bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Kinetic Resolution and Desymmetrization Processes: A Straightforward Methodology for the Enantioselective Synthesis of Piperidines.
Authors: Amat Mercedes , Bassas Oriol , Llor Nuria , Canto Margalida , Perez Maria , Molins Elies , Bosch Joan
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rapid Synthesis of Tetrahydroquinolines by Indium Trichloride Catalyzed Mono‐ and Bis‐intramolecular Imino Diels—Alder Reactions.
Authors: Manian Rathna Durga R. S. , Jayashankaran Jayadevan , Ramesh Rasappan , Raghunathan Raghavachary
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Facile Tandem Route to Oxo‐ and Thioxo[1,2,4]triazolo[1,5‐a]pyridinium Salts.
Authors: Palko Roberta , Riedl Zsuzsanna , Egyed Orsolya , Fabian Laszlo , Hajos Gyoergy
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Environmentally Benign Protocol for the Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones Using Solid Acid Catalysts under Solvent‐Free Conditions.
Authors: Kumar Dalip , Mishra Braja Gopal , Rao V. S.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Sulfated Zirconia Catalyzed One‐Pot Benign Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones under Microwave Irradiation.
Authors: Kumar Dalip , Sundaree M. Swapna , Mishra Braja Gopal
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of 2‐Substituted 1‐Tosyl‐3‐(1‐tosyliminoalkyl)imidazolidines and ‐hexahydropyrimidines.
Authors: Pokhvisneva G. V. , Luk'yanov O. A.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Improved Synthesis and Efficient Chemoselective Reduction of Fused Tetrazoles under Phase‐Transfer Conditions.
Authors: Desai Nirmal D. , Shah Rina D.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Highly Selective Substitutions in 2,3‐Dichloropyrazine. A Novel General Approach to Aloisines.
Authors: Chekmarev Dmitriy S. , Shorshnev Sergey V. , Stepanov Alexander E. , Kasatkin Alexander N.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Novel Poly(ethylene glycol) Supported Benzazepines: The Crucial Role of PEG on the Selectivity of an Intramolecular Heck Reaction.
Authors: Ribiere Patrice , Declerck Valerie , Nedellec Yannig , Yadav‐Bhatnagar Neerja , Martinez Jean , Lamaty Frederic
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Facile Transformation of Benzocyclobutenones into 2,3‐Benzodiazepines via 4π—8π Tandem Electrocyclic Reactions Involving Net Insertion of Diazomethylene Compounds.
Authors: Matsuya Yuji , Ohsawa Noriko , Nemoto Hideo
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reaction of Ene‐bis(phosphinylallenes): [2 + 2] versus [4 + 2] Cycloaddition.
Authors: Kitagaki Shinji , Okumura Yuki , Mukai Chisato
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Diels—Alder Approach to Polysubstituted Biaryls: Rapid Entry to Tri‐ and Tetra‐ortho‐substituted Phosphorus‐Containing Biaryls.
Authors: Ashburn Bradley O. , Carter Rich G.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Unified Strategy for the Regiospecific Assembly of Homoallyl‐Substituted Butenolides and γ‐Hydroxybutenolides: First Synthesis of Luffariellolide.
Authors: Boukouvalas John , Robichaud Joel , Maltais Francois
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Total Synthesis of Guanacastepene N Using an Uncommon 7‐Endo Heck Cyclization as a Pivotal Step.
Authors: Iimura Shin , Overman Larry E. , Paulini Ralph , Zakarian Armen
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Allenic Alder‐ene Reaction: Constitutional Group Selectivity and Its Application to the Synthesis of Ovalicin.
Authors: Brummond Kay M. , McCabe Jamie M.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of ω‐(Hetero)arylalkynylated α‐Amino Acid by Sonogashira‐type Reactions in Aqueous Media.
Authors: Brea Roberto J. , Lopez‐Deber M. Pilar , Castedo Luis , Granja Juan R.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Phosphine‐Catalyzed Allylic Substitution of Morita—Baylis—Hillman Acetates: Synthesis of N‐Protected β‐Aminophosphonic Acid Esters.
Authors: Park Haell , Cho Chang‐Woo , Krische Michael J.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Norstatines from Aldehydes by Sequential Organocatalytic α‐Amination and Passerini Reaction.
Authors: Umbreen Sumaira , Brockhaus Manfred , Ehrenberg Helmut , Schmidt Boris
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of (‐)‐Himgaline (I).
Authors: Shah Unmesh , Chackalamannil Samuel , Ganguly Ashit K. , Chelliah Mariappan , Kolotuchin Sergei , Buevich Alexei , McPhail Andrew
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of (+)‐Phyllantidine.
Authors: Carson Cheryl A. , Kerr Michael A.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
π‐Allyl Palladium Approach Toward the Diazabicyclo[3.2.1]octane Core of the Naphthyridinomycin Alkaloids.
Authors: Woo Grace H. C. , Kim Se‐Ho , Wipf Peter
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Studies Directed Toward the Synthesis of the Scabrosins: Validation of a Tandem Enyne Metathesis Approach.
Authors: Middleton Mark D. , Peppers Brian P. , Diver Steven T.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Novel Approach to Oligonucleotide Synthesis Using an Imidazolium Ion Tag as a Soluble Support.
Authors: Donga Robert A. , Khaliq‐Uz‐Zaman Syed M. , Chan Tak‐Hang , Damha Masad J.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Full Structural Characterization of the Lipooligosaccharide of a Burkholderia pyrrocinia Clinical Isolate.
Authors: Silipo Alba , Molinaro Antonio , Comegna Daniela , Sturiale Luisa , Cescutti Paola , Garozzo Domenico , Lanzetta Rosa , Parrilli Michelangelo
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
General and Convenient Approach to Flavan‐3‐ols: Stereoselective Synthesis of (‐)‐Gallocatechin.
Authors: Higuchi Takashi , Ohmori Ken , Suzuki Keisuke
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Marinomycins A—C.
Authors: Nicolaou K. C. , Nold Andrea L. , Milburn Robert R. , Schindler Corinna S.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Insect Pheromones (R)‐4‐Dodecanolide and (S)‐5‐Hexadecanolide.
Authors: Sabitha Gowravaram , Reddy E. Venkata , Yadagiri K. , Yadav J. S.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Short Stereoselective Synthesis of (+)‐Boronolide.
Authors: Raghavan Sadagopan , Krishnaiah V.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Physicochemical Stereodescriptors of Atomic Chiral Centers.
Authors: Zhang Qing‐You , Aires‐de‐Sousa Joao
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Pot Synthetic Strategy to Core Cross‐Linked Micelles with pH‐Sensitive Cross‐Linked Cores and Temperature‐Sensitive Shells Through RAFT Polymerization.
Authors: Yang Li‐Ping , Pan Cai‐Yuan
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Lead Chalcogenide Nanotubes Synthesized by Biomolecule‐Assisted Self‐Assembly of Nanocrystals at Room Temperature.
Authors: Tong Hua , Zhu Ying‐Jie , Yang Li‐Xia , Li Liang , Zhang Ling
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
SiO2/Ta2O5 Core—Shell Nanowires and Nanotubes.
Authors: Chueh Yu‐Lun , Chou Li‐Jen , Wang Zhong Lin
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Properties and Perspectives of Hybrid Nanocrystal Structures
Authors: Cozzoli Pantaleo Davide , Pellegrino Teresa , Manna Liberato
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Platina‐β‐diketones — Electronically Unsaturated, Kinetically Labile Acyl(hydroxycarbene)platinum Complexes
Authors: Steinborn D. , Werner M. , Albrecht Ch. , Schwieger S.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Taming the Free Radical Shrew — Learning to Control Homolytic Reactions at Higher Heteroatoms
Authors: Schiesser Carl H.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Engineering of Coordination Polymers Using 4,4′‐Bipyridine as a Bond Between Transition Metal Atoms
Authors: Biradha Kumar , Sarkar Madhushree , Rajput Lalit
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chiral Oxazolopiperidone Lactams: Versatile Intermediates for the Enantioselective Synthesis of Piperidine‐Containing Natural Products
Authors: Escolano Carmen , Amat Mercedes , Bosch Joan
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metallacumulenes as Potential Electron Reservoir Devices.
Authors: Venkatesan Koushik , Blacque Olivier , Berke Heinz
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Optically Active Supramolecular Systems Based on Porphyrins
Authors: Borovkov V. V. , Mamardashvili N. Zh. , Inoue Y.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Vinyl Sulfones: Synthetic Preparations and Medicinal Chemistry Applications
Authors: Meadows D. Christopher , Gervay‐Hague Jacquelyn
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Tamiflu: The Supply Problem
Authors: Farina Vittorio , Brown Jack D.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Pyrrole Protection
Authors: Jolicoeur Benoit , Chapman Erin E. , Thompson Alison , Lubell William D.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metamorphosis of Tetrapyrrole Macrocycles
Authors: Senge Mathias O. , Sergeeva Natalia N.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Studies Towards the Total Synthesis of Di‐ and Sesterterpenes with Dicyclopenta[a,d]cyclooctane Skeletons — Three‐Component Approach to the A/B Ring Building Blocks
Authors: Michalak Karol , Michalak Michal , Wicha Jerzy
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
3‐Phenoxychromones: Natural Distribution, Synthetic and Modification Methods, Biological Properties
Authors: Vasil'ev S. A. , Garazd M. M. , Khilya V. P.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metathesis of Olefins
Authors: Dwyer Catherine L.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Self‐Assembly of Fibers and Fibrils
Authors: Binder Wolfgang H. , Smrzka Oskar W.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemistry and Biochemistry of Insulin‐Mimetic Vanadium and Zinc Complexes. Trial for Treatment of Diabetes Mellitus
Authors: Sakurai Hiromu , Katoh Akira , Yoshikawa Yutaka
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemical Constituents of the Plants in the Genus Achillea.
Authors: Si Xiao‐Tang , Zhang Man‐Li , Shi Qing‐Wen , Kiyota Hiromasa
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reactions in Droplets in Microfluidic Channels
Authors: Song Helen , Chen Delai L. , Ismagilov Rustem F.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Pharmacokinetics of fexofenadine enantiomers in healthy subjects
Authors: Miura Masatomo , Uno Tsukasa , Tateishi Tomonori , Suzuki Toshio
Published: January 2007

Fexofenadine, a substrate of P‐glycoprotein and an organic anion transporter polypeptide, is commonly used to assess P‐glycoprotein activity in vivo. The purpose of this study was to elucidate the pharmacokinetics of each fexofenadine enantiomer. After a single oral dose of racemic fexofenadine (60 mg), the plasma and urine concentrations of fexofenadine enantiomers were measured over the course of 24 h in six healthy subjects. The mean plasma concentration ofR(+)‐fexofenadine was higher than that ofS(−)‐fexofenadine. The area under the plasma concentration‐time curve (AUC0–∞) and the maximum plasma concentration (Cmax) ofR(+)‐fexofenadine were significantly greater than those of theS(−)‐enantiomer (P= 0.0018 and 0.0028, respectively). TheR/Sratios of AUC andCmaxof fexofenadine were 1.75 and 1.63, respectively. The oral clearance and renal clearance ofS(−)‐fexofenadine were significantly greater than that ofR(+)‐fexofenadine (P= 0.0074 and 0.0036). On the other hand, the stereoselective metabolism of fexofenadine using recombinant CYP3A4 was investigated; however, fexofenadine enantiomers were not metabolized by CYP3A4. Fexofenadine is transported by both P‐glycoprotein and OATP and is not metabolized by intestinal CYP3A. Our findings suggest that the affinity of P‐glycoprotein forS(−)‐fexofenadine is greater than its affinity for theR(+)‐enantiomer. Thus, P‐glycoprotein is likely to have chiral discriminatory abilities. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Enantiomeric analysis of amino acids by using comprehensive two‐dimensional gas chromatography
Authors: Junge Melanie , Huegel Helmut , Marriott Philip J.
Published: January 2007

The chiral separation of amino acids (AA) derivatised with ethyl chloroformate by using comprehensive two‐dimensional gas chromatography is reported. A commercially available enantioselective capillary column (Chirasil‐l‐Val) has been tested as first‐dimension column. Two nonenantioselective stationary phases (BPX50 and BP1) with different column lengths were combined with the enantioselective column, which represent chiral/polar and chiral/low‐polarity column sets, respectively. These column sets were evaluated to determine the most useful column combination to provide improved separation efficiency of enantioselective AA analysis. Separations of AA mixtures derivatised either as their N‐trifluoroacetyl methyl esters or with methyl chloroformate, performed on a chiral/low‐polarity column set, are also shown. The method was demonstrated for chiral analysis of AAs in different beer samples. The major AA in the beer samples was proline with amounts ranging from around 65–95% with minor contents of glycine and the l‐enantiomers of alanine, valine, leucine, and isoleucine. Small amounts of d‐alanine, at about 1, 1.5, and 15% were detected in the three samples. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Analyzing and visualizing the semantic coverage of Wikipedia and its authors
Authors: Holloway Todd , Bozicevic Miran , Börner Katy
Published: January 2007

This article presents a novel analysis and visualization of English Wikipedia data. Our specific interest is the analysis of basic statistics, the identification of the semantic structure and the age of the categories in this free online encyclopedia, and the content coverage of its highly productive authors. © 2007 Wiley Periodicals, Inc. Complexity: 12: 30–40, 2007
Using self‐dissimilarity to quantify complexity
Authors: Wolpert David H. , Macready William
Published: January 2007

For many systems characterized as “complex” the patterns exhibited on different scales differ markedly from one another. For example, the biomass distribution in a human body “looks very different” depending on the scale at which one examines it. Conversely, the patterns at different scales in “simple” systems (e.g., gases, mountains, crystals) vary little from one scale to another. Accordingly, the degrees of self‐dissimilarity between the patterns of a system at various scales constitute a complexity “signature” of that system. Here we present a novel quantification of self‐dissimilarity. This signature can, if desired, incorporate a novel information‐theoretic measure of the distance between probability distributions that we derive here. Whatever distance measure is chosen, our quantification of self‐dissimilarity can be measured for many kinds of real‐world data. This allows comparisons of the complexity signatures of wholly different kinds of systems (e.g., systems involving information density in a digital computer vs. species densities in a rain forest vs. capital density in an economy, etc.). Moreover, in contrast to many other suggested complexity measures, evaluating the self‐dissimilarity of a system does not require one to already have a model of the system. These facts may allow self‐dissimilarity signatures to be used as the underlying observational variables of an eventual overarching theory relating all complex systems. To illustrate self‐dissimilarity, we present several numerical experiments. In particular, we show that the underlying structure of the logistic map is picked out by the self‐dissimilarity signature of time series produced by that map. © 2007 Wiley Periodicals, Inc. Complexity 12: 77–85, 2007
An algorithm for detecting community structure of social networks based on prior knowledge and modularity
Authors: Du Haifeng , Feldman Marcus W. , Li Shuzhuo , Jin Xiaoyi
Published: January 2007

An algorithm is proposed to detect community structure in social network. The algorithm begins with a community division based on prior knowledge of the degrees of the nodes, and then combines the communities until a clear partition is obtained. In applications such as a computer‐generated network, Ucinet networks, and Chinese rural‐urban migrants' social networks, the algorithm can achieve higher modularity and greater speed than others in the recent literature. © 2007 Wiley Periodicals, Inc. Complexity 12: 53–60, 2007
Combined single‐clade candidate HIV‐1 vaccines induce T cell responses limited by multiple forms of in vivo immune interference
Authors: Larke Natasha , Im Eung‐Jun , Wagner Ralf , Williamson Carolyn , Williamson Anna‐Lise , McMichael Andrew J. , Hanke Tomáš
Published: January 2007

We assessed in mice whether broad CD8+ T cell responses capable of efficient recognition of multiple HIV‐1 clades could be induced using current single‐clade vaccine constructs that were or will be used in clinical trials in Europe and Africa. We found that single‐clade A, B and C vaccines applied alone induced only limited cross‐clade reactivity and that the epitope hierarchy varied according to the immunizing clade. However, combining single‐clade HIV‐1 vaccines into multi‐clade formulations resulted in multiple forms of in vivo immune interference such as original antigenic sin and antagonism, which dampened or even abrogated induction of responses to epitope variants and reduced the breadth of induced T cell responses. Simultaneous administration of individual clade‐specific vaccines into anatomically separated sites on the body alleviated antagonism and increased the number of detectable epitope responses. Although cross‐reactivity of murine CD8+ T cells does not directly translate to humans, the molecular interactions involved in triggering T cell responses are the same in mouse and man. Thus, these results have important ramifications for the design of both prophylactic and therapeutic vaccines against HIV‐1 and other highly variable pathogens.
Potentially Biodegradable Polymers Based on α‐ or β‐Pinene and Sugar Derivatives or Styrene, Obtained under Normal Conditions and on Microwave Irradiation
Authors: Barros Maria Teresa , Petrova Krasimira T. , Ramos Ana Maria
Published: January 2007

The homopolymerisation of α‐ and β‐pinene and their copolymerisation with styrene and hepta‐O‐benzyl‐6′‐O‐methacryloyl‐sucrose (BMS) have been examined in the presence of AIBN as free‐radical initiator, either in toluene or without solvent at 80 °C at normal pressure and also in a synthetic microwave oven. A study of the effect of the reaction conditions, the monomer structure and the initial ratio of the comonomers on the properties of the final copolymers, each containing two natural products, has been carried out. A new procedure for synthesising poly(β‐pinene), poly(α‐pinene‐co‐styrene), and poly(β‐pinene‐co‐styrene) in short reaction times and under mild conditions with microwave irradiation was found.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Essential oil composition of Achillea lingulata and A. umbellata
Authors: Kundakovic T. , Fokialakis N. , Kovacevic N. , Chinou I.
Published: January 2007

The composition of the essential oils of Achillea lingulata and A. umbellata were analysed by GC and GC–MS. Among the determined constituents, borneol, bornyl acetate, camphor, α‐ and β‐thujone, and 1,8‐cineol were found as the main components. Copyright © 2007 John Wiley & Sons, Ltd.
Valuing real options using implied binomial trees and commodity futures options
Authors: Arnold Tom , Crack Timothy Falcon , Schwartz Adam
Published: January 2007

A real option on a commodity is valued using an implied binomial tree (IBT) calibrated using commodity futures options prices. Estimating an IBT in the absence of spot options (the norm for commodities) allows real option models to be calibrated for the first time to market‐implied probability distributions for commodity prices. In addition, the existence of long‐dated futures options means that good volatility estimates may now be incorporated into capital budgeting evaluations of real options projects with long planning horizons. An example is given using gold futures options and a real option to extract gold from a mine. A detailed out‐of‐sample test is included that shows how IBT option pricing errors evolve on subtrees emanating from future levels of the underlying asset. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:203–226, 2007
HAS1 expression in bladder cancer and its relation to urinary HA test
Authors: Golshani Roozbeh , Hautmann Stefan H. , Estrella Veronica , Cohen Brian L. , Kyle Christopher C. , Manoharan Murugesan , Jorda Merce , Soloway Mark S. , Lokeshwar Vinata B.
Published: January 2007

Hyaluronic acid (HA) levels are elevated in bladder cancer tissues and regulate tumor growth and progression. Urinary HA levels measured by the HA test are an accurate marker for bladder cancer. In cells, HA is synthesized by one of the 3 HA‐synthase(s) i.e., HAS1, HAS2 and HAS3. In this study, we examined HAS1 expression in bladder cancer cells and tissues. Real‐time RT‐PCR and northern blot analyses showed that HAS1 transcript levels are elevated 5‐ to 10‐fold in bladder cancer tissues, when compared with normal tissues (p < 0.001). Among the 3 HAS1 splice variants, only HAS1‐va was expressed in bladder tissues, but the expression was significantly lower than the wild type HAS1 transcript. Increased HAS1 expression in bladder tumor tissues correlated with increased tissue HA levels (p < 0.001). Size of the large HA species (2.0 × 106 D) present in bladder tissues was consistent with the size of the HA polymer synthesized by HAS1. The amount of HA produced by bladder cancer cell lines correlated with the expression of HAS1 protein. Immunohistochemical analyses of bladder tumor tissues showed that HAS1 and HA expression had 79–88% sensitivity and 83.3–100% specificity. Both HAS1 and HA expression in bladder cancer tissues correlated with a positive HA urine test (p < 0.001). HAS1 expression correlated with tumor recurrence, prior treatment (p < 0.05) and possibly disease progression (p = 0.058). Therefore, elevated HAS1 expression in bladder tumor tissues contributes to a positive HA urine test and may have some prognostic potential. © 2007 Wiley‐Liss, Inc.
Enhancing dendritic cell vaccine potency by combining a BAK/BAX siRNA‐mediated antiapoptotic strategy to prolong dendritic cell life with an intracellular strategy to target antigen to lysosomal compartments
Authors: Kang Tae Heung , Lee Jin Hyup , Noh Kyung Hee , Han Hee Dong , Shin Byung Cheol , Choi Eun Young , Peng Shiwen , Hung Chien‐Fu , Wu T.‐C. , Kim Tae Woo
Published: January 2007

Dendritic cell (DC)‐based vaccines have become important in immunotherapeutics as a measure for generating antitumor immune responses. We have previously demonstrated that linkage of the antigen gene to a lysosomal targeting signal, a sorting signal of the lysosome‐associated membrane protein type 1 (LAMP‐1), enhances the potency of DC‐based vaccines. DCs have a limited life span, hindering their long‐term ability to prime antigen‐specific T cells. In this study, we attempted to further improve the potency of a DC vaccine that targets human papilloma virus 16 (HPV16) E7 to a lysosomal compartment (DC‐Sig/E7/LAMP‐1) by combining a strategy to prolong DC life. We show that small interfering RNA‐targeting Bak and Bax proteins can be used to allow transfected DCs to resist being killed by T cells. This is done by downregulating these proapoptotic proteins, which have been known as so‐called gate keepers in mitochondria‐mediated apoptosis. DCs expressing intact E7 or Sig/E7/LAMP‐1 became resistant to attack by CD8+ T cells after transfection with BAK/BAX siRNA, leading to enhanced E7‐specific T cell activation in vitro and in vivo. More importantly, vaccination with E7‐presenting DCs transfected with BAK/BAX siRNA generated a strong therapeutic effect against an E7‐expressing tumor in vaccinated mice, compared with DCs transfected with control siRNA. Our data indicate that a combination of strategies to enhance intracellular Ag processing and to prolong DC life may offer a promising strategy for improving DC vaccine potency. © 2007 Wiley‐Liss, Inc.
Effects of a catechol‐O‐methyltransferase inhibitor on catechol estrogen‐induced cellular transformation, chromosome aberrations and apoptosis in Syrian hamster embryo cells
Authors: Hirose Yutaka , Tsutsui Takeo W. , Ohno Maki , Barrett J. Carl , Tsutsui Takeki
Published: January 2007

To examine a possible mechanism of endogenous estrogen‐induced carcinogenesis, we studied the effect of the catechol‐O‐methyltransferase (COMT) inhibitor Ro 41‐0960 on cell transforming and clastogenic activities of 2 catechol estrogens 2‐ and 4‐hydroxyestrone (2‐ or 4‐OHE1) using Syrian hamster embryo (SHE) cells. COMT activity was assayed by determining the methylation of 2‐ or 4‐OHE1 using gas chromatography. The production of 2‐methoxyestrone in cultures treated with 2‐OHE1 was approximately 2‐fold that of 4‐methoxyestrone in cultures treated with 4‐OHE1. 4‐OHE1 induced morphological transformation at a higher frequency than 2‐OHE1 did and the frequencies of cell transformation and chromosome aberrations were not significantly changed in cells treated with 4‐OHE1 in the presence of Ro 41‐0960. In contrast, the frequencies of cell transformation and chromosome aberrations were markedly increased in cells treated with 2‐OHE1 along with Ro 41‐0960 when compared to cells treated with 2‐OHE1 alone. In addition, both catechol estrogens induced P53 protein expression and apoptosis. The frequencies of apoptotic cells induced by the catechol estrogens were modified by the COMT inhibition in a manner similar to those observed with the chromosome aberrations assay and the cell transformation assay, indicating that each effect by the catechol estrogens at the three measured endpoints might be caused by a mechanism similar to the others. Our findings indicate that COMT activity has an influence on cell transforming activity and its related genetic effects of catechol estrogens in SHE cells, which implies that an individual activity of COMT may be one of the etiological factors in endogenous estrogen‐induced carcinogenesis. © 2007 Wiley‐Liss, Inc.
Inhibitors of histone deacetylases as potential therapeutic tools for high‐risk embryonal tumors of the nervous system of childhood
Authors: Furchert Sarah E. , Lanvers‐Kaminsky Claudia , Juürgens Heribert , Jung Manfred , Loidl Adele , Frühwald Michael C.
Published: January 2007

The origin of malignant embryonal tumors is incompletely understood and certain risk groups remain difficult to treat. The epigenetic structure of DNA and its lesions play a role in the origin of these neoplasms. Manipulation of the epigenome may offer novel treatment options. The authors evaluated the cytotoxicity of histone deacetylase inhibitors (HDI) [MS‐275, SAHA, TSA, M344, M360, D85, SW55, SW187 and valproic acid (VPA)] on 13 embryonal tumor cell lines [4 medulloblastomas, 5 neuroblastomas, 2 atypical teratoid/rhabdoid tumors (AT/RT), and 2 malignant rhabdoid tumors of the kidney (RTK)] in MTT assay. In addition, HDI effects on hyperacetylation, reexpression of growth regulatory genes and apoptosis were characterized by Western analysis, RT‐PCR and annexin‐V staining. All HDI inhibited cell proliferation in a time‐ and dose‐dependent manner. VPA was least cytotoxic with GI50 values after 72 hr ranging from 53.6 to 332.9 μM, while TSA was most efficient with GI50 values after 72 hr ranging from 0.01 to 8.8 μM. M344 and M360 were also highly effective. Western blot revealed hyperacetylation of histone H4 after HDI treatment. Reactivation of several genes including the proapoptotic CASP8 was identified by RT‐PCR. Annexin‐V staining demonstrated a dose and time dependent induction of apoptosis. HDI inhibited the growth of medulloblastoma, neuroblastoma and rhabdoid tumors in vitro. Treatment with HDI induced the reactivation of growth regulatory genes and consequently apoptosis. Our results warrant further studies and may help in the design of new protocols geared at the treatment of high risk embryonal tumors. © 2007 Wiley‐Liss, Inc.
The use of histone deacetylase inhibitor FK228 and DNA hypomethylation agent 5‐azacytidine in human bladder cancer therapy
Authors: Karam Jose A. , Fan Jinhai , Stanfield Jennifer , Richer Edmond , Benaim Elie A. , Frenkel Eugene , Antich Peter , Sagalowsky Arthur I. , Mason Ralph P. , Hsieh Jer‐Tsong
Published: January 2007

The long‐term disease‐free survival in patients with metastatic transitional cell carcinoma (TCC) is still considerably low. Novel chemotherapeutic agents are needed to decrease the morbidity and mortality of TCC. In this study, we have evaluated several epigenetic modifiers for their therapeutic application in bladder cancer. Both histone deacetylase inhibitors (FK228, TSA) and DNA hypomethylating agent (5‐Azacytidine) were tested using in vitro assays such as cell viability, cell cycle analysis and western blot to determine their mechanisms of action. Drug combination experiments were also designed to study any additive or synergistic effects of these agents. In addition, two bladder cancer xenograft models (one subcutaneous and one orthotopic) were employed to assess the therapeutic efficacy of these agents in vivo. Three agents exhibited various growth inhibitory effects on 5 different TCC cell lines in a dose‐ and time‐dependent manner. In addition to G2/M cell cycle arrest, FK228 is more potent in inducting apoptosis than the two other single agents, and combination of both FK228 and 5‐Aza further enhances this effect. p21 induction is closely associated with FK228 or TSA but not 5‐Aza, which is mediated via p53‐independent pathway. Consistent with in vitro results, FK228 exhibited a significant in vivo growth inhibition of TCC tumor in both subcutaneous and orthotopic xenograft models. FK228 is a potent chemotherapeutic agent for TCC in vivo with minimal undesirable side effects. The elevated p21 level mediated via p53 independent pathway is a hallmark of FK228 mechanism of action. © 2007 Wiley‐Liss, Inc.
Neurotensin stimulates expression of early growth response gene‐1 and EGF receptor through MAP kinase activation in human colonic epithelial cells
Authors: Zhao Dezheng , Zhan Yanai , Zeng Huiyan , Koon Hon Wai , Moyer Mary P. , Pothoulakis Charalabos
Published: January 2007

Neurotensin (NT) is a highly expressed gastrointestinal (GI) neuropeptide, which modulates GI motility, secretion and cell growth as well as intestinal inflammation. Since EGF receptor is highly expressed in human colon cancer cells, we sought to examine whether NT stimulation contributes to the EGFR overexpression using nontransformed colonocyte NCM460 cells. The results show that NT treatment caused a significant increase in EGFR protein expression and gene transcription. Pretreatment with MAP kinase pathway inhibitor PD98059 blocked NT‐induced EGFR expression. As the EGFR promoter has a functional Egr‐1 site, previously shown to mediate its transcription in response to hypoxia, we examined the role of Egr‐1 in the NT response. We first show that NT stimulated Egr‐1 expression, which can be inhibited by PD98059. We also determined whether NT increases Egr‐1 binding to its site within the EGFR promoter. The data indicate that NT enhanced the amount of Egr‐1 binding to the EGFR Egr‐1 site and that this binding was significantly decreased by PD98059. To verify that Egr‐1 mediated NT‐induced EGFR transcription, Egr‐1 siRNA was used to knock down its expression. The data show that transfection of Egr‐1 siRNA significantly inhibited NT‐stimulated EGFR transcription. Together, our results suggest that NT can stimulate MAP kinase‐mediated Egr‐1 and EGFR gene expression in human colonocytes. Our results may be relevant to the mechanisms by which NT participates in the development of colon cancer. © 2007 Wiley‐Liss, Inc.
Preferential expression and frequent IgG responses of a tumor antigen, SOX5, in glioma patients
Authors: Ueda Ryo , Yoshida Kazunari , Kawase Takeshi , Kawakami Yutaka , Toda Masahiro
Published: January 2007

We previously reported to identify SOX5 as a glioma antigen by serological screening using a testis cDNA library. The present study was designed to analyze SOX5 expression, its immunoreactivity, and the correlation between SOX5 IgG responses and clinical features in glioma patients to evaluate the possibility of its use as a diagnostic marker. Quantitative RT‐PCR and Western blot analysis revealed that SOX5 was expressed in glioma tissues, but not in normal adult tissues, except in the testis. An immunohistochemical analysis showed that SOX5 was expressed in glioma cells, but only a few SOX5‐positive cells were detected in non‐neoplastic tissues from the cerebral cortex. IgG antibodies against SOX5 were detected in sera from 8 of the 27 glioma patients (27.6%), 0 of the 14 patients with other brain diseases (0%), 1 of the 54 other cancer patients (1.9%) and 1 of the 37 healthy individuals (2.7%). Patients with glioblastoma (GBM) who showed IgG responses against SOX5 exhibited significantly better survival periods than GBM patients without SOX5 antibodies. In summary, SOX5 is aberrantly expressed in glioma and can be recognized as a glioma antigen using IgGs from the sera of glioma patients. Furthermore, there is a statistically significant correlation between the presence of SOX5 IgGs and survival in GBM patients, suggesting that the glioma antigen SOX5 may be useful not only as a diagnostic marker, but also as a prognositic marker in glioma patients. © 2007 Wiley‐Liss, Inc.
Shape‐engineered fibroblasts: Cell elasticity and actin cytoskeletal features characterized by fluorescence and atomic force microscopy
Authors: Kidoaki Satoru , Matsuda Takehisa
Published: January 2007

The regulation of cell shape, which determines cell behaviors including adhesion, spreading, migration, and proliferation in an engineered artificial extracellular milieu, is an important task in tissue engineering and in development of functional biomaterials. To deepen the understandings of shape‐dependent cell mechanics, the cell elasticity and structural features of the actin cytoskeleton (CSK) were characterized for shape‐engineered fibroblasts; round and spindle‐shaped cells cultured on photolithographically microprocessed surfaces, employing the cellular microindentation tests and fluorescence observation of actin CSK by the combination of atomic force microscopy (AFM) and fluorescence microscopy (FM). The relationships among cell elasticity, the structural features of actin CSK, and engineered cell shape were analyzed and compared with those of control cells that had been cultured on nonprocessed surfaces (termed naturally extended cells). Results showed that the spindle‐shaped cells with sparse or no apical stress fibers (ASFs) exhibited similar stiffness to that of the naturally extended cells with dense ASFs. The elasticity of spindle‐shaped cells was affected only slightly by the stress fiber (SF) density, which is in marked contrast to the significant correlation shown between cell elasticity and SF density in naturally extended cells. This result implies that the elasticity of regionally restricted adhesion‐surface‐induced shape‐engineered cells, particularly of highly elongated cells, is affected predominantly by cell shape rather than by structural features of SFs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Site specificity of α‐H abstraction reaction among secondary structure motif—Anab initiostudy
Authors: Lu Hsiu‐Feng , Li Feng‐Yin , Lin S. H.
Published: January 2007

The initial step of protein oxidation is studied through α‐H abstraction by an OH radical with various secondary structure motifs of proteins. It is found that there exist preferential α‐Hs in this kind of abstractions. The typical abstraction mechanism involves three steps: forming a pre‐reactive complex before abstraction, the abstraction reaction, and the H2O detachment from a post‐reactive complex to form the product, Cα‐center radical. Using the stability of the pre‐reactive complex and the reaction barrier, we provide some explanation for this site preference. The feasibility of α‐H abstraction by OH radical depends not only on the types of secondary structure, but also on the reaction condition, such as in aqueous or in gas phase. Moreover, the reactivity of the abstraction also depends on the location of α‐H in the secondary structure motifs. The preferential α‐Hs to be abstracted in β‐sheet are those immediate to the amide or carbonyl group, and without involving hydrogen bonding, whereas in reverse turns, the preferential α‐Hs are near the C‐terminal of type I and near the N‐terminal of type II. In general, the α‐Hs in α‐helix are more difficult to be abstracted than those in β‐sheet and polypeptide in linear form. It is consistent with the trend of their bond dissociation energies. Our theoretical rate constant ofN‐acetyldiglycin‐methylamide (Ac(Gly)2NHCH3) in aqueous solution (6.75 × 108M−1s−1) is close to the experimental observation ofN‐acetyldiglycinamide (Ac(Gly)2NH2) (8.6 × 108M−1s−1). © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 783–794, 2007
The phosphodiesterase 5 inhibitor sildenafil stimulates angiogenesis through a protein kinase G/MAPK pathway
Authors: Pyriochou Anastasia , Zhou Zongmin , Koika Vasiliki , Petrou Christos , Cordopatis Paul , Sessa William C. , Papapetropoulos Andreas
Published: January 2007

cGMP‐degrading pathways have received little attention in the context of angiogenesis. In the present study we set out to determine whether cGMP‐specific phosphodiesterase 5 (PDE5) inhibition affects new blood vessel growth. Incubation of chicken chorioallantoic membranes (CAMs) in vivo with sildenafil increased vascular length in a dose‐dependent manner. Moreover, incubation of cultured endothelial cells (ECs) with the PDE5 inhibitor promoted proliferation, migration, and organization into tube‐like structures. The effects of sildenafil on the angiogenesis‐related properties of EC could be blocked by pre‐treatment with the soluble guanylyl cyclase (sGC) inhibitor ODQ or the protein kinase G (PKG) I inhibitor DT‐3. In addition, over‐expression of sGC in EC led to an enhanced growth and migratory response to sildenafil. To study the signaling pathways implicated in the sildenafil‐stimulated angiogenic responses we determined the phosphorylation status of mitogen‐activated protein kinase (MAPK) members. Incubation of cells with sildenafil increased both extracellular signal regulated kinase 1/2 (ERK1/2) and p38 phosphorylation in a time‐dependent manner. Inhibition of MEK by PD98059 and p38 with SB203580 blocked sildenafil‐induced proliferation and migration, respectively, suggesting that these MAPK members are downstream of PDE5 and mediate the angiogenic effects of sildenafil. PDE5 inhibitors could, thus, be used in disease states where neo‐vessel growth is desired. J. Cell. Physiol. 211: 197–204, 2007. © 2007 Wiley‐Liss, Inc.