bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of AR associated protein 55 (ARA55) and androgen receptor in prostate cancer
Authors: Miyoshi Yasuhide , Ishiguro Hitoshi , Uemura Hiroji , Fujinami Kiyoshi , Miyamoto Hiroshi , Miyoshi Yoshiko , Kitamura Hitoshi , Kubota Yoshinobu 
Published: July 2003

AbstractBACKGROUNDAndrogen receptor (AR) transcription is modulated by several cofactors such as AR associated proteins (ARA) including ARA70, ARA54, and ARA55. ARA55 increases AR transcription and alters ligand specificity. We hypothesized that ARA55 might play an important role in prostate cancer development or progression. We evaluated the messenger RNA (mRNA) expression of ARA55 in prostate cancer tissues, and analyzed the relation between ARA55 expression and clinical characteristics.METHODSA total of 30 prostate cancer specimens (20 previously untreated prostate cancers and 10 recurrent, hormone‐refractory prostate cancers (HRPC)) and 5 benign prostatic hypertrophy (BPH) tissue samples were examined. mRNA expression of ARA55 and AR were analyzed by quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) using real time PCR.RESULTSARA55 expression was identified in all tissue samples of previously untreated prostate cancer, HRPC and BPH. ARA55 expression level in HRPC specimens was significantly lower than that in previously untreated prostate cancer (P = 0.02) or BPH (P = 0.005) samples using quantitative PCR. On the other hand, higher ARA55 expression was associated with shorter recurrence‐free survival (P = 0.02) and overall survival (P = 0.01) in HRPC patients. AR expression was also revealed in all specimens of both prostate cancer and BPH. AR expression level in HRPC samples was significantly higher than that in previously untreated prostate cancer (P = 0.001) and BPH (P = 0.01) samples.CONCLUSIONSARA55 may be associated with prostate cancer development and progression. ARA55 expression level in HRPC specimens was significantly lower than that in previously untreated prostate cancer or BPH specimens. On the contrary, our results suggested that a higher ARA55 expression level may result in unfavorable recurrence‐free survival and overall survival in HRPC patients. The role of ARA55 may differ between prostate cancer development and the process of progression to a hormone‐refractory state. These data not only help to understand the molecular mechanism of prostate cancer development or recurrence, but may also lead to a therapeutic strategy for recurrent prostate cancer that is refractory to hormonal treatment. Prostate 56: 280–286, 2003. © 2003 Wiley‐Liss, Inc.
Differential expression of the human kallikrein gene 14 (KLK14) in normal and cancerous prostatic tissues
Authors: Yousef George M. , Stephan Carsten , Scorilas Andreas , Ellatif Mohamed Abd , Jung Klaus , Kristiansen Glen , Jung Monika , Polymeris Mary‐Ellen , Diamandis Eleftherios P. 
Published: July 2003

AbstractBACKGROUNDMany members of the human kallikrein gene family are differentially expressed in cancer and a few have potential as diagnostic/prognostic markers. KLK14 is a newly discovered human kallikrein gene that is mainly expressed in the central nervous system and endocrine tissues. Since KLK14 was found to be regulated by steroid hormones in prostate cancer cell lines, we hypothesized that it will be differentially expressed in prostate cancer tissues compared to their normal counterparts.METHODSMatched prostate tissue samples from the cancerous and non‐cancerous parts of the same prostates were obtained from 100 patients who underwent radical prostatectomy. Quantitative analysis of KLK14 expression levels were performed by real‐time RT‐PCR using SYBR Green I dye on the LightCycler™ system. Associations with clinico‐pathological parameters were analyzed.RESULTSKLK14 overexpression in the cancerous compared to non‐cancerous tissue was found in 74% of patients (P < 0.001). Mean level of expression was 154 arbitrary units (Au) in cancerous tissues and 14.2 Au in the non‐cancerous tissues. The ratio of the cancerous to non‐cancerous KLK14 expression values was higher in patients with late stage (stage III) compared to stage II (P = 0.002), and in grade 3 compared to grade 1/2 tumors (P = 0.001). A statistically significant increase was also observed in patients with higher in Gleason score (>6) compared to Gleason score = 6 tumors (P = 0.027). No correlation was found between KLK14 tissue expression levels and serum prostate‐specific antigen.CONCLUSIONSKLK14 expression is significantly higher in cancerous compared to non‐cancerous prostatic tissue. The up‐regulation of the KLK14 gene in advanced and more aggressive tumors may indicate a possible role for the hK14 protein in tumor spread and opens the possibility of hK14 being a candidate new marker for prostate cancer diagnosis and prognosis. Prostate 56: 287–292, 2003. © 2003 Wiley‐Liss, Inc.
Interstitial cells in the human prostate: A new therapeutic target?
Authors: Aa Frank Van der , Roskams Tania , Blyweert Wim , Ridder Dirk De 
Published: July 2003

AbstractBACKGROUNDInterstitial cells have been described in different human organs, including gut and bladder. In the gut they function as pacemaker cells, generating slow wave potentials. Absence or defects in these cells result in motility disorders. In the bladder these cells express the vanilloid receptor and may contribute to the working mechanism of vanilloid therapy. Recently, slow wave potentials and interstitial cells were described in the guinea‐pig prostate. In this study we describe the presence of interstitial cells in the human prostate gland.METHODSWe performed immunohistochemical staining for c‐kit, vanilloid receptor (VR1), cannabinoid receptor (CB1) connexin43, and neurofilament on fresh frozen tissue from 14 prostatectomy specimens.RESULTSA large number of cells with a stellate aspect were noticed under the basal layer of the prostatic duct system and in between the smooth muscle cells. They were immunoreactive for c‐kit, VR1, and connexin43 but not to CB1 or neurofilament.CONCLUSIONSThere is evidence for interstitial cells in the human prostate. Taken together their topography and immunohistochemical characterization, the discovery of slow wave potentials in guinea pig prostate and the knowledge of interstitial cells in other organs, interstitial cells are likely to be involved in normal prostate physiology. Prostate 56: 250–255, 2003. © 2003 Wiley‐Liss, Inc.
Identification of an HLA‐A*0201‐restricted T‐cell epitope derived from the prostate cancer‐associated protein trp‐p8
Authors: Kiessling Andrea , Füssel Susanne , Schmitz Marc , Stevanovic Stefan , Meye Axel , Weigle Bernd , Klenk Ulrich , Wirth Manfred P. , Rieber Ernst P. 
Published: July 2003

AbstractBACKGROUNDNew concepts for the immunotherapy of prostate carcinoma (PCa) largely depend on the identification of suitable target antigens that are present in a high percentage of prostate tumors. Their expression in normal tissues should be restricted to the prostate and they should be immunogenic in vivo. The number of antigens displaying these properties is still limited. Here, we identify for the first time an immunogenic peptide derived from the prostate‐specific protein transient receptor potential‐p8 (trp‐p8) that is recognized by cytotoxic T lymphocytes (CTLs) from PCa patients.METHODSTo determine the abundance of trp‐p8 in prostate tumors, the expression level of trp‐p8 mRNA was quantitatively analyzed in a panel of prostate cancer tissues. Trp‐p8‐derived human leukocyte antigen (HLA)‐A*0201‐restricted peptides were selected and tested for the in vitro activation of CTLs when loaded on autologous dendritic cells (DCs).RESULTSTrp‐p8 mRNA was found to be expressed in all prostate tumors and in the corresponding normal prostate tissue. Of five selected trp‐p8‐derived peptides, only peptide GLMKYIGEV was shown to activate specific CTLs, which effectively lysed PCa cells confirming the endogenous generation and presentation of this peptide by tumor cells.CONCLUSIONSOur results suggest this antigen as a suitable target for the T‐cell‐based immunotherapy of PCa. Prostate 56: 270–279, 2003. © 2003 Wiley‐Liss, Inc.
Norepinephrine activates P44 and P42 MAPK in human prostate stromal and smooth muscle cells but not in epithelial cells
Authors: Kanagawa Kenji , Sugimura Kazunobu , Kuratsukuri Katsuyuki , Ikemoto Shin‐ichi , Kishimoto Taketoshi , Nakatani Tatsuya 
Published: July 2003

AbstractBACKGROUNDIn vascular smooth muscle cells, α1‐adrenergic stimulation increases DNA synthesis and cell proliferation via activation of p44/42 (ERK1/2) MAPK. We examined whether norepinephrine (NE) activates MAPK and stimulates the proliferation of prostatic epithelial and non‐epithelial cells.METHODSHuman prostatic epithelial cells, stromal cells, and smooth muscle cells were purchased from BioWhittaker (Walkersville, MD). After reaching a semi‐confluent condition, the cells were cultured in RPMI‐1640 without serum for 1 day. At 10 min after adding NE (10−6 or 10−7 M) to the medium, the cells were collected. Cell lysate was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) followed by Western blot using anti‐phospho‐p44/42 and anti‐p44/42 antibodies. The activation of p44/42 was estimated by the ratio of phospho‐p44/42 to total p44/42. Cell proliferation was evaluated by 3H‐thymidine uptake assay. After reaching a semi‐confluent condition, the cells were cultured in RPMI‐1640 containing 0.5% FCS with or without NE (10−6 or 10−7 M) for 16 hr followed by a 3H‐thymidine uptake period (24 hr).RESULTSP44/42 MAPK was significantly activated by NE in non‐epithelial cells (stromal cells and smooth muscle cells) while not in epithelial cells. The uptake of 3H‐thymidine was significantly increased by NE in both non‐epithelial cells, which was inhibited by α1‐adrenoceptor antagonists.CONCLUSIONSThese results suggest that NE may stimulate the proliferation of non‐epithelial prostatic cells, which may be involved in the pathogenesis of BPH. Prostate 56: 313–318, 2003. © 2003 Wiley‐Liss, Inc.
Strain effects on photoluminescence polarization of InAs/GaAs self‐assembled quantum dots
Authors: Jayavel P. , Tanaka H. , Kou K. , Kita T. , Wada O. , Ebe H. , Nakata Y. , Sugawara M. 
Published: July 2003

AbstractWe have investigated the photoluminescence (PL) polarization properties of InAs/GaAs self‐assembled quantum dots (QDs). An 8 nm InxGa1–xAs capping layer was overgrown on InAs QDs in order to modify the strain distribution in the dots. TE and TM mode PL polarizations of samples with capping layer indium composition of x = 0 and x = 0.13 were detected and analyzed. The TE/TM ratio shows heavy‐hole dominant optical transition for samples with x = 0. On the other hand, samples with x = 0.13 show light‐hole dominant optical transition. These results indicate valence band state inversion through in‐plane strain distribution dependent on the capping layer composition.
High‐quality InxGa1–xAs/Al0.30Ga0.70As quantum dots grown in inverted pyramids
Authors: Pelucchi E. , Baier M. , Ducommun Y. , Watanabe S. , Kapon E. 
Published: July 2003

AbstractWe report here on the fabrication by organometallic chemical vapour deposition of InxGa1–xAs quantum dots (QDs) with x up to 35% grown in pyramidal recess patterns with Al0.30Ga0.70As barriers. We show QD luminescence with narrow PL lines, tuning of the emission energies varying by more than 180 meV and ground state to first excited state separations as large as 80 meV.
Two‐dimensional ordering of InGaAs quantum dots formed on an artificial nano‐hole array with 100 nm periodicity
Authors: Nakamura Y. , Ikeda N. , Sugimoto Y. , Nakamura H. , Ohkouchi S. , Asakawa K. 
Published: July 2003

AbstractWe have successfully formed two‐dimensionally ordered InGaAs and InAs quantum dots (QDs) by controlling the nucleation sites on artificially prepared nano‐hole arrays with a 100 nm periodicity. The ordered InGaAs QDs were realized by a combination of a low‐temperature deposition of InGaAs and its annealing on the nano‐hole arrays. These ordered InGaAs played a role as a template for upper InAs QDs. In this study, we used in situ scanning tunneling microscopy (STM), which enabled us to observe each grown surface on the samples.
Theory of optical manipulation of semiconductor quantum dots confining excitons
Authors: Iida T. , Ishihara H. 
Published: July 2003

AbstractWe present a theoretical study of optical manipulation of spherical semiconductor quantum dots confining excitonic center‐of‐mass motion. The radiation force that is exerted on a dot floating in a vacuum is calculated by using the Maxwell stress tensor expressed in terms of the microscopic response field. The following advantageous effects are clarified: (1) The acceleration (the force normalized by the mass of a dot) exerted by the resonant light is greatly enhanced for a dot with a radius of less than 100 nm. Especially, for smaller dots with a radius near 10 nm, this enhancement is conspicuous. (2) The spectral peak position of exerted force is extremely sensitive to nanoscale‐size changes, which can be utilized for size selection of quantum dots. Such results will open the way to the fabrication of nanostructures composed of arranged quantum dots with ultrahigh homogeneity.
Optical spin polarization in negatively charged InAs self‐assembled quantum dots under applied electric field
Authors: Kalevich V. K. , Ikezawa M. , Okuno T. , Shiryaev A. Yu. , Zhukov A. E. , Ustinov V. M. , Brunkov P. N. , Masumoto Y. 
Published: July 2003

AbstractWe have studied the influence of an external electric field on the optical spin polarization of initially negatively charged InAs/GaAs quantum dots (QDs). The spin polarization of the carriers was controlled by measuring the photoluminescence (PL) circular polarization. We have found that the PL polarization of the QD is negative under an excitation above the GaAs barrier, and that it becomes positive under an excitation below the barrier. An applied negative electric field destroys both positive and negative polariza‐tion. The time decay of the negative polarization was found from time‐resolved measurements to exceed strongly the QD radiative lifetime. This fact indicates a long‐living spin memory in the dots under study.
Polaron relaxation in InAs/GaAs self‐assembled quantum dots
Authors: Sauvage S. , Boucaud P. , Bras F. , Fishman G. , Lobo R. P. S. M. , Glotin F. , Prazeres R. , Ortega J.‐M. , Gérard J.‐M. 
Published: July 2003

AbstractPolaron dynamics in n‐doped InAs/GaAs self‐assembled quantum dots is investigated using far infrared pump–probe spectroscopy around 22 μm wavelength of the s–p intersublevel transition. Despite the strong coupling between the confined electron and the phonon continuum, forming a priori an everlasting polaron, we show experimentally that the polaron actually relaxes over a tens‐of‐picoseconds time range even at detuning far away from the phonon resonance. Measured decay times scale from 45 ps to 70 ps at low temperature depending on the transition energy. The energy dependence of this relaxation time is consistent with the polaron nature of the elementary excitation in InAs/GaAs self‐assembled quantum dots. As the temperature increases, the polaron decay time slightly decreases, with still a value of 37 ps at 300 K. The experiment shows that the polaron relaxation is driven by the instability of its one‐phonon component. It is consistent with a phonon part disintegrating into two acoustic phonons as proposed theoretically by Li, Nakayama and Arakawa in 1999 [4].
Hole storage in GaSb/GaAs quantum dots for memory devices
Authors: Geller M. , Kapteyn C. , Müller‐Kirsch L. , Heitz R. , Bimberg D. 
Published: July 2003

AbstractThe hole confinement of self‐organized GaSb/GaAs quantum dots embedded in n+p‐diodes is investigated experimentally by admittance spectroscopy. The highest thermal activation energy obtained, 400 meV, refers to only weakly charged quantum dots. Detailed bias‐dependent investigations allow to study state‐ filling and Coulomb charging effects. State filling lowers the activation energy down to 150 meV in quantum dots charged with the maximum number of about 15 holes. The observed thermal activation barrier for GaSb/GaAs quantum dots is about twice as high as for structurally comparable InAs/GaAs quantum dots.
Investigation of spin state in a quantum dot by using strongly asymmetric tunnel barriers
Authors: Hayashi T. , Fujisawa T. , Hirayama Y. 
Published: July 2003

AbstractWe investigate the spin state of a GaAs lateral quantum dot (QD) by using strongly asymmetric tunnel barriers. The saturated current depends on the current polarity, which switches the direction of the dominant tunneling transition that increases or decreases the total spin. With this technique, the spin polarization and the Coulomb interaction are investigated. We find that high spin states appearing in some magnetic field regions can be understood by considering simple Coulomb interactions.
Polarized electrons, trions, and nuclei in charged quantum dots
Authors: Bracker A. S. , Tischler J. G. , Korenev V. L. , Gammon D. 
Published: July 2003

AbstractWe have investigated spin polarization in GaAs quantum dots. Excitons and trions are polarized directly by optical excitation and studied through polarization of photoluminescence. Electrons and nuclei are polarized indirectly through subsequent relaxation processes. Polarized electrons are identified by the Hanle effect for exciton and trion photoluminescence, while polarized nuclei are identified through the Overhauser effect in individual charged quantum dots.
Shape‐dependent properties of self‐organized quantum dots: Few‐particle states and exciton‐phonon coupling
Authors: Heitz R. , Rodt S. , Schliwa A. , Bimberg D. 
Published: July 2003

AbstractThe electronic and optical properties of self‐organized InAs/GaAs quantum dots are investigated in view of the actual structural properties. Focussing on the shape we demonstrate theoretically a strong impact of the varying strain distribution on the electronic and, in particular, the exciton properites in such quantum dots. The inhomogeneous strain, typical for self‐organized quantum dots, lowers the symmetry and increases the local charge density. Resonant Raman experiments on pyramidal InAs/GaAs quantum dots show an enhance exciton–LO‐phonon coupling reflecting the strain‐induced local charge density. Experiments on single InAs/GaAs quantum dots demonstrate an unexpected strong impact of the structural properties on few‐particle complexes on the example of the biexciton complex. Anti‐binding biexciton complexes are demonstrated. The apparent correlation of the biexciton binding energy and exciton transition energy, with a transition from binding to anti‐binding at ∼1.24 eV, is attributed to a decreasing exciton localization, resulting from the finite barrier height. The Coulomb interaction with delocalized states is negligible for the energy of the localized states.
Magneto‐photoluminescence studies of a novel quantum dot–quantum well coupled system
Authors: Child R. A. , Nicholas R. J. , Mason N. J. 
Published: July 2003

AbstractWe report a study of novel structures in which an InSb quantum dot (QD) layer in GaSb is coupled to a nearby narrow InAs quantum well (QW). Magnetic fields have been used to probe the photoluminescence (PL) of the dots and the wells separately and in the coupled structures. We have found that the introduction of the dot–well coupling leads to a dramatic suppression of the diamagnetic shift of the exciton when the magnetic field is oriented parallel to the well plane. The observed shift is 1–2 meV with an applied field of 17 T. In contrast, when the field is perpendicular to the layer plane, there is little difference in the response of the coupled structures compared to that of the quantum wells on their own, suggesting that the behaviour is dominated by the motion of the electrons in the wells.
Real‐space mapping of exciton wave function in a GaAs quantum dot by near‐field optical imaging spectroscopy
Authors: Matsuda Kazunari , Saiki Toshiharu , Nomura Shintaro , Mihara Masaru , Aoyagi Yoshinobu 
Published: July 2003

AbstractWe describe near‐field photoluminescence imaging spectroscopy of a single naturally occurring GaAs quantum dot in a narrow quantum well. A spatial mapping of the center‐of‐mass wave function of the exciton state in the quantum dot is demonstrated due to the realization of a high spatial resolution (30 nm) of imaging spectroscopy and the selection of a large quantum dot (100 nm). We observe an elongation along the [110] crystal axis of the wave function in the exciton state.
Effect of strain variation on photoluminescence from InGaAs quantum dots in air‐bridge structures
Authors: Nakaoka T. , Kakitsuka T. , Saito T. , Kako S. , Ishida S. , Nishioka M. , Yoshikuni Y. , Arakawa Y. 
Published: July 2003

AbstractWe have fabricated freestanding wire (air‐bridge) structures with a bowed shape by introducing a strain layer to vary the strain around quantum dots. The photoluminescence peak energy shift following the shape change of the bridge can be observed for individual InGaAs quantum dots. We find systematic dependence of the peak shift on the dot position along the growth direction. The dependence of the peak shift is explained by strain distribution in the bridge. The strain distribution in the bridge as well as in the dot is calculated using a finite element method. Using the strain data, the electronic structures of the dots embedded in the bridge structures are calculated within the effective mass approximation. The calculated energy shifts agree well with the experimental ones.
Magnetic properties of charged excitons in self‐assembled quantum dots
Authors: Schulhauser C. , Högele A. , Warburton R. J. , Govorov A. O. , Schoenfeld W. , Garcia J. M. , Petroff P. M. , Karrai K. 
Published: July 2003

AbstractWe report on low temperature (4.2 K) magneto‐luminescence measurements performed on charged tuneable GaInAs self‐assembled quantum dots. We mapped the magnetic field dispersion (0–9 Tesla) of the exciton with excess electron charges set from 0 to 3. For the doubly and triply charged excitons the emission line shows a doublet corresponding to the singlet and triplet configuration of the quantum dot in the final state after photon emission. We map here for the first time the dispersion of the singlet state of the doubly charged exciton and show that the triply charged exciton undergoes a transition resulting from a magnetic field induced frustration of the Hund's rule.
Quantum dots: a source of multicolor photons with tunable statistics and correlated polarizations
Authors: Mizrahi U. , Regelman D. V. , Gershoni D. , Ehrenfreund E. , Petroff P. M. 
Published: July 2003

AbstractWe report on measurements of temporal and polarization correlations measurements of multi‐color photons emitted from cw optically excited single semiconductor quantum dots. We show that there are tunable intensity and polarization correlations among photons emitted at the same, and at different wavelengths due to the recombination of electron–hole pairs from different collective many‐carrier quantum states confined in the dots. The observed polarization correlations between the emitted photons are qualitatively explained in terms of long electronic spin memory.
Pattern‐effect‐free amplification and cross‐gain modulation achieved by using ultrafast gain nonlinearity in quantum‐dot semiconductor optical amplifiers
Authors: Akiyama Tomoyuki , Hatori Nobuaki , Nakata Yoshiaki , Ebe Hiroji , Sugawara Mitsuru 
Published: July 2003

AbstractWe demonstrate that the pattern effect of semiconductor optical amplifiers appearing in amplified signals and in cross‐gain modulated signals can be suppressed by using quantum dots as active media. This property, which originates from the ultrafast (less than 3 ps) gain nonlinearity of quantum dots dominated by spectral‐hole burning, in principle enables pattern‐effect‐free operations at up to 160 Gb/s. Experimental confirmation of this property was conducted at 40 Gb/s.