSCHAGNE M. T.
Published: January 2004

Durum wheat genotypes with different responses to moisture stress were studied in a glasshouse under moisture stress and non-stress conditions to investigate differences in water use and transpiration efficiency and interrelationships among water use and transpiration efficiency and associated traits. Significantly high genotypic variability in the cumulative amount of water used before (ETba) and after (ETpa) anthesis was observed. Susceptible genotypes used higher amounts of water before anthesis and lower amounts after anthesis. In contrast, tolerant genotypes used a higher proportion of water during the post-anthesis period. Significantly high variability among the genotypes was observed for various measures of water use and transpiration efficiency, total dry matter and harvest index. Ranking of cultivars for water use efficiency based on grain yield (WUEG) and transpiration efficiency based on grain yield was consistent with ranking of cultivars for drought susceptibility indices. Drought susceptibility index was significantly but negatively correlated with harvest index, WUEG and grain yield. However, it was positively and significantly correlated with the ETba[ratio ]ETpa ratio. A high positive correlation of WUEG with harvest index and grain yield with harvest index was found. It was concluded that selection for lower ETba[ratio ]ETpa ratios up to about 0·8 could indirectly lead to improved WUEG and HI, hence improved grain yield. Selection for increased WUEG and/or grain yield would increase yield in water-limited environments.
Dietary effects on the composition and plant utilization of nitrogen in dairy cattle manure
Authors: SØRENSEN P. , WEISBJERG M. R. , LUND P.
Published: January 2004

The influence of dairy cattle feed composition on the manure composition and on the dynamics and plant availability of cattle slurry N was studied. Dairy cows were fed seven different forages either with or without supplemental concentrates. The concentration of N in faeces dry matter varied from 18 to 38 g/kg dry matter and increased with increasing digestibility of the feed. Cattle slurries consisting of a mixture of 0·5 faecal N and 0·5 urinary N were stored according to common agricultural practice in Northern Europe. The mineralization of faecal N during slurry storage was very variable (0·09–0·50). The plant availability of N in the slurries originating from cattle fed with known diets was tested in small, framed field plots with spring barley, under conditions with minimal N losses. The nitrogen uptake in barley was determined and the mineral fertilizer equivalent (MFE) of slurry N was calculated. The net release of mineral N and CO2 from the slurries in soil was also measured in a parallel incubation study. The MFE of cattle slurry N varied from 53 to 75%. After correcting for the measured urine-N/faeces-N ratio and expected ammonia emission, the MFE varied from 51 to 78%. The plant availability and net release of cattle slurry N were influenced by forage type and feeding level. The MFE was negatively correlated with the concentration of crude fibre and neutral detergent fibre (NDF) in the diet, and positively correlated with the dietary protein content. The net release of CO2 from the slurries after 12 weeks in soil was significantly influenced by the concentration of crude fibre in the diet. The plant availability of slurry N was significantly correlated with the ammonium content (R2=0·53) and negatively correlated with the slurry C[ratio ]N ratio (R2=0·67) and the dry matter[ratio ]N ratio (R2=0·58). Residual slurry N left in the soil after harvest of the first crop varied from 0·25 to 0·47 of total slurry N. It is concluded that the fibre and the protein content of cattle diets have a significant influence on the plant availability of cattle slurry N and on the amount of residual slurry N remaining in the soil after the first growing season.
The influence of drought stress on growth, yield and yield components of selected maize genotypes
Authors: KAMARA A. Y. , MENKIR A. , BADU-APRAKU B. , IBIKUNLE O.
Published: January 2004

The risk of drought is high in the Sudan savannah zone of West and Central Africa because rainfall in this area is unpredictable in quantity and distribution. Thus, improved maize genotypes tolerant to drought could stabilize maize grain yield in this zone, where recurrent drought threatens grain production. Six maize genotypes, two each of hybrids, open-pollinated varieties (OPVs) and landraces, were evaluated for tolerance to terminal water deficit before flowering. Water deficit significantly reduced growth, grain yield and yield components of the maize genotypes. Significant differences were observed among genotypes for all the traits measured. One hybrid, 9011-30, and two improved OPVs, STR-EV-IWD and IYFD-C0, that showed tolerance to water stress recorded higher grain yield, and accumulated and partitioned more assimilates to the grain than the drought-susceptible genotypes. Also the drought-tolerant genotypes, 9011-30, STR-EV-IWD and IYFD-C0 had more ears/plant and greater numbers of kernels/ear. These genotypes could serve as sources of drought tolerance for the development and improvement of new drought-tolerant maize genotypes.
Seasonal variation in the dynamic growth and development traits of peanut lines
Authors: BANTERNG P. , PATANOTHAI A. , PANNANGPETCH K. , JOGLOY S. , HOOGENBOOM G.
Published: January 2004

Physiological traits responsible for differences in yield performance among pre-released genotypes are normally not known. The objective of the present study was to evaluate seasonal variations in dynamic growth and development traits between 12 large-seeded Virginia-type and 14 small-seeded Spanish-type advanced breeding lines of peanut (Arachis hypogaea L.). The experiment was conducted in 1999 and 2000 at Khon Kaen University in Northeast Thailand for three planting dates, representing the early-rainy season, mid-rainy season and dry season. Very similar phenological development was observed for all lines within each group and between the early and the mid-rainy seasons. However, a lower temperature during the early growth stage in the dry season delayed flower initiation and extended maturity. During this period, crop growth rates as well as the development rate for leaf area index and specific leaf area were also lower compared with the rainy seasons. On average, both pod yield and total biomass for the rainy season and the dry season were about the same. Variations among lines within each group were also small. For these advanced breeding lines, the pod growth rate was the most important yield determinant while the crop growth rate had lesser effect and the partitioning coefficient and pod-filling duration had no significant effect. However, the crop growth rate, pod growth rate and partitioning coefficient were important traits for a line to be the top yielder. Pod-filling duration was also important when the lines involved were considerably diverse in maturity and seed size. Information on these traits, if used together with final pod yield, will make varietal selection more efficient.