bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of p21‐activated kinase 1 alters the behavior of renal cell carcinoma
Authors: O'Sullivan Gerald C. , Tangney Mark , Casey Garret , Ambrose Monica , Houston Aileen , Barry Orla P. 
Published: July 2007

AbstractThe p21‐activated kinase 1 (Pak1) is a serine/threonine kinase whose activity is regulated by both Rho GTPases and AGC kinase family members. It plays a role in cytoskeletal remodeling and cell motility as well as cell proliferation, angiogenesis, tumorigenesis and metastasis. An involvement of Pak1 in renal cell carcinoma (RCC), which remains highly refractory to chemotherapy and radiotherapy, remains to be investigated. Pak1 expression, phosphorylation and kinase activity were examined in RCC cell lines and human tissue from normal and renal carcinoma. We report increased Pak1 expression and constitutive activity in the membrane and nucleus but not the cytoplasm of resected human RCC. To study a role for Pak1 in RCC, we developed 786‐0 clones that expressed either a kinase‐active Pak1L83,L86 2 different Pak1 dominant negative mutants, Pak1R299 and Pak1L83,L86,R299 or Pak1 siRNA. The expression of Pak1L83,L86 increased 786‐0 proliferation, motility and anchorage independent growth, while the dominant negative mutants and Pak1 siRNA abrogated these effects. In addition, Pak1L83,L86 conferred resistance to 5‐fluorouracil with a 40% ± 10% increase in cell viability. Conversely, Pak1L83,L86,R299, Pak1R299 and Pak1 siRNA conferred sensitivity with a 65.2% ± 5.5%, 69.2% ± 3.3% and 73.0% ± 8.4% loss in viability, respectively. Finally, Pak1 plays a role in renal tumor growth in vivo. Only 33% of mice developed tumors in the Pak1L83,L86,R299 group and no tumors developed from Pak1R299 cell challenge. Together these findings point to Pak1 as an exciting target for therapy of renal cancer, which remains highly refractory to existing treatments. © 2007 Wiley‐Liss, Inc.
Total loss of HLA class I expression on a melanoma cell line after growth in nude mice in absence of autologous antitumor immune response
Authors: Paco Laura , Garcia‐Lora Angel Miguel , Casares Carlos , Cabrera Carmen , Algarra Ignacio , Collado Antonia , Maleno Isabel , Garrido Federico , Lopez‐Nevot Miguel Angel 
Published: July 2007

AbstractLoss of HLA class I expression on tumor cells is a frequent event as an immune escape mechanism. Seven different altered HLA phenotypes have been defined in tumors. Various molecular mechanisms have been described as responsible for HLA class I loss. HLA class I expression alterations occur successively and unpredictably during tumor progression in vivo and immunoselection has been implicated in this process. We present an experimental xenograft model in which melanoma cell line Ando‐2 injected into athymic nude mice lost total surface HLA class I expression and exhibited HLA class II cell surface expression. A strong down‐regulation of HLA class I expression and de novo HLA class II expression were also found when Ando‐2 melanoma cells were injected into SCID‐Beige mice. These phenomena were reproducible and were only observed in local growth in nude or SCID‐Beige mice and not in vitro after multiple passages. HLA class I surface expression was recovered after IFN‐γ treatment, indicating regulatory defects. The mechanism implicated in loss of HLA class I molecule expression were a down‐regulation of different components of antigen processing machinery and HLA class I heavy chains. These data suggest that HLA class I alterations can also occur in absence of autologous adaptive immune response. This is a good experimental in vivo model to study the relationship between tumor progression and HLA class I alterations. © 2007 Wiley‐Liss, Inc.
Interleukin‐8 modulates growth and invasiveness of estrogen receptor‐negative breast cancer cells
Authors: Yao Chen , Lin Ying , Chua Mei‐Sze , Ye Cai‐Sheng , Bi Jiong , Li Wen , Zhu Yi‐Fan , Wang Shen‐Ming 
Published: July 2007

AbstractBreast cancer, especially estrogen receptor (ER)‐negative breast cancer, remains hard to treat despite major advances in surgery and adjuvant therapies. The deletion of ER has been consistently associated with tumor progression, recurrence, metastasis and poor prognosis. Among other differences in biological features, ER‐negative breast cancers express high levels of interleukin‐8 (IL‐8), whereas their ER‐positive counterparts do not. IL‐8 is a multi‐functional cytokine with many important biological functions in tumor formation and development. We aimed to study the role(s) of IL‐8 in ER‐negative breast cancer progression by using RNA interference to specifically knockdown IL‐8 expression in ER‐negative breast cancer cell lines MDA‐MB‐231 and MDA‐MB‐468. In vitro, suppression of IL‐8 led to significant reductions in cell invasion (p < 0.001), but had no effects on cell proliferation or cell cycle. In vivo, suppression of IL‐8 significantly reduced the microvessel density (p < 0.05), and markedly reduced neutrophil infiltration into the tumors (p < 0.05). In contrast to in vitro observations, suppression of IL‐8 promoted tumor growth in nude mice (p < 0.05). Our results imply that the complex roles of IL‐8 in the regulation of ER‐negative breast cancer progression may in part be related to its potent chemotactic effects on neutrophils, which in turn mediates many of the biological functions of IL‐8. © 2007 Wiley‐Liss, Inc.
The response of subcutaneous connective tissue to a new endodontic filling material
Authors: Bodrumlu Emre , Muglali Mehtap , Sumer Mahmut , Guvenc Tolga 
Published: July 2007

AbstractThe purpose of this histopathologic study was to assess and compare the subcutaneous connective tissue reaction to a new root canal filling material, Resilon and gutta‐percha. The test materials were directly inserted subcutaneously into the dorsal connective tissue of Wistar albino rats. Histopathological examinations were done at 7, 15, 30, and 60 days after the implantation procedure. The presence of inflammation, predominant cell types, and the thickness of fibrous connective tissue adjacent to each inserted sample were recorded. There were no differences in tissue reaction between Resilon cone material and gutta‐percha cone groups for first three observation periods (p > 0.05). However, there were highly significant differences among observation periods within both groups (7, 15, 30, and 60 days) (p < 0.01). The tissues showed high tolerance to Resilon and gutta‐percha at the 60th day. Resilon may serve as an alternative to gutta‐percha in terms of biocompatibility. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Comparison of cell culture with RT‐PCR for enterovirus detection in stool specimens from patients with acute flaccid paralysis
Authors: Shoja Zabih‐Ollah , Tabatabie Hamideh , Shahmahmoudi Shohreh , Nategh Rakhshandeh 
Published: July 2007

AbstractSince October 2000, Iran has been declared polio‐free by the World Health Organization (WHO). Despite the fact that poliomyelitis caused by polioviruses has been eliminated from Iran, the number of acute flaccid paralysis (AFP) cases has not been reduced. Therefore, it is of great importance to investigate the other viral agents that may cause AFP (mainly nonpolio enteroviruses, which play a significant role in the etiology of neurological syndromes). Some enteroviruses do not grow in the conventional cell lines that are being used for enterovirus detection. Furthermore, the virus titer is an important factor in the sensitivity of cell culture to detect the virus. The fact that cell culture is a time‐consuming procedure is another reason to find a more practical method for enterovirus detection. Therefore, a more sensitive and rapid method should be used to detect enteroviruses as efficiently as possible in the stool specimens of AFP cases. The aim of this study was to evaluate cell culture and RT‐PCR in enterovirus detection. Findings have shown that RT‐PCR can increase the rate of nonpolio enterovirus detection by up to 10% in comparison with cell culture. Also, the rapid detection of enteroviruses by RT‐PCR can decrease both the unnecessary use of antibiotics and the costs in clinical practice. For this reason, we find that RT‐PCR is a more practical technique for enterovirus detection. J. Clin. Lab. Anal. 21:232–236, 2007. © 2007 Wiley‐Liss, Inc.
P2Y nucleotide receptor signaling through MAPK/ERK is regulated by extracellular matrix: Involvement of β3 integrins
Authors: Kudirka Julie C. , Panupinthu Nattapon , Tesseyman Mark A. , Dixon S. Jeffrey , Bernier Suzanne M. 
Published: July 2007

AbstractExtracellular matrix influences cell behavior through receptors such as integrins and through transmission of mechanical forces. Nucleotides are released in response to mechanical stimuli and bind to P2 nucleotide receptors. As chondrocytes are subjected to frequent mechanical stimulation within a rich extracellular matrix, they are an excellent model for studying integration of signals induced by matrix and nucleotides. We investigated signaling of G protein‐coupled P2Y receptors to MAPK/ERK and how this is influenced by matrix. Rat articular chondrocytes expressed transcripts for P2Y1, P2Y2, P2Y4, and P2Y6 receptors and responded to extracellular nucleotides by transient elevation of cytosolic calcium and MAPK/ERK phosphorylation. ERK1/2 activation was suppressed by the protein kinase C (PKC) inhibitors bisindolylmaleimide I and rottlerin, and by the phospholipase D inhibitor 1‐butanol. Thus, nucleotides stimulate P2Y receptors to activate ERK1/2 through a mechanism dependent on PKC and phospholipase D. We next examined the involvement of integrins. Both an RGD‐containing pentapeptide and a β3 integrin blocking antibody, but not a β1 integrin blocking antibody, abolished nucleotide‐induced ERK1/2 phosphorylation. Moreover, chondrocytes adhering to fibronectin (which binds to β1 and β3 containing integrins in an RGD‐dependent manner) displayed prolonged ERK1/2 signaling compared to cells grown on type I or II collagen (which bind to β1‐containing integrins in an RGD‐independent manner). In conclusion, P2Y receptor signaling through ERK1/2 is gated selectively by matrix proteins. Thus, nucleotides released in response to mechanical stimulation will have differing effects on cell function due to changes in the composition of the extracellular matrix during development and disease. J. Cell. Physiol. 213: 54–64, 2007. © 2007 Wiley‐Liss, Inc.
Ca2+ signaling differentiation during oocyte maturation
Authors: Machaca Khaled 
Published: July 2007

AbstractOocyte maturation is an essential cellular differentiation pathway that prepares the egg for activation at fertilization leading to the initiation of embryogenesis. An integral attribute of oocyte maturation is the remodeling of Ca2+ signaling pathways endowing the egg with the capacity to produce a specialized Ca2+ transient at fertilization that is necessary and sufficient for egg activation. Consequently, mechanistic elucidation of Ca2+ signaling differentiation during oocyte maturation is fundamental to our understanding of egg activation, and offers a glimpse into Ca2+ signaling regulation during the cell cycle. J. Cell. Physiol. 213: 331–340, 2007. © 2007 Wiley‐Liss, Inc.
Soluble receptor inhibits leptin transport
Authors: Tu Hong , Kastin Abba J. , Hsuchou Hung , Pan Weihong 
Published: July 2007

AbstractEvidence both from mice and cultured cells suggests an important role of soluble leptin receptors in obesity and leptin signaling. However, the direct effects of soluble receptors on leptin uptake by cells are not clear. This study shows that soluble leptin receptors antagonize the permeation of leptin across the mouse blood‐brain barrier by reducing the binding and endocytosis of leptin. This is illustrated by analysis of radioactively labeled and fluorescent‐tagged leptin in normal mice and in cultured cells overexpressing various forms of leptin receptors. Three constructs of soluble leptin receptors were generated in this study: ObRe (805 aa), ObR839, and ObR852. 125I‐leptin was injected intravenously and its influx rate from blood to brain determined by multiple‐time regression analysis. Pre‐incubation with ObR839 caused a significant reduction of leptin influx across the blood‐brain barrier. Endocytosis assays and fluorescent image analysis further showed that ObRe, ObR839, and ObR852 failed to mediate leptin internalization and trafficking within the cells. Instead, these soluble receptors inhibited surface binding and endocytosis of leptin. Thus, we provide novel direct evidence both in vivo and in vitro that soluble receptors of leptin serve as antagonists of the transport of leptin. J. Cell. Physiol. 214: 301–305, 2008. © 2007 Wiley‐Liss, Inc.
Effect of the pineal hormone melatonin on teleost fish phagocyte innate immune responses after in vitro treatment
Authors: Cuesta Alberto , Rodríguez Alejandro , Calderón Ma Victoria , Meseguer José , Esteban Ma Ángeles 
Published: July 2007

AbstractAlthough neuroendocrine‐immune system interaction has been shown in teleost fish, no study has evaluated the role of melatonin (Mel) on fish immune response even considering that it is affected by the photoperiod. Gilthead seabream (Sparus aurata L.) and sea bass (Dicentrarchus labrax L.) head‐kidney leucocytes were incubated with Mel (0‐control‐, 20 pM–400 µM) and leucocyte viability and main innate cellular immune parameters were evaluated. Overall, seabream and sea bass head‐kidney leucocytes incubated with low (similar to physiological) doses of Mel unchanged the innate immune response, whereas very high (pharmacological) dosages did. Phagocytosis was not affected by any Mel treatment while the peroxidase activity was significantly inhibited with the highest Mel concentration. In contrast, the sea bass respiratory burst activity was increased in a dose‐dependent manner with 400 nM Mel or higher. Further studies are needed to clarify whether there are interactions between the fish pineal gland, and its hormone Mel, and the fish immune system. J. Exp. Zool. 307A:509–515, 2007. © 2007 Wiley‐Liss, Inc.
Chain Propagation Kinetics on Melt Grafting Reaction
Authors: Shi Qiang , Cai Chuan‐Lun , Zhu Lian‐Chao , Yin Jing‐Hua 
Published: July 2007

AbstractGraft copolymerization in the molten state is of fundamental importance as a probe of chemical modification and reactive compatibilization. However, few grafting kinetic studies on reactive extrusion have been carried out because of the inherent difficulties, as expected. In this work, we have studied chain propagation kinetics on melt grafting using pre‐irradiated linear low density polyethylene (LLDPE) and three monomers, acrylic acid (AA), methacrylic acid (MAA), and methyl methacrylate (MMA), as the model system. We measured the apparent chain propagation rate coefficients of grafting (kp,g) and homopolymerization (kp,h) at an initial stage for the melt grafting by FT‐IR spectroscopy and electron spin resonance spectroscopy. It was observed that the convective mixing affected the rate coefficients. The magnitude of kp,h and kp,g were in the same order, but kp,h was slightly larger than kp,g. The kp,g of the three grafting systems increased in the order: LLDPE/MMA < LLDPE/MAA < LLDPE/AA. These results are explained in terms of phase separation, solubility, and inherent reactivity of the monomer.magnified image
Dynamic Behavior of the Minority Phase of Photoaddressable Block Copolymers
Authors: Kreger Klaus , Löffler Christina , Walker Roland , Wirth Nadine , Bingemann Dieter , Audorff Hubert , Rössler Ernst A. , Kador Lothar , Schmidt Hans‐Werner 
Published: July 2007

AbstractWe present an analysis of the temperature‐dependent dynamic behavior of the minority phase of photoaddressable block copolymers. Solid‐state 2H NMR investigations are compared with holographic experiments. The samples are diblock copolymers based on polystyrene (PS) and poly(1,2‐butadiene) (PB), where the PB minority segment is functionalized with different deuterated moieties. Solid‐state 2H NMR investigations were performed from 320 to 380 K in order to study the thermal behavior of the minority segment. Holographic experiments on thin films of the block copolymers yielded the photoinduced diffraction efficiency at different temperatures. The comparison of both datasets enables us to identify the glass transition temperature Tg of the minority phase.magnified image
Kinetics of Shear Microphase Orientation and Reorientation in Lamellar Diblock and Triblock Copolymer Melts as Detected via FT‐Rheology and 2D‐SAXS
Authors: Oelschlaeger Claude , Gutmann Jochen S. , Wolkenhauer Markus , Spiess Hans‐Wolfgang , Knoll Konrad , Wilhelm Manfred 
Published: July 2007

AbstractThe microphase orientation/reorientation alignment kinetics behaviour of lamellar PS‐b‐PB diblock and PS‐b‐PB‐b‐PS triblock copolymers under LAOS conditions is studied. By online monitoring the degree of the mechanical nonlinearity during the orientation process, as determined via the higher harmonics in FT rheology [i.e:I3/1(t),ϕ3(t)], and investigation of the orientation distribution by 2D‐SAXS, the kinetics of the microphase alignment for different experimental shear conditions was followed. For di‐ and triblock copolymers, the shear orientation into parallel alignment is possible and the kinetics of orientation is strongly dependent on the strain amplitude.magnified image
Recent Gelation Studies on Irreversible and Reversible Systems with Dynamic Light Scattering and Rheology ‐ A Concise Summary
Authors: Richter Sven 
Published: July 2007

Abstract“What, then, is truth? A mobile army of metaphors, metonyms, and anthropomorphisms ‐ in short, a sum of human relations which have been enhanced, transposed, and embellished poetically and rhetorically, and which after long use seem firm, canonical, and obligatory to a people: truths are illusions about which one has forgotten that this is what they are; metaphors which are worn out and without sensuous power; coins which have lost their pictures and now matter only as metal, no longer as coins.”[Friedrich Nietzsche:On Truth and Lie in an Extra‐Moral Sens (1873)]This contribution is a short summary of the recent achievements of the author in the field of gelation research on irreversible gelling systems based onN‐vinylcaprolactam and on thermoreversible systems (xanthan gum/locust bean gum, and gelatin) mainly based on dynamic light scattering and oscillatory shear rheology. These investigations are discussed in the framework of studies of other authors. It will be pointed out that both methods are well suited to detect the sol‐gel transition, but some expectations that the two different methods can lead to different results will be given, which may be of importance to other systems. In the main focus is the comparison of dynamical critical exponents yielded from the two methods at the sol‐gel transition.magnified image
Raman and Infrared Imaging of Dynamic Polymer Systems
Authors: Koenig Jack L. , Bobiak John P. 
Published: July 2007

AbstractThis work reviews principles of Raman and infrared imaging, as well as applications of the art to understand physiochemical phenomena in polymer systems. Image sequences may be assessed in terms of spatial or spectral changes that occur over time, either within a specific region or across the field of view. As such, the methods have enabled the analysis of diffusion and dissolution processes at polymer interfaces, drug release from polymer matrices, and structural transitions among others. Despite analytical limitations imposed by resolution (spectral or spatial) and sample preparation, Raman and infrared imaging are powerful tools for relating performance attributes to molecular‐level characteristics.magnified image
Weak asymptotics of the spectral shift function
Authors: Bruneau Vincent , Dimassi Mouez 
Published: July 2007

AbstractWe consider the three‐dimensional Schrödinger operator with constant magnetic field of strength b > 0, and with smooth electric potential. The weak asymptotics of the spectral shift function with respect to b ↗ +∞ is studied. First, we fix the distance to the Landau levels, then the distance to Landau levels tends to infinity as b ↗ +∞. In particular we give explicitly the leading terms in the asymptotics and in some case we obtain full asymptotics expansions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Higher order Teodorescu operators in quaternionic analysis related to the Helmholtz operator
Authors: Ha Vu Thi Ngoc 
Published: July 2007

AbstractThe properties of the Teodorescu integral operator in quaternionic analysis related to the Helmholtz operator and its iteration are investigated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oscillatory behavior of linear matrix Hamiltonian systems
Authors: Sun Yuan Gong , Meng Fanwei 
Published: July 2007

AbstractWe establish some new oscillation criteria for the matrix linear Hamiltonian system X ′ = A (t)X + B (t)Y, Y ′ = C (t)X –A *(t)Y by using a new function class X and monotone functionals on a suitable matrix space. In doing so, many existing results are generalized and improved. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unboundedness of solutions of a class of planar Hamiltonian systems
Authors: Yang Xiaojing , Lo Kueiming 
Published: July 2007

AbstractIn this paper, the unboundedness of solutions for the following planar Hamilton systemJu ′ = ∇H (u) + h (t)is discussed, where the function H (u) ∈ C2(R2, R) is positive for u ≠ 0 and is positively (q, p)‐quasihomogeneous of quasi‐degree pq, where p > 1 and $ 1 \over p $ + $ 1 \over q $ = 1, h: S1 → R2 with h ∈ L∞(0, 2π) is 2π ‐periodic and J is the standard symplectic matrix. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Duals of Hardy spaces on homogeneous groups
Authors: Bownik Marcin , Folland Gerald B. 
Published: July 2007

AbstractHardy spaces on homogeneous groups were introduced and studied by Folland and Stein [3]. The purpose of this note is to show that duals of Hardy spaces Hp , 0 < p ≤ 1, on homogeneous groups can be identified with Morrey–Campanato spaces. This closes a gap in the original proof of this fact in [3]. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Bourgain property and convex hulls
Authors: Rodríguez José 
Published: July 2007

AbstractLet (Ω, Σ, μ) be a complete probability space and let X be a Banach space. We consider the following problem: Given a function f: Ω → X for which there is a norming set B ⊂ BX * such that Zf,B = {x * ○ f: x * ∈ B } is uniformly integrable and has the Bourgain property, does it follow that f is Birkhoff integrable? It turns out that this question is equivalent to the following one: Given a pointwise bounded family ℋ︁ ⊂ ℝΩ with the Bourgain property, does its convex hull co(ℋ︁) have the Bourgain property? With the help of an example of D. H. Fremlin, we make clear that both questions have negative answer in general. We prove that a function f: Ω → X is scalarly measurable provided that there is a norming set B ⊂ BX * such that Zf,B has the Bourgain property. As an application we show that the first problem has positive solution in several cases, for instance: (i) when BX * is weak* separable; (ii) under Martin's axiom, for functions defined on [0, 1] with values in a Banach space with density character smaller than the continuum. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)