bluuebunny/crossref_metadata_2025 huggingface dataset:
Utility of on‐line three‐dimensional transesophageal echocardiography during percutaneous atrial septal defect closure
Authors: Price Matthew J. , Smith Michael R. , Rubenson David S.
Published: June 2009

Key echocardiographic assessments during percutaneous atrial septal defect (ASD) closure are the maximal defect diameter, the presence or absence of tissue rims, and the spatial relationships between the implanted device and cardiac structures. These assessments drive device selection and may help identify situations that may place a patient at risk for device erosion or other complications. On‐line three‐dimensional (3D) transesophageal echocardiography (TEE) enables the rendering of nearly unlimited tissue planes within an acquired pyramidal‐shaped volume with minimal image post‐processing. We present several cases of percutaneous ASD closure guided by on‐line 3D TEE imaging that highlight the potential advantages of this new imaging technology. © 2009 Wiley‐Liss, Inc.
Pulmonary artery growth following arterial duct stenting in congenital heart disease with duct‐dependent pulmonary circulation
Authors: Santoro Giuseppe , Palladino Maria Teresa , Capozzi Giovanbattista , Iacono Carola , Russo Maria Giovanna , Calabrò Raffaele
Published: June 2009

Objectives:

The aim of this study was to assess the pulmonary artery (PA) growth following arterial duct (AD) stenting in neonates with congenital heart disease (CHD) with duct‐dependent pulmonary circulation.

Background:

AD stenting is increasingly deemed as a reliable alternative to surgical shunt in CHD with duct‐dependent pulmonary circulation. Allowing the stent to conform to the PA anatomy might avoid any unbalance of lung perfusion and promote a uniform growth of the main PAs.

Methods:

Of the 47 neonates and infants submitted to AD stenting as palliation of CHD with duct‐dependent pulmonary circulation at our Institution, 15 underwent angiographic evaluation of the PA development before surgical repair due to progressive decrease of the systemic oxygen saturation. The Nakata and McGoon indexes as well as the left‐to‐right PA diameter ratio were considered as being indicative of global and balanced growth.

Results:

Ductal stabilization was achieved with coronary stents dilated to 3.3 ± 0.4 mm (range 2.5–4). The control angiography was performed 7 ± 3 months (range 3–13) after the stenting procedure. At that time, the Nakata and McGoon indexes had significantly increased from 132 ± 67 to 287 ± 94 mm/m2 and from 1.6 ± 0.3 to 2.1 ± 0.2 mm/m2, respectively (P < 0.0001 for both comparisons), due to uniform vascular growth (left PA z‐score from −0.7 ± 1.6 to 1.4 ± 1.2; right PA from −0.8 ± 1.4 to 1.4 ± 1.2, P < 0.0001 for both comparisons; final left‐to‐right PA ratio 0.9 ± 0.1).

Conclusions:

Percutaneous AD stabilization with highly flexible coronary stents is effective in promoting a significant and balanced growth of the PAs in CHD with duct‐dependent pulmonary circulation. © 2009 Wiley‐Liss, Inc.
Long‐term outcomes of drug‐eluting stents versus bare‐metal stents in saphenous vein graft disease: Results from the Prairie “Real World” Stent Registry
Authors: Goswami Nilesh J. , Gaffigan Matthew , Berrio Gadiel , Plessa Anna L. , Pfeiffer Amanda M. , Markwell Stephen J. , Mishkel Gregory J.
Published: June 2009

Objectives:

This study was designed to compare long‐term clinical outcomes of drug‐eluting stents (DES) versus bare metal stents (BMS) in patients with saphenous vein graft (SVG) disease in the “real world.”

Background:

The safety and efficacy of DES versus BMS in SVG remains uncertain due to contradictory reports of either lower revascularization rates with DES; or clinical equivalence to BMS; or even an excess of clinical events associated with DES use.

Methods:

We identified consecutive patients who underwent stent placement within a de novo SVG lesion between May 1, 2003 and July 31, 2007. Follow‐up was obtained at regular intervals. The Kaplan–Meier method was used to produce actuarial survival estimates. Cox regression analysis was used to predict the risk associated with stent type, and propensity scores were generated to risk‐adjust the results.

Results:

The study group included 379 stent recipients (284 DES; 95 BMS) with 410 stented lesions. BMS were placed more frequently in current smokers, acute myocardial infarctions, larger vessels, and longer lesions. In‐hospital mortality was higher in BMS recipients than in their DES counterparts (3.2% vs. 0, respectively; P = 0.015). At 3 years, there was no significant difference in clinical adverse event rates between DES and BMS recipients, even after risk adjustment.

Conclusions:

Three‐year adverse event rates are similar among patients treated with DES or BMS in SVG lesions. Therefore, while DES are safe, they do not appear to offer an advantage in terms of long‐term graft patency. © 2009 Wiley‐Liss, Inc.
Diastolic transmitral valve pressure gradients in patients with severe calcific aortic stenosis
Authors: Yong Gerald , Ali Aman , Feldman Ted
Published: June 2009

Background:

During hemodynamic assessment prior to antegrade balloon aortic valvuloplasty (BAV), unanticipated transmitral valve pressure gradients (MVG) were noted frequently.

Aim:

To determine the prevalence and significance of a significant MVG in patients with aortic stenosis and no previously diagnosed mitral valve stenosis.

Method:

Retrospective chart review of patients with severe aortic stenosis who underwent antegrade BAV. During antegrade BAV, direct transseptal left atrial (LA) and left ventricular (LV) pressure measurements were obtained allowing for accurate assessment of MVG. Significant MVG is defined as a LA–LV gradient of ≥5 mm Hg.

Results:

Eighty‐two BAV patients were reviewed (mean age 84 ± 8.9 years, mean additive Euroscore 10.5 ± 2.2). The mean MVG was 5.0 ± 3.5 mm Hg (range 0–14 mm Hg). A significant MVG was seen in 54.9% and, compared with no significant MVG, was associated at with significantly higher LA mean pressure (26.0 ± 6.0 mm Hg vs. 16.8 ± 6.6 mm Hg, P < 0.001), higher pulmonary arterial systolic pressure (59.3 ± 14.7 mm Hg vs. 43.1 ± 16.5 mm Hg, P < 0.001), and higher pulmonary mean systolic pressure (37.7 ± 10.4 mm Hg vs. 28.0 ± 11.4 mm Hg, P < 0.001). Statistically significant correlations were seen between MVG and LA mean pressure (r = 0.65, P < 0.001), pulmonary arterial systolic (r = 0.49, P < 0.001) and pulmonary arterial mean pressures (r = 0.41, P < 0.001). There was no association with cardiovascular risk factors, with presence or severity of mitral annular calcification (visually assessed on cine‐fluoroscopy) or with the presence of mitral regurgitation.

Conclusions:

A significant MVG is commonly seen in patients with severe calcific aortic stenosis and is associated with higher pulmonary arterial and left atrial pressures. © 2009 Wiley‐Liss, Inc.
Nonnegative approximations of nonnegative tensors
Authors: Lim Lek‐Heng , Comon Pierre
Published: June 2009

We study the decomposition of a nonnegative tensor into a minimal sum of outer product of nonnegative vectors and the associated parsimonious naïve Bayes probabilistic model. We show that the corresponding approximation problem, which is central to nonnegative PARAFAC, will always have optimal solutions. The result holds for any choice of norms and, under a mild assumption, even Brègman divergences. Copyright © 2009 John Wiley & Sons, Ltd.
The Catalytic Mechanism of Fluoroacetate Dehalogenase: A Computational Exploration of Biological Dehalogenation
Authors: Kamachi Takashi , Nakayama Tomonori , Shitamichi Osamu , Jitsumori Keiji , Kurihara Tatsuo , Esaki Nobuyoshi , Yoshizawa Kazunari
Published: June 2009

The biological dehalogenation of fluoroacetate carried out by fluoroacetate dehalogenase is discussed by using quantum mechanical/molecular mechanical (QM/MM) calculations for a whole‐enzyme model of 10 800 atoms. Substrate fluoroacetate is anchored by a hydrogen‐bonding network with water molecules and the surrounding amino acid residues of Arg105, Arg108, His149, Trp150, and Tyr212 in the active site in a similar way to haloalkane dehalogenase. Asp104 is likely to act as a nucleophile to attack the α‐carbon of fluoroacetate, resulting in the formation of an ester intermediate, which is subsequently hydrolyzed by the nucleophilic attack of a water molecule to the carbonyl carbon atom. The cleavage of the strong CF bond is greatly facilitated by the hydrogen‐bonding interactions between the leaving fluorine atom and the three amino acid residues of His149, Trp150, and Tyr212. The hydrolysis of the ester intermediate is initiated by a proton transfer from the water molecule to His271 and by the simultaneous nucleophilic attack of the water molecule. The transition state and produced tetrahedral intermediate are stabilized by Asp128 and the oxyanion hole composed of Phe34 and Arg105.
A Mechanistic Study of the Effects of Antioxidants on the Formation of Malondialdehyde‐Like Products in the Reaction of Hydroxyl Radicals with Deoxyribose
Authors: Rachmilovich‐Calis Sandra , Meyerstein Naomi , Meyerstein Dan
Published: June 2009

The reactions of .OH radicals with deoxyribose, DR, form five different DR. radicals, only one of which is transformed into malondialdehyde (MDA)‐like products. The radiolytic yield of the MDA‐like products increases with the increase in the DR concentration indicating that some of the initially formed “unproductive” radicals react with DR to form the “productive” radicals. The yield of the MDA‐like products also increases with the dose rate delivered to the solution suggesting that the formation of the MDA‐like products involves the reaction of the “productive” radicals with a radical. The addition of ascorbate, AH−, to the solution decreases the yield of the MDA‐like products as expected from the relative rates of the reaction of DR and AH− with .OH radicals. On the other hand the addition of the exogenous thiol, N‐acetylcysteine (NAC), to the solutions decreases the yield of the MDA‐like products considerably more than expected from the rate constants of the reaction with .OH radicals. The addition of the endogenous thiol, glutathione (GSH), to the solutions affects the yield of the MDA‐like products at low concentration less than expected and at “high” concentrations more than expected from the rate constant of the reaction. Addition of low concentration of AH− to solutions containing GSH increases considerably its antioxidant activity whereas addition of small concentrations of AH− to solutions containing NAC has no effect on its antioxidant activity. The results point out that the DR. radicals react differently with NAC and GSH and that the GS. and NAC. radicals react differently with DR, the GS. radical being considerably more active than the NAC. radical. Thus it has to be concluded that the relative activity of antioxidants depends also on the rate constants of many secondary reactions and on the concentrations of all the solutes present in the system.
Reversible Uptake of COS, CS2, and SO2: Ionic Liquids with O‐Alkylxanthate, O‐Alkylthiocarbonyl, and O‐Alkylsulfite Anions
Authors: Heldebrant David J. , Yonker Clement R. , Jessop Philip G. , Phan Lam
Published: June 2009

CO2‐binding organic liquids (CO2BOLs) are mixtures of a base (typically an amidine or guanidine) and an alcohol, and have been shown to reversibly capture and release CO2 with low reaction energies and high gravimetric CO2 capacity. We now report the ability of such liquid blends to chemically bind and release other acid gases such as CS2, COS, and SO2 analogously to CO2. These systems bind with sulfur‐containing acid gases to form colored ionic liquids with new O‐alkylxanthate, O‐alkylthiocarbonyl, and O‐alkylsulfite anions. The capture and thermal stripping of each acid gas from these systems and their applicability towards flue gas desulfurization is discussed.
Release of Toxic Gd3+ Ions to Tumour Cells by Vitamin B12 Bioconjugates
Authors: Siega Patrizia , Wuerges Jochen , Arena Francesca , Gianolio Eliana , Fedosov Sergey N. , Dreos Renata , Geremia Silvano , Aime Silvio , Randaccio Lucio
Published: June 2009

Two probes consisting of vitamin B12 (CNCbl) conjugated to Gd chelates by esterification of the ribose 5′‐OH moiety, Gd–DTPA–CNCbl (1; DTPA=diethylenetriamine‐N,N,N′,N′′,N′′‐pentaacetic acid) and Gd–TTHA–CNCbl (2; TTHA=triethylenetetramine‐N,N,N′,N′′,N′′′,N′′′‐hexaacetic acid), have been synthesised and characterised. The crystal structure of a dimeric form of 1, obtained by crystallisation with an excess of GdCl3, has been determined. The kinetics of binding to and dissociation from transcobalamin II show that 1 and 2 maintain high‐affinity binding to the vitamin B12 transport protein. Complex 2 is very stable with respect to Gd3+ release owing to the saturated co‐ordination of the Gd3+ ion by four amino and five carboxylate groups. Hydrolysis of the ester functionality occurs on the time scale of several hours. The lack of saturation and the possible involvement of the ester functionality in co‐ordination result in lower stability of 1 towards hydrolysis and in a considerable release of Gd3+ in vitro. Gd3+ ions released from 1 are avidly taken up by the K562 tumour cells to an extent corresponding to approximately 1010 Gd3+ per cell. The internalisation of toxic Gd3+ ions causes a marked decrease in cell viability as assessed by Trypan blue and WST‐1 tests. On the contrary, the experiments with the more stable 2 did not show any significant cell internalisation of Gd3+ ions and any influence on cell viability. The results point to new avenues of in situ generation of cytotoxic pathways based on the release of toxic Gd3+ ions by vitamin B12 bioconjugates.
From Azides to Nitrogen‐Centered Radicals: Applications of Azide Radical Chemistry to Organic Synthesis
Authors: Minozzi Matteo , Nanni Daniele , Spagnolo Piero
Published: June 2009

Over the last thirty years organic azides have drawn a great deal of attention as radical traps for carbon‐ and heteroatom‐centered radicals, both in intra‐ and in intermolecular processes. The resulting intermediates (nitrogen‐centered radicals such as triazenyls, aminyls, or even iminyls) can be conveniently employed in the synthesis of a variety of cyclic and acyclic nitrogen‐containing compounds.
Heterogeneous Wheel‐Shaped Cu20‐Polyoxotungstate [Cu20Cl(OH)24(H2O)12(P8W48O184)]25− Catalyst for Solvent‐Free Aerobic Oxidation of n‐Hexadecane
Authors: Chen Lifang , Hu Juncheng , Mal Sib Sankar , Kortz Ulrich , Jaensch Helge , Mathys Georges , Richards Ryan M.
Published: June 2009

The selective oxidation of alkanes as a green process remains a challenging task because partial oxidation is easier to achieve with sacrificial oxidants, such as hydrogen peroxide, alkyl hydroperoxides or iodosylbenzene, than with molecular oxygen or air. Here, we report on a heterogeneous catalyst for n‐hexadecane oxidation comprised of the wheel shaped Cu20‐polyoxotungstate [Cu20Cl(OH)24(H2O)12(P8W48O184)]25− anchored on 3‐aminopropyltriethoxysilane (apts)‐modified SBA‐15. The catalysts were characterized by powder X‐ray diffraction (XRD), N2‐adsorption measurements and Fourier transform infrared reflectance (FT‐IR) spectroscopy. The heterogeneous Cu20‐polyanion system catalyzed the solvent‐free aerobic oxidation of n‐hexadecane to alcohols and ketones by using air as the oxidant under ambient conditions. The catalyst exhibits an exceptionally high turn over frequency (TOF) of 20 000 h−1 at 150 °C and is resistant to poisoning by CS2. Moreover, it can be easily recovered and reused by filtration without loss of its catalytic activity. Possible homogeneous contributions also have been examined and eliminated. Thus, this system can use air as oxidant, which, in combination with its good overall performance and poison tolerance, raises the prospect of this type of heterogeneous catalyst for practical applications.
Modelling the Magnetic Behaviour of Square‐Pyramidal CoII5 Aggregates: Tuning SMM Behaviour through Variations in the Ligand Shell
Authors: Klöwer Frederik , Lan Yanhua , Nehrkorn Joscha , Waldmann Oliver , Anson Christopher E. , Powell Annie K.
Published: June 2009

Three new μ4‐bridged CoII5 clusters with similar core motifs have been synthesised with the use of N‐tert‐butyldiethanolamine (tbdeaH2) and pivalic acid (piv): [CoII5(μ4‐N3)(tbdea)2(μ‐piv)4(piv)(CH3CN)2]⋅CH3CN (1), [CoII5(μ4‐Cl)(Cl)(tbdea)2(μ‐piv)4(pivH)2] (2) and [CoII5(μ4‐N3)(Cl)(tbdea)2(μ‐piv)4(pivH)2] (3). Magnetic measurements were performed for all three compounds. It was found that while the chloride‐bridged cluster 2 does not show an out‐of‐phase signal, which excludes single‐molecule magnet (SMM) behaviour, the azide‐bridged compounds 1 and 3 show out‐of‐phase signals as well as frequency dependence of the ac susceptibility, as expected for SMMs. We confirmed that 1 is a SMM with zero‐field quantum tunnelling of the magnetisation at 1.8 K. Compound 3 is likely a SMM with a blocking temperature well below 1.8 K. We established a physical model to fit the χT versus T and M versus B curves of the three compounds to reproduce the observed SMM trend. The analysis showed that small changes in the ligand shell modify not only the magnitude of exchange constants, but also affect the J and g matrices in a non‐trivial way.
High‐Throughput Reaction Optimisation and Activity Screening of Ferrocene‐Based Lewis Acid–Catalyst Complexes by Using Continuous‐Flow Reaction Detection Mass Spectrometry
Authors: Martha Cornelius T. , Heemskerk Anton , Hoogendoorn Jan‐Carel , Elders Niels , Niessen Wilfried M. A. , Orru Romano V. A. , Irth Hubertus
Published: June 2009

Optimising synthetic conversions and assessing catalyst performance is a tedious and laborious endeavour. Herein, we present an automated alternative to the commonly applied sequential approaches that are used to increase catalyst discovery process efficiencies by increasing the number of entities that can be tested. This new approach combines conversion of the reactants and determination of product formation into a single comprehensive reaction detection system that can be operated with minimal catalyst and reactant consumption. With this approach, rudimentary reaction conditions can be quickly optimised and the same system can then be used to screen for the optimal homogenous catalyst in a selected solution‐phase synthetic conversion. The system, which is composed of standard HPLC components, can be used to screen catalyst libraries at a repetition rate of five minutes and can be run unsupervised. The sensitive mass spectrometric detection that is implemented in the reaction detection methodology can be used for the simultaneous monitoring of reactants, catalysts and product ions. In the experiments, the three‐component reaction that gives a substituted 2‐imidazoline was optimised. Afterwards, the same method was used to assess a library of ferrocene‐based Lewis acid catalysts for performance in the aforementioned conversion in six different solvents. We demonstrate the feasibility of using this methodology to directly compare the performance results obtained in different solvents by calibrating the solvent‐specific MS responses.
Large Di‐ and Heptafullerene Polyelectrolytes Composed of C60 Building Blocks Having a Highly Symmetrical Hexakisaddition Pattern
Authors: Witte Patrick , Hörmann Frank , Hirsch Andreas
Published: June 2009

We report here on the synthesis of three new prototypes (types I–III) of very large fullerene‐based polyelectrolytes which can carry up to 60 charges on their periphery. All fullerene moieties incorporated in these macromolecular structures have an octahedral hexakisaddition pattern. Dumbbell‐shaped icosacarboxylate 5 (type I), which can accumulate up to twenty negative charges, is very soluble in methanol as well as in neutral and basic water. On the other hand, Janus dumbbell 13 (type II) contains both positively and negatively chargeable fullerene building blocks and is very soluble in acidic and basic media. However, in the region of the isoelectric point at pH 6.0–6.5 it precipitates as a pale orange solid due to pronounced intermolecular Coulomb interactions. Giant heptafullerene 15 (type III) can store up to 60 positive charges in its periphery and is the largest molecular polyelectrolyte with defined three‐dimensional structure.
Synthesis and Orthogonal Functionalization of [60]Fullerene e,e,e‐Trisadducts with Two Spherically Defined Addend Zones
Authors: Beuerle Florian , Hirsch Andreas
Published: June 2009

e,e,e‐Trisadducts 13 and 15 have been prepared by a highly regioselective threefold cyclopropanation of tripodal malonates 10 and 12 with C60. The yield and regioselectivity depend on the length and structure of the tethers that connect the malonate units to the focal benzene core of 13–15. As a consequence of the template‐directed synthesis, all e,e,e‐trisadducts were formed as in/out isomers exclusively and contain two spherically well‐defined addend zones with equatorial and polar orientation, respectively. By variation of the outer malonate termini of the tethers, selective functionalization of the equatorial addend zone could be achieved, thus leading to fine‐tuning of intermolecular interactions, such as solubility or aggregation phenomena. After removal of the focal benzene moiety in 14 and 15, selective functionalization of the polar addend zone could be achieved. Strong intramolecular hydrogen‐bonding networks of the polar substituents in the polar addend zone could be observed by 1H NMR spectroscopic analysis. By orthogonal functionalization of both addend zones, fullerene derivatives 44–48 could be synthesized as one single in/out isomer, thus greatly enhancing the potential of e,e,e‐trisadducts as building blocks in supramolecular architectures.
Polydiacetylene‐Based Colorimetric Self‐Assembled Vesicular Receptors for Biological Phosphate Ion Recognition
Authors: Jose D. Amilan , Stadlbauer Stefan , König Burkhard
Published: June 2009

Self‐assembled vesicular polydiacetylene (PDA) particles with embedded metal complex receptor sites have been prepared. The particles respond to the presence of ATP and PPi (pyrophosphate) in buffered aqueous solution by visible changes of their color and emission properties. Blue PDA vesicles of uniform size of about 200 nm were obtained upon UV irradiation from mono‐ and dinuclear zinc(II)–cyclen and iminodiacetato copper [CuII–IDA] modified diacetylenes, embedded in amphiphilic diacetylene monomers. Addition of ATP and PPi to the PDA vesicle solution induces a color change from blue to red observable by the naked eye. The binding of ATP and PPi changes the emission intensity. Other anions such as ADP, AMP, H2PO4−, CH3COO−, F−, Cl−, Br− and I−, failed to induce any spectral changes. The zinc(II)–cyclen nanoparticles are useful for the facile detection of PPi and ATP in millimolar concentrations in neutral aqueous solutions, while CuII–IDA modified vesicular PDA receptors are able to selectively discriminate between ATP and PPi.
Solvent‐Enhanced Diastereo‐ and Regioselectivity in the PdII‐Catalyzed Synthesis of Six‐ and Eight‐Membered Heterocycles via cis‐Aminopalladation
Authors: Balázs Árpád , Hetényi Anasztázia , Szakonyi Zsolt , Sillanpää Reijo , Fülöp Ferenc
Published: June 2009

The PdII‐catalyzed intramolecular oxidative cyclization of tosyl‐protected cis‐ and trans‐N‐allyl‐2‐aminocyclohexanecarboxamides was examined, and efficient syntheses of cyclohexane‐fused pyrimidin‐4‐ones and 1,5‐diazocin‐6‐ones were developed. In the course of the research, a marked solvent effect was observed on both the regio‐ and diastereoselectivity. Additionally, a novel PdII‐mediated domino oxidation, oxidative amination reaction was discovered. Our experimental and theoretical findings suggest that the reactions proceed via a cis‐aminopalladation mechanism.
Stereochemistry of Compounds with Coordination Number Ten
Authors: Ruiz‐Martínez Antonio , Alvarez Santiago
Published: June 2009

The stereochemistry of ten‐coordinate rare‐earth and transition‐metal compounds is studied from the point of view of continuous shape measures (CShM) and derived tools. A total of 19 ideal ten‐vertex polyhedra belonging to 12 different symmetry point groups have been considered, from which nine are retained for the description of the stereochemistries of all studied compounds. The structures of the coordination spheres are analyzed by families, according to the denticity and topology of the ligands. Some ligand topologies are seen to consistently favor usually neglected ideal polyhedra, such as the capped trigonal cupola.
Is Cyclopropane Really the σ‐Aromatic Paradigm?
Authors: Wu Wei , Ma Ben , I‐Chia Wu Judy , Schleyer Paul von Ragué , Mo Yirong
Published: June 2009

Dewar proposed the σ‐aromaticity concept to explain the seemingly anomalous energetic and magnetic behavior of cyclopropane in 1979. While a detailed, but indirect energetic evaluation in 1986 raised doubts—“There is no need to involve ‘σ‐aromaticity’,”—other analyses, also indirect, resulted in wide‐ranging estimates of the σ‐aromatic stabilization energy. Moreover, the aromatic character of “in‐plane”, “double”, and cyclically delocalized σ‐electron systems now seems well established in many types of molecules. Nevertheless, the most recent analysis of the magnetic properties of cyclopropane (S. Pelloni, P. Lazzeretti, R. Zanasi, J. Phys. Chem. A 2007, 111, 8163–8169) challenged the existence of an induced σ‐ring current, and provided alternative explanations for the abnormal magnetic behavior. Likewise, the present study, which evaluates the σ‐aromatic stabilization of cyclopropane directly for the first time, fails to find evidence for a significant energetic effect. According to ab initio valence bond (VB) computations at the VBSCF/cc‐PVTZ level, the σ‐aromatic stabilization energy of cyclopropane is, at most, 3.5 kcal mol−1 relative to propane, and is close to zero when n‐butane is used as reference. Trisilacyclopropane also has very little σ‐aromatic stabilization, compared to Si3H8 (6.3 kcal mol−1) and Si4H10 (4.2 kcal mol−1). Alternative interpretations of the energetic behavior of cyclopropane (and of cyclobutane, as well as their silicon counterparts) are supported.
Electron‐Transfer Kinetics of Microperoxidase‐11 Covalently Immobilised onto the Surface of Multi‐Walled Carbon Nanotubes by Reactive Landing of Mass‐Selected Ions
Authors: Mazzei Franco , Favero Gabriele , Frasconi Marco , Tata Alessandra , Pepi Federico
Published: June 2009

Controlled deposition of biological molecules on nanostructured materials is a basic step towards the realisation of biochip components. In this study we report the investigation of the first covalent immobilisation of mass‐selected redox protein on a carboxyl‐functionalised multi‐walled carbon nanotube (MWCNT) electrode surface by means of ion soft landing. The immobilised protein maintains its biochemical properties, displaying an excellent electrochemical behaviour on the electrode surface. The deposition of mass‐selected ions is influenced by several factors, including the charge state and the collision energy of the projectile ions. To elucidate the mechanism involved in the protein reactive landing onto the MWCNT surface, the data obtained from cyclic voltammetry experiments were modelled according to the Marcus theory. The proposed method opens up the way to the development of a new generation of biocomponents with potential use in biosensors, diagnostics, biofuel cells and bioactive films.
Synthesis and Antimalarial Properties of Streptocyanine Dyes
Authors: Maether Marie‐Pierre , Desoubzdanne Denis , Izquierdo Albert , Guieu Valérie , Maturano Marie , André‐Barrès Christiane , Valentin Alexis , Jullian Valérie , Chevalley Séverine , Maynadier Marjorie , Vial Henri , Payrastre Corinne
Published: June 2009

Several streptocyanine dyes were synthesized that contain polymethine chains of varying length. Their in vitro antimalarial activities were evaluated against the virulent P. falciparum parasite. In addition to the influence of polymethine chain length, the effects of structural modifications at nitrogen end groups, para substitution of the phenyl groups, and counter‐anions were studied. The most potent antimalarial activities were found for heptacarbon chain streptocyanines, with an IC50 value of 60 nM. Interestingly, most of the compounds were less cytotoxic toward the mammalian cells tested. The best selective toxicity profiles were found for pentacarbon chain streptocyanines, which have a good in vitro specificity index.
Screening for the Drug–Phospholipid Interaction: Correlation to Phospholipidosis
Authors: Alakoskela Juha‐Matti , Vitovič Pavol , Kinnunen Paavo K. J.
Published: June 2009

Phospholipid bilayers represent a complex, anisotropic environment fundamentally different from bulk oil or octanol, for instance. Even “simple” drug association to phospholipid bilayers can only be fully understood if the slab‐of‐hydrocarbon approach is abandoned and the complex, anisotropic properties of lipid bilayers reflecting the chemical structures and organization of the constituent phospholipids are considered. The interactions of drugs with phospholipids are important in various processes, such as drug absorption, tissue distribution, and subcellular distribution. In addition, drug–lipid interactions may lead to changes in lipid‐dependent protein activities, and further, to functional and morphological changes in cells, a prominent example being the phospholipidosis (PLD) induced by cationic amphiphilic drugs. Herein we briefly review drug–lipid interactions in general and the significance of these interactions in PLD in particular. We also focus on a potential causal connection between drug‐induced PLD and steatohepatitis, which is induced by some cationic amphiphilic drugs.
Stereoselective HDAC Inhibition from Cysteine‐Derived Zinc‐Binding Groups
Authors: Butler Kyle V. , He Rong , McLaughlin Kathryn , Vistoli Giulio , Langley Brett , Kozikowski Alan P.
Published: June 2009

A series of small‐molecule histone deacetylase (HDAC) inhibitors, which feature zinc binding groups derived from cysteine, were synthesized. These inhibitors were tested against multiple HDAC isoforms, and the most potent, compound 10, was determined to have IC50 values below 1 μM. The compounds were also tested in a cellular assay of oxidative stress‐induced neurodegeneration. Many of the inhibitors gave near‐complete protection against cell death at 10 μM without the neurotoxicity seen with hydroxamic acid‐based inhibitors, and were far more neuroprotective than HDAC inhibitors currently in clinical trials. Both enantiomers of cysteine were used in the synthesis of a variety of novel zinc‐binding groups (ZBGs). Derivatives of L‐cysteine were active in the HDAC inhibition assays, while the derivatives of D‐cysteine were inactive. Notably, the finding that both the D‐ and L‐cysteine derivatives were active in the neuroprotection assays suggests that multiple mechanisms are working to protect the neurons from cell death. Molecular modeling was employed to investigate the differences in inhibitory activity between the HDAC inhibitors generated from the two enantiomeric forms of cysteine.
Invasion characteristics of oral tongue cancer
Authors: Goodman Michael , Liu Lihua , Ward Kevin , Zhang Juanjuan , Almon Lyn , Su Gan , Berglund Lenard , Chen Amy , Sinha Uttam K. , Young John L.
Published: June 2009

BACKGROUND:

The 2000 College of American Pathologists (CAP) guidelines recommend that a characterization of carcinomas of the upper aerodigestive tract, including tongue cancer, should include depth of invasion (DI) and the presence of lymphovascular invasion (LVI) or perineural invasion (PNI).

METHODS:

This study included patients who were diagnosed with cancer of the oral tongue, who underwent tumor resection, and who were reported to either the Metropolitan Atlanta and Rural Georgia Surveillance, Epidemiology, and End Results (SEER) registry or the Los Angeles SEER registry. The authors assessed the completeness of pathology reporting with respect to the documentation of PNI or LVI and DI. Generalized estimating equations were used to examine factors that influenced reporting while taking into consideration clustering of observations within the hospitals. Univariate and multivariate survival analyses were conducted to examine the impact of tumor invasion characteristics on mortality while controlling for other prognostic factors.

RESULTS:

DI reporting increased from 13% between 1997 and 1999 to 23% between 2000 and 2004 after the CAP issued its recommendations; whereas mode of invasion (the presence of LVI and/or PNI) reporting for the same period increased from 13% to 38%. The observed increase in reporting was most pronounced in the first 2 years (2000 and 2001) and appeared to decline again afterward. Tumor invasion >3 mm in depth and the presence of PNI were among the strongest predictors of survival in multivariate analyses.

CONCLUSIONS:

The current results indicated the importance of reporting tumor invasion characteristics for patients diagnosed with cancer of the oral tongue. The findings also underscore the need for continuous monitoring of adherence to the CAP protocol. Cancer 2009. © 2009 American Cancer Society.
Platin‐based exclusive chemotherapy for selected patients with squamous cell carcinoma of the larynx and pharynx
Authors: Holsinger F. Christopher , Lin Heather Y. , Bassot Vincent , Laccourreye Ollivier
Published: June 2009

BACKGROUND:

The current study was conducted to determine the long‐term outcomes of patients with squamous cell carcinoma of the larynx and pharynx who were treated with platin‐based exclusive chemotherapy (EC) after they achieved a complete clinical response (CCR) to induction chemotherapy.

METHODS:

One hundred forty‐two who achieved a CCR after platin‐based induction chemotherapy were treated exclusively with additional chemotherapy, and 98.6% were followed for a minimum of 3 years or until death. Thirty‐five patients had >10 years of follow‐up.

RESULTS:

The survival rates at 1 year and 5 years were 95.8% and 61.2%, respectively. The main causes of death were metachronous second primary tumors (n = 27) and intercurrent disease (n = 21). Death related to EC was not encountered, and only 2 patients (1.4%) had grade 4 toxicity. In multivariate analysis, primary tumor arising outside the glottic larynx (P = .0001) and a Charlson comorbidity index >1 (P = .0001) were associated with a statistically significant reduction in survival. The 1‐year and 5‐year Kaplan‐Meier local control estimates were 76.1% and 50.7%, respectively. Salvage treatment resulted in an observed final local control rate of 93% that varied from 97.2% in patients who had glottic cancer to 88.7% in patients who had tumor originating from other sites (P = .097). Combined chemotherapy with cisplatin and 5‐fluorouracil (PF) allowed for the successful modulation of local therapy in 54.9% of patients.

CONCLUSIONS:

For selected patients, EC may provide long‐term, durable disease control. For patients who developed recurrent disease after EC, this approach did not diminish survival and maintained function in the majority of patients. Future work should be directed toward select markers of response to PF chemotherapy with which to identify those patients who are suited optimally for this approach. Cancer 2009. © 2009 American Cancer Society.
Etiology and outcome of extreme leukocytosis in 758 nonhematologic cancer patients
Authors: Granger John M. , Kontoyiannis Dimitrios P.
Published: June 2009

BACKGROUND:

To the authors' knowledge, the literature regarding extreme leukocytosis in solid tumor patients is sparse, consisting of a few case reports and small case series.

METHODS:

A total of 3770 consecutive solid tumor patients with a white blood cell count>40,000/μL were retrospectively identified over a 3‐year period (2005‐2008). Those patients without a secondary cause of their leukocytosis were defined as having a paraneoplastic leukemoid reaction.

RESULTS:

A total of 758 (20%) patients with solid tumors and extreme leukocytosis were identified. The etiology of the leukocytosis was hematopoietic growth factors in 522 (69%) patients, infection in 112 (15%) patients, high‐dose corticosteroids in 38 (5%) patients, newly diagnosed leukemia in 9 (1%) patients, and paraneoplastic leukemoid reaction in 77 (10%) patients. The patients diagnosed with a paraneoplastic leukemoid reaction typically had neutrophil predominance (96%) and radiographic evidence of metastatic disease (78%), were clinically stable, and had a poor prognosis; 78% either died or were discharged to hospice within 12 weeks of their initial extreme leukocyte count. All of the 8 (10%) patients who survived>1 year received effective antineoplastic therapy.

CONCLUSIONS:

Infection was an uncommon cause of extreme leukocytosis in patients with solid tumors. Patients with paraneoplastic leukemoid reactions typically were clinically stable despite having large tumor burdens. However, clinical outcomes were poor unless effective antineoplastic treatment was received. Cancer 2009. © 2009 American Cancer Society.
Outcomes of patients with stage III nonsmall cell lung cancer treated with chemotherapy and radiation with and without surgery
Authors: Caglar Hale B. , Baldini Elizabeth H. , Othus Megan , Rabin Michael S. , Bueno Raphael , Sugarbaker David J. , Mentzer Steven J. , Jänne Pasi A. , Johnson Bruce E. , Allen Aaron M.
Published: June 2009

BACKGROUND:

The objective of this study was to identify the factors associated with improved outcome after treatment for stage III nonsmall cell lung cancer (NSCLC).

METHODS:

A retrospective review of stage III NSCLC patients treated at who were treated at the Dana‐Farber Cancer Institute/Brigham and Women's Cancer Center was done with institutional review board approval. Patients were followed for toxicity, local and distant failure, and overall survival. Multivariate Cox logistic regression analysis was used to determine the factors associated with treatment outcome.

RESULTS:

Between August 2000 and November 2006, 144 patients received concurrent chemoradiation (CRT) for stage III NSCLC. Eighty of 144 patients were men (56%), and the median age was 61 years (range, 33‐81 years). Sixty‐two patients (43%) had stage IIIA NSCLC, and 82 patients (57%) had stage IIIB NSCLC. Radiotherapy (RT) was given concurrently with chemotherapy to all patients; 100 patients (69%) received CRT without surgery, and 44 patients (31%) received with neoadjuvant CRT followed by surgical resection. The median RT dose was 60 grays (Gy) (range, 46‐70 Gy). The median follow‐up was 15 months (range, 3‐64 months), the median potential follow‐up was 37 months (range, 12‐84 months), and the median overall survival was 22 months (95% confidence interval, 15‐28 months). The 1‐year and 2‐year survival rates were 68% and 47%, respectively. Among the 44 patients who underwent resection, the median survival was 61 months, and the 2‐year survival rate was 73%. On multivariate analysis, stage at the time of treatment (stage IIIA vs stage IIIB) and use of surgery were the only factors associated with improved outcome (P = .01 and P = .001, respectively).

CONCLUSIONS:

In this retrospective series, those patients who were able to undergo resection appeared to have improved outcome after induction CRT. Cancer 2009. © 2009 American Cancer Society.
p53‐induced RING‐H2 protein, a novel marker for poor survival in hepatocellular carcinoma after hepatic resection
Authors: Wang Xiao‐Min , Yang Lian‐Yue , Guo Lei , Fan Chun , Wu Fan
Published: June 2009

BACKGROUND:

Currently, the role of p53‐induced RING‐H2 protein (PIRH2) in the development of hepatocellular carcinoma (HCC) remains unknown. The objective of this retrospective study was to investigate the expression of PIRH2 and its relation to prognosis in patients with HCC after hepatic resection.

METHODS:

Reverse transcriptase‐polymerase chain reaction (RT‐PCR), quantitative real‐time RT‐PCR, and Western blot analyses were used to detect expression levels of PIRH2 in 30 samples of HCC tissue and paracarcinomatous liver tissue (PCLT) and in 5 samples of normal liver tissue (NL). In addition, immunohistochemical analysis was performed on 122 HCC specimens and follow‐up information data from those patients were reviewed.

RESULTS:

Both messenger RNA and protein expression levels of PIRH2 were elevated significantly in HCC tissues compared with PCLT and NL tissues. The increased PIRH2 expression was correlated with vein invasion, Edmondson‐Steiner grade, TNM stage, and multiple tumor nodes (P<.05). It is noteworthy that the patients with HCC who had high PIRH2 expression had shorter overall survival and disease‐free survival than the patients who had low PIRH2 expression (median survival, 280 days vs 372 days; P = .0002; median disease‐free survival, 220 days vs 310 days; P = .0016). Multivariate Cox regression analysis revealed that high PIRH2 expression was an independent prognostic factor for patients with HCC (relative risk, 1.792; P = .009).

CONCLUSIONS:

The current data revealed that increased expression of PIRH2 was correlated with poor survival in patients with HCC, indicating that PIRH2 is a novel prognostic marker for HCC. Cancer 2009. © 2009 American Cancer Society.
Mental status changes after hematopoietic stem cell transplantation
Authors: Chang Grace , Meadows Mary‐Ellen , Orav E. John , Antin Joseph H.
Published: June 2009

BACKGROUND:

The growing numbers of survivors of innovative cancer treatments, such as hematopoietic stem cell transplantation (HSCT), often report subsequent cognitive difficulties. The objective of this study was to evaluate and compare neurocognitive changes in patients with chronic myelogenous leukemia (CML) or primary myelodysplastic syndrome (MDS) after allogeneic HSCT or other therapies.

METHODS:

In this prospective cohort study, serial evaluations of attention, concentration, memory, mood, and quality of life were used in a consecutive sample of 106 eligible patients who had CML (n = 91) or MDS (n = 15) at enrollment and then 12 months and 18 months after HSCT or other therapy.

RESULTS:

The 3 evaluations at enrollment, 12 months, and 18 months were completed by 98%, 95%, and 89% of surviving participants, respectively. Among all patients, there was significant improvement in memory over 18 months. For example, the 45 patients who underwent HSCT (42 patients with CML and 3 patients with MDS) compared favorably with the patients who received other treatment on most measures of neuropsychological function, except they had improved mental health (P = .034), worse physical function (P = .049), and more difficulty with coordination and fine motor speed bilaterally (dominant hand, P = .005; nondominant hand, P = .0019). Patients with CML overall had improved phonemic fluency (P = .014).

CONCLUSIONS:

The current study indicated that time and diagnosis may be important factors when assessing neurocognitive and other changes. Complaints regarding “chemobrain” after HSCT merit further study, because deficits actually may predate the initiation of treatment and subsequently may improve. The study results could reassure prospective HSCT recipients, because HSCT compared favorably with other treatments when mental status side effects were considered. Cancer 2009. © 2009 American Cancer Society.
Immunohistochemical detection of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression in breast carcinomas
Authors: Hanley Krisztina Z. , Birdsong George G. , Cohen Cynthia , Siddiqui Momin T.
Published: June 2009

BACKGROUND:

Fine‐needle aspiration (FNA) is a rapid and accurate procedure for the detection of breast carcinomas. The evaluation of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression by immunohistochemistry (IHC) is performed routinely on formalin‐fixed, paraffin‐embedded needle‐core (NC) or excision tissue block (TB) preparations, according to the American Society of Clinical Oncology/College of American Pathologist guidelines. In this retrospective study, the authors compared expression levels of ER, PR, and HER2 in ethanol‐fixed BC FNA cell block (CB) samples with expression levels in formalin‐fixed NC and TB samples.

METHODS:

Forty‐one breast carcinoma CB samples with concurrent or subsequent NC and TB samples were identified. Patients who had received neoadjuvant or adjuvant chemotherapy were excluded. CB samples initially were fixed in 50% ethanol (4‐12 hours), and this was followed by formalin fixation (minimum, 6 hours). NC samples were placed promptly in formalin for a minimum of 6 hours. Within 4 to 8 hours, TB samples were fixed in formalin for 6 to 48 hours. Fluorescence in situ hybridization (FISH) results were also compared.

RESULTS:

IHC for ER on alcohol‐fixed CB samples had good correlation with NC and TB samples. PR results on TB samples had excellent agreement with NC samples. A higher discordance rate wais observed when PR results were compared between CB samples and NC samples. HER2 detection on ethanol‐fixed CB samples resulted in a higher rate of positive and equivocal staining than NC or TB samples. HER2 IHC on TB samples demonstrated better correlation with FISH results than CB or NC samples.

CONCLUSIONS:

Alcohol fixation did not affect ER results in breast carcinoma, but it may alter tumor cell PR antigenicity. The authors concluded that CB samples could be used to triage patients for tamoxifen therapy, but they are not reliable for the assessment of HER2 status; therefore, CB results should be correlated with results from NC or TB samples. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.
The method of particular solutions for solving scalar wave equations
Authors: Wen P. H. , Chen C. S.
Published: June 2009

A standard approach for solving 2D scalar wave propagation problems is presented with the use of the method of particular solutions (MPS). Motivated by the method of fundamental solutions for solving homogeneous equations, we propose a similar approach using the MPS for solving linear inhomogeneous differential equations without the need of finding the homogeneous solution. The wave equations are analyzed in the Laplace transformed domain and the Durbin inversion method is used to determine the solutions in the time domain. To demonstrate the effectiveness and simplicity of the new approach, three numerical examples have been given with excellent accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
A standards‐based Grid resource brokering service supporting advance reservations, coallocation, and cross‐Grid interoperability
Authors: Elmroth Erik , Tordsson Johan
Published: June 2009

The problem of Grid‐middleware interoperability is addressed by the design and analysis of a feature‐rich, standards‐based framework for all‐to‐all cross‐middleware job submission. The architecture is designed with focus on generality and flexibility and builds on extensive use, internally and externally, of (proposed) Web and Grid services standards such as WSRF, JSDL, GLUE, and WS‐Agreement. The external use provides the foundation for easy integration into specific middlewares, which is performed by the design of a small set of plugins for each middleware. Currently, plugins are provided for integration into Globus Toolkit 4 and NorduGrid/ARC. The internal use of standard formats facilitates customization of the job submission service by replacement of custom components for performing specific well‐defined tasks. Most importantly, this enables the easy replacement of resource selection algorithms by algorithms that address the specific needs of a particular Grid environment and job submission scenario. By default, the service implements a decentralized brokering policy, striving to optimize the performance for the individual user by minimizing the response time for each job submitted. The algorithms in our implementation perform resource selection based on performance predictions, and provide support for advance reservations as well as coallocation of multiple resources for coordinated use. The performance of the system is analyzed with focus on overall service throughput (up to over 250 jobs per min) and individual job submission response time (down to under 1 s). Copyright © 2009 John Wiley & Sons, Ltd.