bluuebunny/crossref_metadata_2025 huggingface dataset:
Ternary phase separation in polyurethane elastomers with immiscible soft segments
Authors: Mormann Werner , Zhang Chenxi
Published: August 2003

Polyurethane elastomers with two immiscible hard‐segment polyols have been synthesized from homogeneous prepolymer mixtures, to obtain incompatibility on a molecular scale from reaction driven phase separation. Miscibility of a series of different soft‐segment polyols and of their prepolymers with 4,4′‐diisocyanatodiphenyl methane (MDI) has been investigated by cloud point analysis. UCST‐behavior was observed for all binary combinations of polyols and of prepolymers; prepolymer formation lowered UCST with respect to polyols with the option to adjust it by further addition of MDI. Polyurethane elastomers have been synthesized and characterized with respect to their thermal, mechanical and viscoelastic (DMTA) behavior. Broad temperature ranges of loss factor above 0.1 were observed from polyurethanes with two immiscible soft‐segment polyols. Rebound resilience, however, was still significant at room temperature, because of the low transition temperatures of the polyols used. Introduction of a third partially miscible component, a hard‐segment from tetraethyleneglycol and MDI gave materials with a loss factor above 0.1 over a temperature range from −50 to 120 °C and higher. The studies proved that the concept of intimate mixing of immiscible soft‐segments in polyurethanes works for the design of viscoelastic materials with good damping properties.
Thermodynamic analysis of the reaction‐induced phase separation in model systems based on blends of a rubber in diepoxide / monoamine precursors
Authors: Zucchi Ileana A. , Galante María J. , Borrajo Julio , Williams Roberto J.J.
Published: August 2003

The reaction‐induced phase separation in blends based on a carboxyl‐terminated poly(butadiene‐co‐acrylonitrile) rubber (CTBN), dissolved in diglycidyl ether of bisphenol A (DGEBA) ‐ benzylamine (BA) monomers, was studied. The polymerization kinetics was followed by size exclusion chromatography, for both the neat DGEBA‐BA system and for blends containing 10 wt% CTBN. No effect of CTBN addition on the polymerization rate was observed within experimental error. The kinetics could be fitted with a model based on the presence of non‐catalytic and OH‐catalyzed reactions and assuming equal reactivity of primary and secondary amine hydrogens. Cloud‐point conversions were determined at 60, 70 and 80 °C. The Flory‐Huggins model provided a reasonable fitting of experimental data using an interaction parameter depending exclusively on temperature, and taking polydispersities of both linear polymers into account. Linear epoxy/amine systems may be used to test the reliability of thermodynamic theories in more complex situations (e.g., modifiers with a broad distribution of molar masses or mixtures of several modifiers).
DGEBA monomer as a solvent for syndiotactic polystyrene
Authors: Schut Jaap , Stamm Manfred , Dumon Michel , Gérard Jean‐François
Published: August 2003

Syndiotactic polystyrene (sPS) has to be processed at high temperatures (i.e. >290°C due to its melting point of 270°C), which approaches its degradation temperature. We aim to facilitate the processing of sPS by lowering its melt temperature and viscosity with a curable epoxy/amine model system as reactive solvent, which will result in a thermoplastic‐thermoset polymer blend. As a first step we therefore investigated the melting behaviour of sPS in epoxy monomer, established its phase diagram, and investigated the crystalline form of sPS in these mixtures. DGEBA epoxy monomer is found to be a solvent for syndiotactic polystyrene at temperatures above 220°C. The DGEBA‐sPS phase diagram was established by means of DSC, on the basis of crystallization and melting peaks. The form of the curve in the phase diagram indicates that DGEBA is a poor solvent for sPS. In WAXS studies of blends only the β crystalline form was detected, not the δ form, thus no sPS‐DGEBA polymer‐solvent compounds (clathrates) were detected. However, DGEBA can still serve as a monomer for improved processing as it depresses the crystallization temperature by 20 to 60 K upon addition of 20 to 90 wt% DGEBA respectively, while a 16 to 45 K melting peak depression can be observed by adding 20 to 90 wt% DGEBA.
Dielectric in situ sensor monitoring of phase separation and changes in the state of each phase
Authors: Kranbuehl D. , Rogozinski J. , Warner J. , Best P. , Pascault J.P. , Sautereau H. , Boiteux G. , Seytre G.
Published: August 2003

Frequency dependent dielectric measurements have been used to monitor and characterize the phase separation process and changes in state of each phase. The measurements are made in situ using a micro planar sensor. They can be made both in the laboratory as well as in an industrial production or use environment. Two examples are presented. The first is monitoring the onset of phase separation, the buildup in Tg and change in composition of each phase during “reactive processing” of a high performance thermoplastic (TP) PPI, thermoset precursors (TS) DGEBA‐MCDEA intially homogeneous blend. The second example involves monitoring the stability, onset of phase separation, as a function of temperature on a mineral oil, stearyl alcohol, water, sufactant emulsion used in the cosmetic industry.
In situ real‐time monitoring of a diglycidyl ether of bisphenol a epoxy resin modified with poly(etherimide)/polysulphone blends by simultaneous dielectric/near‐infrared spectroscopy
Authors: Kortaberria G. , Arruti P. , Mondragon I.
Published: August 2003

Simultaneous dielectric and near infrared measurements were performed in “real‐time” to follow polymerisation reactions on blends of a diglycidyl ether of bisphenol A (DGEBA) epoxy resin with 4,4′‐diaminodiphenylmethane (DDM) hardener and a mixture of polysulphone (PSU) and polyetherimide (PEI) as modifier. All the blends had a 10 wt% of PSU/PEI mixture. The effect of the PEI/PSU ratio in the mixture was studied. Monitoring of the α‐relaxation (related to vitrification) was performed by dielectric measurements, while epoxy conversion was followed by near infrared spectroscopy. The effect of the PEI/PSU ratio on this behaviour was studied, as well as that of the curing temperature. Obtained results were compared with that of the blends with neat PSU and PEI as modifiers.
Processability and chemical resistance of the polymer blend of thermoplastic polyurethane and polydimethylsiloxane
Authors: Damrongsakkul Siriporn , Sinweeruthai Ratirat , Higgins Julia S.
Published: August 2003

This work is aimed to develop the melt blend of thermoplastic polyurethane (TPU) and polydimethylsiloxane (PDMS) and to study the effect of the chemical resistance on the tensile properties and morphology of the blends. The master batch blends at 2% of PDMS with 98% of TPU were firstly prepared by an internal mixer and then the blends of TPU/PDMS were prepared by melt mixing using a twin screw extruder. The maximum PDMS content that can be mixed with TPU was found to be no higher than 1%. Higher PDMS content leaves an unmelted TPU fraction in the blends due to the short residence time in the twin screw extruder. The resultant blends show an increase in the elongation at break up to 30% and in Young's modulus up to 40% at the optimum PDMS concentration of around 0.6%‐0.8%, beyond which these properties diminish. The ultimate tensile strength and the energy to break are decreased by about 20% and 10%, respectively. The Scanning Electron Micrographs of the blends show dispersed phases of PDMS in a TPU matrix. The domain size of the PDMS phase becomes smaller when increasing PDMS content from 0.2% to 0.8%. The morphology of the fractured surface of TPU/PDMS blends shows less fibrous characteristics with increasing PDMS content in the blends.

For the study of the effects of chemical resistance on the tensile properties and morphology of TPU/PDMS blends, two chemical reagents, sulfuric acid (H2SO4, 3% v/v) and sodium hydroxide (NaOH, 10% w/v) are selected. The results on the relationship of chemical resistance to tensile properties and morphology of the blends show that NaOH solution has a stronger effect on the tensile properties and morphology of virgin TPU and the blends than H2SO4 solution. The ultimate tensile strength and the energy to break of virgin TPU after base immersion was found to be strongly decreased, which could be caused by the base hydrolysis of the polyester soft segment of polyurethane. The effect of PDMS content in the blends on the base resistance and tensile properties is similar to results before immersion, i.e. the effective PDMS content in the blends that can generally improve tensile properties of the blends after immersion in NaOH does not exceed 0.8%. The results are in agreement with the weight loss of TPU/PDMS blends after base immersion and the morphology of the fractured surface of TPU/PDMS blends after base immersion that exhibit very small amounts of a fibrous character. There are also some small particles detached at the surface. This could be the result of an occurrence of a corrosive reaction between the sample surface and NaOH solution.
Effect of fillers on fire retardancy of intumescent polypropylene blends
Authors: Almeras X. , Le Bras M. , Poutch F. , Bourbigot S. , Marosi G. , Anna P.
Published: August 2003

Addition of Ammonium Polyphosphate/Polyamide‐6 system is known to provide flame retardancy in many polymers blends via an intumescent process. Particulate fillers (talc and calcium carbonate) are used in large quantities in PP. Combination of fillers in PP can modify the properties of the polymeric matrix. This study investigates the effect of fillers (talc and calcium carbonate) on the fire performance of the Polypropylene/Ammonium polyphosphate/Polyamide‐6 blend. It is shown that the fire performance strongly depends on the nature of the filler used. Talc increases and calcium carbonate decreases in the fire performance of the blend.
Water sorption and electrical/dielectric properties of organic‐inorganic polymer blends
Authors: Mamunya Yevgen , Kanapitsas Athanasios , Pissis Polycarpos , Boiteux Gisele , Lebedev Eugene
Published: August 2003

Organic‐inorganic polymer blends (OIPB) were obtained by reaction of organic and inorganic oligomers. The organic oligomer was synthesized with 2,4‐toluene diisocyanate (TDI) and oligooxypropylene glycols (OPG) with various molecular weights (MW). The inorganic component was a water solution of sodium silicate. The OIPB obtained are hydrophilic and have great water sorption ability (the relative weight of sorbed water reaches 2000 %). The kinetics of water sorption and the changes of electrical conductivity during sorption were studied. Sorption ability, and mechanical, electrical and dielectric properties of OIPB depend on molecular weight of OPG: conductivity increases with increasing MW, whereas the sorption ability correlates with the mechanical properties. The influence of the inorganic phase content on the electrical and dielectric properties was studied as well.
Structure and dielectric properties of a thermoplastic blend containing dispersed metal
Authors: Zois Haralampos , Mamunya Yevgen P. , Apekis Lazaros
Published: August 2003

In the present work broadband dielectric relaxation spectroscopy measurements were employed to investigate the dielectric properties of polymer composites. A polyethylene/polyoxymethylene (PE/POM) thermoplastic blend was used as a matrix, while the inclusions were iron (Fe) particles. For comparison, the two pure polymers‐ PE and POM‐ were used as a matrix, too. In the PE/POM‐Fe composites, the polymer matrix is two‐phase and the filler particles are localized only in the POM phase, resulting in an ordered distribution of the dispersed filler particles within the blend. In PE‐Fe and POM‐Fe composites, the filler spatial distribution is random. The behaviour of all the composites studied is described in terms of the percolation theory. The PE/POM‐Fe composites, based on the PE/POM blend, demonstrate different electrical behaviour compared to that of POM‐Fe and PE‐Fe systems. The percolation threshold value of the PE/POM‐Fe composites was found much lower than that of the other two systems. The results were related to the microstructure of the composites. A schematic model for the morphology of the composites studied has been proposed. This model explains the peculiar behaviour of the PE/POM‐Fe composites by taking into account the ordered distribution of the filler particles in a binary polymer matrix. Optical microscopy photographs confirm this model.
Characterization of extruded ethylene‐vinyl alcohol copolymer based barrier blends with interest in food packaging applications
Authors: Lagarón J.M. , Giménez E. , Altava B. , Del‐Valle V. , Gavara R.
Published: August 2003

Based on previous work a number of optimum extruded blends with high contents of a high barrier ethylene‐vinyl alcohol copolymer were selected and characterized in terms of phase morphology, water sorption and barrier properties. Blend components were an ethylene vinyl‐alcohol copolymer (EVOH with 32 mol% ethylene), an amorphous polyamide (aPA) and a nylon‐containing ionomer. A fine two phase structure was found for these blends in all cases. However, Raman spectroscopy results indicated a poor interface interaction between the blend components in the case of the EVOH/aPA blends. Higher interface interaction had been previously found in the dry EVOH/ionomer blends. Equilibrium moisture solubility and diffusion were found to be higher than expected from simple additivity. However, the oxygen transmission rate was found to be clearly lower than expected from the rule of mixtures, particularly under dry conditions, fitting closely a simple Maxwell model.
Androgen‐independent expression of adrenomedullin and peptidylglycine α‐amidating monooxygenase in human prostatic carcinoma
Authors: Jiménez Nuria , Abasolo Ibane , Jongsma Johan , Calvo Alfonso , Garayoa Mercedes , van der Kwast Theodorus H. , van Steenbrugge Gert J. , Montuenga Luis M.
Published: August 2003

Most of the locally advanced and metastatic prostate carcinomas (PCs) treated with antiandrogenic therapy eventually become refractory to this treatment. Locally produced factors may control prostate tumor biology after androgen withdrawal. Adrenomedullin (AM) is expressed in the prostate and could control cell growth in androgen‐independent conditions. AM needs to be amidated by the enzyme peptidylglycine α‐amidating monooxygenase (PAM) to become fully active. The objective of the present study was to analyze whether the expression of preproadrenomedullin (preproAM) and PAM in PC is regulated by androgens. For this purpose, human in vitro and in vivo PC models were grown in the presence or absence of androgens, and the expression of AM and PAM was examined by immunohistochemistry, Western blotting, RT‐PCR, and Northern blotting. Furthermore, immunohistochemical analysis of AM in clinical specimens was performed to test if its expression is related to Gleason score and antiandrogenic therapy. In PC cell lines and xenografts, mRNA and protein AM levels were similar in the presence or absence of androgens. PAM expression seemed to be induced by androgen‐withdrawal. Our results in clinical samples showed no relationship between AM expression and Gleason score or antiandrogenic treatment. In conclusion, our results demonstrate that preproAM and PAM expression in the human prostate is androgen‐independent. In addition, we also report for the first time the expression of a novel PAM transcript in PC, which has not been previously described in other tissues. © 2003 Wiley‐Liss, Inc.
Chemotherapeutic efficacy of topical celecoxib in a murine model of ultraviolet light B–induced skin cancer
Authors: Wilgus Traci A. , Koki Alane T. , Zweifel Ben S. , Rubal Patricia A. , Oberyszyn Tatiana M.
Published: August 2003

Over a million nonmelanoma skin cancer cases will be reported in the United States this year alone. Currently the primary form of treatment for these types of skin tumors is excision. However, excision of the initial lesion may not be curative because almost 50% of patients with one nonmelanoma skin cancer lesion develop another tumor within the next 5 yr at the site or adjacent to the site of excision. As with other types of epithelial based cancers, there is mounting evidence for the role of cyclooxygenase‐2 (COX‐2) and its products, particularly prostaglandin E2 (PGE2), in the development of nonmelanoma skin cancer. To avoid the excision process, the present study was designed to evaluate the possible chemotherapeutic effect of directly treating established tumors with a topical formulation of the specific COX‐2 inhibitor celecoxib. Skh/hr hairless mice were irradiated three times per wk for 16 wk to induce tumor formation. The mice were then divided into two groups and treated topically with either 500 μg celecoxib or the vehicle for 6 wk. Our results demonstrated that although topical treatment with celecoxib was not able to induce regression of established tumors, it did prevent new tumor formation after the onset of photocarcinogenesis. Although further studies are warranted, these data suggest that topical celecoxib treatment may prove to be effective in preventing the recurrence of tumors at the site of nonmelanoma skin cancer excision. © 2003 Wiley‐Liss, Inc.
Promyelocytic leukaemia (PML) protein expression in human placenta and choriocarcinoma
Authors: Kim Chong Jai , Yoon Bo Hyun , Jun Jong Kwan , Park Jung Ok , Cho So Young , Romero Roberto , Kim Yeon Mee , Yu Eun‐Sil
Published: August 2003

Promyelocytic leukaemia (PML) protein, the product of the pml gene, is heterogeneously expressed in various normal and neoplastic tissues, and the fusion of the pml gene with retinoic acid receptor‐α is believed to be a central mechanism in acute PML tumourigenesis. As PML is important for controlling major cellular processes, such as growth and differentiation, it is believed that it plays an important role during human gestation. The human placenta is a critical organ for the maintenance of gestation, but the expression pattern and functional significance of PML in the placenta have not been documented. The present study has therefore investigated the expression of PML in the human placenta and in choriocarcinoma, and has observed the biological effects following the overexpression of PML in choriocarcinoma cell lines (BeWo and JEG‐3). In the human placenta, PML expression was readily found in villous stromal fibroblasts, capillary endothelial cells, Hofbauer cells, and occasionally in amnion cells. Moreover, immunoblotting of placental lysates demonstrated increased PML expression with increasing gestation. Interestingly, PML expression was confined to intermediate trophoblasts and syncytiotrophoblastic giant cells at the placental site (placental site giant cells) in the trophoblastic cell population. Intermediate trophoblasts at non‐placental sites, and villous cytotrophoblasts and syncytiotrophoblasts consistently did not express PML. Further screening of PML expression in hydatidiform moles (n = 4) and choriocarcinomas (n = 7) also revealed selective PML expression in intermediate trophoblastic cells and syncytiotrophoblastic cells, but not in the cytotrophoblastic populations, which corresponds well with observations in the placental bed. Adenoviral transduction of PML resulted in a marked reduction in cell growth in both choriocarcinoma cell lines, which was associated with increased apoptosis. The findings of the present study strongly suggest that PML plays an important role in human placental development and growth, and in the pathobiology of trophoblasts and trophoblastic neoplasia. Copyright © 2003 John Wiley & Sons, Ltd.
Differential expression of telomerase activity in neuroendocrine lung tumours: correlation with gene product immunophenotyping
Authors: Zaffaroni Nadia , De Polo Daniela , Villa Raffaella , Della Porta Chiara , Collini Paola , Fabbri Alessandra , Pilotti Silvana , Daidone Maria Grazia
Published: August 2003

Telomerase activity was examined by the telomeric repeat amplification protocol (TRAP) assay in 38 neuroendocrine (NE) lung tumours. A significantly (p = 0.001) different frequency of telomerase positivity was observed among different histological tumour types. Specifically, a positive TRAP signal was observed in 14 of 15 (93%) small cell lung cancers (SCLCs), 7 of 8 (87%) large‐cell NE carcinomas (LCNECs), and only 1 of 15 (7%) typical carcinoid tumours. When telomerase activity was correlated with the gene product‐based immunophenotypic profile of individual tumours, it was found that the absence of telomerase activity was associated with a lack of bcl‐2, p53, and c‐kit expression, and characterized by a low proliferation index consistent with the absence of cdk‐4 expression and the presence of the cdk inhibitor Rb. Such a phenotype was appreciable in most of the carcinoid tumours. Conversely, telomerase‐positive tumours generally showed an immunophenotype consistent with gene product alterations (including high expression of bcl‐2, p53, and c‐kit, and loss of Rb) and were characterized by a high proliferation index. These telomerase data support the previously reported evidence for two genetically unrelated groups of NE lung tumours (SCLC, and to some extent LCNEC, versus carcinoid tumours) that have distinct phenotypic profiles. Copyright © 2003 John Wiley & Sons, Ltd.
Imbalanced secondary mucosal antioxidant response in inflammatory bowel disease
Authors: Kruidenier Laurens , Kuiper Ineke , van Duijn Wim , Mieremet‐Ooms Marij AC , van Hogezand Ruud A , Lamers Cornelis BHW , Verspaget Hein W
Published: August 2003

Intestinal mucosal damage in the inflammatory bowel diseases (IBD) Crohn's disease (CD) and ulcerative colitis (UC) involves reactive oxygen metabolites (ROMs). ROMs are neutralized by endogenous antioxidant enzymes in a carefully balanced two‐step pathway. Superoxide dismutases (SODs) convert superoxide anion to hydrogen peroxide (H2O2), which is subsequently neutralized to water by catalase (CAT) or glutathione peroxidase (GPO). Remarkably changed expression levels of the three isoforms of SOD in paired non‐inflamed and inflamed mucosae from CD and UC patients have been previously reported in comparison to normal control mucosa. Most notable was the strong up‐regulation of Mn‐SOD in inflamed epithelium. It was hypothesized that in order to provide optimal protection against ROM‐mediated damage, these changes should be coordinately counterbalanced by an increased H2O2‐neutralizing capacity. Therefore, the same tissue samples were used to assess the levels, activities, and/or localization of the most prominent mucosal H2O2‐related antioxidants CAT, GPO, glutathione (GSH), myeloperoxidase (MPO), and metallothionein (MT). Quantitative measurements showed that in both CD and UC patients, intestinal inflammation was associated with increased activities of CAT, GPO, and MPO, whereas the mucosal GSH content was unaffected and the concentration of MT was decreased. Despite this overall increase in mucosal H2O2‐metabolizing enzyme capacity, immunohistochemical analysis revealed a differentially disturbed antioxidant balance in IBD epithelium and lamina propria. In the lamina propria, the risk of direct H2O2‐mediated damage seemed to be restrained by the increasing numbers of CAT‐ and MPO‐positive monocytes/macrophages and neutrophils that infiltrated the inflamed areas. On the other hand, MPO overexpression might increase the lamina propria levels of hypochlorous acid, a stable ROM with multiple pro‐inflammatory effects. In the epithelium, the number of cells that expressed CAT remained unchanged during inflammation and GPO was found in only a very low and constant number of epithelial cells. In addition, the inflamed epithelium displayed decreased expression of the hydroxyl radical (OH•) scavenger MT. In view of the high epithelial SOD levels in inflamed IBD epithelium, it is speculated that the efficient removal of excess H2O2 is hampered in these cells, thereby increasing not only the risk of detrimental effects of H2O2 directly, but also those of its extremely reactive derivatives such as OH•. Taken together, the results suggest an imbalanced and inefficient endogenous antioxidant response in the intestinal mucosa of IBD patients, which may contribute to both the pathogenesis and the perpetuation of the inflammatory processes. Copyright © 2003 John Wiley & Sons, Ltd.
Respective roles of porto‐septal fibrosis and centrilobular fibrosis in alcoholic liver disease
Authors: Michalak Sophie , Rousselet Marie‐Christine , Bedossa Pierre , Pilette Christophe , Chappard Daniel , Oberti Frédéric , Gallois Yves , Calès Paul
Published: August 2003

In alcoholic liver disease, fibrosis classically begins around the centrilobular veins, while portal tract fibrosis is described as inconstant and septal fibrosis is a late event. The aim of this study was to compare the roles of centrilobular fibrosis (CLF) and portal tract/septal fibrosis (PTF) especially in alcoholic chronic liver disease. One hundred and sixty patients with alcoholic chronic liver disease and 83 controls with viral chronic hepatitis were included. The PTF score, derived from the Metavir score, CLF and the area of fibrosis, assessed by image analysis, were evaluated on liver biopsies in addition to blood markers of fibrosis. The correlation between the PTF score and the area of fibrosis was higher in alcoholic liver disease (r = 0.87, p < 10−4) than in viral chronic hepatitis (r = 0.66, p < 10−4). The PTF score correlated with the CLF score (r = 0.92, p < 10−4), serum hyaluronate (r = 0.76, p < 10−4), and the prothrombin index (r = −0.77, p < 10−4). Multiple regression analyses showed that the area of fibrosis was explained only by the PTF score and not by the CLF score. PTF appears more frequent than CLF in alcoholic chronic liver disease, suggesting that PTF may precede CLF. PTF is more responsible for the amount of fibrosis than CLF. The results of this study also validate the use of the Metavir fibrosis score in alcoholic chronic liver disease. Copyright © 2003 John Wiley & Sons, Ltd.
Platelet‐derived growth factor and its receptors are related to the progression of human muscular dystrophy: an immunohistochemical study
Authors: Zhao Yajuan , Haginoya Kazuhiro , Sun Guilian , Dai Hongmei , Onuma Akira , Iinuma Kazuie
Published: August 2003

This study has examined the immunological localization of platelet‐derived growth factor (PDGF)‐A, PDGF‐B, and PDGF receptor (PDGFR) alpha and beta to clarify their role in the progression of muscular dystrophy. Biopsied frozen muscles from patients with Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and congenital muscular dystrophy (CMD) were analysed immunohistochemically using antibodies raised against PDGF‐A, PDGF‐B, and PDGFR alpha and beta. Muscles from two dystrophic mouse models (dy and mdx mice) were also immunostained with antibodies raised against PDGFR alpha and beta. In normal human control muscle, neuromuscular junctions and vessels were positively stained with antibodies against PDGF‐A, PDGF‐B, PDGFR alpha and PDGFR beta. In human dystrophic muscles, PDGF‐A, PDGF‐B, PDGFR alpha and PDGFR beta were strongly immunolocalized in regenerating muscle fibres and infiltrating macrophages. PDGFR alpha was also immunolocalized to the muscle fibre sarcolemma and necrotic fibres. The most significant finding in this study was a remarkable overexpression of PDGFR beta and, to a lesser extent, PDGFR alpha in the endomysium of DMD and CMD muscles. PDGFR was also overexpressed in the interstitium of muscles from dystrophic mice, particularly dy mice. Double immunolabelling revealed that activated interstitial fibroblasts were clearly positive for PDGFR alpha and beta. However, DMD and CMD muscles with advanced fibrosis showed very poor reactivity against PDGF and PDGFR. Those findings were confirmed by immunoblotting with PDGFR beta. These findings indicate that PDGF and its receptors are significantly involved in the active stage of tissue destruction and are associated with the initiation or promotion of muscle fibrosis. They also have roles in muscle fibre regeneration and signalling at neuromuscular junctions in both normal and diseased muscle. Copyright © 2003 John Wiley & Sons, Ltd.
Molecular alterations in pancreatic carcinoma: expression profiling shows that dysregulated expression of S100 genes is highly prevalent
Authors: Crnogorac‐Jurcevic Tatjana , Missiaglia Edoardo , Blaveri Ekaterina , Gangeswaran Rathi , Jones Melanie , Terris Benoit , Costello Eithne , Neoptolemos John P , Lemoine Nicholas R
Published: August 2003

In order to expand our understanding of the molecular changes underlying the complex pathology of pancreatic malignancy, global gene expression profiling of pancreatic adenocarcinoma compared with normal pancreatic tissue was performed. Human cDNA arrays comprising 9932 elements were interrogated with fluorescence‐labelled normal and adenocarcinoma samples (nine tumours, three normal pancreata, and three cell lines). The data were analysed for differential gene expression, which was confirmed by serial analysis of gene expression (SAGE), digital differential display (DDD) analysis, and immunohistochemistry for selected cases. The array data were filtered to produce lists of a total of 75 genes significantly up‐regulated or down‐regulated in pancreatic adenocarcinoma. Two of those showing the highest differential were members of the S100 family of Ca‐binding proteins, namely S100P and S100A6, and therefore the S100 genes were studied in more detail. By immunohistochemical analysis of custom‐built, pancreas‐specific tissue arrays and commercially available, normal/cancer tissue arrays that included a wide variety of different tumour types, differential expression of S100P protein was found to be almost exclusive to pancreatic cancer. S100P could therefore represent a useful biomarker for pancreatic adenocarcinomas. Copyright © 2003 John Wiley & Sons, Ltd.
Consulting about lifestyle change: Evaluation of a training course for specialist diabetes nurses
Authors: Lane C , Johnson S , Rollnick S , Edwards K , Lyons M
Published: August 2003

The National Service Framework (NSF) for Diabetes highlights the importance of sharing decision making with patients when helping them to adopt and maintain a healthy lifestyle. It was felt that this shift in focus with the development of a more patient‐centred approach would require the teaching of new skills to health care professionals. The Communication Skills Unit in Cardiff worked with the local Diabetes Unit to design a training programme that allows professionals to develop their skills in behaviour change counselling. The nurse specialists in the Diabetes Unit were very involved in talking to patients about lifestyle issues, and yet they had little or no previous communication skills training.

A pilot course was designed, in which four audiotaped simulated consultations were conducted before and after two seminars led by an expert in behaviour change counselling. The consultations were carried out in six nurses' normal clinical settings to ensure a truer representation of a normal consultation. The results showed that initially most participants were using a didactic and nurse‐centred approach when offering lifestyle advice. Following the course, all the nurses were using skills that were more aligned with behaviour change counselling, and interviews afterwards revealed that the course was acceptable and enjoyable. This pilot study provides the rationale for paying closer attention to practitioner skill acquisition before examining the efficacy of behaviour change counselling for improving lifestyles among those with chronic diseases like diabetes. Copyright © 2003 John Wiley & Sons, Ltd.
The adherence of type 2 diabetes patients to their therapeutic regimens: a qualitative study from the patient's perspective
Authors: Vermeire E , Van Royen P , Coenen S , Wens J , Denekens J
Published: August 2003

In chronic diseases such as type 2 diabetes, adherence to treatment is a major public health problem, seriously undercutting the benefits of medical care. Many studies have assessed factors associated with compliance, but the patient perspective is remarkably absent. From these studies, it seems that the patient's role in the process of adhering was to be passive and since the prescriber's view was rational and based on scientific research, it may have been assumed to be superior to the patient's beliefs and wishes. This paper reports on type 2 diabetes patients' health beliefs in relation to their illness, their communication with caregivers and the problems encountered in adhering to treatment regimens.

Seven focus groups were held for type 2 diabetes patients recruited by pharmacists in primary care in Flanders, Belgium. These groups focussed on participants' experience of their treatment. Possible explanatory models were generated by qualitative content analysis of the focus group discussions.

Forty‐six patients recruited from primary care participated in six semi‐structured group discussions. The data demonstrate that health beliefs, the quality of doctor/patient communication, and the quality of the information patients receive are important factors for patient adherence to treatment. Possible explanatory models for adherence emerged, relating to knowledge of the illness, body awareness and the doctor/patient relationship.

This qualitative research identified explanatory models for adhering to medical treatment from the patient's perspective. Interventions designed to enhance adherence should address the patient perspective using these models in order to maximise effectiveness. Copyright © 2003 John Wiley & Sons, Ltd.
Advantages of training Asian diabetes support workers for Asian families and diabetes health care professionals
Authors: Curtis S , Beirne J , Jude E
Published: August 2003

Local consultation with Asian groups and community members in Tameside, Greater Manchester during 1999 on issues around diabetes identified barriers towards optimal self‐care. Six local Asian trainees were recruited in male and female cultural pairs (Bangladeshi, Indian and Pakistani) to participate in a modular Asian Diabetes Support Worker training programme. The training was accredited with Greater Manchester Open College Network, in association with Tameside College, at NVQ Levels 2 and 3. The Asian Diabetes Support Worker Service was evaluated from patient/family and health professional perspectives 12 months after referrals began to be accepted by the team. This article describes the process and outcomes of the service and discusses plans to improve its utilisation. Copyright © 2003 John Wiley & Sons, Ltd.
Capacity building in human service organizations
Authors: Jones Robert B.
Published: August 2003

The health and vitality of the human service sector will be shaped much less by external trends and crises and much more by the ability of boards and executives to develop new visions of leadership and organizational capacity.
Higher education consortia: Raising aspirations through collaboration
Authors: Horgan Thomas R.
Published: August 2003

Higher education consortia offer colleges and universities opportunities to improve services, quality, and resources for the benefit of their students, faculties, and staffs. This chapter explores several components necessary for collaborative ventures to succeed
Positive correlation between single or combined genotypes of CYP1A1 and GSTM1 in relation to prostate cancer in Chilean people
Authors: Acevedo Cristian , Opazo Jose Luis , Huidobro Christian , Cabezas Juan , Iturrieta Jeannette , Quiñones Sepúlveda Luis
Published: August 2003

BACKGROUND

The prostate cancer is a slowly progressing disease that begins decades prior to diagnosis. It has been suggested that there might be differences in susceptibility due to genetic polymorphisms in biotransformation enzyme genes. In the present work, associations between CYP1A1(Msp1), GSTM1(−/−) polymorphisms, and prostate cancer were analyzed in a case‐control study.

METHODS

Genomic DNA was isolated from peripheral blood samples, collected on EDTA. PCR‐RFLP was used to determine simultaneously Msp1 and GSTM1(−/−) polymorphisms.

RESULTS

In cancer patients, frequency of m2 variant allele (0.377) and GSTM1(−/−) (0.362) showed statistically significant increases compared to the control group (0.262 and 0.227, respectively). The estimate relative risks (OR) were higher for individuals carrying combined CYP1A1 and GSTM1 rare genotypes, in relation to individuals carrying CYP1A1 or GSTM1 alone. Multivariate logistic regression analysis including confounding factors (age, digital examination, and PSA antigen) showed even higher risk for individuals carrying m2m2 genotype (OR = 3.99; 95% CI, 1.27–12.54), GST(−/−) genotype (OR = 2.75; 95% CI, 1.31–5.79), and m2m2/GST(−) genotype (OR = 16.63; 95% CI, 1.67–165.48).

CONCLUSIONS

Taken together, these findings suggest that Chilean people carrying single or combined GSTM1 and CYP1A1 polymorphisms are more susceptible to prostate cancer. Prostate 57: 111–117, 2003. © 2003 Wiley‐Liss, Inc.
Adrenergic regulation of the intracellular [Ca2+] and voltage‐operated Ca2+ channel currents in the rat prostate neuroendocrine cells
Authors: Kim Jun Hee , Shin Sun Young , Nam Joo Hyun , Hong Eun‐Kyung , Chung Young‐Shin , Jeong Jeong Yun , Kang Jeongyoon , Uhm Dae‐Yong , Kim Sung Joon
Published: August 2003

BACKGROUND

The prostate gland contains numerous neuroendocrine cells (PNECs) innervated by adrenergic neurons. PNECs are believed to influence the growth and physiological function of the prostate gland via paracrine release of hormones.

MATERIALS AND METHODS

Using fura‐2 fluorescence measurement and patch‐clamp techniques, we investigated the effects of adrenergic stimulation on cytosolic concentration of Ca2+ ([Ca2+]c) and high voltage‐activated Ca2+ channel currents (HVA‐ICa) of the putative rat prostate neuroendocrine cells (RPNECs) freshly isolated by an enzymic digestion.

RESULTS

Noradrenaline (NA, 1 μM) induced a sharp, transient increase of [Ca2+]c measured by the fura‐2 fluorescence. Pharmacological studies showed that α1‐adrenoceptors (α1‐ARs) coupled with PLC/IP3 signaling pathway induce the release of stored Ca2+, which subsequently recruits store‐operated Ca2+ entry pathways. In the whole‐cell voltage clamp experiment, NA decreased the amplitude of HVA‐ICa by 40%, which was mimicked by an α2‐AR agonist (UK14304) but not by an α1‐AR agonist (phenyleprine). After selective blockade of N‐type Ca2+ channels by ω‐conotoxin GVIA, the addition of NA showed no further inhibition on the remaining L‐type Ca2+ channel currents. The adrenergic inhibition of HVA‐ICa was partially prevented by the pretreatment with pertussis toxin (PTX) (5 μg/ml, 4 hr, 37°C).

CONCLUSIONS

RPNECs express both α1‐ and α2‐ARs, signaling the release of stored Ca2+ and the inhibition of N‐type Ca2+ channels, respectively. Prostate 57: 99–110, 2003. © 2003 Wiley‐Liss, Inc.
Early detection of prostate cancer with low PSA cut‐off values leads to significant stage migration in radical prostatectomy specimens
Authors: Berger Andreas P. , Spranger Robert , Kofler Kurt , Steiner Hannes , Bartsch Georg , Horninger Wolfgang
Published: August 2003

BACKGROUND

The introduction of prostate‐specific antigen (PSA) contributed to a shift in tumor stage at diagnosis in patients with prostate cancer. The aim of the present study was to evaluate the effects of PSA screening with low PSA cut‐off values on mean total and percent‐free PSA levels in patients with prostate cancers at the time of diagnosis as well as on pathologic stage and mean Gleason scores in positive biopsies and radical prostatectomy specimens.

METHODS

Data of 875 patients who were diagnosed with prostate cancers between 1996 and 2001 were analyzed. Patients were stratified into six groups according to the year of biopsy. Annual changes in total and percent‐free PSA values, in Gleason scores of biopsies and radical prostatectomy specimens, and in pathologic stages of radical prostatectomy specimens were assessed.

RESULTS

Mean PSA of patients diagnosed with prostate cancer decreased from 13.11 ng/ml (percent‐free PSA: 11.89%) in 1996 to 7.33 ng/ml (percent‐free PSA: 12.58%) in 2001 (P < 0.05). The percentage of organ‐confined prostatectomy specimens increased from 64.3% in 1996 to 81.5% in 2001 (P < 0.05). However, mean Gleason scores increased from 5.23 to 6.33 over the 6 years (P < 0.05). The percentage of patients with biopsy‐proven prostate cancers and PSA values below 4 ng/ml increased from 14.0% in 1996 to 39.2% in 2001. In the group with PSA values below 4 ng/ml organ‐confined cancers were found in 80.0–95.2% of patients.

CONCLUSIONS

PSAg screening with low cut‐off levels has led to a significant reduction of mean baseline PSA levels in prostate cancer patients and to a significant increase in the percentage of organ‐confined radical prostatectomy specimens, whereas mean Gleason scores have remained relatively constant. Prostate 57: 93–98, 2003. © 2003 Wiley‐Liss, Inc.
TR2 orphan receptor functions as negative modulator for androgen receptor in prostate cancer cells PC‐3
Authors: Mu Xiaomin , Chang Chawnshang
Published: August 2003

BACKGROUND

Both androgen receptor (AR) and orphan receptor TR2 (TR2) belong to the steroid nuclear receptor superfamily and are expressed in prostate cancer tissue and cell lines. AR has been known to be involved in prostate proliferation and prostate cancer progression. AR binds to androgen response elements and regulates target gene expression via a mechanism involving coregulators. However, the function of TR2 in prostate and prostate cancer and the relationship between TR2 and AR in the prostate cancer is unclear.

METHODS

Transient transfection and CAT reporter gene assays were employed to assess AR‐mediated transactivation. The expression level of prostate specific antigen (PSA) was measured by Northern blot analysis. The interaction between AR and TR2 was assessed by glutathione‐S‐transferase (GST) pull‐down assay and mammalian two‐hybrid system assay.

RESULTS

Orphan nuclear receptor TR2 suppressed androgen‐mediated transactivation in prostate cancer PC‐3 cells, and over‐expression of TR2 suppressed PSA expression. The suppression of AR mediated transactivation by TR2 is not due to competition for the limited coregulator availability by these two receptors, but possibly through the interaction between TR2 and AR nuclear receptors.

CONCLUSIONS

TR2 may function as a negative modulator to suppress AR function in prostate cancer. Further studies on how to control TR2 function may result in the ability to modulate AR function in prostate cancer. Prostate 57: 129–133, 2003. © 2003 Wiley‐Liss, Inc.
Effect of carbohydrate moieties on the folate hydrolysis activity of the prostate specific membrane antigen
Authors: Ghosh Arundhati , Heston Warren D.W.
Published: August 2003

BACKGROUND

Prostate specific membrane antigen or PSMA has been recognized as one of the important cellular markers for prostate cancer, the expression of which is enhanced many fold in prostate cancer and other tumor neovasculature. PSMA is a type II membrane glycoprotein with a short cytoplasmic N‐terminal region, a transmembrane domain, and a 701 amino acid extracellular portion with 10 potential N‐linked glycosylation sites. PSMA is a folate hydrolase, which cleaves terminal glutamates from poly‐ and gamma‐glutamated folates; and NAALADase, which hydrolyses alpha‐glutamate‐linked dipeptide, N‐acetyl‐aspartyl‐glutamate (NAAG) and is a glutamate carboxypeptidase.

METHODS

In our study we have used various enzymes or site directed mutagenesis to remove sugar molecules from PSMA protein and studied its folate hydrolase function. We have performed a biochemical characterization of N‐linked glycosylation of the various mutant proteins.

RESULTS

PSMA protein expressed in different prostate cancer cell lines is differentially glycosylated. Removal of sugar residues either enzymatically or by mutagenesis abolishes the enzyme activity of PSMA protein completely.

CONCLUSION

N‐linked carbohydrate structures are important for the folate hydrolase function of the protein. Removal of sugars partially or completely causes PSMA to be enzymatically inactive, improperly folded, resulting in increased rate of degradation. Prostate 57: 140–151, 2003. © 2003 Wiley‐Liss, Inc.
Electronic properties of the metallic zigzag single‐walled carbon nanotube ropes
Authors: Chen Jiangwei , Wan Xiangang , Dong Jinming
Published: August 2003

Using Slater–Koster tight‐binding calculations, we found that, due to the coexistence of the π–σ electron hybridization and the inter‐tube interactions, the electronic properties of the rope formed by small‐radius metallic zigzag single‐walled carbon nanotubes (SWNTs) have some unique characters: for the rope formed by (9,0) SWNTs, its electronic properties near the Fermi level are mainly affected by the π–σ electron hybridization; and for the rope formed by (12,0) SWNTs, both factors affect the electronic properties significantly. With increasing SWNT radius, the effect of the π–σ electron hybridization decreases quickly. Finally, boundary effects of the finite sized rope have also been investigated, which reduce the pseudogap generally.
Temperature and pressure dependence of phonon frequencies in GeS2, GeSe2, and SnGeS3
Authors: Jakšić Z. M.
Published: August 2003

The Raman spectra of β‐GeS2, β‐GeSe2, and SnGeS3 crystals have been investigated as a function of temperature (18 to 300 K) at ambient pressure, and as a function of hydrostatic pressure, up to 4.9 GPa, at room temperature. Our aim was to separate the phonon–excitation–driven (“explicit”) and the thermal–expansion–driven (“implicit”) contribution to the total observed temperature coefficient (dν/dT). β‐GeS2 exhibits a regular behavior: when its “external” modes are excited the coefficient is dominated by the implicit effect, while in the case of excited “internal” modes by the explicit effect. In the cases of β‐GeSe2 and SnGeS3 a clear separation into external and internal modes was not possible, as in the case of β‐GeS2. For β‐GeSe2 the explicit–implicit contributions to (dν/dT) were determined for five “internal” modes. For most of the modes in SnGeS3 “explicit” and “implicit” contributions to (dν/dT) are of comparable magnitude.
Classical limit for electronic disordered systems: spectral tails and thermodynamical properties
Authors: Flores J. C.
Published: August 2003

We consider the classical limit for the density of states of an electron in a disordered one‐dimensional chain. The low energy tail of the density of states is analytically studied and we evaluate the thermodynamical properties of this system. For the Boltzmann distribution the heat capacity grows when disorder increases. On the other hand in the quantum case, corresponding to the Fermi‐Dirac statistic, the heat capacity diminishes when disorder increases.