bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increase in amphiregulin and epiregulin in prostate cancer xenograft after androgen deprivation—impact of specific HER1 inhibition
Authors: Tørring Niels , Hansen Frederik Dagnæs , Sørensen Boe Sandahl , Ørntoft Torben F. , Nexø Ebba 
Published: January 2005

AbstractBACKGROUNDWe investigated the expression of the epidermal growth factor (EGF) network before and after castration in the prostate cancer xenograft CWR22 implanted in nude mice, and examined the effects of gefitinib (Iresssa, ZD1839), a new drug directed towards the EGF tyrosine kinase receptor (HER1) of the EGF network.METHODSCWR22 prostate cancer xenografts were propagated in immunodeficient male mice. The expression of the growth factors and receptors in the EGF network was examined by real‐time PCR analysis and ELISA at 0, 7, 14, and 30 days after castration, and the tumor growth was examined after treatment with gefitinib or placebo.RESULTSA fraction of growth factors showed a steady increase in the mRNA expression reaching between fourfold and eightfold 30 days after castration, including amphiregulin (P < 0.005) and epiregulin (P < 0.001). ELISA for amphiregulin showed a fivefold increase 30 days after castration. Tumor bearing mice were castrated and treated with or without the HER1 tyrosine kinase inhibitor gefitinib. Tumor involution was significantly increased by castration plus gefitinib as compared to castration alone.CONCLUSIONSCastration leads to adaptive increase in the concentrations of a subset of growth factors from the EGF network in the androgen sensitive CWR22 prostate cancer xenograft. Specific inhibition of the HER1 tyrosine kinase receptor significantly increases the tumor involution, and suggests that HER1 targeted drugs could be of therapeutic relevance in the treatment of advanced prostate cancer. © 2005 Wiley‐Liss, Inc.
Decreasing age at prostate cancer diagnosis over successive generations in prostate cancer families
Authors: Bock Cathryn H. , Peyser Patricia A. , Montie James E. , Cooney Kathleen A. 
Published: January 2005

AbstractBACKGROUNDThe decline in age at prostate cancer diagnosis over the past decade is partially attributable to prostate specific antigen (PSA) screening. We examined age at diagnosis over successive generations within prostate cancer families.METHODSFamilies with at least two affected men were selected from the University of Michigan Prostate Cancer Genetics Project. The 1,345 individuals from 489 families were grouped into three generations.RESULTSRisk of prostate cancer diagnosis at a given age was estimated to increase 1.31 (95% CI: 1.13–1.51) times from one generation to the next. Among men diagnosed prior to the PSA era, inferences were similar (hazard ratio = 1.28, 95% CI: 0.97–1.68). No maternal versus paternal disease transmission effect was observed.CONCLUSIONSAge at prostate cancer diagnosis was observed to decrease over successive generations in families from an ongoing familial prostate cancer study. This finding, if confirmed, may have important implications for familial prostate cancer risk assessment. © 2005 Wiley‐Liss, Inc.
High dose fractionated ionizing radiation inhibits prostate cancer cell adhesion and β1 integrin expression
Authors: Simon Edmund L. , Goel Hira L. , Teider Natalia , Wang Tao , Languino Lucia R. , FitzGerald T.J. 
Published: January 2005

AbstractBACKGROUNDThe effect of ionizing radiation on extracellular matrix (ECM)‐mediated cellular functions is an important area of research for translational science. Mechanisms of tumor cell ability to proliferate, migrate, and survive appear dependent on integrin‐mediated adhesion to the ECM; however, the exact role therapeutic radiation plays in altering signaling pathways and promoting cell death within remains less well established.METHODSTo examine these effects on prostate carcinoma cell lines, cells were irradiated at sub‐lethal doses. We have studied two human prostate cancer cell lines (PC3 and DU‐145) irradiated with different fractionated radiation schedules. Three groups were compared to non‐irradiated controls. Group A was given a single dose of 5 Gy. Group B was given 5 Gy the first week and then 10 Gy the second week for a total of 15 Gy. Group C was given 5 Gy the first week, and then 10 Gy the second and third week for a total of 25 Gy. Cells were analyzed at their prescribed total dose. At 48 hr post irradiation, cells were detached from culture dishes and were subsequently used for adhesion assays and immunoblotting analysis.RESULTSOur findings revealed that two prostate carcinoma cell lines, PC3 and DU‐145, had a reduced cellular adhesion to fibronectin (FN) compared to the non‐irradiated control groups. Both prostate cancer cell lines showed decreased adhesion to FN and reduced β1 integrin protein levels at a total dose of 25 Gy, but not at the doses of 15 and 5 Gy. In a parallel analysis, at the maximum total dose of 25 Gy, both PC3 and DU‐145 demonstrated a significant decrease in cell proliferation.CONCLUSIONSHigh dose radiation treatment of prostate cancer cell lines inhibits integrin expression. Our study suggests that promoting a synergistic decrease in adhesion could bring additional therapeutic benefit to patients treated with radiation therapy. © 2005 Wiley‐Liss, Inc.
Expression of tumor‐associated trypsinogens (TAT‐1 and TAT‐2) in prostate cancer
Authors: Bjartell Anders , Paju Annukka , Zhang Wan‐Ming , Gadaleanu Virgil , Hansson Jens , Landberg Göran , Stenman Ulf‐Håkan 
Published: January 2005

AbstractBACKGROUNDTrypsinogens are pancreatic serine proteinases and expressed in several cancers as tumor‐associated trypsinogens (TAT). Trypsin mediates activation of pro‐uPA and pro‐MMPs, thus promoting angiogenesis and tumor invasion. Recently, we described expression of TAT in the human male genital tract and now we studied TAT in relation to PSA in PCa.METHODSTAT expression was studied by immunohistochemistry, in situ hybridization, RT‐PCR, DNA‐sequencing and IFMA. LNCaP cells were used to study secretion of TAT and PSA after androgen stimulation.RESULTSImmunoreactive TAT was localized in all prostatic tumors (n = 109), lymph node (n = 16), and bone metastases (n = 17). Immunostaining intensity increased with higher Gleason's grade, whereas PSA immunostaining decreased significantly. PSA and TAT were not identically distributed in benign and malignant cells. Androgen stimulation of LNCaP cells decreased secretion of TAT and increased that of PSA. TAT mRNA was demonstrated in tissue sections and identified as TAT‐1 and ‐2 by RT‐PCR and DNA‐sequencing.CONCLUSIONSExpression of TAT is better preserved than PSA in high‐grade PCa. Expression of TAT and PSA is regulated by different mechanisms as demonstrated in tissue sections and in vitro. Locally produced TAT may act in a paracrine mode to promote angiogenesis and tumor invasion in PCa by both activating and degrading of other proteinases. Further studies on the role of TAT in invasive PCa and on the mechanisms involved in the regulation of TAT expression are warranted. © 2005 Wiley‐Liss, Inc.
Exciton delocalization of the J‐aggregate of oxacyanine dye and thiacyanine dye in LB films
Authors: Yonezawa Yoshiro , Yamaguchi Atsushi , Kometani Noritsugu 
Published: January 2005

AbstractDelocalization and energy transfer of the molecular exciton of the J‐aggregate of oxacyanine dye, N,N′‐dioctadecyl‐oxacyanine perchlorate (S9) in LB films have been examined. Fluorescence lifetime of the S9 J‐aggregate (S9(J)) appears to be ca. 1/20 of the isolated S9 molecules (S9(M)), which suggests that the coherent size of the J‐aggregate, Ncohe, is about 22 at room temperature. Quenching of resonance fluorescence of S9(J) by thiacyanine dye, N,N′‐dioctadecyl‐thiacyanine perchlorate (S11) obeys the Stern–Volmer relation with a Stern–Volmer constant of 1.2 × 103 nm2 molecules–1 at room temperature, which is responsible to the incoherent size Ninco of about 2000. The rate constant of energy transfer kET amounts to 1.5 × 1013 nm2 molecules–1 s–1. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adsorption and dissociation of water on relaxed alumina clusters: a first principles study
Authors: Fernandez E. M. , Eglitis R. , Borstel G. , Balbás L. C. 
Published: January 2005

AbstractUsing previous results for the equilibrium geometries of stoichiometric (Al2O3)n clusters as models for non ideal alumina surfaces, we obtain, from ab‐initio total energy LCAO calculations, the corresponding relaxed structures of the complexes H2O–(Al2O3)n with n ≤ 7. Depending on the initial position of the water molecule relative to the cluster site, the complex evolves to different equilibrium structures, with and without dissociation of H2O, whose energetic, bond lengths, and charge transfer trends are studied as the morphology and size of the initial cluster change. Dissociation of H2O with the radical OH– bound on top of an Al atom and the proton H+ bound to the second nearest neighbour O, is the dominant process for the reaction (Al2O3)n + H2O with n = 4, in agreement with the one observed for the adsorption of H2O on the extended real surface. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Forms of adsorption and transition states of oxidation of carbon monoxide by molecular oxygen and dissociation of nitrogen monooxide, catalyzed by monovalent copper
Authors: Ermakov A. I. , Mashutin V. Y. , Vishnjakov A. V. 
Published: January 2005

AbstractWith the help of the results of semiempirical (parametric method 3) and ab initio (second‐order Møller–Plesset [MP2] unrestricted Hartree–Fock [UHF] 6‐31G**, unrestricted density functional theory [UDFT] 6‐31G** Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Paar [B3LYP] and UDFT LANL2DZ B3LYP) quantum‐chemical calculations has been studied the complexation CO and NO with molecular hydroxide of copper(I). The influence of charge defects has been simulated by the calculations of anionic, neutral, and cationic systems. It is shown that CO and NO are mainly coordinated by nonoxygen atom on an atom of copper(I) hydroxide as one‐ and two‐center forms. These forms are suitable for appearance of prereactionary complexes of catalytic oxidation CO by molecular oxygen and decomposition NO into atoms of nitrogen and oxygen. The corresponding prereactionary complexes for systems with participation of copper(II) hydroxide and copper(III) hydroxide are not revealed. The calculations predict inhibiting impact of copper(II) and copper(III) of the observed reactions. Computed stability of complexes CO and NO with copper(I) hydroxide and activation energy of catalytic conversion of monooxides essentially depend on an excessive charge of the system. Introduction of electron‐donating additives into copper(I) hydroxide promotes rise of catalytic activity of copper(I) compound. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Polaron‐induced conformation change in single polypyrrole chain: An intrinsic actuation mechanism
Authors: Lin Xi , Li Ju , Smela Elisabeth , Yip Sidney 
Published: January 2005

AbstractAb initio calculations show that a neutral polypyrrole chain in the ground state assumes a helical shape resulting from a novel bending mechanism, while upon oxidation the chain becomes planar within the polarons, an effect due to enhanced inter‐ring π bonding. This polaron‐induced conformation change leads to an intrinsic potential for inducing macroscopic strains in the single chain, with implications for further theoretical studies and experiments. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Spectral properties of minimal‐basis‐set orbitals: Implications for molecular electronic continuum states
Authors: Langhoff P. W. , Winstead C. L. 
Published: January 2005

AbstractEarly studies of the electronically excited states of molecules by John A. Pople and coworkers employing ab initio single‐excitation configuration interaction (SECI) calculations helped to simulate related applications of these methods to the partial‐channel photoionization cross sections of polyatomic molecules. The Gaussian representations of molecular orbitals adopted by Pople and coworkers can describe SECI continuum states when sufficiently large basis sets are employed. Minimal‐basis virtual Fock orbitals stabilized in the continuous portions of such SECI spectra are generally associated with strong photoionization resonances. The spectral attributes of these resonance orbitals are illustrated here by revisiting previously reported experimental and theoretical studies of molecular formaldehyde (H2CO) in combination with recently calculated continuum orbital amplitudes. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The use of elementary reaction coordinates in the search for conical intersections
Authors: Haas Yehuda , Cogan Semyon , Zilberg Shmuel 
Published: January 2005

AbstractA method to locate conical intersections between the ground‐state potential surface and the first electronically excited states of polyatomic molecules is described. It is an extension of the Longuet‐Higgins sign‐change theorem and uses reaction coordinates of elementary reactions as the starting point of the analysis. It is shown that the complete molecular landscape 1 can be partitioned into 2‐D domains, each bordered by a Longuet‐Higgins loop formed from reaction coordinates of elementary reactions. A domain may contain a conical intersection and if it does, it contains only one (the uniqueness theorem), whose energy is higher than the neighboring minima or transition states. The method can be helped by symmetry, but applies also to systems having no symmetry elements. It is demonstrated for some simple cases. The presence of a conical intersection is manifested by the nature of ground‐state thermal reactions, as shown for instance by the fact that the transition state in the ring opening of the cyclopropyl radical is nonsymmetric. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
DFT and experimental studies of the structure and vibrational spectra of curcumin
Authors: Kolev Tsonko M. , Velcheva Evelina A. , Stamboliyska Bistra A. , Spiteller Michael 
Published: January 2005

AbstractThe potential energy surface of curcumin [1,7‐bis(4‐hydroxy‐3‐methoxyphenyl)‐1,6‐heptadiene‐3,5‐dione] was explored with the DFT correlation functional B3LYP method using 6‐311G* basis. The single‐point calculations were performed at levels up to B3LYP/6‐311++G**//B3LYP/6‐311G*. All isomers were located and relative energies determined. According to the calculation the planar enol form is more stable than the nonplanar diketo form. The results of the optimized molecular structure are presented and compared with the experimental X‐ray diffraction. In addition, harmonic vibrational frequencies of the molecule were evaluated theoretically using B3LYP density functional methods. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. Our vibrational data show that in both the solid state and in all studied solutions curcumin exists in the enol form. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Density functional study of the heme moiety of cytochrome c
Authors: Kumar Anil , Mishra P. C. , Verma C. S. , Renugopalakrishnan V. 
Published: January 2005

AbstractA model of cytochrome c (Cyt‐c) including the porphyrin ring, a methionine residue (Met), and the imidazole ring of histidine (His), the latter two being situated above and below the iron (Fe) atom of the porphyrin ring, was studied using Density Functional Theory (DFT). The geometries of the model Cyt‐c complex with the Fe atom in two different charge states were fully optimized, i.e., in singlet and triplet states for Fe and in doublet and quartet states for Fe3+. The B3LYP method of DFT along with the 3‐21G* basis set for C, H, N, and O atoms and the Lanl2dz basis set for the Fe atom was used. We found that with Fe3+, the doublet spin state is the ground state and the quartet state lies slightly above it. The geometry of the singlet spin state is similar to that of the doublet and quartet states. However, methionine has different conformations when Fe has zero charge (singlet, triplet states) relative to the situation when Fe has +3 charges (doublet, quartet states). The Met chain is folded instead of remaining extended in going from the singlet or triplet spin state to the doublet or quartet state and the folding is stabilized by an intramolecular CH..O hydrogen bond. The optimized geometrical parameters of the model of Cyt‐c are usually in satisfactory agreement with those observed experimentally. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Random subgraphs of finite graphs: I. The scaling window under the triangle condition
Authors: Borgs Christian , Chayes Jennifer T. , van der Hofstad Remco , Slade Gordon , Spencer Joel 
Published: January 2005

AbstractWe study random subgraphs of an arbitrary finite connected transitive graph 𝔾 obtained by independently deleting edges with probability 1 − p. Let V be the number of vertices in 𝔾, and let Ω be their degree. We define the critical threshold pc = pc (𝔾, λ) to be the value of p for which the expected cluster size of a fixed vertex attains the value λV1/3, where λ is fixed and positive. We show that, for any such model, there is a phase transition at pc analogous to the phase transition for the random graph, provided that a quantity called the triangle diagram is sufficiently small at the threshold pc. In particular, we show that the largest cluster inside a scaling window of size |p − pc| = Θ(Ω−1V−1/3) is of size Θ(V2/3), while, below this scaling window, it is much smaller, of order O(ϵ−2 log(Vϵ3)), with ϵ = Ω(pc − p). We also obtain an upper bound O(Ω(p − pc)V) for the expected size of the largest cluster above the window. In addition, we define and analyze the percolation probability above the window and show that it is of order Θ(Ω(p − pc)). Among the models for which the triangle diagram is small enough to allow us to draw these conclusions are the random graph, the n‐cube and certain Hamming cubes, as well as the spread‐out n‐dimensional torus for n > 6. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
Counting subgraphs in quasi‐random 4‐uniform hypergraphs
Authors: Rödl Vojtĕch , Skokan Jozef 
Published: January 2005

AbstractA bipartite graph G = (V1 ∪ V2, E) is (δ, d)‐regular if

whenever $V^{\prime}_{i}\subset V_{i}, |V^{\prime}_{i}| \geq \delta|V_{i}|, i = 1,2.$ Here, $d(V^{\prime}_{1}, V^{\prime}_{2}) = e(V^{\prime}_{1}, V^{\prime}_{2})/|V^{\prime}_{1}||V^{\prime}_{2}|$ stands for the density of the pair $(V^{\prime}_{1}, V^{\prime}_{2}).$ An easy counting argument shows that if G = (V1 ∪ V2 ∪ V3, E) is a 3‐partite graph whose restrictions on V1 ∪ V2, V1 ∪ V3, V2 ∪ V3 are (δ, d)‐regular, then G contains $(d^{3} \pm f(\delta))|V_{1}||V_{2}||V_{3}|$ copies of K3. This fact and its various extensions are the key ingredients in most applications of Szemerédi's Regularity Lemma. To derive a similar results for r‐uniform hypergraphs, r > 2, is a harder problem. In 1994, Frankl and Rödl developed a regularity lemma and counting argument for 3‐uniform hypergraphs. In this paper, we exploit their approach to develop a counting argument for 4‐uniform hypergraphs. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
Biology and Revolution in Twentieth-Century China. By Laurence Schneider. [Lanham, MD: Rowman and Littlefield Publishers, 2003. xi +305 pp. ISBN 0-7425-2696-8.]
Authors: Dikötter Frank 
Published: January 2005

Readers who expect a comprehensive analysis of biological science in modern China, as the blurb on the jacket promises, may be disappointed: this book specifically contrasts the small community of followers of T. H. Morgan in Republican China with the state-sponsored rise of Lysenkoism after 1949. The first part follows the development of genetics and evolutionary theory in three universities in China, namely National Central University in Nanjing; the missionary school of Yanjing University in Beijing, linked to the Rockefeller Foundation's Peking Union Medical College; and Nanjing University, an American missionary school closely tied to Cornell. The author shows that training in biology and genetics developed in these three schools, thanks to substantial philanthropic involvement from the United States, as a “transfer” of knowledge took place between Chinese life scientists and major American institutions.While the author presents valuable biographies of a small number of scientists such as Chen Zhen, Tan Jiazhen and Tang Peisong, and succeeds in recreating the political and institutional context within which these three geneticists operated, his work is insufficiently grounded in primary sources. The literature produced by biologists in Republican China is never invoked in any systematic way, the first chapter being largely based on Chen Zhen's biology textbook to create the impression of a neat “transfer” of knowledge from the United States. However, incompatible theories in biology were often invoked, contradictory ideas about evolution were bandied around, and vague phrases on “struggle for survival” were widespread in dozens of biology textbooks, many far more popular than Chen Zhen's work: neo-Lamarckism and Mendel-Morganism were never tidily organized into two “schools,” and they could even overlap, as very different writers from complex backgrounds struggled to make sense of an ever-growing global repertoire of biological theories. In Europe and the United States too, biologists disagreed over the relative importance of nurture versus nature, and China was no exception: diversity, elided by the author in favour of a fairly simplistic notion of an American success in Republican China before the failure of Lysenkoism under Soviet influence, is precisely what makes pre-1949 biology such a fascinating field.
Preparation of rhodamine-labelled tubulin and its reassembly in guard cells in leaves of Vicia faba L.
Authors: Rong Yu , Ming Yuan , Xue-Chen Wang 
Published: January 2005

AbstractTubulin from fresh pig brain was extracted through two cycles of polymerization and depolymerization, purified by chromatography on an ion-exchange column and labelled with 5(6)-carboxytetramethylrhodamine succinimidyl ester. We prepared 10.8 mg/ml rhodamine-labelled tubulin probe (dye/protein=0.6) and then microinjected it into living guard cells in leaves of Vicia faba L. After 5–10 min, a network of microtubules (MTs) could clearly be observed in the guard cells under a confocal laser scanning microscope. In opening guard cells, the cortical MTs radiated from the ventral wall to the dorsal wall and in closed guard cells the radial MTs were completely depolymerized into random and diffuse fragments. This shows that pig brain tubulin can easily be incorporated into MTs in guard cells, and that the dynamic behaviour of MTs can be examined directly in vivo during stomatal movement.