bluuebunny/crossref_metadata_2025 huggingface dataset:
Amphiphilic [5:1]‐ and [3:3]‐Hexakisadducts of C60
Authors: Braun Martin , Hartnagel Uwe , Ravanelli Elena , Schade Boris , Böttcher Christoph , Vostrowsky Otto , Hirsch Andreas
Published: April 2004

We have synthesized and characterized a variety of new amphiphilic hexakisadducts of C60 involving mixed octahedral [5:1]‐ and [3:3]‐addition patterns. The [5:1]‐adducts 3 and 13 contain five pairs of didodecyl or diethyl malonates as non‐polar addends and, as their polar part, an extended bis(malonate) involving C14 and ethylene glycol chains and two biotin termini. For the first time, amphiphilic [3:3]‐hexakisadducts have been prepared using the e,e,e‐trisadduct 18, which contains a cyclo‐[3]‐octyl malonate addend, as the precursor. As polar groups, we used malonates featuring carboxy, amino, or peptide termini. The charge on the termini, which can range from zero up to sixfold positive or sixfold negative, can be built up by protonation or deprotonation. All the amphiphilic [3:3]‐hexakisadducts are very soluble in water in their completely charged forms. Initial investigations on the aggregation properties of the amphiphilic [3:3]‐hexakisadducts, conducted using transmission electron microscopy (TEM) and pulse‐gradient spin echo (PGSE) NMR spectroscopy, reveal the pH‐dependent formation of aggregates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Competition between Non‐Classical Single and Double Epimerizations in Cyclitol Chemistry
Authors: Miethchen Ralf , Neitzel Katharina , Weise Kathrin , Michalik Manfred , Reinke Helmut , Faltin Franziska
Published: April 2004

Two competitive regio‐ and stereoselective epimerization reactions were investigated in four cyclitols characterized by four contiguous OH groups with a cis‐trans‐trans sequence and by varied substituents (OMe, OBz, F, H) adjacent to this tetrol unit. The starting materials were synthesized from L‐quebrachitol (compounds 5−7) and myo‐inositol (compound 8). Their acetalization with the chloral/DCC reagent system gave cyclic acetals with one epimerized chiral ring atom and also with two epimerized chiral centres. The single epimerization takes place exclusively at the middle C‐atom of the cis‐trans triol unit in the tetrol sequence (products 15, 17, 19/20 and 24−27), whereas the double epimerization occurs at both of the "centrally located" C‐atoms in the cis‐trans‐trans tetrol unit (products 16, 18, 21 and 28). The product ratios of singly to doubly inverted compounds change as follows: the lower the electron‐withdrawing effect of the substituents adjacent to the tetrol unit, the higher the percentage of the corresponding doubly inverted product. However, the singly inverted products remain the major products in all cases. X‐ray analyses are given for the starting material 1‐fluoro‐2‐O‐(methyl)cyclohexane‐2,3,4,5,6‐pentol (5) and for the products 1‐O‐cyclohexylcarbamoyl‐2,3‐O‐(2,2,2‐trichloroethylidene)5‐O‐(methyl)cyclohexane‐1,2,3,4,5‐pentol (17), 3‐O‐acetyl‐1‐O‐benzoyl‐6‐O‐cyclohexylcarbamoyl‐2‐O‐methyl‐4,5‐O‐(2,2,2‐trichloroethylidene)‐muco‐inositol (22) and 2,3‐di‐O‐ethylidene)‐(+/‐)‐chiro‐inositol (24). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
9‐Fluoro‐18‐hydroxy‐[3.3]metacyclophane: Synthesis and Estimation of a C−F···H−O Hydrogen Bond
Authors: Takemura Hiroyuki , Kotoku Masayuki , Yasutake Mikio , Shinmyozu Teruo
Published: April 2004

A cyclophane composed of fluorobenzene and phenol units was synthesized in order to observe the C−F···H−O hydrogen bond. In the crystal structure, 20% of the molecule clearly shows the intramolecular hydrogen bond and the other 80% is free from hydrogen bonding. On the other hand, a distinct low‐field shift of the phenolic OH proton was observed in the 1H NMR spectrum compared to that of the F‐free analog. Furthermore, O−H···F through‐space coupling was observed. From the results of the crystallographic analysis, IR, and NMR spectra, the C−F···H−O hydrogen bond energy of this system was estimated to be 0.84−3.7 kJ·mol−1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Ketonic Decarboxylation Catalysed by Weak Bases and Its Application to an Optically Pure Substrate
Authors: Renz Michael , Corma Avelino
Published: April 2004

Ketonic decarboxylation is a very old reaction that transforms two carboxylic acids into a ketone or a dicarboxylic acid into a cyclic ketone, in particular adipic acid into cyclopentanone. Herein it is reported that catalytic amounts of weak bases such as sodium carbonate can carry out this reaction selectively. This is in accordance with a mechanism involving decarboxylation and nucleophilic attack at a second carboxyl group. The reaction can be employed in asymmetric syntheses since the stereogenic centres in the β‐positions retain their stereochemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Peptide Bond Formation Using Polymer‐Bound BOP
Authors: Filip Sorin V. , Lejeune Valérie , Vors Jean‐Pierre , Martinez Jean , Cavelier Florine
Published: April 2004

A new polymer‐supported BOP (P‐BOP) has been prepared starting from the commercially available polystyrene‐bound 1‐hydroxybenzotriazole (P‐HOBt) and successfully used as a solid‐supported reagent for peptide‐coupling reactions. Compared to BOP, less epimerization was observed. P‐BOP is also a suitable activating reagent for difficult peptide coupling reactions involving α,α‐dialkyl amino acids. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Stereochemistry of the Four Himachalene‐Type Sesquiterpenes Isolated from the Flea Beetle (Aphthona flava) as Pheromone Candidates
Authors: Muto Shin‐etsu , Bando Masahiko , Mori Kenji
Published: April 2004

Both the (1S,2R) and (1R,2S) isomers of 2,6,6‐trimethylbicyclo[5.4.0]undec‐7‐en‐9‐one (1) were synthesized by starting from (S)‐ and (R)‐citronellal (5), respectively. The stereochemistry of (1R,2S)‐(−)‐1 was established by an X‐ray analysis; it exhibits a CD spectrum similar to that of cholest‐4‐en‐3‐one, in agreement with its absolute configuration. The ketones (1S,2R)‐ and (1R,2S)‐1 were converted into the enantiomers of three other himachalene hydrocarbons, 2,2,6‐trimethyl‐10‐methylenebicyclo[5.4.0]undec‐1(11)‐ene (2), 1,1,5,8‐tetramethyl‐1,2,3,4,5,6,5a‐heptahydrobenzo[1,2‐a][7]annulene (3), and 1,1,5,8‐tetramethyl‐1,2,3,4,5‐pentahydrobenzo[a][7]annulene (ar‐himachalene, 4). The stereochemistry of these himachalene‐type sesquiterpenes isolated from flea beetles such as Aphthona flava and Phyllotreta cruciferae as their male‐pheromone components was revised to (1S,2R)‐1, (6R,7S)‐2, (5R,5aS)‐3, and (R)‐4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cycloaddition of Benzonitrile Oxide to Acetonitrile, Propyne and Propene − A Comparative Theoretical Study of the Reaction Mechanism and Regioselectivity
Authors: Vullo Vincenzo , Danks Timothy N. , Wagner Gabriele
Published: April 2004

Quantum chemical calculations (MP2/6‐31G* and B3LYP/6‐31G*) were used to compare the reactivity, regioselectivity and orbital involvement of the reaction of benzonitrile oxide with the dipolarophiles acetonitrile, propyne and propene. All reactions are thermodynamically favoured. The product stability decreases in an order propyne > acetonitrile > propene, and reflects the degree of aromatic stabilisation of the product. The activation barriers depend strongly on the computational method used and decrease in the expected order of increasing reactivity (acetonitrile > propyne > propene) in the MP2 calculations, but are similar to each other when B3LYP is applied. The regiochemistry is correctly predicted for all reactions and the experimentally observed regioisomer is both thermodynamically and kinetically favoured. The transition state geometries indicate that, in some of the reactions, the benzonitrile oxide does not interact through its frontier orbitals, as traditionally assumed. Instead, the FMO±2 are involved in the reaction, indicating that the classical FMO concept should be applied with care as it might lead to wrong conclusions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Enantioselective Routes to Sulfoxides Based Upon the Use of Carbanionic Leaving Groups (Eur. J. Org. Chem. 9/2004)
Authors: Capozzi Maria Annunziata M. , Cardellicchio Cosimo , Naso Francesco
Published: April 2004

The cover picture shows a typical street with “trulli”, characteristic Apulian houses with a conical roof, which are rather common in Alberobello, a town located near Bari (Italy), where part of the research reported in the Microreview by F. Naso et al. on p. 1855 ff. was performed. The view acts as a background for the scheme demonstrating the use of carbanionic leaving groups in enantioselective routes to sulfoxides.
Application of cycling gradient capillary electrophoresis to detection of APC, K‐ras, and DCC point mutations in patients with sporadic colorectal tumors
Authors: Minarik Marek , Minarikova Lucie , Hrabikova Michala , Minarikova Petra , Hrabal Petr , Zavoral Miroslav
Published: April 2004

A previously introduced technique of cycling gradient capillary electrophoresis (CGCE) was applied to monitoring of molecular changes during adenoma‐carcinoma transition in progression of sporadic colorectal cancer. The purpose of this work was optimization of separation parameters for selected mutation regions in tumor suppressor genes involved in the early stages of colorectal carcinogenesis, followed by scanning for these mutations in clinical tissue samples from patients with adenomatous polyps and early carcinomas. A total of 47 colorectal tumors in various stages of progression were examined. Main emphasis was given to evaluation of mutation detection sensitivity and specificity required for effective early disease detection. A total of 7 different somatic mutations was identified among 32 K‐ras mutant samples, 1 inherited mutation and 5 somatic mutations were identified among 15 adenomatous polyposis coli (APC) mutated samples. None of the two previously reported “deleted in colorectal carcinomas” (DCC) mutations was found in any of the clinical samples. In addition to simple optimization of running conditions, CGCE has demonstrated sensitivity and selectivity allowing detecting small mutant fractions as well as combination of multiple mutants within a single target sequence.
Fast visible dye staining of proteins in one‐ and two‐dimensional sodium dodecyl sulfate‐polyacrylamide gels compatible with matrix assisted laser desorption/ionization‐mass spectrometry
Authors: Choi Jung‐Kap , Chae Ho‐Zoon , Hwang Sun‐Young , Choi Hoon‐In , Jin Li‐Tai , Yoo Gyurng‐Soo
Published: April 2004

A fast and matrix assisted laser desorption/ionization‐mass spectrometry (MALDI‐MS) compatible protein staining method in one‐ and two‐dimensional sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (1‐ and 2‐D SDS‐PAGE) is described. It is based on the counterion dye staining method that employs oppositely charged two dyes, zincon (ZC) and ethyl violet (EV) to form an ion‐pair complex. The protocol, including fixing, staining and quick washing steps, can be completed in 1–1.5 h depending upon gel thickness. It has a sensitivity of 4–8 ng, comparable to that of colloidal Coomassie Brilliant Blue G (CBBG) staining with phosphoric acid in the staining solution. The counterion dye stain does not induce protein modifications that complicate interpretation of peptide mapping data from MS. Considering the speed, sensitivity and compatibility with MS, the counterion dye stain may be more practical than any other dye‐based protein stains for routine proteomic researches.
Application of in‐gel protease assay in a biological sample: Characterization and identification of urokinase‐type plasminogen activator (uPA) in secreted proteins from a prostate cancer cell line PC‐3
Authors: Zhao Zhenjun , Raftery Mark J. , Niu Xiao Mei , Daja Merilla M. , Russell Pamela J.
Published: April 2004

A considerable problem in proteomics is to separate and identify functional proteins that participate in specific biological processes. To expedite the analysis of active proteases, we have developed a substrate‐specific, sensitive in‐gel trypsin activity assay after two‐dimensional (2‐D) separation in a sodium dodecyl sulphate (SDS)‐polyacrylamide gel [22]. Using this method, we detected and characterized Arg‐specific protease activity in the secreted protein sample of a prostate cancer cell line, PC‐3, in 1‐D and 2‐D gels. Mass spectrometry (MS) identified the protease as urokinase‐type plasminogen activator (uPA). Western blotting using anti‐uPA antibody and protease inhibition tests confirmed the identification. Since no antibody was involved in the procedure, the result clearly demonstrates the feasibility of this method for identifying novel proteases in biological samples.
Optimum sample medium for single‐nucleotide polymorphism and mutation detection by capillary electrophoresis
Authors: Kozlowski Piotr , Krzyzosiak Wlodzimierz J.
Published: April 2004

Capillary electrophoresis (CE) is a versatile analytical platform widely used for nucleic acids analysis. Its applications in research and diagnostics include scanning and screening for mutations and polymorphisms by such reliable methods as single‐strand conformation polymorphism (SSCP), heteroduplex analysis (HA), and combined SSCP/HA. This study, aimed at the further development of these methods, is focused on detailed sample‐media characteristics. Factors affecting single‐strand conformer stability and DNA intake efficiency were analyzed. The sample media optimal for efficient mutation or SNP detection were determined, and complex SSCP‐CE patterns arising from unpurified PCR products were explained. It turns out, that the nondenaturing aqueous media assure both efficient DNA intake, and single‐strand conformers stability required for the SSCP and combined SSCP/HA. The results of this study are applicable to all these areas of biomedical research, in which capillary electrophoresis is used for the characterization of nucleic acids.
Determination of dissociation constants by competitive binding in partial filling capillary electrophoresis
Authors: Nilsson Mikael , Johansson Gunnar , Isaksson Roland
Published: April 2004

The determination of dissociation constands (Kd) by competitive ligand binding in partial filling capillary electrophoresis is demonstrated. Two different strategies were applied, one of which only uses a single reporter ligand and a more elaborated one which suppresses systemic disturbances by using a racemic mixture as reporter. The dissociation constants obtained by both alternatives were virtually identical and in good agreement with those previously reported.
An efficient protocol for the identification of protein phosphorylation in a seedless plant, sensitive enough to detect members of signalling cascades
Authors: Heintz Dimitri , Wurtz Virginie , High Anthony A. , Van Dorsselaer Alain , Reski Ralf , Sarnighausen Eric
Published: April 2004

We describe a reproducible protocol to explore for the first time the phosphoproteome of a seedless plant, the moss Physcomitrella patens. Following tryptic digestion of a total protein extract, phosphorylated peptides were isolated using the combination of C18 reverse‐phase chromatography (RP‐C18), immobilized Fe3+ metal affinity chromatography (IMAC), capillary zone electrophoresis (CZE), liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) and matrix assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS) analysis. The total protein extracts were first prepared as usually made for plant two‐dimensional gel electrophoresis, the tryptic digest was desalted and concentrated by reverse phase chromatography, and from this mixture the phosphorylated peptides were captured by IMAC. Subsequently, the complex phosphopeptide mixture was separated into ten fractions by RP‐C18‐HPLC and each analyzed by CZE. This permitted the detection of 253 distinct phosphopeptides. These were identified by nano‐LC‐MS/MS and MALDI‐TOF‐MS analysis in conjunction with alkaline phosphatase treatment to remove covalently bound phosphate to specifically identify the phosphopeptides. Among others, several kinases and a transcription factor were identified. This protocol will be taken as a basis to unravel early events in plant signal transduction known to occur via rapid phosphorylation/dephosphorylation of proteins.
Moving boundaries in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis
Authors: Buzás Zsuzsanna , Chrambach Andreas
Published: April 2004

In sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), moving boundaries I–IV (Table 1) form. They migrate isotachophoretically at displacement rates that increase in the order of I to II to III. Moving boundaries IV and V comprising Pyronin‐SDS as a leading constituent are retarded at high gel concentrations in comparison with the isotachophoretically migrating species. Since analytes depending on their net mobilities stack within any of those moving boundaries, previous Rf values and Ferguson plots may have to be revised.
Prevention of artifactual protein oxidation generated during sodium dodecyl sulfate‐gel electrophoresis
Authors: Sun Gang , Anderson Vernon E.
Published: April 2004

Prevention of artifactual protein oxidation occurring during sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis is critical for identifying physiological protein oxidation implicated in human diseases due to the routine use of gel electrophoresis to separate the multiple proteins in proteomic studies. To develop a methodology that completely prevents artifactual protein oxidation in SDS acrylamide gel electrophoresis, cytochrome c was electrophoresed on polyacrylamide gels and subjected to trypsin in‐gel digestion followed by tryptic peptide analysis by mass spectrometry. It was found that degassing the acrylamide solution to remove molecular oxygen prior to gel polymerization is a crucial process to protect the electrophoresed protein from reactive oxygen species generated during electrophoresis. However, significant artifactual protein oxidation remains that can only be eliminated entirely, if proteins are electrophoresed on an SDS gel photopolymerized with flavin as the photoinitiator and thioglycolate included in the cathode buffer as a reactive oxygen species scavenger. Using this combination of methodologies, cytochrome c isolated from adult rat heart mitochondria was purified and digested followed by mass spectrometric analysis, demonstrating the requisite high resolution of the polyacrylamide gel and the entire elimination of artifactual oxidation.
Electrophoretically mediated microanalysis with partial filling technique and indirect or direct detection as a tool for inhibition studies of enzymatic reaction
Authors: Telnarová Magdaléna , Vytisková Soňa , Monincová Marta , Glatz Zdeněk
Published: April 2004

The inhibition of the model enzyme, haloalkane dehalogenase from Sphingomonas paucimobilis, was investigated by a combination of electrophoretically mediated microanalysis with a partial filling technique, followed by indirect or direct detection. In this setup, part of the capillary is filled with a buffer suitable for the enzymatic reaction (20 mM glycine buffer, pH 8.6) whereas the rest of the capillary is filled with the background electrolyte optimal for separation of substrates and products. Two different background electrolytes and corresponding detection approaches were used to show the versatility of the developed method. The inhibition effect of 1,2‐dichloroethane on the dehalogenation of brominated substrate 1‐bromobutane was studied by means of 10 mM chromate − 0.1 mM cetyltrimethylammonium bromide (pH 9.2) in combination with indirect detection or 20 mM β‐alanine – hydrochloric acid (pH 3.5) in combination with direct detection. The method was used to estimate the inhibition constant KI (0.44 mM by indirect detection and 0.63 mM by of direct detection) and to determine the inhibition type. Compared to spectrophotometric and other discontinuous assays, the method is rapid, can be automated, and requires only small amount of reagents that is especially important in the case of enzymes and inhibitors.
Proteomic profiling of human hippocampus
Authors: Yang Jae‐Won , Czech Thomas , Lubec Gert
Published: April 2004

The hippocampus is an important brain region playing a central role in short‐term memory formation. Information on protein expression in human hippocampus is limited and we therefore decided to generate a protein map of this pivotal brain structure thus providing protein building blocks and an analytical tool. Two‐dimensional electrophoresis with in‐gel digestion of protein spots followed by mass spectrometrical identification coupled to the Mascot search program was applied. Matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF) or in special cases MALDI‐TOF/TOF was used in order to warrant unambiguous identification. 266 protein spots representing 165 different proteins and 101 probable isoforms or post‐translational modifications were identified. The identified proteins were categorized into several protein groups as metabolic, cytoskeleton, antioxidant, chaperone, signaling, transcriptional, proteolytic, synaptosomal and neuronal, hypothetical and miscellaneous structures. This human hippocampus protein map provides an analytical tool for hydrophilic and even relatively small‐molecular‐weight proteins and contributes to the knowledge on protein building blocks thus forming the basis for protein‐chemical work in this brain area in health and disease.
Impulsive Dirac‐delta forces in the rocking motion
Authors: Prieto F. , Lourenço P. B. , Oliveira C. S.
Published: April 2004

In this work the classical theory of one block rocking motion is revisited. A Dirac‐delta type interaction as impact mechanism is found to be an alternative for the traditional model. Numerical computations with this new formulation have shown that the agreement with the classical theory is excellent for the case of slender blocks and small displacements. Good agreement with experimental data has also been found for the case of arbitrary angles and slenderness.

The approach presented in this paper opens new lines for further theoretical developments and computational applications. Copyright © 2004 John Wiley & Sons, Ltd.
Life‐cycle cost analysis based on a renewal model of earthquake occurrences
Authors: Takahashi Yuji , Kiureghian Armen Der , Ang Alfredo H‐S.
Published: April 2004

A decision methodology for the management of seismic risk of a single building is presented. The decision criterion aims at minimizing the expected life‐cycle cost, including the initial cost of the design and the expected cost of damage due to future earthquakes. The expected life‐cycle cost of each design alternative is formulated using a renewal model for the occurrence of earthquakes in a seismic source, which accounts for the temporal dependence between the occurrence of ‘characteristic’ earthquakes. The formulation involves the expected damage cost from an earthquake of specified magnitude in a given source. This term is estimated by simulating the processes of fault rupture, elastic wave propagation, surface soil amplification, dynamic structural response and generation of damage costs. As an example, the methodology is applied to an actual office building in Tokyo. A simple decision problem between two design alternatives is set: a bare steel moment frame, and the same frame equipped with oil dampers. Through this case study, the installation of the oil dampers is demonstrated to be effective in reducing the life‐cycle cost of the building under consideration. Copyright © 2004 John Wiley & Sons, Ltd.
The seismic shear of ductile cantilever wall systems in multistorey structures
Authors: Rutenberg Avigdor
Published: April 2004

The distribution of seismic base shear demand among ductile flexural cantilever walls, comprising the lateral load resisting system of a multistorey building, is studied. It is shown that the base shear force demand depends on the sequence of hinge formation at the wall bases, and this in turn depends on the relative wall lengths. Hence, the routine elastic approach in which the shear forces are allocated per relative flexural rigidity or (when some consideration is given to plastic hinge formation) to moment capacity at the wall base, may appreciably underestimate the shear force demand on the walls, particularly the shorter (usually the more flexible) ones.

A simple procedure yielding the results of ‘cyclic’ pushover analysis is proposed to predict the peak seismic wall forces for a given total base shear when plastification is confined to the wall base. The effects of plastic hinges developing at higher floors on (1) shear distribution among the walls and (2) the in‐plane floor forces are also considered. Two numerical examples are presented to demonstrate the main points made. Copyright © 2004 John Wiley & Sons, Ltd.
The Army, readiness, and sustainability
Authors: Flannery Mike
Published: April 2004

Emerging as a principal theme of the new millennium, sustainability is based in collaboration for problem solving—as opposed to confrontation and intransigence. Sustainability concerns the environment, the economy, and social equity. Each April 22 (the anniversary of the first Earth Day in 1970—as well as the formation of the Environmental Protection Agency) provides a symbolic context as we move beyond compliance and link America's environmental performance to our future needs. Sustainability is inspired by our appreciation for the goodness of nature and God's gifts to us all. It is amplified by the freedom with which we have been blessed as a nation. It is a journey—a path forward—through which we can demonstrate responsibility for future generations. And securing our nation's freedom implies a non‐negotiable demand on our Army to be ready for the task. © 2004 Wiley Periodicals, Inc.
Evaluating bias due to population stratification in case‐control association studies of admixed populations
Authors: Wang Yiting , Localio Russell , Rebbeck Timothy R.
Published: April 2004

The potential for bias from population stratification (PS) has raised concerns about case‐control studies involving admixed ethnicities. We evaluated the potential bias due to PS in relating a binary outcome with a candidate gene under simulated settings where study populations consist of multiple ethnicities. Disease risks were assigned within the range of prostate cancer rates of African Americans reported in SEER registries assuming k=2, 5, or 10 admixed ethnicities. Genotype frequencies were considered in the range of 5–95%. Under a model assuming no genotype effect on disease (odds ratio (OR)=1), the range of observed OR estimates ignoring ethnicity was 0.64–1.55 for k=2, 0.72–1.33 for k=5, and 0.81–1.22 for k=10. When genotype effect on disease was modeled to be OR=2, the ranges of observed OR estimates were 1.28–3.09, 1.43–2.65, and 1.62–2.42 for k=2, 5, and 10 ethnicities, respectively. Our results indicate that the magnitude of bias is small unless extreme differences exist in genotype frequency. Bias due to PS decreases as the number of admixed ethnicities increases. The biases are bounded by the minimum and maximum of all pairwise baseline disease odds ratios across ethnicities. Therefore, bias due to PS alone may be small when baseline risk differences are small within major categories of admixed ethnicity, such as African Americans. © 2004 Wiley‐Liss, Inc.
Hypoosmotic swelling increases protein tyrosine nitration in cultured rat astrocytes
Authors: Schliess Freimut , Foster Natalie , Görg Boris , Reinehr Roland , Häussinger Dieter
Published: April 2004

Astrocyte swelling is observed in different types of brain injury. We studied a potential contribution of swelling to protein tyrosine nitration (PTN) by using cultured rat astrocytes exposed to hypoosmotic (205 mosmol/L) medium. Hypoosmolarity (2 h) increases total PTN by about 2‐fold in 2 h. The hypoosmotic PTN is significantly inhibited by the NMDA receptor antagonist MK‐801, the nitric oxide synthase (NOS) inhibitor L‐NMMA, the extracellular Ca2+ chelator EGTA and the calmodulin antagonist W13, suggesting the involvement of NMDA receptor activation, influx of extracellular Ca2+ and Ca2+/calmodulin‐dependent NO synthesis. Further, superoxide dismutase plus catalase and uric acid strongly inhibit hypoosmotic PTN, suggesting the involvement of the toxic metabolite peroxynitrite (ONOO−) as a nitrating agent. Hypoosmotic astrocyte swelling rapidly stimulates generation of reactive oxygen intermediates; this process is prevented by MK‐801 and EGTA. In addition, MK‐801 inhibits the hypoosmotic elevation of [Ca2+]i. The findings support the view that astrocyte swelling as induced, for example, by toxins relevant for hepatic encephalopathy is sufficient to produce oxidative stress and PTN and thus contributes to altered astroglial and neuronal function. © 2004 Wiley‐Liss, Inc.
Zn and Cu alteration in connection with astrocyte metallothionein I/II overexpression in the mouse brain upon physical stress
Authors: Beltramini Mariano , Di Pisa Cristina , Zambenedetti Pamela , Wittkowski Werner , Mocchegiani Eugenio , Musicco Massimo , Zatta Paolo
Published: April 2004

The distribution of metallothioneins I/II in the mouse brain and their specific area distribution upon physical stress were studied. To induce physical stress, groups of mice were subjected to total darkness for different periods (2 weeks, 1 month, and 2 months). The concentration of metallothioneins, evaluated by immunohistochemistry, as well as area‐specific protein expression, were found in the following quantitative order: corpus striatum, cerebellum, mesencephalon, hippocampus with fornix, parts of thalamus, and pons. All other brain areas were marginally affected, or even unaffected, in terms of immunopositive metallothionein reaction. Metallothionein I/II expression was compared with the immunopositivity of glial fibrillary acidic protein (GFAP). It is noteworthy that metallothioneins and GFAP are expressed in different types of astrocytes. © 2004 Wiley‐Liss, Inc.
Mitochondrial pathway is involved in hydrogen‐peroxide‐induced apoptotic cell death of oligodendrocytes
Authors: Mronga Thomas , Stahnke Thomas , Goldbaum Olaf , Richter‐Landsberg Christiane
Published: April 2004

Oligodendrocytes, the myelin‐forming cells of the CNS, are specifically sensitive to oxidative stress and respond by the onset of programmed cell death (PCD). To further unravel the molecular events underlying their enhanced susceptibility, we have investigated whether mitochondrial damage occurs during oxidative stress‐induced PCD in cultured rat brain oligodendrocytes. Mitochondria are considered as a central control point of apoptosis, and mitochondrial dysfunction has been linked to neurodegenerative disease. Upon a number of stimuli through the release of cytochrome c, they coordinate caspase activation, causing morphological and biochemical changes associated with PCD. Oxidative stress was exerted by the application of hydrogen peroxide. The data show that hydrogen peroxide‐induced apoptosis in oligodendrocytes involves mitochondrial damage and cytochrome c release and is accompanied by the activation of the death‐related caspases 3 and 9. Concomitantly, the activation and nuclear translocation of extracellular signal regulated kinases ERK1,2 are observed, which have been implicated to participate in the regulation of cell death and survival. DNA fragmentation could not be attenuated by the ERK1,2 inhibitor PD 98059, indicating that the ERK1,2‐ pathway in oligodendrocytes may be involved in the initial survival response after exposure to stressful stimuli. © 2004 Wiley‐Liss, Inc.
Differential subcellular localization of Ror tyrosine kinase receptors in cultured astrocytes
Authors: Paganoni Sabrina , Anderson Kelsi L. , Ferreira Adriana
Published: April 2004

Ror1 and Ror2 belong to a family of tyrosine kinase receptors that are highly conserved among species. They are expressed throughout the organism, including the central nervous system. In the present study, we analyzed the expression and subcellular localization of Ror1 and Ror2 in astrocytes by means of reverse transcription‐polymerase chain reaction, Western blot analysis, and immunocytochemistry. Our results indicated that both Ror1 and Ror2 are readily detectable in cultured astrocytes. They also showed that Ror1 and Ror2 are associated with different components of the cytoskeleton. While Ror1 co‐localized with F‐actin along stress fibers, Ror2 partially co‐localized with microtubules. In addition, our results suggest that Ror1 and Ror2 undergo different posttranslational modifications in cultured astrocytes. Ror1 is highly glycosylated in these cells. In contrast, no glycosylation was detected in Ror2. Taken together, these results suggest distinct roles for these tyrosine kinase receptors in astrocytes. © 2004 Wiley‐Liss, Inc.
Depression in dementia: a comparative and validation study of four brief scales in the elderly Chinese
Authors: Lam Chee Kum , Joy Lim P'ing Ping , Low Bee Lee , Ng Li‐Ling , Chiam Peak Chiang , Sahadevan Suresh
Published: April 2004

Aim

The study aimed to determine: (i) the diagnostic accuracy of four brief depression scales, the Geriatric Depression Scale (GDS), Even Briefer Assessment Scale for Depression (EBAS DEP), Single Question and Cornell Scale for Depression in Dementia (Cornell) in an elderly Chinese population with varying dementia severity; and (ii) which scale had the best diagnostic performance.

Method

All four scales were administered to 88 elderly outpatients with dementia: 66 without and 22 with depression. Receiver Operating Characteristic (ROC) analysis was used to establish the optimal cut‐off scores of the GDS, EBAS DEP and Cornell scales. The patients' dementia‐severity was dichotomously categorized into mild and moderate‐severe dementia, and the above analysis was repeated in both these groups to look at changes in the scales' diagnostic performance as dementia advances.

Results

The best diagnostic scale for detecting depression in dementia was the Cornell scale. Its optimal cut‐off score was 6/7 (sensitivity 91.7%, specificity 80.0%) in the mild dementia group and 12/13 (sensitivity 70.0%, specificity 87.0%) in the more advanced dementia group. The optimal cut‐off scores of the GDS and EBAS DEP also shifted to higher values when moving from the mild to the more advanced dementia groups, indicating the increasing difficulty on all these scales to detect depression with worsening cognitive impairment. The Single Question, however, was more robust with much less changes in its diagnostic parameters in both dementia cohorts: sensitivity 58.3%, specificity 90.0% for mild dementia, and 60.0 and 84.8%, respectively, for more advanced dementia.

Conclusion

An efficient strategy to diagnose depression in dementia amongst elderly Chinese patients is to administer the Single Question followed by, when necessary, the Cornell scale. Copyright © 2004 John Wiley & Sons, Ltd.
Measuring the health of populations: the veil of ignorance approach
Authors: Pinto‐Prades José‐Luis , Abellán‐Perpiñán José‐María
Published: April 2004

We report the results from two surveys designed to explore whether an application of Harsanyi's principle of choice form behind a veil of ignorance (VEI) can be used in order to measure the health of populations. This approach was tentatively recommended by Murray et al. (Bull. World Health Organ 2000; 78: 981–994; Summary Measures of population health: Concepts, Ethics, Measurement and Applications, WHO, 2002.) as an appropriate way of constructing summary measures of population health (SMPH) for comparative purposes. The operationalization of the VEI approach used in this paper was suggested by Nord (Summary Measures of Population Health: Concepts, Ethics, Measurement and Applications, WHO, 2002.). We test if VEI and person trade‐off (PTO) methods generate similar quality‐of‐life weights. In addition, we compare VEI and PTO weights with individual utilities estimated by means of the conventional standard gamble (SG) and a variation of it we call double gamble. Finally, psychometric properties like feasibility, reliability, and consistency are examined. Our main findings are next: (1) VEI and PTO approaches generate very different weights; (2) it seems that differences between PTO and VEI are not due to the ‘rule of rescue’; (3) the VEI resembled more a DG than a classical SG; (4) PTO, VEI, and DG exhibited good feasibility, reliability and consistency. Copyright © 2004 John Wiley & Sons, Ltd.
‘You be the big sister’: Maternal‐preschooler internal state discourse, perspective‐taking, and sibling caretaking
Authors: Howe Nina , Rinaldi Christina M.
Published: April 2004

Maternal–preschooler internal state discourse, preschooler perspective‐taking, and sibling caretaking for 32 dyads (preschooler M age=46.4 months, toddlers=14 months) was examined across three contexts varying in emotional demands: (a) naturalistic home observations, (b) mother–preschooler book reading (Parent–Child Affect Communication Task; Zahn‐Waxler, Ridgeway, Denham, Usher and Cole, 1993), and (c) a laboratory maternal separation session. Preschooler perspective‐taking was positively associated with emotional understanding during book reading. However, mothers did not adjust their internal state discourse in any of the three contexts to reflect preschoolers' perspective‐taking skills. Both preschooler internal state language during sibling conflict and maternal leave‐taking discourse were associated with sibling caretaking. Findings are discussed in light of the role of family discourse and dynamics in the development of children's social understanding. Copyright © 2004 John Wiley & Sons, Ltd.
A high proportion of founder BRCA1 mutations in Polish breast cancer families
Authors: Górski Bohdan , Jakubowska Anna , Huzarski Tomasz , Byrski Tomasz , Gronwald Jacek , Grzybowska Ewa , Mackiewicz Andrzej , Stawicka Malgorzata , Bębenek Marek , Sorokin Dagmara , Fiszer‐Maliszewska Łucja , Haus Olga , Janiszewska Hanna , Niepsuj Stanisław , Góźdź Stanisław , Zaremba Lech , Posmyk Michał , Płużańska Maria , Kilar Ewa , Czudowska Dorota , Waśko Bernard , Miturski Roman , Kowalczyk Jerzy R. , Urbański Krzysztof , Szwiec Marek , Koc Jan , Dębniak Bogusław , Rozmiarek Andrzej , Dębniak Tadeusz , Cybulski Cezary , Kowalska Elzbieta , Tołoczko‐Grabarek Aleksandra , Zajączek Stanisław , Menkiszak Janusz , Mędrek Krzysztof , Masojć Bartłomiej , Mierzejewski Marek , Narod Steven Alexander , Lubiński Jan
Published: April 2004

Three mutations in BRCA1 (5382insC, C61G and 4153delA) are common in Poland and account for the majority of mutations identified to date in Polish breast and breast–ovarian cancer families. It is not known, however, to what extent these 3 founder mutations account for all of the BRCA mutations distributed throughout the country. This question has important implications for health policy and the design of epidemiologic studies. To establish the relative contributions of founder and nonfounder BRCA mutations, we established the entire spectrum of BRCA1 and BRCA2 mutations in a large set of breast–ovarian cancer families with origins in all regions of Poland. We sequenced the entire coding regions of the BRCA1 and BRCA2 genes in 100 Polish families with 3 or more cases of breast cancer and in 100 families with cases of both breast and ovarian cancer. A mutation in BRCA1 or BRCA2 was detected in 66% of breast cancer families and in 63% of breast–ovarian cancer families. Of 129 mutations, 122 (94.6%) were in BRCA1 and 7 (5.4%) were in BRCA2. Of the 122 families with BRCA1 mutations, 119 (97.5%) had a recurrent mutation (i.e., one that was seen in at least 2 families). In particular, 111 families (91.0%) carried one of the 3 common founder mutations. The mutation spectrum was not different between families with and without ovarian cancer. These findings suggest that a rapid and inexpensive assay directed at identifying the 3 common founder mutations will have a sensitivity of 86% compared to a much more costly and labor‐intensive full‐sequence analysis of both genes. This rapid test will facilitate large‐scale national epidemiologic and clinical studies of hereditary breast cancer, potentially including studies of chemoprevention. © 2004 Wiley‐Liss, Inc.
Germline mutation and large deletion analysis of the CDKN2A and ARF genes in families with multiple melanoma or an aggregation of malignant melanoma and breast cancer
Authors: Dębniak Tadeusz , Górski Bohdan , Scott Rodney J. , Cybulski Cezary , Mędrek Krzysztof , Zowocka Elzbieta , Kurzawski Grzegorz , Dębniak Boguslaw , Kadny Józef , Bielecka‐Grzela Stanislawa , Maleszka Romuald , Lubiński Jan
Published: April 2004

The CDKN2A/ARF genes have been associated with increased risk of malignant melanoma (MM) in families with multiple members affected by disease and in families characterized by the constellation of breast cancer and MM. The exact contribution of CDKN2A/ARF to disease risk remains poorly characterized, especially in diverse populations. In this report, the contribution of CDKN2A/ARF germline mutations and large rearrangements to disease in Polish familial MM (FMM) and aggregations of breast cancer and MM were assessed using a strategy that included genomic sequencing, restriction fragment length polymorphism and multiplex ligation‐dependent probe amplification. We examined 16 FMM cases (group 1), 44 MM probands with a cancer family aggregation (CFA) that included at least one breast cancer (group 2) and 22 breast cancer probands with CFA and MM (group 3). The results revealed a paucity of mutations in CDKN2A/ARF, suggesting that in the Polish population this gene does not contribute significantly to either FMM or MM within the context of CFA. © 2004 Wiley‐Liss, Inc.
Overexpression of cdk4/cyclin D1, a possible mediator of apoptosis and an indicator of prognosis in human primary lung carcinoma
Authors: Dobashi Yoh , Goto Akiteru , Fukayama Masashi , Abe Akihisa , Ooi Akishi
Published: April 2004

The relation between expression of cell cycle–regulator molecules and apoptosis was examined in surgical specimens and cultured human lung carcinoma cell lines. Immunohistochemical analysis for 133 cases revealed 2 types of staining pattern. The first group consisted of 95 cases (71.4%) characterized by apoptotic cells showing intensely positive staining for cdk4 and cyclin D1 but negative for other proteins (type A). In the second group (type B), comprising 38 cases (28.6%), apoptotic cells exhibited intense positive staining for any cyclins and cdks. Most of the latter cases had lost expression of Rb protein. When tumor cells retrieved from paraffin‐embedded tissue were examined by flow cytometry, higher proportions of cells expressing only cdk4 or cyclin D1 in type A cases and of cells expressing any cyclin or cdk in type B cases showed a subdiploid DNA content. In survival analysis using the LI of apoptotic cells and cyclin/cdk‐positive cells, the high‐apoptosis/high‐cyclin D1 group showed the poorest prognosis. Furthermore, forced overexpression of only cdk4 or cyclin D1 induced apoptosis in cultured cells with normal Rb protein, whereas overexpression of any cyclin or cdk induced apoptosis in cells defective for Rb protein. In conclusion, upregulation of cdk4/cyclin D1 may be a primary and critical factor in induction of apoptosis in human lung carcinomas in vivo. Moreover, inactivation of Rb protein renders cells more prone to apoptosis by abnormal expression of any cell‐cycle protein. © 2004 Wiley‐Liss, Inc.
Profiling and functional annotation of mRNA gene expression in pediatric rhabdomyosarcoma and Ewing's sarcoma
Authors: Baer Claudia , Nees Mattias , Breit Stephen , Selle Barbara , Kulozik Andreas E. , Schaefer Karl‐Ludwig , Braun Yvonne , Wai Daniel , Poremba Christopher
Published: April 2004

Using Affymetrix oligonucleotide microarrays, we analyzed mRNA gene expression patterns of 12 primary pediatric rhabdomyosarcomas (RMS) and 11 Ewing's sarcomas (EWS), which belong to the small round blue cell tumors (SRBCTs). Diagnostic classification of these cancers is frequently complicated by the highly similar appearance in routine histology, and additional molecular markers could significantly improve tumor classification. A combination of three independent statistical approaches (t‐test, SAM, k‐nearest neighborhood analysis) resulted in 101 highly significant probe sets that clearly discriminate between EWS and RMS. We identified novel marker transcripts that have not been previously associated with either RMS or EWS yet, including CITED2, glypican 3 (GPC3), and cyclin D1 (CCND1). Expression levels for selected candidate genes were validated by quantitative real‐time reverse‐transcription PCR. Furthermore, to identify biologically meaningful trends, functional annotations were assigned to 946 genes differentially expressed between EWS and RMS (t‐test). Genes involved in protein biosynthesis (n = 28) and complex assembly (n = 9), lipid metabolism (n = 23), energy generation (n = 22), and mRNA processing (n = 11) were expressed significantly higher in EWS. Thus, functional annotation of tumor‐specific genes reveals detailed insights into tumor biology and differentiation‐specific expression patterns and gives important clues related to the possible cellular origin of these pediatric tumors. Supplementary material for this article is available at the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020‐7136/suppmat/index.html. © 2004 Wiley‐Liss, Inc.
Identification of FHOD1‐binding proteins and mechanisms of FHOD1‐regulated actin dynamics
Authors: Westendorf Jennifer J. , Koka Sreenivas
Published: April 2004

Formin homology‐2‐domain containing protein 1 (FHOD1) regulates gene transcription, actin‐cytoskeleton structure, and cell migration. To gain insight into the mechanisms by which FHOD1 mediates these diverse activities, a yeast‐two‐hybrid screen was performed to identify FHOD1‐binding proteins. Three proteins specifically interacted with the carboxy‐terminal two‐thirds of FHOD1, which includes the FH1, FH2, and diaphanous activating domains (DAD). The newly identified FHOD1‐binding proteins are protein kinase C binding protein 1 (PRKCBP1), cyclophilin B, and an isoform of WASP‐interacting SH3‐domain protein/diaphanous‐interacting protein 1 (WISH/DIP1), named WISH‐B. The proline‐rich FH1 domain of FHOD1 was sufficient to interact with the central portion of PRKCP1 and full‐length cyclophilin B. The FH1 domain also interacted with full‐length WISH‐B, but the extreme amino‐terminus was sufficient to associate with WISH‐B as well. WISH‐B altered the solubility of FHOD1 in vitro and a truncation mutant containing the amino‐terminal 227 residues of WISH‐B disrupted FHOD1‐induced stress fibers. WISH‐B did not affect FHOD1‐induced gene transcription through the serum response factor (SRF) recognition site on the skeletal α actin promoter (SkA). However, stabilization of F‐actin prevented FHOD1 dependent activation of this promoter in presence of high, but not low serum concentrations. Thus, the identification of a new FHOD1‐binding protein provides insight into the mechanisms by which FHOD1 regulates actin polymerization and transcription. © 2004 Wiley‐Liss, Inc.