bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal and Molecular Structures of the Pentafluorosulfanyl Compounds, SF5X (X = ‐NC, ‐CN, ‐NCO, ‐NCS and ‐NCCl2) by X‐ray Diffraction at Low Temperature
Authors: Buschmann Jürgen , Lentz Dieter , Luger Peter , Perpetuo Genivaldo , Preugschat Dagmar , Thrasher Joseph S. , Willner Helge , Wölk Hans‐Jörg 
Published: July 2004

AbstractA new method for the synthesis of the unstable pentafluorosulfanyl isocyanide from N‐(pentafluorosulfanyl)(dichloromethanimine) was developed, thereby allowing for the study of its spectroscopic data. The structure of pentafluorosulfanyl isocyanide was determined by X‐ray crystallography at 113 K. The molecule possesses an almost linear S‐N‐C arrangement and an unexpectedly long S‐N bond. In addition, the structures of pentafluorosulfanyl cyanide, pentafluorosulfanyl isocyanate, pentafluorosulfanyl isothiocyanate, and N‐(pentafluorosulfanyl)(dichloro)methanimine were determined by single crystal X‐ray crystallography at low temperatures.
Dimeric Silsesquioxanes and Metallasilsesquioxanes — En route to large, welldefined Si‐O‐assemblies
Authors: Lorenz Volker , Edelmann Frank T. 
Published: July 2004

AbstractRecent advances in the chemistry of dimeric silsesquioxanes and metallasilsesquioxanes are reviewed. The number of metal‐free silsesquioxane dimers is still quite limited, although some promising synthetic routes have already been developed. In contrast, metallasilsesquioxanes containing two silsesquioxane ligands are known with numerous metals, including Li, K, Be, Al, In, Sc, Sm, Yb, U, Ti, Zr, V, Ta, Cr, and Cu. A major breakthrough in this chemistry was the successful synthesis of fully metalated silsesquioxane precursors such as (Cy7Si7O12)2Li6(THF)2 (15).
Über die Bildung von Trithiatetrazocin‐Derivaten aus bicyclischen Kohlenstoff‐Schwefel‐Stickstoff‐Heterocyclen, RCN5S3
Authors: Knapp Carsten , Lork Enno , Maggiulli Roberto , Watson Paul G. , Mews Rüdiger , Borrmann Tobias , Stohrer Wolf‐Dieter , Behrens Ulrich 
Published: July 2004

AbstractF3CCN5S3 (1a) bildet mit AsF5 ein 1:1‐Addukt F3CCN5S3˙AsF5 (2), welches sich in CDCl3‐Lösung langsam zum kationischen, achtgliedrigem Ring [F3CCN4S3]+ [AsF6]— (3) zersetzt. Der Angriff des AsF5 erfolgt an dem verbrückenden Stickstoffatom, das die größte negative Partialladung trägt. Im Gegensatz dazu wird in der protonierten Verbindung [F3CCN5S3H]+ [AsF6]— (6) ein dem Ringkohlenstoff benachbartes Stickstoffatom angegriffen, was mit den unterschiedlichen Basizitäten der Stickstoffatome erklärt werden kann. Mit PPh3 und AsPh3 öffnen die Bicyclen RCN5S3 (1) zu den Phosphanimino‐ bzw. Arsaniminotetrazocin‐Derivaten RCN4S3N=EPh3 (R = F3C, E = P (endo), 4a; E = As (endo), 5a; R = Me2N, E = P (endo), 4c). Der dafür in der Literatur vorgeschlagene Reaktionsmechanismus wird durch die Isolierung von [TAS]+ [F3CCN5S3NC(NH2)CF3]— (7) gestützt. Die durch Röntgenbeugung bestimmten Strukturen von 2, 3, 4a, 4c, 5a, 6 und 7 werden diskutiert.
Manganese(II), Cobalt(II), and Nickel(II) Perchlorate Complexes Containing N, O Donor Macrocyclic Ligands
Authors: Lodeiro Carlos , Capelo Jose Luis , Bértolo Emilia , Bastida Rufina 
Published: July 2004

AbstractMononuclear macrocyclic complexes of manganese(II), cobalt(II) and nickel(II) perchlorate using 10 different oxaazamacrocyclic ligands (L1 — L10) have been prepared and characterized. The complexation reactions with the diiminic ligands were obtained by template condensation of the appropriate dialdehyde and diamine precursors; the reduced macrocycle complexes were synthesized using a direct route. The complexes have been characterized by elemental analyses, molar conductivity, mass spectrometry, IR, UV‐vis spectroscopy, diffuse reflectance and magnetic susceptibility measurements.
Tetranitratogoldsäure, (H5O2)[Au(NO3)4]·H2O: Synthese, Kristallstruktur und thermisches Verhalten des ersten sauren Nitrates des Goldes
Authors: Büchner Oliver , Wickleder Mathias S. 
Published: July 2004

AbstractGelbe Einkristalle von (H5O2)[Au(NO3)4]·H2O bilden sich beim Abkühlen einer Lösung von Au(OH)3 in konz. Salpetersäure. In der Kristallstruktur (monoklin, C2/c, Z = 4, a = 1214, 5(2), b = 854, 4(1), c = 1225, 7(2) pm, β = 117, 75(1)°, Rall = 0, 0331) wird Au3+ von vier einzähnig angreifenden NO3—‐Ionen umgeben. Die [Au(NO3)4]—‐Einheiten werden von H5O2+‐Ionen zusammengehalten, die mit den H2O‐Molekülen über starke Wasserstoffbrückenbindungen verknüpft sind. Die thermische Analyse läßt auf einen fünfstufigen Abbau schließen und führt zu elementarem Gold.
Reaktionsverhalten verschiedener Carbodiimide mit Ferrocen‐1, 1'‐dicarbonsäure
Authors: Schetter Bernd 
Published: July 2004

Abstract1, 1'‐Bis‐(1, 3‐dicyclohexylureidocarbonyl)‐ferrocen (1), 1, 1'‐Bis‐(1, 3‐diisopropylureidocarbonyl)‐ferrocen (2) und Ferrocen‐1, 1'‐bis‐N‐p‐tolylcarboxamid (6) wurden bei kurzer Reaktionszeit durch lösungsmittelfreies Zusammenschmelzen von Ferrocen‐1, 1'‐dicarbonsäure (7) mit N, N'‐Dicyclohexylcarbodiimid (DCC), N, N'‐Diisopropylcarbodiimid (DIC) und N, N'‐Di‐p‐tolylcarbodiimid (8) erhalten. 1, 2, 1, 1'‐Bis‐(1‐ethyl‐3‐tert‐butylureidocarbonyl)‐ferrocen (3), 1‐(1‐tert‐butyl‐3‐ethylureidocarbonyl)‐1'(1‐ethyl‐3‐tert‐butylureidocarbonyl)‐ferrocen (4) und 1, 1'‐Bis(1‐tert‐butyl‐3‐ethylureidocarbonyl)‐ferrocen (5) wurden durch wochenlange Reaktion von 7 mit DCC, DIC, bzw. N‐tert‐Butyl‐N'‐ethylcarbodiimid (9) in Ethylacetat in hohen Ausbeuten erhalten. Transannulares Ferrocendicarbonsäureanhydrid (10) entsteht bei diesen Reaktionen nicht. Alle Verbindungen wurden durch 1H‐NMR‐, 13C‐NMR‐, IR‐Spektrometrie, MS und Elemantaranalyse charakterisiert. Für 1 wurde eine Röntgenstrukturanalyse durchgeführt.
Structural and Coordinative Variability in Zinc(II), Cadmium(II), and Mercury(II) Complexes of 2‐Pyridineformamide 3‐Hexamethyleneiminylthiosemicarbazone
Authors: Bermejo Elena , Castiñeiras Alfonso , García‐Santos Isabel , West Douglas X. 
Published: July 2004

AbstractSodium in dry methanol reduces 2‐cyanopyridine in the presence of 3‐hexamethyleneiminylthiosemicarbazide and produces 2‐pyridineformamide 3‐hexamethyleneiminylthiosemicarbazone, HAmhexim (1). Complexes with zinc(II), cadmium(II) and mercury(II) have been prepared and characterized by spectroscopic techniques. In addition, the crystal structures of HAmhexim (1), [Zn(Amhexim)(OAc)]2μ·μDMSO (2), [Cd(HAmhexim)Cl2]μ·μDMSO (7), [Cd(Amhexim)2] (8), [Cd(HAmhexim)Br2]μ·μDMSO (9), [Cd(HAmhexim)I2]μ·μEtOH (10), [Hg(HAmhexim)Cl2]μ·μDMSO (11), [Hg(Amhexim)Br]2 (13), [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O (14) and [Hg(Amhexim)I]2 (15) have been determined. Coordination of the anionic and neutral thiosemicarbazone ligand occurs through the pyridine nitrogen atom, imine nitrogen atom, and thiolato or thione sulfur atom. In [Zn(Amhexim)(OAc)]2 one of the bridging acetato ligands has monodentate coordination and the other bridges in a bidentate manner. [Cd(Amhexim)2] is a 6‐coordinate species while the other cadmium complexes are 5‐coordinate. In [Hg(Amhexim)Br]2 and [Hg(Amhexim)I]2 the thiolato sulfur atoms act as bridges between the Hg atoms to form dimeric compounds and [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O is a trinuclear complex with three different centers — two metallic centers have a 5‐coordination and the another one has 4‐coordination. In addition, [Hg(HAmhexim)Cl2]μ·μDMSO and [Hg3(HAmhexim)(Amhexim)Br5]μ·μH2O shown a supramolecular one‐dimensional hydrogen‐bonded self‐assembling.
Chemischer Transport fester Lösungen. 12 [1] Der Chemische Transport von Mischphasen im System ZnS/ZnTe
Authors: Rose C. , Binnewies M. 
Published: July 2004

AbstractMithilfe chemischer Transportreaktionen (Transportmittel Iod, 1000 → 900 °C) konnten im System ZnS/ZnTe, das eine breite Mischungslücke aufweist, schwefelreiche und tellurreiche Mischkristalle durch chemischen Transport erhalten werden. Während der Transport der tellurreichen Phasen ZnTe1‐xSx (x = 0 … ca. 0, 1) etwa kongruent erfolgt, kommt es beim Transport der schwefelreichen Mischkristalle ZnS1‐xTx (x = 0 … ca. 0, 1) zu einer deutlichen Schwefelanreicherung. Aus der Mischungslücke heraus wird nur die tellurreiche Mischphase transportiert, danach kommt der Transport zum Erliegen.
Chemischer Transport fester Lösungen. 13 [1] Bildung von Mischphasen im System ZnS/Zn3P2 im Temperaturgefälle
Authors: Locmelis S. , Binnewies M. 
Published: July 2004

AbstractErhitzt man ZnS und Zn3P2 gemeinsam mit Iod im Temperaturgefälle (z.B. 1000 → 900 °C), werden bei 900 °C die Mischphasen ZnS:P (0, 7 %) (ZnS1—xP0, 67x, x = 0 …0, 019) und Zn3P2:S (1, 2 %) (Zn3P2—xS1, 5x, x = 0 …0, 005) erhalten. Der Einbau von Sulfid‐Ionen in Zn3P2 führt zu einer Verkleinerung, der Einbau von Phosphid‐Ionen in ZnS zu einer Vergrößerung der Elementarzelle. Die ablaufenden Fest/Gas‐Reaktionen werden diskutiert.
Mono‐, Di‐ and Trinuclear Dioxo Complexes of Uranium Containing Hydrazonato and Azomethine Ligands
Authors: Gatto C. C. , Schulz Lang E. , Kupfer A. , Hagenbach A. , Abram Ulrich 
Published: July 2004

AbstractMono‐, di or trinuclear dioxouranium complexes with benzoylhydrazonato or azomethine ligands were prepared by reactions of common dioxouranium precursors such as UO2(NO3)2 · 6 H2O or [NBu4]2[UO2Cl4] with vanillin benzoylhydrazone (H2L4), salicylaldehyde benzoylhydrazone (H2L5), 2‐hydroxyacetylbenzene salicylhydrazone (H3L6) or N‐(2‐ethoxycarbonyl‐3‐oxo‐but‐1‐en(1)yl)‐2‐aminophenol (H2L7).Spectroscopic and X‐ray crystallographic studies on the complexes [NBu4]2[UO2Cl4] · 2 H2L4, [UO2(HL5)(H2L5)2](NO3), [HNEt3]2[{UO2(L6)}2] and [HNEt3]2[{UO2(L7}3O] confirm that the individual donor atom constellation, the size of the potential chelate rings and the acidity of the OH and NH functionalities of the proligands have a strong influence on the structure of the products.
Neubestimmung der Ladungsdichte und topologische Analyse von β‐Diboran bei 94 K
Authors: Hübschle Christian B. , Messerschmidt Marc , Lentz Dieter , Luger Peter 
Published: July 2004

AbstractDie experimentelle Ladungsdichte von β‐Diboran wurde aus 1779 Reflexen neu bestimmt, die bis (sinθ/λ)max = 1.11Å—1 mit MoKα‐Strahlung und CCD‐Flächendetektion bei 94(1) K gemessen wurden. Im Gradientenvektorfeld der Elektronendichte wurden die stark gebogenen Bindungspfade der B‐Hμ‐Bindungen verifiziert. Eine topologische Analyse ergab in Übereinstimmung mit theoretischen Ergebnissen keinen Hinweis auf einen bindungskritischen Punkt zwischen den beiden Boratomen.
Mass Spectrometric Investigations of Thermodynamic Properties of the RbCl/GdCl3 System
Authors: Rutkowska Iwona , Hilpert Klaus , Miller Mirosław 
Published: July 2004

AbstractThe vaporization of pure RbCl, GdCl3, and RbCl‐GdCl3 samples of different phase compositions was investigated in the temperature range between 666 K and 982 K by use of the Knudsen effusion mass spectrometry. The gaseous species RbCl, Rb2Cl2, GdCl3, and RbGdCl4 were identified in the equilibrium vapours and their partial pressures were determined. The enthalpy of dissociation of RbGdCl4(g), ΔdissH°(859 K) = 263.1 ± 7.7 kJ mol—1, was evaluated by second law treatment of the equilibrium partial pressures. The thermodynamic activities of RbCl and GdCl3 were obtained at 800 K in the two‐phase fields {Rb3GdCl6(s) + liquid} and {RbGd2Cl7(s) + GdCl3(s)}. The Gibbs free energies of formation of the pseudo‐binary phases Rb3GdCl6(s), ΔfG°(800 K) = —75.1 ± 2.5 kJ mol—1 and RbGd2Cl7(s), ΔfG°(800 K) = —40.6 ± 1.2 kJ mol—1, were evaluated from the thermodynamic activities of the components. The results are compared with the available literature data.
Trans‐bis(saccharinato)cadmium(II) Complexes with 2‐Aminomethylpyridine and 2‐Aminoethylpyridine — Synthesis, Crystal Structures, Spectral and Thermal Characterization of trans‐[Cd(sac)2(ampy)2] and trans‐[Cd(sac)2(aepy)2]
Authors: Yilmaz Veysel T. , Caglar Sema , Harrison William T. A. 
Published: July 2004

AbstractTwo trans‐bis(saccharinato) (sac) complexes of cadmium(II) with 2‐aminomethylpyridine (ampy) and 2‐aminoethylpyridine (aepy) were synthesized and characterized by means of elemental analysis, FT‐IR spectroscopy and thermal analysis. In addition, their solid‐state structures were determined by single crystal X‐ray diffraction studies. The [Cd(sac)2(ampy)2] (1) and [Cd(sac)2(aepy)] (2) complexes consist of neutral monomeric units and crystallize in the orthorhombic (Pbca) and monoclinic (P21/c) crystal systems, respectively. The cadmium(II) ions in 1 and 2 sit on inversion centres andexhibit distorted octahedral coordination by two sac anions and two aminopyridine ligands. The sac ligands in both complexes are N‐coordinated and located in trans positions, while the ampy and aepy ligands act as a bidentate ligand forming two symmetrically chelate rings around cadmium(II). IR spectra and thermal decompositions of the complexes are also discussed.
Formation of Carboxylato‐bridged Dipalladium(II) Complexes via Ligand Displacement with a Ferrocene Phosphanocarboxylate
Authors: Štěpnička Petr , Císařová Ivana 
Published: July 2004

AbstractRacemic potassium [2‐(diphenylphosphano)ferrocenyl]acetate reacts with the dinuclear palladium(II) methyl‐phosphane complexes [{Pd(μ‐Cl)Me(PR3)}2] (1; R = Me (a), 2‐furyl (b), and Ph (c)) under formation of a dipalladium(II) complex with triply coordinated phosphanocarboxylate ligand: (Rp, Sp)‐[μ‐1κ2P, O: ‐2κO′‐{2‐(diphenylphosphano)ferrocenyl}acetato][μ‐1κO′:2κ2P, O{2‐(diphenylphosphano)ferrocenyl}acetato]bis{methylpalladium(II)} (2), exclusively as (Rp, Sp) diastereoizomer (meso‐form). The solid‐state structures of 1a and 2 have been determined by single‐crystal X‐ray diffraction.
Darstellung und Eigenschaften von dreizähnigen Schiff‐Basen‐Komplexen des Titans
Authors: Hecht Elmar , Rüffer Tobias , Lang Heinrich 
Published: July 2004

AbstractBis[iminoalkoxy]‐Komplexe des Titans wurden durch Umsetzung der entsprechenden Schiff‐Basen mit Titan‐tetraisopropoxid im Molverhältnis 2:1 in n‐Hexan erhalten. Selbst bei einer äquimolaren Umsetzung der Ausgangsstoffe konnten nur die disubstituierten Iminoalkoxy‐Komplexe erhalten werden. Die Schiff‐Basen‐Komplexe wurden mittels ihrer NMR‐Spektren und im Falle von 4 durch Einkristallstrukturanalyse charakterisiert. Als Folge von Ti—N und Ti—O Wechselwirkungen bildet 4 sechsfach koordinierte Ti‐Atome aus. Die Ti‐Atome sind von den entsprechenden Ligandatomen in Form eines verzerrten Oktadeders umgeben. 4: Raumgruppe C2/c, Z = 8, Gitterdimensionen bei 20 °C: a = 18.690(4), b = 16.281(3), c = 15.086(3) Å, b = 109.040(4)°, R1 = 0.0553, wR2 = 0.1598, GooF = 1.040.
Two Conformers in Solution and Solid State for a Novel Phosphoramidate — Synthesis, Characterization and Crystal Structures of C6H5C(O)NHP(O)[NH(tert‐C4H9)]2 and CCl3C(O)NHP(O)[NH(tert‐C4H9)]2
Authors: Gholivand Khodayar , Pourayoubi Mehrdad 
Published: July 2004

AbstractTwo new phosphoramidates with formula RC(O)NHP(O)[NH(tert‐C4H9)]2, R=C6H5, (1) and CCl3, (2) were synthesized and characterized by IR, 1H‐, 13C‐, 31P NMR, mass spectroscopy and elemental analysis. The structures confirmed by X‐ray single crystal determination. Compound 1 appears as two conformers (1a and 1b) in solid state as well as solution. Both compounds (1 and 2) exist in the polymeric chains in crystalline lattice produced by hydrogen bonding that for compound 1, there are two independent infinite chains; each of them composed of one of the two conformers.
Das Vaterunser: Gründe für seine Durchsetzung als ‘Urgebet’ der Christenheit
Authors: OSTMEYER KARL-HEINRICH 
Published: July 2004

Wie konnte ein inhaltlich jüdisches Gebet ohne exklusiv christliche Anteile zum Zentralgebet der Christen werden? Mit der Suche nach den Gründen der Durchsetzung wird oft die Frage nach der Urheberschaft Jesu verbunden. Der Versuch einer Antwort mit Hilfe der Analyse des Inhaltes führt zu widersprüchlichen Ergebnissen. Sicher greifbar ist dagegen das Phänomen der frühen und unumstrittenen Akzeptanz des Vaterunsers, hier nimmt die vorliegende Untersuchung ihren Ausgang.Entscheidend für die Durchsetzung des Vaterunsers war weniger sein Inhalt als seine Funktion. Durch seine schon in den Evangelien grundgelegte Kennzeichnung als ‘Gebet des κυριος’ wirkte das Vaterunser nach innen integrierend und nach außen abgrenzend. Eine weitere Christianisierung seines Inhaltes erübrigte sich. Daraus ergeben sich neue Perspektiven auf das Herkunftsproblem.
Effect of pH on the production of the antitumor antibiotic retamycin by Streptomyces olindensis
Authors: Guimarães Luciana M. , De Araújo Furlan Renata L. , Garrido Leandro M. , Ventura Armando , Padilla Gabriel , Facciotti Maria Cândida R. 
Published: July 2004

The effect of pH on cell growth and retamycin production in batch bioreactor cultures of Streptomyces olindensis ICB20 was investigated. In fermentations pH‐controlled over the range 6.0–8.0, the highest retamycin production was achieved at pH 7.0, and the maximum concentration of retamycin, about 1.36 A (absorbance) units, was about 43, 58 and 232% higher than the values obtained at pH 7.5, 6.0 and 8.0 respectively.
The effect of hyperosmotic pressure on antibody production and gene expression in the GS‐NS0 cell line
Authors: Wu Mon‐Han , Dimopoulos George , Mantalaris Athanasios , Varley Julie 
Published: July 2004

It has been widely reported that metabolism, cell growth, cell density, product secretion and specific antibody productivity in mammalian cells are strongly affected by osmotic conditions. Previous studies have shown that hyperosmotic pressure suppresses cell growth while enhancing the productivity of individual cells, but the effect of these two changes does not result in an increase in final product concentration in the culture. An improved understanding of the basic cellular processes of a GS‐NS0 mammalian cell culture system would assist in the design of a more efficient mammalian cell culture system and in further optimization of production processes. In this study, various properties of mammalian culture systems, such as productivity, cell viability, metabolism, ion balance and the genes regulated during the culture of the GS‐NS0 system under osmotic pressure of iso‐ (290 mOsm/kg) and hyper‐ (450 mOsm/kg) osmolarity have been investigated, and we demonstrate that there is a decrease in the growth rate and an increase in specific production rate of hyperosmotic cultures as compared with iso‐osmotic cultures. Furthermore, differences between iso‐ and hyper‐osmotic cultures have been identified in calcium accumulation and metabolism of NH4+, glucose and lactate. Analysis of gene expression reveals regulation of over 600 genes that are implicated in processes known to be affected by changes in osmotic pressure, such as ion transport, accumulation of osmolytes, cell cycle distribution, proliferation, cytoskeletal organization and cell metabolism.
An improved, inexpensive procedure for the large‐scale purification of recombinant human erythropoietin
Authors: Hu Yunlong , Chen Song , Xu Mei , Zhang Shuangquan 
Published: July 2004

A rapid and simple chromatographic procedure has been developed for the large‐scale purification of therapeutic‐grade rHuEPO (recombinant human erythropoietin) from medium‐conditioned cell cultures, which includes ion‐exchange, hydrophobic‐interaction and gel‐filtration chromatography. A combination of these well‐connected steps results in highly purified rHuEPO (>99%), as revealed by SDS/PAGE and HPLC analyses, with a total yield of 38%. The specific activity of purified rHuEPO was 160104 i.u./mg. Immunoblotting studies revealed that the protein possesses native EPO immunity. N‐terminal sequencing of rHuEPO shows that the first 15 amino acids coincide with those of native EPO reported previously.
The C-terminus of rat L-histidine decarboxylase specifically inhibits enzymic activity and disrupts pyridoxal phosphate-dependent interactions with L-histidine substrate analogues
Authors: FLEMING John V. , FAJARDO Ignacio , LANGLOIS Michael R. , SÁNCHEZ-JIMÉNEZ Francisca , WANG Timothy C. 
Published: July 2004

Full-length rat HDC (L-histidine decarboxylase) translated in reticulocyte cell lysate reactions is inactive, whereas C-terminally truncated isoforms are capable of histamine biosynthesis. C-terminal processing of the ∼74 kDa full-length protein occurs naturally in vivo, with the production of multiple truncated isoforms. The minimal C-terminal truncation required for the acquisition of catalytic competence has yet to be defined, however, and it remains unclear as to why truncation is needed. Here we show that ∼74 kDa HDC monomers can form dimers, which is the conformation in which the enzyme is thought to be catalytically active. Nevertheless, the resulting dimer is unable to establish pyridoxal phosphate-dependent interactions with an L-histidine substrate analogue. Protein sequences localized to between amino acids 617 and 633 specifically mediate this inhibition. Removing this region or replacing the entire C-terminus with non-HDC protein sequences permitted interactions with the substrate analogue to be re-established. This corresponded exactly with the acquisition of catalytic competence, and the ability to decarboxylate natural L-histidine substrate. These studies suggested that the ∼74 kDa full-length isoform is deficient in substrate binding, and demonstrated that C-terminally truncated isoforms with molecular masses between ∼70 kDa and ∼58 kDa have gradually increasing specific activities. The physiological relevance of our results is discussed in the context of differential expression of HDC isoforms in vivo.
Analysis of the ERK1,2 transcriptome in mammary epithelial cells
Authors: GRILL Constance , GHEYAS Ferdous , DAYANANTH Priya , JIN Weihong , DING Wei , QIU Ping , WANG Luquan , DOLL Ronald J. , ENGLISH Jessie M. 
Published: July 2004

MAPK (mitogen-activated protein kinase) pathways constitute major regulators of cellular transcriptional programmes. We analysed the ERK1,2 (extracellular-signal-regulated kinase 1,2) transcriptome in a non-transformed MEC (mammary epithelial cell) line, MCF-12A, utilizing rAd MEK1EE, a recombinant adenovirus encoding constitutively active MEK1 (MAPK/ERK kinase 1). rAd MEK1EE infection induced morphological changes and DNA synthesis which were inhibited by the MEK1,2 inhibitor PD184352. Hierarchical clustering of data derived from seven time points over 24 h identified 430 and 305 co-ordinately up-regulated and down-regulated genes respectively. c-Myc binding sites were identified in the promoters of most of these up-regulated genes. A total of 46 candidate effectors of the Raf/MEK/ERK1,2 pathway in MECs were identified by comparing our dataset with previously reported Raf-1-regulated genes. These analyses led to the identification of a suite of growth factors co-ordinately induced by MEK1EE, including multiple ErbB ligands, vascular endothelial growth factor and PHRP (parathyroid hormone-related protein). PHRP is the primary mediator of humoral hypercalcaemia of malignancy, and has been implicated in metastasis to bone. We demonstrate that PHRP is secreted by MEK1EE-expressing cells. This secretion is inhibited by PD184352, but not by ErbB inhibitors. Our results suggest that, in addition to anti-proliferative properties, MEK1,2 inhibitors may be anti-angiogenic and possess therapeutic utility in the treatment of PHRP-positive tumours.