bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti‐metastatic effect of capecitabine on human colon cancer xenografts in nude mouse rectum
Authors: Ninomiya Itasu , Terada Itsuro , Yoshizumi Tetsuya , Takino Takahisa , Nagai Noboru , Morita Akihiko , Fushida Sachio , Nishimura Genichi , Fujimura Takashi , Ohta Tetsuo , Miwa Koichi
Published: June 2004

Capecitabine (N 4‐pentyloxycarbonyl‐5′‐deoxy‐5‐fluorocytidine) is a new fluoropyrimidine carbamate, which is converted to 5‐fluorouracil (5‐FU) by 3 sequential steps of enzyme reactions. We investigated the possibility of using capecitabine to prevent metastasis with a metastasis model of gastrointestinal cancer developed by the intrarectal injection of green fluorescent protein (GFP)‐expressing colon cancer HT‐29 cells (HT‐29‐GFP) into nude mice. Lung and lymph node metastasis in the HT‐29‐GFP rectal xenograft was assessed through both observation of GFP fluorescence and quantification of metastasis by amplification of a cancer‐related human DNA by TaqMan PCR. Furthermore, for each organ, we examined mRNA levels of cancer‐specific thymidine phosphorylase (dThdPase), which is an essential enzyme for capecitabine activation, by the quantitative RT‐PCR method. Capecitabine inhibited the HT‐29‐GFP xenograft growth by 60.8% and 43.8% in the subcutaneous and rectal xenograft models, respectively. Furthermore, it inhibited both lung and lymph node metastasis by 99.9%. dThdPase expression in the tumor cells of both the rectal xenograft and metastatic lung tumor cells was upregulated by 10.0‐ and 24.3‐fold that in the HT‐29‐GFP cells in vitro, respectively. These results indicated that capecitabine might effectively inhibit or suppress metastasis via upregulation of dThdPase expression. Capecitabine administration might be highly expected to reduce metastasis and improve survival of patients with gastrointestinal cancers. © 2004 Wiley‐Liss, Inc.
αV integrin promotes in vitro and in vivo survival of cells in metastatic melanoma
Authors: Koistinen Pekka , Ahonen Matti , Kähäri Veli‐Matti , Heino Jyrki
Published: June 2004

The expression of integrin αV subunit on 4 melanoma‐derived cell lines (A2058, SK‐mel‐5, WM‐115 and WM‐266‐4) was analyzed. WM‐115 cells, which originate from a primary tumor, were negative, whereas all 3 metastasis‐derived lines had high levels of αV. To study αV integrins in the survival of melanoma cells, we developed a novel strategy that is exempt from extracellular inhibitors of ligand binding, which can activate integrin signaling and have integrin‐independent effects on apoptosis. A recombinant adenovirus was used to transfer cDNA coding for a single‐chain intracellular anti‐αV integrin antibody into the melanoma cells. Anti‐αV integrin adenovirus effectively inhibited the cell surface expression of αV integrins. In cell culture experiments, the depletion of αV integrins detached cells from extracellular matrix and induced apoptosis. Moreover, it prevented WM‐266‐4 cells from forming tumors in severe combined immunodeficiency mice but it could not prevent the growth of tumors that were formed by αV‐negative WM‐115 cells. Our results indicate that in primary melanomas there are cells that survive without αV integrins, whereas during the progression of disease cells can develop a dependency on these receptors. Furthermore, the data oppose the possibility that in melanoma cells apoptosis could occur due to direct activation of caspases by ligand‐free αV integrins on the cell surface. © 2004 Wiley‐Liss, Inc.
Activation of the orphan nuclear receptor RORα counteracts the proliferative effect of fatty acids on prostate cancer cells: Crucial role of 5‐lipoxygenase
Authors: Moretti Roberta M. , Montagnani Marelli Marina , Sala Angelo , Motta Marcella , Limonta Patrizia
Published: June 2004

The incidence of prostate carcinoma is very low in Eastern countries, such as Japan, suggesting that life style conditions may play a crucial role in the development of this pathology. Dietary ω‐6 polyunsaturated fatty acids, such as linoleic (LA) and arachidonic (AA) acids, have been shown to stimulate the proliferation of prostate cancer cells after being converted into 5‐HETE by means of the 5‐lipoxygenase (5‐LOX) pathway. Blockade of 5‐LOX activity has been proposed as an attractive target for the prevention of the mitogenic action of dietary fats on prostate cancer. The 5‐LOX gene has been shown to carry a response element for the orphan nuclear receptor RORα (for its RORα1 isoform in particular) in its promoter region. We attempt to clarify whether activation of RORα might modulate the expression of 5‐LOX, thus interfering with the mitogenic activity of fatty acids in prostate cancer cells. We show that in androgen‐independent DU 145 prostate cancer cells, LA, AA and their metabolite 5‐HETE exert a strong stimulatory action on cell proliferation. This effect is completely counteracted by the simultaneous treatment of the cells with a non redox inhibitor of 5‐LOX activity. We then demonstrate that: i) RORα, and specifically its RORα1 isoform, is expressed in DU 145 cells; ii) activation of RORα, by means of the thiazolidinedione derivative CGP 52608 (the synthetic RORα activator), significantly reduces 5‐LOX expression, both at mRNA (as evaluated by comparative RT‐PCR) and at protein (as investigated by Western blot analysis) level (this was confirmed by the reduced activity of 5‐LOX in CGP 52608 treated cells); and iii) the treatment of DU 145 cells with CGP 52608 completely abrogated the proliferative action of both LA and AA. These results have been confirmed in another androgen‐independent prostate cancer cell line (PC3). Our data indicate that, by decreasing the expression of 5‐LOX, activation of RORα might interfere with the mitogenic activity of fatty acids on prostate cancer. We have shown previously that CGP 52608 reduces the proliferation and the metastatic behavior of DU 145 cells. These observations indicate that the orphan nuclear receptor RORα might be considered as a molecular target for the development of new chemopreventive or chemotherapeutic strategies for prostate carcinoma. © 2004 Wiley‐Liss, Inc.
Hormone replacement therapy and incidence of hormone‐dependent cancers in the Norwegian Women and Cancer study
Authors: Bakken Kjersti , Alsaker Elin , Eggen Anne Elise , Lund Eiliv
Published: June 2004

Increasing use of HRT over the last 2 decades could have contributed to the increasing incidence of cancer in women. Our aim was to investigate the relation between use of HRT and risk of hormone‐dependent cancers in a Norwegian cohort of women. The Norwegian Women and Cancer (NOWAC) study is a representative, national, population‐based cohort study. This report includes 35,456 postmenopausal women aged 45–64 years who answered a postal questionnaire in 1996–1998 providing information on reproduction, lifestyle and use of HRT. The women were followed up for cancer incidence. The main analyses were restricted to 31,451 postmenopausal women with complete information. Ever use of HRT was reported by 43.5% and current use, by 35% of the women. Current users had an increased risk of breast cancer (adjusted RR = 2.1, 95% CI 1.5–2.5). The risk increased with increasing duration of use (ptrend < 0.0001). Using a regimen of continuous estrogen–progestagen implied an increased risk. Adjusted RRs associated with <5 and ≥5 years' duration of use were 2.6 (95% CI 1.9–3.7) and 3.2 (95% CI 2.2–4.6), respectively. The population‐attributable risk of breast cancer due to current use of HRT was 27%. We found no significant increase in risk of ovarian cancer. Neither did we find users of estrogen–progestagen preparations to have any increase in risk of endometrial cancer. Our results suggest that HRT could be considered a major determinant for the increasing incidence of breast cancer in Norway. © 2004 Wiley‐Liss, Inc.
Gene expression profiles in primary ovarian serous papillary tumors and normal ovarian epithelium: Identification of candidate molecular markers for ovarian cancer diagnosis and therapy
Authors: Santin Alessandro D. , Zhan Fenghuang , Bellone Stefania , Palmieri Michela , Cane Stefania , Bignotti Eliana , Anfossi Simone , Gokden Murat , Dunn Donna , Roman Juan J. , O'Brien Timothy J. , Tian Erming , Cannon Martin J. , Shaughnessy John , Pecorelli Sergio
Published: June 2004

With the goal of identifying genes with a differential pattern of expression between ovarian serous papillary carcinomas (OSPCs) and normal ovarian (NOVA) epithelium and using this knowledge for the development of novel diagnostic and therapeutic markers for ovarian cancer, we used oligonucleotide microarrays with probe sets complementary to 12,533 genes to analyze the gene expression profiles of 10 primary OSPC cell lines, 2 established OSPC cell lines (UCI‐101, UCI‐107) and 5 primary NOVA epithelial cultures. Unsupervised analysis of gene expression data identified 129 and 170 genes that exhibited >5‐fold upregulation and downregulation, respectively, in primary OSPC compared to NOVA. Genes overexpressed in established OSPC cell lines had little correlation with those overexpressed in primary OSPC, highlighting the divergence of gene expression that occurs as a result of long‐term in vitro growth. Hierarchical clustering of the expression data readily distinguished normal tissue from primary OSPC. Laminin, claudin 3, claudin 4, tumor‐associated calcium signal transducers 1 and 2 (TROP‐1/Ep‐CAM, TROP‐2), ladinin 1, S100A2, SERPIN2 (PAI‐2), CD24, lipocalin 2, osteopontin, kallikrein 6 (protease M), kallikrein 10, matriptase (TADG‐15) and stratifin were among the most highly overexpressed genes in OSPC compared to NOVA. Downregulated genes in OSPC included transforming growth factor‐β receptor III, platelet‐derived growth factor receptor α, SEMACAP3, ras homolog gene family member I (ARHI), thrombospondin 2 and disabled‐2/differentially expressed in ovarian carcinoma 2 (Dab2/DOC2). Differential expression of some of these genes, including claudin 3, claudin 4, TROP‐1 and CD24, was validated by quantitative RT‐PCR and flow cytometry on primary OSPC and NOVA. Immunohistochemical staining of formalin‐fixed, paraffin‐embedded tumor specimens from which primary OSPC cultures were derived further confirmed differential expression of CD24 and TROP‐1/Ep‐CAM markers on OSPC vs. NOVA. These results, obtained with highly purified primary cultures of ovarian cancer, highlight important molecular features of OSPC and may provide a foundation for the development of new type‐specific therapies against this disease. © 2004 Wiley‐Liss, Inc.
Environmental influences on endovascular stent platelet reactivity: An in vitro comparison of stainless steel and gold surfaces
Authors: Kolandaivelu Kumaran , Edelman Elazer R.
Published: June 2004

Thrombosis is an initiating reaction to vascular injury that follows the placement of vascular devices. Platelets play a crucial role in this response. Their interaction with endovascular devices is not solely a function of device properties, but a multifaceted response dependent on several biological factors that interact in the context of a hemodynamic environment. We sought to investigate the role of local environmental variations on determining indices of biocompatibility. Using a recently described in vitro flow apparatus, we separately studied the platelet and coagulative component responses to stainless steel endovascular stents with and without gold coating. When allowed to interact, these biological mediators of thrombosis enabled varied biocompatibility outcomes in a manner that was dependent on flow. Using platelet reactivity as an index, the stainless steel faired better under some conditions, while under other conditions, gold was superior. Considering such impacts of local environment on biocompatibility is important, both in the interpretation of experimental findings, as well as the continued use and optimized development of vascular devices. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 186–193, 2004
Oxidative mechanisms of poly(carbonate urethane) and poly(ether urethane) biodegradation: In vivo and in vitro correlations
Authors: Christenson Elizabeth M. , Anderson James M. , Hiltner Anne
Published: June 2004

This study used an in vitro environment that simulated the microenvironment at the adherent cell‐material interface to reproduce and accelerate the biodegradation of poly(ether urethane) (PEU) and poly(carbonate urethane) (PCU). Polyurethane films were treated in vitro for 24 days in 20% hydrogen peroxide/0.1 M cobalt chloride solution at 37°C. Characterization with ATR‐FTIR and SEM showed soft segment and hard segment degradation consistent with the chemical changes observed after long‐term in vivo treatment. Overall, the PCU underwent less degradation and the degraded surface layer was much thinner than PEU. Nevertheless, the results supported a common oxidation mechanism for biodegradation of these polymers. The observed in vitro degradation was inhibited by adding an antioxidant to the polyurethane film. Our findings further support the use of the in vitro H2O2/CoCl2 system in evaluating the biostability of polyurethanes under accelerated conditions. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 245–255, 2004
Inactivating Pit‐1 mutations alter subnuclear dynamics suggesting a protein misfolding and nuclear stress response
Authors: Sharp Z. Dave , Stenoien David L. , Mancini Maureen G. , Ouspenski Ilia I. , Mancini Michael A.
Published: June 2004

Pit‐1, a POU‐class nuclear DNA‐binding transcription factor, specifies three of the parenchymal cell types in anterior pituitary ontogeny. Using fluorescent fusions and live cell imaging, we have compared the dynamic behavior of wild‐type and inactivating Pit‐1 point mutations. Fluorescence recovery after photobleaching (FRAP) and real‐time extraction data indicate that wild‐type Pit‐1 has a dynamic mobility profile, with t1/2s ∼ 5–7 s when expressed from low to high amounts, respectively. Biochemically, Pit‐1 is ∼50% retained according to direct observation during extraction, indicating a dynamic interaction with nuclear structure. An analysis of transiently expressed Pit‐1 carrying two different debilitating mutations reveals that they translocate normally to the nucleus, but exhibit two different levels of mobility, both clearly distinguishable from wild‐type Pit‐1. At low expression levels, the t1/2s of PitW261C and PitA158P are extremely rapid (0.3 and 0.6 s t1/2s, respectively). At higher expression levels, unlike wild‐type Pit‐1, both mutant proteins become immobilized and insoluble, and fractionate completely with the insoluble nuclear matrix. Relative to wild‐type, over expression of mutated Pit‐1 elicits a nuclear stress response indicated by increased levels of heat shock inducible heat shock protein 70 (Hsp70), and reorganization of heat shock factor‐1. The decreased mobility of PitA158P relative to PitW261C at low expression levels correlates with its ability to partially activate when expressed at low levels and its ability to bind cognate DNA. At high expression levels, lower PitA158P activation correlates with its immobilization and insolubility. These data suggest a link between specific rates of intranuclear mobility and Pit‐1 transcription function, perhaps to insure sufficient interactions with chromatin, or in the case of non‐DNA binding Pit‐1, interaction as a repressor (Scully and Rosenfeld [2002]: Science 295:2231–2235). These data imply inactivating mutations can lead to an intranuclear sorting away from transcription related pathways, and at least in part to a misfolded protein pathway. Taken together, caution is suggested when interpreting point (or other) mutational analyses of transactivator function, as new compartmentation, especially in the context of expression levels, may cloud the distinction between defining functional molecular domains and intranuclear processing of misfolded proteins. © 2004 Wiley‐Liss, Inc.
Charge optimization of the interface between protein kinases and their ligands
Authors: Sims Peter A. , Wong Chung F. , McCammon J. Andrew
Published: June 2004

Examining the potential for electrostatic complementarity between a ligand and a receptor is a useful technique for rational drug design, and can demonstrate how a system prioritizes interactions when allowed to optimize its charge distribution. In this computational study, we implemented the previously developed, continuum solvent‐based charge optimization theory with a simple, quadratic programming algorithm and the UHBD Poisson–Boltzmann solver. This method allows one to compute the best set of point charges for a ligand or ligand region based on the ligand and receptor shape, and the receptor partial charges, by optimizing the binding free energy obtained from a continuum‐solvent model. We applied charge optimization to a fragment of the heat‐stable protein kinase inhibitor (PKI) of protein kinase A (PKA), to three flavopiridol inhibitors of CDK2, and to cyclin A which interacts with CDK2 to regulate the cell cycle. We found that a combination of global (involving every charge) and local (involving only charges in a local region) optimization can give useful hints for designing better inhibitors. Although some parts of an inhibitor may already contribute significantly to binding, we found that they could still be the most important targets for modifications to obtain stronger binders. In studying the binding of flavopiridol inhibitors to CDK2, comparable binding affinity could be obtained regardless of whether the net charges of the inhibitors were constrained to −2, −1, 0, 1, or 2 during the optimization. This provides flexibility in inhibitor design when a certain net charge of the inhibitor is desired in addition to strong binding affinity. For the study of the PKA–PKI and CDK2–cyclin A interfaces, we identified residues whose charge distributions are already close to optimal and those whose charge distributions could be refined to further improve binding. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1416–1429, 2004
Regulation of the human organic cation transporter hOCT1
Authors: Ciarimboli Giuliano , Struwe Katja , Arndt Petra , Gorboulev Valentin , Koepsell Hermann , Schlatter Eberhard , Hirsch Jochen R.
Published: June 2004

The human organic cation transporter type 1 (hOCT1) is an important transport system for small organic cations in the liver. Organic cation transporters are regulated by different signaling pathways, but the regulation of hOCT1 has not yet been studied. In this work, we have for the first time investigated the regulation of hOCT1. hOCT1 was expressed in Chinese hamster ovary cells (CHO‐hOCT1) and in human embryonic kidney cells (HEK293‐hOCT1). Its activity was monitored using microfluorimetry with the fluorescent organic cation 4‐(4‐(dimethylamino)styryl)‐N‐methylpyridinium (ASP+) as substrate. hOCT1 expressed in CHO‐cells was inhibited by protein kinase A (PKA) activation (1 µM forskolin, −58 ± 6%, n = 12), calmodulin inhibition (0.1 µM calmidazolium, −68 ± 3%, n = 6; 10 µM ophiobolin A, −48 ± 10%, n = 7), calmodulin‐dependent kinase II inhibition (1 µM KN62, −78 ± 4%, n = 12), and inhibition of p56lck tyrosine kinase (10 µM aminogenistein, −35 ± 7%, n = 12). The apparent affinities for TEA+ were lower in CHO‐hOCT1 than in HEK293‐hOCT1, while those for TPA+ and quinine were almost identical; the rank order of EC50 values (TPA+ > quinine > TEA+) was independent of the expression system. EC50 values for TEA+ in CHO‐hOCT1 or HEK293‐hOCT1 were increased under calmidazolium incubation (6.3 and 1.4 mM, respectively). hOCT1 was inhibited by PKA and endogenously activated by calmodulin, calmodulin‐dependent kinase II, and p56lck tyrosine kinase. Regulation pathways were the same in the two expression systems. Since apparent substrate affinities depend on activity of regulatory pathways, the expression system plays a role in determining the substrate affinities. © 2004 Wiley‐Liss, Inc.
Plasmalogens in rat liver chromatin: New molecules involved in cell proliferation
Authors: Albi Elisabetta , Cataldi Samuela , Magni Mariapia Viola , Sartori Claudia
Published: June 2004

A minor component of chromatin, the phospholipid fraction, changes during cell cycle as result of the activation of intranuclear lipid metabolism enzymes including phosphatidylcholine‐dependent phospholipase C activity. It is known that this enzyme may be activated by phosphatidylcholine plasmalogen (Plg). Until now, there has been little evidences for the presence of Plgs inside the nucleus. The aim of our study is to ascertain if they are present in the nucleus and are responsible of the activation of phosphatidylcholine‐dependent phospholipase C during cell proliferation and apoptosis. Therefore, we have analysed the Plg composition of the whole homogenate, cytosol, nuclei and chromatin of hepatocytes. The phosphatidylcholine‐dependent phospholipase C activity was assayed using both phosphatidylcholine and plasmalogenyl‐phosphatidylcholine as substrates. Our results show, for the first time, that Plgs are present in chromatin and the plasmalogenyl‐phosphatidylcholine stimulates the phosphatidylcholine‐dependent phospholipase C activity more than phosphatidylcholine. Finally, in order to verify the possible role of these molecules during cell proliferation and apoptosis, we used liver of rats fed with ciprofibrate which stimulates hepatocytes proliferation during the treatment and, after withdrawal, apoptosis. After 3 days of ciprofibrate treatment, the chromatin plasmalogenyl‐phosphatidylcholine increases as well as the phosphatidylcholine‐dependent phospholipase C activity. After drug withdrawal, when the hepatocytes undergo to apoptosis, the plasmalogenyl‐phosphatidylcholine content together with phosphatidylcholine‐dependent phospholipase C activity decreases. Therefore, it can be concluded that plamalogens are present in the chromatin, and probably may have a function both in regulating phosphatidylcholine dependent phospholipase C and cell cycle. © 2004 Wiley‐Liss, Inc.
Late Quaternary submarine bedforms and ice‐sheet flow in Gerlache Strait and on the adjacent continental shelf, Antarctic Peninsula
Authors: Evans Jeffrey , Dowdeswell Julian A. , Cofaigh Colm Ó
Published: June 2004

Geophysical data from Gerlache Strait, Croker Passage, Bismarck Strait and the adjacent continental shelf reveal streamlined subglacial bedforms that were produced at the bed of the Antarctic Peninsula Ice Sheet (APIS) during the last glaciation. The spatial arrangement and orientation of these bedforms record the former drainage pattern and flow dynamics of an APIS outlet up‐flow, and feeding into, a palaeo‐ice stream in the Western Bransfield Basin. Evidence suggests that together, they represent a single ice‐flow system that drained the APIS during the last glaciation. The ice‐sheet outlet flowed north/northeastwards through Gerlache Strait and Croker Passage and converged with a second, more easterly ice‐flow tributary on the middle shelf to form the main palaeo‐ice stream. The dominance of drumlins with low elongation ratios suggests that ice‐sheet outlet draining through Gerlache Strait was comparatively slower than the main palaeo‐ice stream in the Western Bransfield Basin, although the low elongation ratios may also partly reflect the lack of sediment. Progressive elongation of drumlins further down‐flow indicates that the ice sheet accelerated through Croker Passage and the western tributary trough, and fed into the main zone of streaming flow in the Western Bransfield Basin. Topography would have exerted a strong control on the development of the palaeo‐ice stream system but subglacial geology may also have been significant given the transition from crystalline bedrock to sedimentary strata on the inner–mid‐shelf. In the broader context, the APIS was drained by a number of major fast‐flowing outlets through cross‐shelf troughs to the outer continental shelf during the last glaciation. Copyright © 2004 John Wiley & Sons, Ltd.
Changing marine productivity off northern Chile during the past 19 000 years: a multivariable approach
Authors: Mohtadi M. , Romero O. E. , Hebbeln D.
Published: June 2004

A multivariable approach utilising bulk sediment, planktonic Foraminifera and siliceous phytoplankton has been used to reconstruct rapid variations in palaeoproductivity in the Peru–Chile Current System off northern Chile for the past 19 000 cal. yr. During the early deglaciation (19 000–16 000 cal. yr BP), our data point to strongest upwelling intensity and highest productivity of the past 19 000 cal. yr. The late deglaciation (16 000–13 000 cal. yr BP) is characterised by a major change in the oceanographic setting, warmer water masses and weaker upwelling at the study site. Lowest productivity and weakest upwelling intensity are observed from the early to the middle Holocene (13 000–4000 cal. yr BP), and the beginning of the late Holocene (<4000 cal. yr BP) is marked by increasing productivity, mainly driven by silicate‐producing organisms. Changes in the productivity and upwelling intensity in our record may have resulted from a large‐scale compression and/or displacement of the South Pacific subtropical gyre during more productive periods, in line with a northward extension of the Antarctic Circumpolar Current and increased advection of Antarctic water masses with the Peru–Chile Current. The corresponding increase in hemispheric thermal gradient and wind stress induced stronger upwelling. During the periods of lower productivity, this scenario probably reversed. Copyright © 2004 John Wiley & Sons, Ltd.
CFOs in e‐business: e‐architects or foot‐soldiers?
Authors: O'Donnell David , Bontis Nick , O'Regan Philip , Kennedy Tom , Cleary Peter , Hannigan Ailish
Published: June 2004

Both the role of the CFO (chief financial officer) and the discipline of accounting can be viewed as being in transition due to developments in the e‐Business world. One perspective suggests that CFOs are becoming ‘e‐process architects’—an alternative suggests that the CFO role is becoming commoditized to ‘foot‐soldier’ status with other roles such as CIOs (chief information officers) and CTOs (chief technology officers) staking a claim to its traditional accounting space. In this paper we present some preliminary evidence relating to this e‐architect/foot‐soldier question, and on levels of e‐Business activity, based on data obtained from over 120 CFOs in the Irish ICT sector. Copyright © 2004 John Wiley & Sons, Ltd.
The influence of knowledge attributes on innovation protection mechanisms
Authors: Nieto Mariano , Pérez‐Cano Carmen
Published: June 2004

This article deals with the appropriability of technological innovations. Specifically, it looks at how certain attributes of technological knowledge (codifiability, teachability, complexity, observability and dependency) may influence the choices that firms make among different protection mechanisms (patents, secrecy, lead time, learning curve and complementary resources). Based on a sample of 670 innovations developed by Spanish industrial firms, it is found that dependency and, to a lesser extent, codifiability are the attributes that have the most influence the choice of appropriation method. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and Photophysical Investigations of Novel Polymerizable Blue Emitting Fluorophores – Combination of a Hindered Amine with a Benzo[de]isoquinoline‐1,3‐dione
Authors: Bojinov Vladimir , Ivanova Galya , Simeonov Danail
Published: June 2004

Summary: New monomeric benzo[de]isoquinoline‐1,3‐dione blue emitting fluorophores, containing hindered amine stabilizer fragment have been synthesized under phase transfer catalysis conditions and their ability for “one‐step” optical bleaching and stabilization of poly(methyl methacrylate) has been demonstrated. During the co‐polymerization, no changes in the chromophoric system of the fluorophore occurred. The chemical bonding of the synthesized monomers in the polymer chain was confirmed spectrophotometrically. The absorption and some basic photophysical characteristics of the low and high molecular weight fluorescent brighteners have been determined. Photostability of the new monomeric fluorophores and their influence on the photostability of the blue emitting side‐group co‐polymers obtained have been established. A significant stabilizing effect against photodegradation was determined.

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Stereochemical Structure of Polypropylene Obtained in the Presence of Half‐Sandwich Titanium Complexes
Authors: Csok Zsolt , Liguori Dario , Sessa Irene , Zannoni Carla , Zambelli Adolfo
Published: June 2004

Summary: The polymerization of propene in the presence of CpTi(CH3)3/B(C6F5)3, at low temperature, affords prevailingly syndiotactic elastomeric polypropylene. In the presence of methylalumoxane (MAO) and under the same polymerization conditions, both CpTi(CH3)3 and CpTiCl3 afford elastomeric polypropylene with a stereochemical structure ranging from prevailingly syndiotactic to prevailingly isotactic, depending on the concentration of MAO. A tentative rationalization of these results is provided.

The methyl regions of the 13C NMR spectra of polypropylenes obtained for different amounts of MAO (0.001 mol: top and 0.09 mol: bottom).

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The methyl regions of the 13C NMR spectra of polypropylenes obtained for different amounts of MAO (0.001 mol: top and 0.09 mol: bottom).
Analysis of nucleic acids by FTICR MS
Authors: Hofstadler Steven A. , Sannes‐Lowery Kristin A. , Hannis James C.
Published: June 2004

Fourier transform ion cyclotron resonance (FTICR) mass spectrometry represents a unique platform with which to study nucleic acids and non‐covalent complexes containing nucleic acids moieties. In particular, systems in which very high mass measurement accuracy is required, very complex mixtures are to be analyzed, or very limited amounts of sample are available may be uniquely suited to interrogation by FTICR mass spectrometry. Although the FTICR platform is now broadly deployed as an integral component of many high‐end proteomics‐based research efforts, momentum is still building for the application of the platform towards nucleic acid‐based analyses. In this work, we review fundamental aspects of nucleic acid analysis by FTICR, focusing primarily on the analysis of DNA oligonucleotides but also describing applications related to the characterization of RNA constructs. The goal of this review article is to give the reader a sense of the breadth and scope of the status quo of FTICR analysis of nucleic acids and to summarize a few recently published reports in which researchers have exploited the performance attributes of FTICR to characterize nucleic acids in support of basic and applied research disciplines including genotyping, drug discovery, and forensic analyses. © 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:265–285, 2005
Biochemical applications of mass spectrometry in pharmaceutical drug discovery
Authors: Geoghegan Kieran F. , Kelly Michele A.
Published: June 2004

Biochemical applications of mass spectrometry (MS) are important in the pharmaceutical industry. They comprise compositional analyses of biomolecules, especially proteins, and methods that measure molecular functions such as ligand binding. In early drug discovery, MS is used to characterize essential reagents and in structural biology. A number of MS‐based methods have been proposed for use in high‐throughput screening (HTS), but are unlikely to supplant established radiometric and fluorometric methods for this purpose. These methods, which include pulsed‐ultrafiltration MS, frontal affinity chromatography‐MS, and size‐exclusion chromatography‐MS, may ultimately be most successful in the post‐screening lead development phase. In full development, MS is used heavily in the search for biomarkers that can be used to gauge disease progression and drug action. This review gives equal attention to the technical aspects of MS‐based methods and to selective pressures present in the industrial environment that influence their chances of gaining wide application. © 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:347–366, 2005
Mechanical response and rheological properties of polycarbonate layered‐silicate nanocomposites
Authors: Hsieh Alex J. , Moy Paul , Beyer Frederick L. , Madison Phil , Napadensky Eugene , Ren Jiaxiang , Krishnamoorti Ramanan
Published: June 2004

The effect of clay loading on the mechanical behavior and melt state linear viscoelastic properties of intercalated polycarbonate (PC) nanocomposites was investigated. At low frequencies, the linear dynamic oscillatory moduli data revealed diminished frequency dependence with increasing nanoclay loading. The 3.5 and 5 wt% clay nanocomposites exhibited dramatically altered relaxation behavior, from liquid‐like to pseudo‐solid–like, compared to the pure PC and the 1.5 wt% clay nanocomposite. Thermal degradation of PC resulted from the melt compounding of organo‐modified nanoclays was evident from the reduction in the glass transition temperature and molecular weight of the PC nanocomposites. These nanocomposites also exhibited a significant decrease in the extent of tensile elongation and ductility with respect to the nanoclay incorporation. A concomitant decrease in the rheological properties at high frequencies was also observed, and was consistent with the lowering of the molecular weight of PC, particularly near or above the percolation threshold of nanoclay. These nanocomposites, nevertheless, exhibited elastic‐plastic deformation in compression, regardless of nanoclay content. Polym. Eng. Sci. 44:825–837, 2004. © 2004 Society of Plastics Engineers.
The study of morphology, thermal and thermo‐mechanical properties of compatibilized TPU/SAN blends
Authors: Ulcnik‐Krump M. , De Lucca Freitas L.
Published: June 2004

The compatibilizing efficiency of three different compatibilizers in thermoplastic polyurethane/styrene‐co‐acrylonitrile (TPU/SAN) blends was investigated after their incorporation via melt‐mixing. The compatibilizers studied were poly‐ε‐caprolactone (PCL), a mixture of polystyrene‐block‐polycaprolactone (PS‐b‐PCL) and polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA), and a mixture of polyisoprene‐block‐polycaprolactone (PI‐b‐PCL) and polybutadiene‐block‐poly(methyl methacrylate) (PB‐b‐PMMA). All compatibilizers were synthesized by living anionic polymerization. Investigations of thermal and thermo‐mechanical properties performed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DTMA), respectively, were systematically classified into two groups, i.e. blends of TPU or SAN with 20 wt% of different compatibilizers (so‐called limit conditions) and TPU/SAN 25/75 blends with 5 wt% of different compatibilizers. In order to determine the compatibilizer's location, morphology of TPU/SAN 25/75 blends was studied with transmission electron microscopy (TEM). Different compatibilization activity was found for different systems. Blends compatibilized with PCL showed superior properties over the other blends. Polym. Eng. Sci. 44:838–852, 2004. © 2004 Society of Plastics Engineers.
On the use of pressure‐volume‐temperature data of polyethylene liquids for the determination of their solubility and interaction parameters
Authors: Zhao L. , Capt L. , Kamal M. R. , Choi P.
Published: June 2004

Specific volumes of high‐density and low‐density polyethylene liquids at several elevated temperatures and pressures were measured. The measured specific volumes were then used to estimate the thermal expansion coefficients
\documentclass{article}\pagestyle{empty}\begin{document}$\left( {{\rm \alpha = }\frac{{\rm 1}}{v}\left( {\frac{{\partial v}}{{\partial T}}} \right)_P } \right)$\end{document} and isothermal compressibility \documentclass{article}\pagestyle{empty}\begin{document}$\left( {{\rm \beta = } - \frac{{\rm 1}}{v}\left( {\frac{{\partial v}}{{\partial P}}} \right)_T } \right)$\end{document} of the polymers. Two different approaches were used in which one was simply to fit the raw data by second order polynomials to obtain (∂v/∂T)P and (∂v/∂P)T, while the other by the Sanchez‐Lacombe (S‐L) equation of state. It was found that the resultant α and β obtained from the above methods differ significantly, indicating that the S‐L equation of state may not be suitable for determining α and β at elevated temperatures. When these two sets of α and β were used to calculate the corresponding solubility parameters and then the Flory‐Huggins interaction parameters (χ) of the polymers, the results also differ considerably. Nonetheless, χ obtained from the first method agrees well with the results obtained from small angle neutron scattering measurements while the S‐L equation of state method does not. The current results suggest that solubility and interaction parameters obtained from pressure‐volume‐temperature experiments depend critically on the manner by which the data analysis is performed. Polym. Eng. Sci. 44:853–860, 2004. © 2004 Society of Plastics Engineers.
Effect of filler dispersion on polypropylene morphology
Authors: Lozano T. , Lafleur P. G. , Grmela M. , Thibodeau C.
Published: June 2004

The evaluation of filler dispersion in compounding machines is an important part of their design. Calcium carbonate–filled polypropylene (PP) was used as a model compound to study filler dispersion. The evolution of dispersion was followed in a twin‐screw extruder where several types of mixing sections were evaluated. Reverse kneading blocks were found to be very efficient for breakup of agglomerates. Depending on extrusion conditions, agglomeration was observed even after the matrix was melted. To study dispersion in a single‐screw extruder, Maddock and reverse Maddock mixing elements were tried. A quantitative evaluation of the dispersion state allowed a better understanding of nucleation in the PP/CaCO3 matrix. A significant content of the β‐phase of polypropylene was observed when the agglomerate size was relatively small. The level of shear stress was also important for the formation of the β‐phase of PP. The quantification of dispersion was mainly evaluated from micrographs of samples obtained by reflected light microscopy in conjunction with image analysis. The characterization of β‐spherulites was carried out using polarized light microscopy and scanning electron microscopy. Polym. Eng. Sci. 44:880–890, 2004. © 2004 Society of Plastics Engineers.
Fluorescence temperature measurements: Methodology for applications to process monitoring
Authors: Bur Anthony J. , Roth Steven C.
Published: June 2004

In previous publications, we described a technique based on fluorescence spectroscopy to monitor resin temperature during processing. The method consists of using optical fiber sensors to monitor fluorescence from a fluorescent dye that has been doped into the processed resin. Temperature is derived from temperature‐induced changes in the fluorescence spectrum. In practice, a temperature calibration function is obtained from the temperature dependence of the ratio of fluorescence intensities at two wavelengths. In this paper, we address several experimental design issues: (a) the supportive role of fluorescence anisotropy measurements to the measuring concept, (b) the experimental setup used for noncontact measurements during capillary rheometry testing, and (c) molecular‐level environmental issues that arise during reactive processing and temperature profiling. We find that fluorescence anisotropy of the dye bis(2,5‐tert‐butylphenyl)‐3,4,9,10‐perylenedicarboximide (BTBP) is independent of shear rate up to 250 s−1, implying that isotropic orientation of the dye is maintained as the matrix resin undergoes dynamic shear flow, i.e. the calibration function made under quiescent conditions applies to dynamic shear flow conditions. Using this technique in a noncontact application to monitor temperature of the extrudate from a capillary rheometer required an optical design that neutralized the focusing attributes of the cylindrical extrudate. Application to reactive processing is complicated by changes in polarization that accompany the reaction, and, in some cases, produce wavelength shifts in the fluorescence spectrum. We overcome these effects by using a dye that yields a calibration independent of the polarization effects and by averaging over a large dataset to reduce measurement uncertainty. Polym. Eng. Sci. 44:898–908, 2004. © 2004 Society of Plastics Engineers.
Fracture behavior at partially miscible polymer interfaces
Authors: Gorga Russell E. , Narasimhan Balaji
Published: June 2004

The fracture behavior for the partially miscible polystyrene/poly (styrene‐r‐4‐bromostyrene) (PS/PBS) interface is analyzed as a function of miscibility. This is achieved by measuring the fracture energy at PS/PBS interfaces over a range of molecular weights (1370 < N < 7144; N is the degree of polymerization) and annealing conditions (150 < T < 200°C) at varying degrees of miscibility (controlled by ƒ, the volume fraction of brominated repeat units in PBS). Correlations between fracture energy, mutual diffusion coefficient (measured using Rutherford backscattering spectroscopy), and the Flory‐Huggins interaction parameter (χ) are presented. It is shown that the fracture energy, Gc, increases as annealing temperature increases and N and ƒ decrease. The presence of two miscibility‐mediated interdiffusion/fracture regimes is postulated depending upon the value of N*χ, where \documentclass{article}\pagestyle{empty}\begin{document}$N^* = \frac{{2N_{PS} N_{PBS} }}{{N_{PS} + N_{PBS} }}$\end{document}. (I) When N*χ < 2, the system is miscible, Gc is high, and the fracture mechanism is crazing; (II) When N*χ > 2, the system exhibits a miscibility gap, interdiffusion is thermodynamically limited, which results in a decreased Gc, which continues to decrease with increasing ƒ. No crazes are observed in regime II and fracture occurs via chain pullout. Polym. Eng. Sci. 44:929–939, 2004. © 2004 Society of Plastics Engineers.
Primary and secondary gas penetration during gas‐assisted injection molding. Part I: Formulation and modeling
Authors: Li C. T. , Isayev A. I.
Published: June 2004

A theoretical study has been carried out on the transient gas‐liquid interface development and gas penetration behavior during the cavity filling and gas packing stage in the gas‐assisted injection molding (GAIM) of a tube cavity. A mathematical formulation describing the evolution of the gas/melt interface and the distribution of the residual wall thickness of skin melt along with the advancement of gas/melt front is presented. The physical model is put forward on the basis of Hele‐Shaw approximation and interface kinematics and dynamics. Numerical simulation is implemented on a fixed mesh covering the entire cavity. The model and simulation can deal with both primary and secondary gas penetrations. The predicted and measuredresults are compared in Part II of this study to validate the theoretical model. Polym. Eng. Sci. 44:983–991, 2004. © 2004 Society of Plastics Engineers.
Primary and secondary gas penetration during gas‐assisted injection molding. Part II: Simulation and experiment
Authors: Li C. T. , Shin J. W. , Isayev A. I. , Lee H. S.
Published: June 2004

Simulation and experimental studies have been carried out on the transient gas‐liquid interface development and gas penetration behavior during the cavity filling and gas packing stage in the gas‐assisted injection molding of a spiral tube cavity. The evolution of the gas/melt interface and the distribution of the residual wall thickness of skin melt along with the advancement of gas/melt front were investigated. Numerical simulations were implemented on a fixed mesh covering the entire cavity. The residual thickness of a polymer layer and the length of gas penetration in the moldings were calculated using both the simulation and model developed in Part I of this study and commercial software (C‐Mold). Extensive molding experiments were performed on polystyrene at different processing conditions. The obtained results on the gas bubble dynamics and penetration behaviors were compared with those predicted by the present simulation and C‐Mold, indicating the good predictive capability of the proposed model. Polym. Eng. Sci. 44:992–1002, 2004. © 2004 Society of Plastics Engineers.
The morality of problem selection in proteomics
Authors: Liska Adam J.
Published: June 2004

The emerging power of new technologies in proteomics and the biological sciences to alter the human condition demands that scientists hold a new perspective on the social reesponsibilities of their research. Ethical theory can help scientists recognize not only those research projects that are harmful, but also those research paths that can create the greatest improvements in human health on a global scale. Whereas individual choices are important for the direction of scientific research, these choices may have limited social effects if they are not coordinated with larger institutional and inter‐institutional structures. The perspective presented here calls for the Human Proteome Organization to recognize the ten most ethically significant proteomes to be characterized, with the hopes of rallying support and directing the research efforts of scientists in the proteomics community toward these goals.
Functional protein microarrays for parallel characterisation of p53 mutants
Authors: Boutell Jonathan M. , Hart Darren J. , Godber Benjamin L. J. , Kozlowski Roland Z. , Blackburn Jonathan M.
Published: June 2004

Understanding the way in which single nucleotide polymorphisms and mutations in the human genome result in individual susceptibility to disease is a major goal in the postgenomic era. Such knowledge should accelerate the development of personalised medicine in which drug treatment can specifically match an individual's genotype. High‐throughput DNA sequencing is generating the initial information required, but new technologies are required that can rapidly characterise the phenotypic effects of the identified polymorphisms. For example, many thousands of allelic variants of the p53 gene have been described and are responsible for more than 50% of cancers, however few of the protein products have been functionally characterised. Here we have quantified in parallel the effects of mutations and polymorphisms on the DNA‐binding function of the p53 oncoprotein using a protein microarray, allowing their subclassification according to functional effect. Protein‐protein interactions between p53 variants and (i) a regulatory oncoprotein, (ii) a regulatory kinase resulting in on‐chip phosphorylation, are also described, suggesting the more general utility of this high‐throughput assay format.
Identification of cellular proteins modified in response to African swine fever virus infection by proteomics
Authors: Alfonso Patricia , Rivera José , Hernáez Bruno , Alonso Covadonga , Escribano José M.
Published: June 2004

Changes in gene expression are produced in cells as a consequence of virus infections. In the present work, we used proteomic technology to globally examine African swine fever virus (ASFV)‐infected Vero cells searching for infection‐associated proteins in order to determine target proteins for pathogenesis studies. We studied the alterations in cellular protein profile after ASFV infection by two‐dimensional electrophoresis, identifying the modified cellular proteins by matrix‐assisted laser desorption/ionization peptide mass fingerprinting. A total of twelve different over‐expressed cellular proteins were unambiguously identified. The most significant changes were in redox‐related proteins, nucleoside diphosphate kinases, heat shock proteins, members of the Ran‐Gppnhp‐Ranbd1 complex and apolipoproteins. These cellular protein modifications could represent distinct roles during infection related to apoptosis and transcriptional modulation mechanisms. The present study constitutes the first attempt to understand the dynamics of ASFV‐host cell interactions by proteomics.