bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer hybrids with functionalized silsesquioxanes via two physical interactions in one system
Authors: Kim Kyung‐Min , Chujo Yoshiki 
Published: March 2003

AbstractTransparent and homogeneous polymer hybrids were obtained from a series of random styrene/N,N‐dimethylacrylamide copolymers (PSnPAm) and octa(3‐hydroxypropyldimethylsiloxy)octasilsesquioxane (Cube‐OH) by means of the sol–gel reaction of phenyltrimethoxysilane (PTMOS). The resulting ternary polymer hybrids were prepared via two simultaneous physical interactions [hydrogen‐bonding and aromatic (π–π) interactions] in one system. Cube‐OH and PTMOS were used to form hydrogen‐bonding and aromatic (π–π) interactions, respectively, with the organic copolymer. When PS90PA10 was used as an organic polymer for the two physical interactions, the transparency was maintained when the weight ratio of Cube‐OH to PTMOS was increased to 0.5. However, the polymer hybrids with PS65PA35 produced optically translucent or turbid materials, which indicated the phase separation of the organic polymer and silica gel. The homogeneity of the ternary polymer hybrids was dependent on the balance between the intensity of the hydrogen‐bonding interaction and that of the aromatic (π–π) interaction. The homogeneity was supported by the results of Fourier transform infrared, differential scanning calorimetry, scanning electron microscopy, and X‐ray diffraction, which demonstrated a nanometer‐level integration of the organic polymer, Cube‐OH, and silica gel. The initial decomposition temperature of the ternary polymer hybrids was more dependent on the amount of PTMOS than on that of Cube‐OH. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1306–1315, 2003
Hyperbranch‐polyethyleniminated functional polymers. I. Synthesis, characterization of novel ABA type of dumbbell‐like polyethyleniminated polyoxypropylenediamines, and their complexing properties with copper(II) ions in aqueous solution
Authors: Kuo Ping‐Lin , Liang Wuu‐Jyh , Wang Fu‐Yu 
Published: March 2003

AbstractNovel ABA‐type dumbbell‐like water‐soluble copolymers [D230(EI)4, D400(EI)4, and D400(EI)8] were synthesized by introducing ethylenimine (EI) groups into both sides of polyoxypropylenediamines via a simple in situ ethylamination of polyoxypropylenediamine with 2‐chloroethylamine hydrochloride. The structures of the resultant polymers were identified by Fourier transform infrared spectroscopy and 1H NMR. The percentages of primary, secondary, and tertiary amine present were determined by the potentiometric titration method after treatments with the appropriate chemicals of salicylaldehyde and acetic anhydride. The surface tension and solubilizing behavior of pyrene in the presence of these polymers in aqueous medium were also investigated, and the efficiency to reduce the surface tension and solubilizing behavior of pyrene depends on the attachments of EI to polymer backbone. The chelating properties of these polymers were examined quantitatively by ultraviolet–visible (UV–vis) spectroscopy in the presence of Cu2+ ions in aqueous solution, and continuous variation analysis revealed that the most stable complex is formed at the normality ratio of [N]/[Cu2+] = 3.0. UV–vis spectroscopy and transmission electron microscopy were used to evaluate the dumbbell‐like water‐soluble copolymer, D400(EI)8, as a stabilizer for preparing colloidal noble metal nanoparticles (Au and Pt) in aqueous solution. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1360–1370, 2003
Latex particles bearing hydrophilic grafted hairs with controlled chain length and functionality synthesized by reversible addition–fragmentation chain transfer
Authors: D'Agosto Franck , Charreyre Marie‐Thérèse , Pichot Christian , Gilbert Robert G. 
Published: March 2003

AbstractA method is described for synthesizing latex particles with anchored hairs by the grafting of hydrophilic chains, synthesized by reversible addition–fragmentation chain transfer, onto functionalized latex particles. These have the potential to bind biologically active species. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1188–1195, 2003
Synthesis, characterization, and mechanism studies on novel rare‐earth calixarene complexes initiating ring‐opening polymerization of 2,2‐dimethyltrimethylene carbonate
Authors: Ling Jun , Shen Zhiquan , Zhu Weipu 
Published: March 2003

AbstractRare‐earth (Nd, Y) p‐tert‐butylcalix[n]arene (n = 4, 6, and 8) complexes without coligands were synthesized from rare‐earth isopropoxides in toluene. The products were characterized as the following structures: [C4(OH)O3 · CH3C6H5]Nd (4), [C6(OH)2O4 · CH3C6H5]3Ln4 [Ln = Nd (5), Y (6)], and [C8(OH)2O6 · CH3C6H5]Nd2 (7). 2,2‐Dimethyl trimethylene carbonate (DTC) can be polymerized with complexes 4–7 alone as the initiator. PolyDTC (weight‐average molecular weight: 5700, polydispersity index: 1.11, measured by gel permeation chromatography) initiated by complex 5 was obtained with a conversion of 69.1% within 6 h in toluene at 80 °C. The thermal behavior of polyDTC has been compared with the published data. The DTC ring is opened via acyl‐oxygen bond cleavage with end‐group examination. NMR analyses of the polymerization reaction mixture indicated that the polymerization proceeds via a coordination‐insertion mechanism. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1390–1399, 2003
A Multi‐Electrode Approach for On‐Line Characterisation of Size and Shape
Authors: Zhang Yanmin , West Robert , Williams Richard A. , Spink Mark 
Published: March 2003

AbstractA multi‐electrode approach is proposed for on‐line characterisation of particle size and shape in dilute particulate suspensions. Based on an electrozone principle, the approach uses four electrodes in a tube rather than two electrodes across an aperture employed in conventional methods. The outer two electrodes are used for current injection, while the inner two electrodes yield voltage measurement. A sensor designed in this way can reduce errors of false counts and oversizing that may occur in conventional methods, thus providing more accurate particle sizing. It is also possible to use the signal slope along with signal peak for particle size and shape characterisation. Both theoretical modelling and experiments were conducted, showing that particle aspect ratio along with particle diameter can be obtained, for example, for cylindrical particles.
Sex hormone‐induced alterations in the activities of antioxidant enzymes and lipid peroxidation status in the prostate of noble rats
Authors: N.C. Tam Neville , Ghatak Shibnath , Ho Shuk‐Mei 
Published: March 2003

AbstractBACKGROUNDOxidative stress has been implicated in prostate carcinogenesis. In the Noble rat model, treatment of rats with testosterone (T) plus 17β‐estradiol (E2) induced dysplasia and adenocarcinoma. Previous reports from us and other have indicated a linkage between steroid hormones and oxidative status in prostate cells in vivo and in vitro. Here, we provide further evidence that androgens and estrogens could induce a lobe‐specific shift of prooxidant–antioxidant balance and alterations in antioxidant enzyme activities, leading to oxidative stress in the rat prostate gland in vivo.METHODSMale Noble rats were subjected to single (T, E2, or diethylstilbestrol [DES] alone) or combined (T + E2 or T + DES) hormone treatments. Lipid peroxidation status and antioxidant enzyme activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GR), glucose‐6‐phosphate dehydrogenase (G6PD) were assayed spectrophotometrically.RESULTSTreatment of rats with T did not alter lipid peroxidation in either the ventral prostate (VP) or the dorsolateral prostate (DLP). In contrast, exposure of rats to DES or E2 modestly elevated lipid peroxidation in rat VP or DLP, respectively. Of importance, T + DES and T + E2 treatments of rats induced marked increases in lipid peroxidation in the VP and the DLP, respectively. Antioxidant enzyme activities in the VP and DLP exhibited differential responses to sex hormone challenges. The activities of catalase, GPx, GR, and G6PD were mostly suppressed in either single or dual hormone‐treated DLP, whereas there is a general increase of GR and G6PD activities in the VP after hormonal exposures. The changes in T + DES‐treated VP were most dramatic with a marked activation of GPx (by one‐fold), GR (by one‐fold), and G6PD (by five‐fold).CONCLUSIONThe lobe‐specific differential responses of hormone‐induced oxidative stress and modulations of antioxidant enzymatic defenses in the rat prostate suggest that reactive oxygen species may play a role in hormone‐induced prostate carcinogenesis. Prostate 55:1–8, 2003. © 2003 Wiley‐Liss, Inc.
Loss of CD10 (neutral endopeptidase) is a frequent and early event in human prostate cancer
Authors: Freedland Stephen J. , Seligson David B. , Liu Alvin Y. , Pantuck Allan J. , Paik Sun H. , Horvath Steve , Wieder Jeffrey A. , Zisman Amnon , Nguyen David , Tso Cho‐Lea , Palotie Aarno V. , Belldegrun Arie S. 
Published: March 2003

AbstractBACKGROUNDWe hypothesized that the aggressive LNCaP‐derived androgen‐independent cell line, CL1, might differ from LNCaP in their repertoire of cell surface markers and that these differences might typify changes that occur during clinical prostate cancer progression.METHODSThe cell surface marker expression profiles of CL1 and LNCaP were examined using flow cytometry. Markedly differential gene expression was confirmed using RT‐PCR and further examined using immunohistochemistry among the prostate cancer cell lines LAPC‐4, LNCaP, CL1, CL2, DU145, and PC‐3. The expression of the most markedly differentially expressed surface marker, CD10, was further explored in a tissue microarray containing radical prostatectomy samples from 219 hormone naïve prostate cancer patients.RESULTSThere were marked differences in the expression of CD10, CD13, CD26, CD33, CD44, CD54, CD55, and CD104 between CL1 and LNCaP. Results from both the RT‐PCR and immunohistochemistry confirmed the differential expression and found that CD10 demonstrated a pattern of expression in hormone sensitive but not hormone refractory cell lines. When CD10 expression was examined in a tissue microarray, CD10 expression was below the 25th percentile of matched normal prostate tissue in 68% of prostate cancers, below the median expression of matched normal prostate tissue in 86% of cancers, and completely absent in 34% of cancers. Samples of prostatic intraepithelial neoplasia demonstrated CD10 expression that was intermediate between normal prostatic tissue and prostate cancer. Among prostate cancer patients, CD10 expression did not correlate with Gleason score, pathological stage, or biochemical recurrence following radical prostatectomy.CONCLUSIONSThese findings demonstrate that loss or decreased expression of CD10 is an early and frequent event in human prostate cancer and implicates CD10 as a potential therapeutic target for early stage hormone sensitive prostate cancer. Prostate 55:71–80, 2003. © 2003 Wiley‐Liss, Inc.
Polarity of prostate specific membrane antigen, prostate stem cell antigen, and prostate specific antigen in prostate tissue and in a cultured epithelial cell line
Authors: Christiansen Jason J. , Rajasekaran Sigrid A. , Moy Peggy , Butch Anthony , Goodglick Lee , Gu Zhennan , Reiter Robert E. , Bander Neil H. , Rajasekaran Ayyappan K. 
Published: March 2003

AbstractBACKGROUNDMadin‐Darby canine kidney (MDCK) cells are immortalized epithelial cells that have been used extensively as a model system to study intracellular molecular trafficking, polarized expression, and secretion of proteins in various epithelia. In order to determine if MDCK cells might serve as a model to study molecular events within prostate epithelial cells, we have evaluated the polarized distribution of three prostate restricted proteins, PSMA, PSCA, and PSA, in situ, and in MDCK cells.METHODSUsing immunofluorescence, confocal microscopy, cell surface biotinylation, antibody internalization, and biochemical assays we evaluated surface expression and secretion of three prostate restricted proteins expressed in MDCK cells. We compared these patterns of expression to results observed within prostatic epithelium.RESULTSWe demonstrate that PSMA is localized primarily to the apical plasma membrane in both the prostatic epithelium and transfected MDCK cells, whereas PSCA is expressed in a non‐polarized fashion. We also show that PSA is secreted predominantly from the apical surface of transfected MDCK cells, consistent with in vivo observations.CONCLUSIONSSimilar patterns of localization among MDCK and prostatic epithelial cells suggest that the mechanisms of polarized sorting within these cell types are conserved. Thus, MDCK cells offer a useful model system to study mechanisms of targeting of these proteins within the prostate. Prostate 55:9–19, 2003. © 2003 Wiley‐Liss, Inc.
Cellular senescence in the pathogenesis of benign prostatic hyperplasia
Authors: Castro Patricia , Giri Dipak , Lamb Dolores , Ittmann Michael 
Published: March 2003

AbstractBACKGROUNDSenescent cells accumulate in tissues with age and show changes in protein expression that may influence the function of adjacent cells and contribute to the development of tissue pathologies associated with aging. Benign prostatic hyperplasia (BPH) is an extremely common disease of older men characterized by increased growth of prostatic epithelial and stromal cells. In BPH, there is an increased expression of Il‐1α by prostatic epithelial cells that results in elevated expression of FGF7 by stromal cells, which in turn is strongly correlated with epithelial proliferation.METHODSHuman BPH tissue and primary cultures of prostatic epithelial cells were analyzed by histochemical and quantitative assays for senescence‐associated β galactosidase (SA‐β gal). Il‐1α expression was localized by immunohistochemistry and Il‐1α tissue content determined by enzyme‐linked immunoabsorption assay.RESULTSExpression of Il‐1α is significantly increased in vitro when cultured prostatic epithelial cells undergo senescence. In BPH tissue a substantial population of epithelial cells express senescence‐associated β galactosidase (SA‐β gal), a marker of cellular senescence. By quantitative assay, SA‐β gal activity is correlated with both tissue levels of Il‐1α and the severity of BPH.CONCLUSIONSOne mechanism driving BPH in older men is the accumulation of senescent epithelial cells expressing Il‐1α, which in turn increases FGF7 secretion and proliferation of non‐senescent epithelial cells. Thus there is a mechanistic linkage between cellular senescence and one of the most common pathologies of older men. Prostate 55:30–38, 2003. © 2003 Wiley‐Liss, Inc.
Laminin alpha‐1, alpha‐3, and alpha‐5 chain expression in human prepubetal benign prostate glands and adult benign and malignant prostate glands
Authors: Brar Preetinder K. , Dalkin Bruce L. , Weyer Chris , Sallam Karim , Virtanen Ismo , Nagle Raymond B. 
Published: March 2003

AbstractBACKGROUNDLaminins (Lns) are a family of extracellular matrix glycoproteins located in the basement membrane (BM) of epithelial cells. They exist as heterotrimers composed of an α, β, and γ chain. Presently, five α (α1–5), three β (β1–3), and three γ (γ1–3) chains have been identified with different combinations of these chains resulting in 14 laminin heterotrimers thus far identified (1, 3–5).METHODSIn this study, using immunohistochemistry with chain‐specific antibodies, we characterized the expression of the α1 (Lns‐1/3), α3 (Lns 5,6,7), and α5 (Lns 10/11) chains in fetal, newborn, infant, prepubertal, and adult benign and malignant prostate glands.RESULTSIn general, α1 expression was higher in normal fetal prostate glands and declined by full‐term birth, whereas the α3 and α5 chains remained highly expressed in the adult normal glands. In carcinoma α1 (Lns 1/3) and α5 (Lns 5,6,7) are lost, whereas α5 (Lns 10/11) persists.CONCLUSIONSAlpha 1 (Lns 1/3) is prominent in BM, but is replaced by a laminin matrix rich in α3 (Lns 5,6,7) and α5 (Lns 10/11) in benign adult prostate glands. In carcinoma, both α1 (Lns‐1/3) and α3 (Lns 5,6,7) are not expressed with persistence of a BM rich in α5 (Lns 10/11). Prostate 55:65–70, 2003. © 2003 Wiley‐Liss, Inc.
MicroPET imaging of prostate cancer in LNCAP‐SR39TK‐GFP mouse xenografts
Authors: Yang Honghao , Berger Frank , Tran Chris , Gambhir Sanjiv S. , Sawyers Charles L. 
Published: March 2003

AbstractBACKGROUNDThe aim of this study was to develop models that allow serial, noninvasive imaging of human prostate cancer cells in immunodeficient mice using a dedicated small animal positron emission tomography scanner (microPET).METHODSLNCaP tumor cells were stably transduced ex‐vivo with the mutant herpes simplex virus type 1 thymidine kinase (HSV‐sr39tk) PET reporter gene and green fluorescent protein (GFP). The stably transduced LNCaP cells were then enriched via fluorescent cell sorting and implanted into SCID mice. Beginning 2 weeks after tumor cell inoculation, mice were repeatedly scanned by microPET performed 1 hr after tail‐vein injection of ∼200 μCi Fluorine‐18 labeled penciclovir (18F‐FHBG). PET‐images were correlated to tumor size, % injected dose (ID)/g tumor tissue, PSA levels, autoradiography, and histology.RESULTSMonitoring LNCaP xenografts using microPET and our reporter gene approaches is feasible. MicroPET was capable of detecting subcutaneous tumors as small as 3 mm in diameter (∼0.2% ID/g). The magnitude of 18F‐FHBG‐uptake in PET‐images correlated with the tumor volumes and the serum PSA levels. Other non‐HSV1‐TK‐specific tracers were also studied. While 18F‐flurodeoxyglucose (18F‐FDG) gave poor imaging results in LNCaP cells, 11C‐acetate gave satisfactory images.CONCLUSIONSWe demonstrated the feasibility of monitoring prostate cancer xenografts in a mouse model using microPET and the HSV1‐sr39tk PET reporter gene/18F‐FHBG reporter probe system. Extension of this approach may allow repetitive imaging of tumor metastases. Prostate 55:39–47, 2003. © 2003 Wiley‐Liss, Inc.
Tissue microarray analysis reveals prognostic significance of syndecan‐1 expression in prostate cancer
Authors: Zellweger Tobias , Ninck Christoph , Mirlacher Martina , Annefeld Matthias , Glass Andrew G. , Gasser Thomas C. , Mihatsch Michael J. , Gelmann Edward P. , Bubendorf Lukas 
Published: March 2003

AbstractBACKGROUNDTissue microarrays (TMA) have recently emerged as powerful tools to rapidly analyze the clinical significance of new molecular markers in human tumors. Here, we have tested several molecular markers on a prostate TMA containing 637 different specimens.METHODSThe specimens were from 551 patients with prostate cancer and long‐term follow‐up information on progression (median 5.3 years), tumor‐specific and overall survival (median 5.9 years). Eighty‐six specimens from benign prostatic hyperplasia were included as controls. Expression of Ki67, Bcl‐2, p53, CD‐10 (neutral endopeptidase), and syndecan‐1 (CD‐138) was analyzed by immunohistochemistry.RESULTSGleason grade and Ki67 Labeling Index (LI) were independent predictors of early recurrence and poor survival. Bcl‐2 predicted early recurrence, whereas p53 was associated with poor survival. Syndecan‐1 overexpression also predicted early recurrence and was significantly associated with tumor specific survival, high Gleason grade, Ki67 LI, and Bcl‐2 overexpression. Neoadjuvant hormonal therapy was associated with overexpression of Bcl‐2 and inhibition of Ki67 LI and CD‐10, but did not affect the expression of the remaining markers.CONCLUSIONSThe results of this TMA study confirm a dominant prognostic significance of Gleason grading and Ki67 LI in prostate cancer, as compared to a less pronounced role of Bcl‐2, and p53. We identified syndecan‐1 as a new prognostic factor and provide evidence for an androgen‐dependent regulation of CD‐10 expression. Prostate 55:20–29, 2003. © 2003 Wiley‐Liss, Inc.
Biochemical recurrence following radical prostatectomy: A comparison between prostate cancers located in different anatomical zones
Authors: Augustin Herbert , Erbersdobler Andreas , Graefen Markus , Fernandez Salvador , Palisaar Jüri , Huland Hartwig , Hammerer Peter 
Published: March 2003

AbstractBACKGROUNDTo assess whether differences of biochemical recurrence after radical prostatectomy exist between prostate cancers located in the transition zone (TZ) and peripheral zone (PZ).METHODSThe 5‐year biochemical recurrence rate of 307 patients was evaluated. A serum prostate specific antigen (PSA) level ≥0.1 ng/ml was defined as biochemical failure. Cancers were characterized by the location of the largest tumor area as TZ or PZ cancers. Pure PZ cancers were matched to TZ cancers by comparable pathological tumor stage, Gleason score, and surgical margin status.RESULTSIn 63 (20.5%) patients the largest tumor area was located in the TZ. A Kaplan–Meier analysis of the matched pairs calculated an 80% actuarial cure rate of TZ cancers compared to 89% of pure PZ cancers (log‐rank test P = 0.742).CONCLUSIONSTZ and pure PZ cancers matched by comparable pathological tumor stage, Gleason score, and surgical margin status showed no statistical difference in regard to biochemical cure following radical prostatectomy. Prostate 55:48–54, 2003. © 2003 Wiley‐Liss, Inc.
Molecular characterization of prostatic small‐cell neuroendocrine carcinoma
Authors: Clegg Nigel , Ferguson Camari , True Lawrence D. , Arnold Hugh , Moorman Alec , Quinn Janna E. , Vessella Robert L. , Nelson Peter S. 
Published: March 2003

AbstractOBJECTIVESA subset of prostate carcinomas is composed predominantly, even exclusively, of neuroendocrine (NE) cells. In this report, we sought to characterize the gene expression profile of a prostate small cell NE carcinoma by assessing the diversity and abundance of transcripts in the LuCaP 49 prostate small cell carcinoma xenograft.METHODSWe constructed a cDNA library (PRCA3) from the LuCap 49 prostate small cell xenograft. Single pass DNA sequencing of randomly selected cDNA clones followed by sequence assembly and annotation produced a library of Expressed Sequence Tags (ESTs) representing the LuCaP 49 transcriptome. Comparative sequence analysis with ESTs derived from prostate adenocarcinoma libraries was performed using statistical algorithms designed to identify differentially expressed sequences. Putative NE cell‐specific genes were further examined by Northern analysis.RESULTSSequence assembly and analysis identified 1,447 distinct genes expressed in the LuCaP 49 cDNA library. These include cDNAs encoding the NE markers secretogranin (SCG2), CD24, and ENO2. Northern analysis revealed that three additional genes, ASCL1, INA, and SV2B are expressed in LuCaP 49 but not in various prostate cancer cell lines or xenografts. Fifteen genes were identified with a statistical probability (P > 0.9) of being up‐regulated in LuCaP 49 small cell carcinoma relative to prostate adenocarcinoma (two primary prostate adenocarcinomas and the LNCaP prostate adenocarcinoma cell line).CONCLUSIONSProstate small cell carcinoma expresses a diverse repertoire of genes that reflect characteristics of their NE cell of origin. ASCL1, INA, and SV2B are potential molecular markers for small cell NE tumors and NE cells of the prostate. This small cell NE carcinoma gene expression profile may yield insights into the development, progression, and treatment of subtypes of prostate cancer. Prostate 55:55–64, 2003. © 2003 Wiley‐Liss, Inc.