bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluoride Ion-Mediated Intramolecular Aldol Cyclization of 7-(t-Butyldimethylsiloxy)-7-octenal
Authors: Hachiya Iwao , Kobayashi Nobutaka , Kijima Hiroyuki , Pudhom Khanitha , Mukaiyama Teruaki
Published: December 2004

Polyoxy 8-membered ring compound was synthesized in moderate to good yields by intramolecular aldol cyclization of 7-(t-butyldimethylsiloxy)-7-octenal using tetrabutylammonium fluoride (TBAF).
Formation of Titania Nanotubes with High Photo-Catalytic Activity
Authors: Adachi Motonari , Murata Yusuke , Harada Makoto , Yoshikawa Susumu
Published: December 2004

Titania nanotubes with high photo-catalytic activity were synthesized in laurylamine hydrochloride / tetraisopropyl orthotitanate modified with acetylacetone system. Formation of nanotubes was confirmed by transmission electron microscope images. These titania nanotubes had crystal structure of anatase and showed high photo-catalytic activity, i.e., the activity is about three times higher than Degussa-P-25 and higher than ST-01.
Retardation of the Molecular Rotation of p-Nitrophenolate Ion in the Cavity of a Positively Charged Derivative of α-Cyclodextrin by Electrostatic Interactions
Authors: Ahmed Jalaluddin , Nagata Takuya , Imaoka Shinji , Matsui Yoshihisa , Yamamoto Tatsuyuki
Published: December 2004

1H NMR signal for the C(5)-H of A, D glucose residues of bis[6A,6D-(1-pyridinio)-6A,6D-deoxy]-α-cyclodextrin shifted downfield, whereas those of B, E and C, F residues shifted upfield, with the addition of p-nitrophenol at pD 11.3. This infers that the molecular rotation of the guest is retarded in the CD cavity.
Effect of Surface Morphology of a Gold Substrate on Photocurrent Efficiency at a Gold Electrode Modified with a Self-Assembled Monolayer of a Porphyrin–Ferrocene–Thiol Linked Molecule
Authors: Kondo Toshihiro , Yanagida Masatoshi , Zhang Xue-Qun , Uosaki Kohei
Published: December 2004

The effect of the surface roughness on the characteristics of self-assembled monolayers (SAMs) was quantitatively examined by measuring the photocurrent efficiency at a gold electrode modified with a SAM of a porphyrin–ferrocene–thiol linked molecule as a function of the surface roughness. The photocurrent efficiency was higher for the flatter substrate. This result confirms the importance of the substrate’s surface roughness to achieve the ordered arrangement of the functional moieties of the SAM, i.e., effective control of the electron/energy transfer.
Experimental Estimation of Hydropathy Scales of Apolar Amino Acid Residues by Measuring Langmuir Monolayer Behaviors of Amino Acid Derivative Polymers
Authors: Ide Makoto , Miyashita Tokuji
Published: December 2004

We described here a novel method for experimental estimation of hydropathy scales of amino acid by measuring Langmuir monolayer behaviors of the amino acid derivative polymers. The collapse pressure of the monolayers had a good correlation with the hydropathy scales.
Selective Oxidation of Ethanol and 1-Propanol over V–Mg–O/TiO2 Catalyst
Authors: Mongkhonsi Tharathon , Pimanmas Purida , Praserthdam Piyasan
Published: December 2004

Ethanol and 1-propanol can be selectively oxidized to ethanal and propanal, respectively, by V–Mg–O catalyst supported on TiO2 (anatase). Aldehyde yields up to 73% and 66% for ethanal and propanal, respectively, were achieved in the temperature range 573–623 K. The catalyst was rather inactive for the further oxidation of aldehyde products to carboxylic acids.
High- versus Low-Dose Oxytocin for Augmentation or Induction of Labor
Authors: Patka John H , Lodolce Amy E , Johnston Angela K
Published: December 2004

OBJECTIVE:

To compare the use of high- and low-dose oxytocin for augmentation or induction of labor.

DATA SOURCES:

Clinical trials were accessed through MEDLINE (1966–November 2003). Published literature relevant to the use of oxytocin for augmentation or induction of labor was evaluated.

STUDY SELECTION AND DATA EXTRACTION:

Articles identified from the data sources were evaluated and included if they were clinical trials comparing high- versus low-dose oxytocin for augmentation or induction of labor.

DATA SYNTHESIS:

Oxytocin is a treatment of choice for augmentation and induction of labor; however, no consensus exists regarding optimal dosing. Relevant studies comparing high-dose (2–6 mU/min) and low-dose (1–2 mU/min) therapy for labor augmentation and induction were evaluated.

CONCLUSIONS:

High-dose oxytocin decreases the time from admission to vaginal delivery, but does not appear to decrease the incidence of cesarean sections when compared with low-dose therapy.
Measurement of Particle Size Distribution in Portland Cement Powder: Analysis of ASTM Round Robin Studies
Authors: Ferraris CF , Hackley VA , Avilés AI
Published: December 2004

A distribution of particle sizes or particle size distribution (PSD) is a fundamental characteristic of cement powder. Accurate PSDs are required in computational efforts to model the hydration process and it is an important practical issue for the cement industry. Presently, the only available standard method for measuring the PSD of cement, namely ASTM C115, is limited in scope, with a lower size detection limit of 7.5 μm. Since there are no standard procedures that adequately cover the broad particle size range associated with portland cement powder, the implementation of different measurement techniques varies widely within the industry. Two ASTM-sponsored round robin tests were performed to (1) ascertain the techniques and methods currently used in the cement industry and (2) develop and refine a standard method or methods. The results have been incorporated into a best practice method based on the technique of laser diffraction. The aim of the current paper is to summarize the findings based on the data generated during the round robins and to summarize the various approaches available to measure the PSD of cement. A summary of the statistical analysis of the test results is described.
Potential for Restrained Shrinkage Cracking of Concrete and Mortar
Authors: See HT , Attiogbe EK , Miltenberger MA
Published: December 2004

Historically, ring tests have been performed to determine the time for concrete or mortar specimens to crack under restrained shrinkage. When the concrete or mortar ring deforms due to shrinkage, the steel ring restrains the material and tensile stresses are induced. Stress development cannot be monitored for test setups in which the degree of restraint is so high that no measurable deformation occurs in the steel as the material shrinks. Such test setups have provided qualitative evaluations and have not enabled a simple procedure to be established to routinely quantify the restrained shrinkage characteristics of the materials. In this study, an instrumented ring setup is used to quantify the restrained shrinkage behavior of concrete and mortar. The setup provides a high degree of restraint while still allowing sufficient strain in the steel as the material shrinks.

It is shown with the ring setup that the cracking potential of concrete or mortar under restrained shrinkage can be classified on the basis of either how long it takes the material to crack or the rate of stress development in the material. The testing and analysis procedure provides a rational basis for assessing the relative performance of concrete or mortar mixtures when subjected to shrinkage under restraint. A simple procedure is also developed for a preliminary assessment of cracking potential using standard values of drying shrinkage and modulus of elasticity obtained at seven days after initiation of drying.
Experimental Bench for Study of Settling-Consolidation Soil Formation
Authors: Alexis A , Le bras G , Thomas P
Published: December 2004

A laboratory experimental bench suiting the evolution survey of little concentrated materials in the course of deposition is presented here. The materials concerned can be in formation soils (mud) or any other fine granular materials, however, all characterized by their strong deformability and by their complex behaviour with constant changes from settling to consolidation phases. First, the already available experimental devices are summed up in a state-of-the-art section. The restraints imposed by the material (properties, consistency, quick evolution) have directed the development towards automated settings consisting of a column containing the material studied, a gammadensitometer and a pressure sensor. The device proposed here, the experimental procedures and the result post-processing are described in detail to provide an accurate follow up of the densities and of the interstitial excess pore pressures. The most original feature of the device lies in the possibility to obtain profiles within the first minutes of the evolution. The results, presented here in terms of effective stress and pore pressure, make it possible to delimit the range of validity of the usually adopted constitutive laws better.
Volumetric Shrinkage Strain Measurements in Expansive Soils Using Digital Imaging Technology
Authors: Puppala AJ , Katha B , Hoyos LR
Published: December 2004

Expansive soils undergo large volumetric shrinkage strains, which eventually lead to high heave movements upon hydration of these soils. Current test methods to determine shrinkage strain potentials of soils are restricted by several limitations including small specimen sizes, molds with rigid walls that restrain shrinkage strains in lateral directions, and manual measurement errors. In this paper, a novel methodology to conduct volumetric shrinkage strain test on cylindrical soil specimens and a digital imaging technique to analyze and determine volumetric shrinkage strains of the test are described. As part of the evaluations of this methodology, volumetric shrinkage strains of four types of medium to high expansive soils were researched. Shrinkage tests were conducted on all four soils at three different moisture contents. Volumetric shrinkage strains were then measured using both digital and conventional manual approaches. Test results showed that the test and the developed measurement methodology provided repeatable and realistic shrinkage strain measurements. Digital measurements provided more accurate results than manual measurements by accounting for even minor shrinkage cracks in the soils. The significance of the digital measurements in relation to the current shrinkage strain characterizations is discussed. Potential geotechnical application areas where these test results could be used are also described.
Nuclear Calcium/Calmodulin Regulates Memory Consolidation
Authors: Limbäck-Stokin Klara , Korzus Edward , Nagaoka-Yasuda Rie , Mayford Mark
Published: December 2004

The neuronal response to a Ca2+stimulus is a complex process involving direct Ca2+/calmodulin (CaM) actions as well as secondary activation of multiple signaling pathways such as cAMP and ERK (extracellular signal-regulated kinase). These signals can act in both the cytoplasm and the nucleus to control gene expression. To dissect the role of nuclear from cytoplasmic Ca2+/CaM signaling in memory formation, we generated transgenic mice that express a dominant inhibitor of Ca2+/CaM selectively in the nuclei of forebrain neurons and only after the animals reach adulthood. These mice showed diminished neuronal activity-induced phosphorylation of cAMP response element-binding protein, reduced expression of activity-induced genes, altered maximum levels of hippocampal long-term potentiation, and severely impaired formation of long-term, but not short-term, memory. Our results demonstrate that nuclear Ca2+/CaM signaling plays a critical role in memory consolidation in the mouse.
Strong Calcium Entry Activates Mitochondrial Superoxide Generation, Upregulating Kinase Signaling in Hippocampal Neurons
Authors: Hongpaisan Jarin , Winters Christine A. , Andrews S. Brian
Published: December 2004

Large increases in cytosolic free Ca2+([Ca2+]i) activate several kinases that are important for neuronal plasticity, including Ca2+/calmodulin-dependent kinase II (CaMKII), protein kinase A (PKA), and protein kinase C (PKC). Because it is also known, mainly in non-neuronal systems, that superoxide radicals (O2-) activate these (and other) kinases and because O2-generation by mitochondria is in part [Ca2+]idependent, we examined in hippocampal neurons the relationship between Ca2+entry, O2-production, and kinase activity. We found that, after large stimulus-induced [Ca2+]iincreases, O2-selectively produced by mitochondria near plasmalemmal sites of Ca2+entry acts as a modulator to upregulate the two kinases, namely, CaMKII and PKA, whose activities are directly or indirectly phosphorylation dependent. The common mechanism involves O2-inhibition of inactivating protein phosphatases. Conversely, because small [Ca2+]iincreases do not promote mitochondrial respiration and O2-generation, weak stimuli favor enhanced phosphatase activity, which therefore leads to suppressed kinase activity. Enhanced O2-production also promoted PKC activity but by a phosphatase-independent pathway. These results suggest that Ca2+-dependent upregulation of mitochondrial O2-production may be a general mechanism for linking Ca2+entry to enhanced kinase activity and therefore to synaptic plasticity. This mechanism also represents yet another way that mitochondria, acting as calcium sensors, can play a role in neuronal signal transduction.
Single-Channel Behavior of Heteromeric α1β Glycine Receptors: An Attempt to Detect a Conformational Change before the Channel Opens
Authors: Burzomato Valeria , Beato Marco , Groot-Kormelink Paul J. , Colquhoun David , Sivilotti Lucia G.
Published: December 2004

The α1β heteromeric receptors are likely to be the predominant synaptic form of glycine receptors in the adult. Their activation mechanism was investigated by fitting putative mechanisms to single-channel recordings obtained at four glycine concentrations (10-1000 μm) from rat α1β receptors, expressed in human embryonic kidney 293 cells. The adequacy of each mechanism, with its fitted rate constants, was assessed by comparing experimental dwell time distributions, open-shut correlations, and the concentration-open probability (Popen) curve with the predictions of the model. A good description was obtained only if the mechanism had three glycine binding sites, allowed both partially and fully liganded openings, and predicted the presence of open-shut correlations. A strong feature of the data was the appearance of an increase in binding affinity as more glycine molecules bind, before the channel opens. One interpretation of this positive binding cooperativity is that binding sites interact, each site sensing the state of ligation of the others. An alternative, and novel, explanation is that agonist binding stabilizes a higher affinity form of the receptor that is produced by a conformational change (“flip”) that is separate from, and precedes, channel opening. Both the “interaction” scheme and the flip scheme describe our data well, but the latter has fewer free parameters and above all it offers a mechanism for the affinity increase. Distinguishing between the two mechanisms will be important for our understanding of the structural dynamics of activation in the nicotinic superfamily and is important for our understanding of mutations in these receptors.
Apoptosis-Inducing Factor Substitutes for Caspase Executioners in NMDA-Triggered Excitotoxic Neuronal Death
Authors: Wang Hongmin , Yu Seong-Woon , Koh David W. , Lew Jasmine , Coombs Carmen , Bowers William , Federoff Howard J. , Poirier Guy G. , Dawson Ted M. , Dawson Valina L.
Published: December 2004

The profound neuroprotection observed in poly(ADP-ribose) polymerase-1 (PARP-1) null mice to ischemic and excitotoxic injury positions PARP-1 as a major mediator of neuronal cell death. We report here that apoptosis-inducing factor (AIF) mediates PARP-1-dependent glutamate excitotoxicity in a caspase-independent manner after translocation from the mitochondria to the nucleus. In primary murine cortical cultures, neurotoxic NMDA exposure triggers AIF translocation, mitochondrial membrane depolarization, and phosphatidyl serine exposure on the cell surface, which precedes cytochromecrelease and caspase activation. NMDA neurotoxicity is not affected by broad-spectrum caspase inhibitors, but it is prevented by Bcl-2 overexpression and a neutralizing antibody to AIF. These results link PARP-1 activation with AIF translocation in NMDA-triggered excitotoxic neuronal death and provide a paradigm in which AIF can substitute for caspase executioners.
The Neural Mechanisms for Minimizing Cross-Modal Distraction
Authors: Weissman D. H. , Warner L. M. , Woldorff M. G.
Published: December 2004

The neural circuitry that increases attention to goal-relevant stimuli when we are in danger of becoming distracted is a matter of active debate. To address several long-standing controversies, we asked participants to identify a letter presented either visually or auditorily while we varied the amount of cross-modal distraction from an irrelevant letter in the opposite modality. Functional magnetic resonance imaging revealed three novel results. First, activity in sensory cortices that processed the relevant letter increased as the irrelevant letter became more distracting, consistent with a selective increase of attention to the relevant letter. In line with this view, an across-subjects correlation indicated that the larger the increase of activity in sensory cortices that processed the relevant letter, the less behavioral interference there was from the irrelevant letter. Second, regions of the dorsolateral prefrontal cortex (DLPFC) involved in orienting attention to the relevant letter also participated in increasing attention to the relevant letter when conflicting stimuli were present. Third, we observed a novel pattern of regional specialization within the cognitive division of the anterior cingulate cortex (ACC) for focusing attention on the relevant letter (dorsal ACC) versus detecting conflict from the irrelevant letter (rostral ACC). These findings indicate novel roles for sensory cortices, the DLPFC, and the ACC in increasing attention to goal-relevant stimulus representations when distracting stimuli conflict with behavioral objectives. Furthermore, they potentially resolve a long-standing controversy regarding the key contribution of the ACC to cognitive control.
Methanol, formaldehyde, and sodium formate exposure in rat and mouse conceptuses: A potential role of the visceral yolk sac in embryotoxicity
Authors: Hansen Jason M. , Contreras Kristi M. , Harris Craig
Published: December 2004

BACKGROUND

Methanol (CH3OH) is believed to be teratogenic based on rodent studies. The mouse is more sensitive than the rat, but mechanisms of toxicity and identification of teratogenic metabolites are uncertain.

METHODS

Rat and mouse whole embryo cultures are used to distinguish toxicity of CH3OH and its metabolites, formaldehyde (HCHO) and formate (HCOONa), which are produced following transit through the visceral yolk sac (VYS), via addition to culture medium, or by direct embryonic exposure through microinjection into the amnion.

RESULTS

Embryonic viability, increased dysmorphogenesis, and decreased growth parameters were altered in a dose‐dependent fashion for each compound. Mouse embryos were more sensitive than rat, as indicated by significant decreases in viability at comparable, lower concentrations. HCHO produced dysmorphogenesis and caused embryolethality at nearly 1000‐fold lower concentrations (0.004 mg/ml) than seen with either CH3OH or HCOONa. All agents produced incomplete axial rotation and delayed neural tube closure in mice, but only CH3OH elicited similar effects in the rat. Increased growth retardation, blood pooling in the head and VYS, enlarged pericardium, accumulation of necrotic matter in the amnion, and hypoplastic prosencephalon were observed in both species with all compounds. Microinjection of compounds into the amnion produced higher mortality in mouse and rat, compared to equimolar amounts added to the culture medium. CH3OH did not prevent neural tube closure in the rat when microinjected.

CONCLUSIONS

HCHO is the most embryotoxic CH3OH metabolite and elicits the entire spectrum of lesions produced by CH3OH. The VYS serves a general protective role against toxicity and inherent differences in the embryonic metabolism of CH3OH may determine species sensitivity. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
On the way to a quality control of the essential oil of fennel by means of Raman spectroscopy
Authors: Strehle M. A. , Rösch P. , Baranska M. , Schulz H. , Popp J.
Published: December 2004

Essential oils are one of the most valuable natural products. The price of special essential oils that can be purchased on the market strongly depends on the quality of the product. The quality, which depends on the quantitative and qualitative variation of different monoterpenes, varies with respect of the origin and the harvesting period. This contribution reports on a Raman spectroscopic study on the essential oil occurring in fennel. Cross‐sections of fennel seed were investigated by use of Raman spectroscopy and Raman mapping to localize the essential oil and to analyze its chemical composition directly in the plant. Furthermore the practicability of a home‐built mobile transportable Raman spectrometer to perform on‐site measurements was successfully tested. © 2004 Wiley Periodicals, Inc. Biopolymers, 2005
Fluorescence enhancement of fluorophores tethered to different sized silver colloids deposited on glass substrate
Authors: Lukomska Joanna , Malicka Joanna , Gryczynski Ignacy , Leonenko Zoya , Lakowicz Joseph R.
Published: December 2004

We studied fluorescence enhancements of fluorescein tethered to silver colloids of different size. Thiolated 23‐mer oligonucleotide (ss DNA‐SH) was bound selectively to silver colloids deposited on 3‐aminopropyltriethoxysilane (APS)–treated quartz slides. Fluorescein‐labeled complementary oligonucleotide (ss Fl‐DNA) was added in an amount significantly lower than the amount of unlabeled DNA tethered to the colloids. The hybridization kinetics, observed as an increase in fluorescence emission, on small (30–40 nm) and large (> 120 nm) colloids were similar. However, the final fluorescence intensity of the sample with large colloids was about 50% higher than that observed for the sample with small colloids. The reference sample without ss DNA‐SH was used to estimate the fluorescence enhancements of fluorescein tethered to the small colloids (E = 2.7) and to the large colloids (E = 4.1) due to its steady fluorescence signal. The proposed method, based on controlled hybridization with minimal amount of fluorophore labeled ss DNA, can be used to reliably estimate the fluorescence enhancements on any silver nanostructures. © 2004 Wiley Periodicals, Inc. Biopolymers, 2005
Conventional bilateral cervical exploration versus open minimally invasive parathyroidectomy under local anaesthesia for primary hyperparathyroidism
Authors: Bergenfelz A , Kanngiesser V , Zielke A , Nies C , Rothmund M
Published: December 2004

Background

Minimally invasive parathyroidectomy (MIP) has been introduced for the treatment of patients with primary hyperparathyroidism (pHPT). Thus far, only one randomized trial has compared video-assisted MIP with conventional bilateral cervical exploration (BCE). The value of open MIP is therefore not known.

Methods

Fifty patients with a solitary parathyroid adenoma localized before surgery by sestamibi scintigraphy were randomized to undergo BCE under general anaesthesia (n = 25) or targeted MIP via a 2-cm incision using local anaesthesia (n = 25). Postoperative hypocalcaemia was the primary endpoint. Secondary outcome measures were operating time, complications, postoperative analgesia and recurrent disease. Follow-up was carried out at 1 and 6 months.

Results

All patients who underwent BCE and 24 of those who had MIP were cured by the primary operation. Operating time was 22 min shorter in the MIP group (P = 0·024). Serum levels of calcium were slightly lower during the first 4 days after surgery in the BCE group (P = 0·022). No other no significant differences were found.

Conclusion

Targeted MIP using local anaesthesia reduces operating time and causes less postoperative biochemical hypocalcaemia compared with bilateral neck exploration.
Cover Picture: Bulky Monodentate Phosphoramidites in Palladium‐Catalyzed Allylic Alkylation Reactions: Aspects of Regioselectivity and Enantioselectivity (Chem. Eur. J. 24/2004)
Authors: Boele Maarten D. K. , Kamer Paul C. J. , Lutz Martin , Spek Anthony L. , de Vries Johannes G. , van Leeuwen Piet W. N. M. , van Strijdonck Gino P. F.
Published: December 2004

The cover picture shows a modeled structure (PM3(tm)‐level) of a TADDOL derived monoligated bulky phosphorus amidite palladium–allyl complex. The allyl fragment, shown in green, has the syn,syn conformation and is clearly blocked by the aryl fragment of the S,S ligand upon counterclockwise rotation. Upon nucleophilic attack only clockwise rotation can occur, which explains the formation of the experimentally observed formation of the R product. A scheme of the reaction is shown in the background. For more information see the article by P. W. N. M. van Leeuwen et al. on p. 6232 ff.
Cyclizations of N‐(1‐Chloro‐2,2,2‐trihaloethylidene)‐O‐methylurethanes with 5‐Amino‐3‐methylisoxazole and 3‐Amino‐5‐methylisoxazole.
Authors: Vovk M. V. , Bolbut A. V. , Dorokhov V. I.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
High Loading Polymer Reagents Based on Polycationic Ultraresins. Polymer‐Supported Reductions and Oxidations with Increased Efficiency.
Authors: Barth Michael , Shah Syed Tasadaque Ali , Rademann Joerg
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Ring‐Closing Metathesis of Vinyl Chlorides for Formation of 5‐, 6‐ and 7‐Membered Carbocyclic and Heterocyclic Systems.
Authors: Chao Wenchun , Meketa Matthew L. , Weinreb Steven M.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
A Facile Method for the Preparation of Pure cis‐2,4‐Pentanediol.
Authors: Bonner Lisa , Frescas Stewart , Nichols David E.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Alkoxybenzylcyanoguanidine Analogues as a Novel Class of Inhibitors for Restenosis.
Authors: Lee Sunkyung , Yi Kyu Yang , Hwang Sun Kyung , Suh Jeehee , Lee Byung Ho , Yoo Sung‐eun
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Diastereoselectivity in [2π + 2π] Photocycloaddition of Cholesteryl Cinnamate to Methyl 9‐Phenanthrenecarboxylate: Control of the Stereoselectivity in Liquid Crystalline Phase.
Authors: Maeda Hajime , Horiuchi Akemi , Koshio Norihiro , Mizuno Kazuhiko
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Structure—Activity Relationship of a Novel Sulfone Series of TNF‐α Converting Enzyme Inhibitors.
Authors: Xue Chu‐Biao , Chen Xiao‐Tao , et al. et al.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Rational Design of 6‐Methylsulfonylindoles as Selective Cyclooxygenase‐2 Inhibitors.
Authors: Campbell Jeffrey A. , et al. et al.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Tandem Overman Rearrangement and Intramolecular Amidomercuration Reactions. Stereocontrolled Synthesis of cis‐ and trans‐2,6‐Dialkylpiperidines.
Authors: Singh Om V. , Han Hyunsoo
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Nonpeptide αvβ3 Antagonists. Part 10. In vitro and in vivo Evaluation of a Potent 7‐Methyl Substituted Tetrahydro‐[1,8]naphthyridine Derivatives.
Authors: Breslin Michael J. , et al. et al.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Spiroquinazolinones as Novel, Potent, and Selective PDE7 Inhibitors. Part 2. Optimization of 5,8‐Disubstituted Derivatives.
Authors: Bernardelli Patrick , et al. et al.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of a Novel Tetrahydroisoquinolino[2,1‐c][1,4]benzodiazepine Ring System with DNA Recognition Potential.
Authors: Kothakonda Kiran Kumar , Bose D. Subhas
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
On Steroids. Part 417. Effects of 3α‐Amino‐5α‐pregnan‐20‐one on GABAA Receptor: Synthesis, Activity and Cytotoxicity.
Authors: Matyas Libor , Kasal Alexander , Babot Riera Zoila , Sunol Cristina E.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Formation of Squaric Acid Amides of Anthracycline Antibiotics. Synthesis and Cytotoxic Properties.
Authors: Tevyashova Anna , Sztaricskai Ferenc , Batta Gyula , Herczegh Pal , Jeney Andras
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Macropolyhedral Boron‐Containing Cluster Chemistry: Pointers Towards the Mechanism of Homofusions of Nine‐Vertex Arachno Metallaboranes
Authors: Londesborough Michael G. S. , MacLean Elizabeth J. , Teat Simon J. , Bould Jonathan , Kilner Colin A. , Thornton‐Pett Mark , Kennedy John D.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
aracho‐Carborane Anions and Their Metal Complexes
Authors: Wang Hong , Xie Zuowei
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Organoelement Compounds with Main Group Hypercoordinate Centers
Authors: Minyaev R. M. , Gribanova T. N.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Industrial and Biological Applications of Germanium and Its Derivatives
Authors: Satge Jacques
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Cyclopropylidenes, Bicyclopropylidenes, and Vinylcarbenes — Some Modes of Formation and Preparative Applications
Authors: de Meijere A. , Schill H. , Kozhushkov S. I. , Walsh R. , Mueller E. M. , Grubmueller H.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Phosphasila‐, Phosphagerma‐, and Phosphaarsaallenes — P=C=E (E: Si, Ge, As) and Arsa‐ and Diarsaallenes — As=C=E′ (E′: C, As)
Authors: Escudie J. , Ranaivonjatovo H. , Bouslikhane M. , El Harouch Y. , Baiget L. , Nemes G. Cretiu
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Total Synthesis of Polycyclic Ether Natural Products Based on Suzuki—Miyaura Cross‐Coupling
Authors: Sasaki Makoto , Fuwa Haruhiko
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Experimental Evidence for Intramolecular ipso Substitution of Alkyl Groups
Authors: Zubkov Fedor I. , Nikitina Eugenia V. , Kouznetsov Vladimir V. , Duarte Luz Dary Avellaneda
Published: December 2004

An acid‐mediated intramolecular Friedel−Crafts intramolecular alkene alkylation of the ortho‐alkyl group in the N‐arylamino moiety of various N‐(1‐allylcycloalkyl)‐N‐arylamines resulting in alkyl‐substituted 3′,4′‐dihydro‐1′H‐spiro[cycloalkane‐1,2′‐quinolines] is described. The mechanistic details of this intramolecular Friedel−Crafts alkylation by an alkene moiety can be explained by an intramolecular alkylation with ipso substitution of alkyl groups and their 1,2‐rearrangement. The scope and limitations of this reaction were determined. As a conclusive proof of the proposed mechanism, previously unknown interesting by‐products, dispiro[quino[6,7‐f]quinoline‐3,1′:9,1′′‐bis(cycloalkanes), were isolated and characterized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Preparation of (all‐E)‐ and (11Z)‐12‐Haloretinals and (11Z,13Z)‐ and (13Z)‐14‐Haloretinals by the C15 + C5 Route − Exploring the Possibility of Preparing any Retinoid Rationally Chemically Modified at any Position in the Conjugated Tail
Authors: Wang Yajie , Lugtenburg Johan
Published: December 2004

In this paper we describe how chemically modified ylides can be prepared by electrophilic substitution in a simple way. A subsequent Horner−Emmons reaction gives access to (all‐E)‐ and (11Z)‐12‐chloro‐, ‐12‐bromo‐, and ‐12‐iodoretinal. It could be expected that many more retinals chemically modified at the 12‐position could be prepared in this manner. Selectfluor®, a good reagent for introducing a fluorine atom by electrophilic substitution, does not give the 12‐fluororetinal system. However, 14‐fluororetinal is simply available by reaction of the anion with Selectfluor®. Cl, Br and I atoms were also introduced at the 14‐position of retinal both in the (11Z,13Z)‐ and (13Z)‐isomeric forms. This strategy could be extended to a whole range of electrophilic‐substitution reactions. We also developed a novel method to prepare 4‐hydroxy‐substituted Horner−Emmons derivatives, which could be converted into the 4‐fluoro derivatives by reaction with (diethylamino)sulfur trifluoride (DAST). This system could simply be converted into 12‐fluororetinal in the (all‐E)‐ and (11Z)‐isomeric forms and we think that this strategy has a good scope to prepare a whole series of 12‐modified retinals. We have also explored the essential steps to give access to retinoids modified at any position of the conjugated chain. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Neighboring‐Group Participation in Nitrile‐Forming Beckmann Fragmentation Reactions: Synthesis of Enantiopure (E)‐2,3‐Di‐O‐substituted‐5‐methoxy‐ pent‐4‐enenitriles and Their Conversion into Pyranosylamines
Authors: Passacantilli Pietro , Centore Clara , Ciliberti Elena , Piancatelli Giovanni , Leonelli Francesca
Published: December 2004

The selective Beckmann fragmentations of multifunctionalised ketoximes have been proven to proceed effectively to give the corresponding nitriles. The chiral (E)‐1,3,4‐tri‐O‐substituted‐6‐methoxy‐hex‐5‐en‐2‐one oxime derivatives, available from glycals and glycosyl glycals, gave enantiopure (E)‐2,3‐di‐O‐substituted‐5‐methoxypent‐4‐enenitriles by treatment with mesyl chloride and triethylamine. The C1−C2 heterolytic fragmentation was completely controlled and directed by the adjacent C1 ether oxygen, which generates a carbonium‐oxonium ion as an active electrofugal group. Unexpectedly, the C3 heteroatom did not assist the cleavage reaction and products derived from C2−C3 fragmentation were never detected. The excellent regio‐ and stereospecificity of the fragmentation reaction, based on the stereochemical outcome, are discussed. A simple synthetic approach to some pyranosylamines is also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
New 1,3‐Disubstituted Enantiomerically Pure Allylboronic Esters by Johnson Rearrangement of Boron‐Substituted Allyl Alcohols
Authors: Pietruszka Jörg , Schöne Niklas
Published: December 2004

Starting from commercially available 1‐substituted propargylic alcohols 6, 18 and ent‐18, stable enantio‐ and diastereomerically pure 1,3‐disubstituted allylboronic esters 10, 19 and 20 were synthesized. The key step − a Johnson rearrangement − was highly diastereoselective and yielded the products with almost complete transfer of the stereogenic information from the intermediate allyl alcohols. The configurations of all the new derivatives were unequivocally assigned either by chemical correlation (e.g. allylboronic ester 10 and its diastereomer 11 were independently synthesized by cross‐metathesis of the known boronates 2a and 3a with styrene) or by analysis of the NMR data, and additionally by X‐ray structural analysis (of 20). Allyl addition to benzaldehyde in all cases yielded enantiomerically highly enriched homoallylic alcohols 15/ent‐15 and 21/ent‐21 (> 98% ee). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Transient inflammatory response induced by apoptotic cells is an important mediator of melanoma cell engraftment and growth
Authors: Correa Mariangela , Machado Joel , Carneiro Célia R.W. , Bosco Pesquero João , Bader Michael , Travassos Luiz R. , Chammas Roger , Jasiulionis Miriam G.
Published: November 2004

Two murine melanoma cell lines, Tm1 and Tm5, were derived from a nontumorigenic lineage of pigmented murine melanocytes, melan‐a. Both Tm1 and Tm5 are invariably tumorigenic in syngeneic mice when inoculated s.c. in doses higher than 104 cells; 103 or fewer cells rarely give rise to tumors. We demonstrate that subtumorigenic inocula of Tm1 or Tm5 cells (103) as well as of a known murine melanoma cell line (B16F10) develop as vigorously growing tumor grafts only when coinoculated with apoptotic, but not necrotic cells. The presence of apoptotic cells correlates with a transient inflammatory infiltrate, composed mainly of neutrophils and macrophages. Kinin B1 receptor–deficient mice, which have impaired transmigration of neutrophils to inflamed tissues, had significant growth inhibition of subtumorigenic doses of melanoma cells coinjected with apoptotic cells. Using the same model, tumor take in athymic mice was similar to that seen in wild‐type mice, suggesting that a T cell–dependent inflammatory response is not necessary to promote the survival and growth of subtumorigenic doses of melanoma cells. Taken together, our results describe how tumor engraftment and growth can be profoundly affected by microenvironmental alterations in response to the presence of apoptotic cells. Disrupting the delicate balance between apoptotic cells and leukocyte infiltration may provide potentially important insights for understanding and interfering with tumor cell viability during treatment with either γ‐radiation or apoptosis‐inducing drugs. © 2004 Wiley‐Liss, Inc.
The Epstein‐Barr virus oncoprotein latent membrane protein 1 induces expression of the chemokine IP‐10: Importance of mRNA half‐life regulation
Authors: Vockerodt Martina , Pinkert Diana , Smola‐Hess Sigrun , Michels Astrid , Ransohoff Richard M. , Tesch Hans , Kube Dieter
Published: December 2004

The latent membrane protein 1 (LMP1) of Epstein‐Barr Virus (EBV) is the main inducer of immuno‐modulatory molecules affecting growth and survival of EBV‐infected cells. However, the network of signalling pathways involved remains to be elucidated. Here we show that LMP1 may regulate cellular genes like IFN‐γ‐inducible protein‐10 kDa (IP‐10) not only through transcriptional but also post‐transcriptional mechanisms. LMP1‐mediated IP‐10 expression is independent from IFN‐γ, TNF‐α or IL‐18. Transcriptional activation of IP‐10 by LMP1 or CD40 stimulation depends on an NF‐κB motif within the proximal 435 bp fragment. Carboxy‐terminal activating regions 1 or 2 of LMP1 are sufficient to direct IP‐10 promoter activation. IP‐10 induction is inhibited by blockade of p38/SAPK2 with SB 202190, which results in decreased IP‐10 mRNA half‐life without affecting IP‐10 promoter activity. Thus, LMP1‐mediated p38/SAPK2 activation regulates transcript stability. This new mechanism of gene regulation demonstrates the potential of the oncoprotein LMP1 to orchestrate a network of signalling pathways at different regulatory levels including mRNA stability. © 2004 Wiley‐Liss, Inc.
Suppression of human melanoma tumor growth in SCID mice by a human high molecular weight‐melanoma associated antigen (HMW‐MAA) specific monoclonal antibody
Authors: Hafner Christine , Breiteneder Heimo , Ferrone Soldano , Thallinger Christiane , Wagner Stefan , Schmidt Wolfgang M. , Jasinska Joanna , Kundi Michael , Wolff Klaus , Zielinski Christoph C. , Scheiner Otto , Wiedermann Ursula , Pehamberger Hubert
Published: December 2004

The lack of efficacy of available therapies for the treatment of malignant melanoma has emphasized the need to develop novel therapeutic strategies to prevent melanoma growth. We have tested whether the anti‐HMW‐MAA mAb 225.28S is able to inhibit human melanoma tumor growth in SCID mice because in vitro data suggested that this antigen plays a role in spreading, migration and invasion of melanoma cells. Tumors were established by subcutaneous injection of the human melanoma cell line 518A2 into SCID mice. When tumors reached a size of 5 mm, the mAb 225.28S was administered intravenously 4 times in 3 day intervals at 100 μg/injection. Within 14 days after the first administration of the mAb 225.28S, tumor growth was reduced by 52% as compared to control mice. Three hundred and seven genes of >20,000 genes contained on the GeneChip were changed in their expression level at least 2‐fold after administration of the mAb 225.28S. The encoded proteins were mostly components or modifiers of the extracellular matrix, tumor suppressors, and melanogenesis associated proteins. Surprisingly, the administration of the control mAb that did not lead to a significant tumor growth inhibition in vivo resulted in the modulation of two‐thirds of these genes. This is the first report of suppression of human melanoma tumor growth in SCID mice by the mAb 225.28S. Our results suggest that anti‐HMW‐MAA mAbs may represent useful reagents to apply passive immunotherapy to patients with malignant melanoma. © 2004 Wiley‐Liss, Inc.
In vitro interaction between silicone gel and human monocyte‐macrophages
Authors: Tavazzani F. , Xing S. , Waddell J. E. , Smith D. , Boynton E. L.
Published: November 2004

Controversy remains regarding the ability of silicone materials to induce a specific immune reaction versus a nonspecific inflammatory response. Histopathological analysis of the tissue around failed breast implants reveals chronic inflammation with silicone gel droplets either surrounded by giant cells or engulfed by macrophages, areas of fibrosis, and necrosis. Macrophages are the key cells engulfing or forming foreign body giant cells. To address the mechanisms of silicone‐induced inflammation a model of human monocyte‐derived macrophages (MDMs) was developed. After sonication of silicone gel, the silicone droplets were embedded in Type I collagen and used to coat glass coverslips; human MDMs were subsequently seeded on the coverslips and maintained in culture for up to 7 days. The advantage of the model was that human macrophages could be studied histologically, and cytochemically as they interacted with well‐characterized silicone materials. Initial analysis of the human macrophages shows phagocytosis of the silicone gel within hours of exposure to the material. Analysis for pro‐inflammatory cytokines reveals significant transient secretion of IL‐1 (p < 0.01) over controls by human macrophages upon exposure to silicone gel at 24 h. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 161–167, 2005
Human trabecular bone‐derived osteoblasts support human osteoclast formation in vitro in a defined, serum‐free medium
Authors: Atkins Gerald J. , Kostakis Panagiota , Welldon Katie J. , Vincent Cristina , Findlay David M. , Zannettino Andrew C.W.
Published: November 2004

While it has been assumed that osteoblasts in the human support osteoclast formation, in vitro evidence of this is currently lacking. We tested the ability of normal human trabecular bone‐derived osteoblasts (NHBCs) to support osteoclast formation from human peripheral blood mononuclear cells (PBMC) in response to treatment with either 1α,25‐dihydroxyvitamin D3 (1,25D) or parathyroid hormone (PTH), using a serum‐replete medium previously used to support human osteoclast formation on a stroma of murine ST‐2 cells. Under these conditions, NHBC did not support osteoclast formation, as assessed by morphological, histochemical, and functional criteria, despite our previous results demonstrating a link between induction of RANKL mRNA expression and NHBC phenotype in these media. We next tested a defined, serum‐free medium (SDM) on NHBC phenotype, their expression of RANKL and OPG, and their ability to support osteoclast formation. SDM, containing dexamethasone (DEX) and 1,25D, induced phenotypic maturation of NHBC, based on the expression of STRO‐1 and the bone/liver/kidney isoform of alkaline phosphatase (AP). PTH as a single factor did not induce phenotypic change. 1,25D and DEX induced the greatest ratio of RANKL:OPG mRNA, predictive of supporting osteoclast formation. Consistent with this, co‐culture of NHBC with CD14+ PBMC, or bone marrow mononuclear cell (BMMC), or CD34+ BMMC precursors in SDM + 1,25D + DEX, resulted in functional osteoclast formation. Osteoclast formation also occurred in PTH + DEX stimulated co‐cultures. Interestingly, SDM supplemented with recombinant RANKL (25–100 ng/ml) and M‐CSF (25 ng/ml), did not induce osteoclast formation from any of the osteoclast precursor populations in stromal‐free cultures, unlike serum‐replete medium. This study demonstrates that under the appropriate conditions, adult human primary osteoblasts can support de novo osteoclast formation, and this model will enable the detailed study of the role of both cell types in this process. © 2004 Wiley‐Liss, Inc.
Fibroblast growth factor‐2 regulates the synthesis of hyaluronan by human periodontal ligament cells
Authors: Shimabukuro Yoshio , Ichikawa Tomoo , Takayama Shinichi , Yamada Satoru , Takedachi Masahide , Terakura Mami , Hashikawa Tomoko , Murakami Shinya
Published: November 2004

Basic fibroblast growth factor (FGF‐2) can enhance biological potentials of periodontal ligament cells and its topical application induces considerable periodontal tissue regeneration in vivo. In this study, we examined the effect of FGF‐2 on the production of hyaluronan (HA), an extracellular matrix playing important roles in homeostasis and inflammatory/wound healing responses, by human periodontal ligament (HPDL) cells. An inhibition binding‐protein assay revealed that FGF‐2 significantly increased HA production by HPDL cells in a dose dependent manner. Analysis by HPLC revealed that in conditioned medium of FGF‐2‐treated HPDL cells HA had a higher molecular mass, compared to that of untreated HPDL cells. RT‐PCR analysis revealed the enhancement of mRNA expression of hyaluronan synthase (HAS) 1 and HAS 2, both of which contribute to the production of HA with a high molecular mass, but not HAS 3 in the FGF‐2‐treated HPDL cells. In contrast, three isoforms of hyaluronidase (HYAL) transcript were unchanged in the FGF‐2‐treated HPDL cells. These results provide new evidence for the possible involvement of FGF‐2 in the regulation of HA production and its appreciable roles in not only homeostasis but also regeneration of periodontal tissues. © 2004 Wiley‐Liss, Inc.
Smad function and intranuclear targeting share a Runx2 motif required for osteogenic lineage induction and BMP2 responsive transcription
Authors: Afzal Faiza , Pratap Jitesh , Ito Kosei , Ito Yoshiaki , Stein Janet L. , van Wijnen Andre J. , Stein Gary S. , Lian Jane B. , Javed Amjad
Published: November 2004

The coordinated activity of Runx2 and BMP/TGFβ‐activated Smads is critical for formation of the skeleton, but the precise structural basis for the Runx2/Smad interaction has not been resolved. By deletion mutagenesis, we have defined the Runx2 motif required for physical and functional interaction with either BMP or TGFβ responsive Smads. Smad responsive transcriptional activity was retained upon deletion of the C‐terminus to amino acid (aa) 432 but lost with deletion to aa 391. Thus the Smad interacting domain (SMID) of Runx2 (432–391) is embedded in the well‐defined nuclear matrix targeting signal (NMTS) that mediates intranuclear trafficking. The SMID suffices as an interacting module when fused to the heterologous Gal‐4 protein. Formation of the Runx2 and Smad complex is dependent on Runx2 phosphorylation through the MAPK signaling pathway, as determined by co‐immunoprecipitation studies. We established that all SMID/NMTS deficient Runx2 mutants do not show in situ association with Smad in the nucleus nor do they support BMP2‐mediated osteogenic induction of the mesenchymal C2C12 cell line. Thus, we provide direct evidence that the SMID/NMTS domain (391–432) of Runx2 is essential for BMP2‐mediated osteoblast differentiation. Our findings suggest that TGFβ/ BMP2 signaling, MAPK dependent phosphorylation, and Runx2 subnuclear targeting converge to induce the osteogenic phenotype. © 2004 Wiley‐Liss, Inc.