bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clenbuterol increases muscle fiber size and GATA‐2 protein in rat skeletal muscle in utero
Authors: Downie Diane , Delday Margaret I. , Maltin Charlotte A. , Sneddon Alan A. 
Published: October 2007

AbstractCertain β2‐adrenoceptor agonists, such as clenbuterol, are known to elicit a muscle‐specific anabolism or hypertrophy in both normal and catabolic muscle in a wide variety of species. However, the underlying mechanism(s) of the β2‐agonist‐induced anabolism remains unclear. This study aimed to determine the effects of clenbuterol administration in utero on skeletal muscle and to examine the underlying molecular mechanisms. Pregnant rats were fed clenbuterol (2 mg/kg diet) from Day 4 of gestation (4 dg) until weanling and fetal samples were taken from 13.5, 15.5, 17.5, and 19.5 dg and from 1d neonatal pups. Muscles were analyzed for total DNA, RNA and protein and sections examined morphologically for changes in muscle development. Western and immunohistochemical analyses were performed to identify changes in known myogenic signaling proteins. Clenbuterol increased the size of both fast and slow fibers in utero which was associated with a decreased DNA:protein ratio (28%) and an increased RNA:DNA ratio (36%). Additionally, drug treatment in utero induced a decrease in the fast:slow fiber ratio (38%). These myogenic changes were correlated with an increase in the GATA‐2 hypertrophic transcription factor at both 17.5 dg (by 250%) and 19.5 dg (by 40%) in fetuses from clenbuterol treated dams. In addition, drug treatment resulted in increased membrane association of PKC‐µ at 17.5 dg (325%) and increased PKC‐α cytosolic abundance (40%) and PKC‐θ membrane abundance at 19.5 dg (250%). These results are the first demonstration that β2‐agonists such as clenbuterol may act through upregulating the GATA‐2 transcription factor and implicate certain PKC isoforms in the drug‐induced regulation of skeletal muscle development. Mol. Reprod. Dev. 75: 785–794, 2008. © 2007 Wiley‐Liss, Inc.
Oocyte morphology and transcriptional silencing in relation to chromatin remodeling during the final phases of bovine oocyte growth
Authors: Lodde Valentina , Modina Silvia , Maddox‐Hyttel Poul , Franciosi Federica , Lauria Antonio , Luciano Alberto M. 
Published: October 2007

AbstractThe complexity of the events which orchestrate mammalian oocyte growth and ultimate acquisition of developmental competence is still unclear and under continuous investigation. Starting from the observation that germinal vesicle (GV) bovine oocytes exhibit different patterns of chromatin configuration (from GV0 to GV3), the present study aimed at analyzing the morphology of the nuclear and the cytoplasmic compartments and to determine the total transcriptional activity of immature oocytes sorted on the basis of their chromatin configuration. The oocyte morphology was analyzed by light microscopy (LM) on semi‐thin sections and transmission electron microscopy, and the global transcriptional activity was analyzed by H3‐Uridine incorporation and subsequent autoradiography on semi‐thin sections. LM confirmed the increase in chromatin condensation from GV0 to GV3. Ultrastructurally, the nucleolus was fibrillo granular at GV0 while the other stages displayed an electron‐dense fibrillar sphere with the remnant of a fibrillar center on the surface. Organelles were dispersed in the cytoplasm at GV0 while at GV1 and GV2 most of them were homogenously distributed in the oocyte cortex. At GV3 most organelles were found in clusters in the oocyte cortex. Typical features of completion of the oocyte growth phase, like undulation of the nuclear envelope and reduction of the size of Golgi complex were found at GV2 and GV3. Moreover, GV3 oocytes presented cortical granules that displayed varying degrees of degeneration. Autoradiographic labeling showed that oocytes with GV0 configuration exhibited high level of RNA synthesis, GV1 and GV2 stages showed a remarkable decrease of transcription, and the acquisition of GV3 configuration was associated with global repression of transcriptional activity. Our findings suggest a temporal relationship between the chromatin remodeling process and the main morpho‐functional events that characterize the final growth phase in bovine oocyte. Mol. Reprod. Dev. 75: 915–924, 2008. © 2007 Wiley‐Liss, Inc.
On the hierarchy of γ‐valid cuts in global optimization
Authors: Porembski Marcus 
Published: October 2007

AbstractConcavity Cuts play an important role in concave minimization. In Porembski, J Global Optim 15 (1999), 371–404 we extended the concept underlying concavity cuts which led to the development of decomposition cuts. In numerical experiments with pure cutting plane algorithms for concave minimization, decomposition cuts have been shown to be superior to concavity cuts. However, three points remained open. First, how to derive decomposition cuts in the degenerate case. Second, how to ensure dominance of decomposition cuts over concavity cuts. Third, how to ensure the finite convergence of a pure cutting plane algorithm solely by decomposition cuts. These points will be addressed in this paper. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Blood–brain barrier permeability to manganese and to Gd‐DOTA in a rat model of transient cerebral ischaemia
Authors: Grillon Emmanuelle , Provent Peggy , Montigon Olivier , Segebarth Christoph , Rémy Chantal , Barbier Emmanuel L. 
Published: October 2007

AbstractLoss of integrity of the blood–brain barrier (BBB) and brain swelling is a potentially lethal complication of reperfusion in human stroke. To assess the time course of BBB modifications, we performed angiography, diffusion‐weighted imaging, T1‐weighted (T1W) imaging and T1 mapping, and monitored acute changes after middle cerebral artery occlusion and recanalization in rats (n = 27). The animals were grouped according to the duration of occlusion: 30 min (group A, n = 8), 1 h 30 min (group B, n = 9), and 2 h 30 min (group C, n = 10). For 17 animals (four in group A, six in group B, and seven in group C), MnCl2 and dimeglumine gadoterate (Gd‐DOTA) were injected at 13 min and 34 min after recanalization, respectively. The 10 remaining animals (control groups) underwent the same acquisition protocols, but no contrast agents were injected. Cell damage was determined 1 h after recanalization on haematoxylin and eosin‐stained sections. Our results indicate that in the middle cerebral artery occlusion model in the rat, changes in BBB permeability assessed by contrast agent extravasation occur within the first hour of reperfusion, even after an occlusion period not exceeding 30 min. No differences between BBB permeability to Gd‐DOTA and Mn2+ were detected in our experimental conditions. The reduction in apparent diffusion coefficient during occlusion appears to be a good predictor of BBB modifications after reperfusion in this model. Copyright © 2007 John Wiley & Sons, Ltd.
A strategy to reduce the control packet load of MANETs with bidirectional links using DSR
Authors: Tamilarasi Muthu , Palanivelu T. G. 
Published: October 2007

AbstractDynamic source routing (DSR) is a robust protocol commonly applied to multi‐hop wireless mobile ad hoc networks (MANETs). In this paper, an algorithm is proposed for modifying the basic DSR protocol to enhance its performance by reducing the number of redundant route reply packets (RREPs). In the modified DSR (MDSR), for a source destination pair, the destination responds to the first received route request packet (RREQ) with an RREP, and the subsequently received RREQs, bearing the same request ID, are responded to only if the hop count is less than that of all the previously received RREQs. The performance of MDSR has been compared with that of the basic DSR for different network densities and for different mobility of nodes. Simulation results show that MDSR gives fewer control packets, less latency and a higher packet delivery ratio than DSR. Copyright © 2007 John Wiley & Sons, Ltd.
A geometrically exact thin membrane model—investigation of large deformations and wrinkling
Authors: Weinberg Kerstin , Neff Patrizio 
Published: October 2007

AbstractWe investigate a geometrically exact membrane model with respect to its capabilities in describing buckling and wrinkling. The concept is distinct from traditional ones by the introduction of an artificial viscosity related to an adjusted orthonormal frame (rotations). In this way our model is able to capture the detailed geometry of wrinkling while the balance of force equations remains elliptic throughout. The movement of rotations is given by a local evolution equation. We discuss the consistent linearization of the model and the local update of rotations. Numerical examples are presented, which demonstrate the effectiveness of the new model for predicting wrinkles in membranes undergoing large deformation. Copyright © 2007 John Wiley & Sons, Ltd.
Shape optimization of geotextile tubes for sandy beach protection
Authors: Isebe Damien , Azerad Pascal , Bouchette Frederic , Ivorra Benjamin , Mohammadi Bijan 
Published: October 2007

AbstractThis paper describes how to tackle new challenging coastal engineering problems related to beach erosion with a shape optimization approach. The method modifies the shape of the sea bottom in order to reduce beach erosion effects. Global optimization is shown to be necessary as the related functionals have several local minima. We describe the physical model used, the proposed protection devices against beach erosion and real case applications. Copyright © 2007 John Wiley & Sons, Ltd.
Risk of breast cancer in relation to antibiotic use
Authors: M. Tamim Hani , A. Hanley James , H. Hajeer Ali , Boivin Jean‐François , Collet Jean‐Paul 
Published: October 2007

AbstractBackgroundThere are conflicting results in the literature regarding the association between the antibiotic exposure and breast cancer risk. The aim of this study was to assess this association using a population‐based approach.MethodsThe source population was the dynamic cohort defined by membership in the Saskatchewan Prescription Drug Plan (Canada) between the years 1981 and 2000. Four matched controls were selected for each case identified by the Saskatchewan Cancer Agency, using incidence density sampling. Detailed drug exposure over a minimum of 15 years before diagnosis allowed studying the respective effects of dosage and timing of antibiotic use on breast cancer risk. Two antibiotic exposure definitions were used: the number of prescriptions and the number of units (tablets, capsules, etc.), which were further categorized into quartiles.ResultsA total of 3099 breast cancer cases and 12 396 matched controls were included. The incidence of breast cancer was higher in subjects who had more antibiotic prescriptions during the 1–15 years prior to the index date (RRs = 1.50, 1.63, 1.71 and 1.79 for the four quartiles, respectively, p‐trend = 0.0001). Similar results were found when a number of units were considered. We did not find any effect of the timing of antibiotic exposure on breast cancer risk. Similar patterns of increased risk of breast cancer were detected for the specific antibiotic classes.ConclusionsWe observed a dose‐dependent increase in breast cancer risk in association with the antibiotic exposure up to 15 years in the past. However, the lack of temporal trends and the absence of class‐specific effects suggest a non‐causal relationship. Copyright © 2007 John Wiley & Sons, Ltd.
The thermal polymerization of amino acids revisited; Synthesis and structural characterization of hyperbranched polymers from L‐lysine
Authors: Scholl Markus , Nguyen Tuan Q. , Bruchmann Bernd , Klok Harm‐Anton 
Published: October 2007

AbstractThis contribution reports on the synthesis of hyperbranched polylysines via thermal polymerization of L‐lysine hydrochloride. Polymerization of L‐lysine hydrochloride in the presence of one equivalent KOH at 150 °C resulted in polymers with a number‐average molecular weight of 4600 g/mol and a polydispersity of 2.6 after 48 h. The rate of polymerization could be significantly enhanced and the polymer molecular weight improved by carrying out the polymerization with 3 mol % of an amidation catalyst. Among the different catalysts that were investigated Zr(OnBu)4 was found to be the most effective. Unequivocal support for the branched architecture of the polymers was obtained from 1H NMR spectroscopy, which allowed the identification and quantification of the four different structural units that constitute the polymer, viz. Nα and Nε linked linear units, dendritic units and terminal units. The structure of the polymers was found to be relatively independent of the reaction conditions. The degree of branching and the average number of branches varied between 0.35–0.45 and 0.15–0.25, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5494–5508, 2007
Chemical modification of metallocene‐based polyolefinic elastomers by acrylic acid and its influence on physico‐mechanical properties: Effect of reaction parameters, crystallinity and pendant chain length
Authors: Biswas Anjan , Bandyopadhyay Abhijit , Singha Nikhil K. , Bhowmick Anil K. 
Published: October 2007

AbstractIn this investigation, solution grafting of acrylic acid (AA) in presence of benzoyl peroxide (BPO) was carried out onto metallocene‐based “poly(ethylene‐octene) elastomers” (POE) as well as “poly(ethylene‐butene) elastomers” (PBE), to impart polarity on the non‐polar rubbery matrix and also to study the effects of crystallinity and pendant chain length on the “grafting percentage” and “percent gel yield” at optimized conditions for all the POE and PBE systems. Reaction parameters were optimized on the basis of the relative proportions of graft and gel formations obtained through %weight gain, Fourier Transform infrared spectroscopy and elemental analysis. The effect of grafting at its maximum level on various physico‐mechanical properties was also thoroughly investigated by using X‐ray diffraction (XRD), differential scanning calorimetry (DSC), mechanical, dynamic mechanical (DMTA), and thermogravimetric analysis (TGA) and the properties were correlated with the structure of the modified polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5529–5540, 2007
Hyperbranched copolyfluorene from a 2,4,7‐trifunctional fluorene monomer
Authors: Tsai Lin‐Ren , Chen Yun 
Published: October 2007

AbstractA new hyperbranched (P1) and linear copolyfluorene (P2) were prepared from 2,4,7‐trifunctional (branching) and 2,7‐bifunctional fluorene monomer, respectively, by the Wittig reaction, followed with end‐capping by aromatic oxadiazole groups, to study the effect of hyperbranch structure. The weight‐average molecular weights (Mw) of P1 and P2, determined by gel permeation chromatography using polystyrene as standard, were 33,000 and 25,700, respectively. The polymers were readily soluble in common organic solvents and exhibited good thermal stability (Td > 400 °C). Optical properties, both in solution and film state, were investigated using absorption and photoluminescence (PL) spectra. In film state, the absorption and PL spectra peaked at 401–425 nm and 480–495 nm, respectively. The P1 showed energy funnel effect and enhanced fluorescence efficiency owing to hyperbranched structure and terminal oxadiazole groups. The HOMO and LUMO levels of P1 (P2), estimated from cyclic voltammograms, are −5.34 (−5.25) eV and −2.94 (−2.94) eV, respectively. Two‐layer polymer light‐emitting diodes devices (ITO/PEDOT/P1/Ca/Al) exhibited maximal luminance and luminous efficiency of 3630 cd/m2 and 0.78 cd/A, respectively, which are superior to its linear counterpart P2 (598 cd/m2, 0.11 cd/A). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5541–5551, 2007
Supramolecular polymer/metal salt complexes containing quadruple hydrogen bonding units
Authors: Lee Kyung Ju , Kim Yong Woo , Koh Joo Hwan , Kim Jong Hak 
Published: October 2007

AbstractA supramolecular material containing quadruple hydrogen bonding sites was prepared by reacting the amines of methyl isocytosine and the epoxy groups of poly (ethylene glycol diglycidyl ether). This supramolecular polymer was complexed with metal salt, that is potassium iodide, to produce polymer electrolytes, and their physical properties, specific interactions, and conductivity behavior were investigated. The ionic conductivity of polymer electrolytes continuously increased with increasing salt concentration up to 0.4 of salt weight fraction, presenting usually high solubility limit of salt in the supramolecular polymer. Wide angle X‐ray scattering data also presented that the metal salt was completely dissolved in the supramolecular polymer up to 0.4 of salt weight fraction. Upon the introduction of metal salt, the mechanical properties of the supramolecular polymer were significantly enhanced by around 10 times and the glass transition temperature of the polymer increased by about 50 °C, as revealed by complex melt viscosities and differential scanning calorimetry. These unusual behaviors of salt solubility and mechanical properties for supramolecular polymer/metal salt complexes were attributed to the strong, additional metal ion coordination to hydrogen bonding sites as well as ether oxygens of polymer matrix, as supported by FTIR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3181–3188, 2007
Lung disease severity, chronic inflammation, iron deficiency, and erythropoietin response in adults with cystic fibrosis
Authors: Fischer R. , Simmerlein R. , Huber R.M. , Schiffl H. , Lang S.M. 
Published: October 2007

AbstractChronic lung disorders are usually associated with a hypoxia driven increase in red cell mass. However, patients with cystic fibrosis (CF) often have normal or decreased haemoglobin levels. The present prospective observational study in cystic fibrosis patients was performed to determine which factors were involved in alterations in the hematopoetic response to corresponding arterial oxygen pressure. Sixty adult patients (age 21–51) with stable CF were included. They all had vitamin A, D, E, and K but no vitamin B12 supplementation. Twenty‐five patients were on oral Fe2+ (100 mg/day). Resting arterial blood gases, lung function, complete blood counts, parameters of iron status, CRP, sputum microbiology and serum erythropoietin were measured at recruitment and after 3 and 6 months. Patients had varying degrees of pulmonary functional impairment and 9% were hypoxemic (arterial oxygen pressure <60 mm Hg). Low‐grade systemic inflammation (CRP > 0.5 mg/dl) was present in 40% of the patients, who all had bacterial colonization. None of the patient had erythrocytosis and 12 patients had anemia. There was no significant difference in iron status between patients with or without chronic iron supplementation and erythropoietin levels were normal. During the 6 months observation period no significant changes occurred. The patients exhibited an impaired erythropoietic response to hypoxemia with normal or low hematocrit in spite of chronic lung disease which might be caused by chronic inflammation associated with CF. Linear multivariate regression analysis revealed CRP levels but neither iron substitution, nor erythropoietin levels nor lung function parameters as independent determinant of haemoglobin levels. CF may be associated with anemia of variable severity as expression of the chronic inflammation present in these patients. The therapeutic consequences are to treat the underlying inflammation rather than to supplement iron. Pediatr Pulmonol. 2007; 42:1193–1197. © 2007 Wiley‐Liss, Inc.
Dominance of CD4+ lymphocytic infiltrates with disturbed effector cell characteristics in the tumor microenvironment of prostate carcinoma
Authors: Ebelt Kathleen , Babaryka Gregor , Figel Ainhoa M. , Pohla Heike , Buchner Alexander , Stief Christian G. , Eisenmenger Wolfgang , Kirchner Thomas , Schendel Dolores J. , Noessner Elfriede 
Published: October 2007

AbstractBACKGROUNDProstate cancer is the most common cancer of men in the Western world. Despite the over‐expression of tumor‐associated antigens, like PSA or PSMA, immune activation is inefficient. The goal of this investigation was to assess in situ characteristics of prostate cancer‐infiltrating lymphocytes and to determine their activation status and effector function.METHODSWe compared 17 carcinoma containing tissues, four benign prostatic hyperplasia tissues and eight healthy prostate tissues regarding lymphocyte subset composition, locoregional distribution, and functional status using immunohistological staining of cryopreserved tissues. For determination of lymphocyte subsets, serial sections were stained with CD3, CD4, and CD8 antibodies. Activation status and effector function were studied using CD69, interferon‐gamma (IFNγ), perforin, and CD3 zeta chain antibodies. T‐cell‐receptor repertoire (TCR) analysis was made to determine the complexity of infiltrating lymphocytes.RESULTSCD3+, CD4+, and CD69+ T lymphocytes were prominent in tissues derived from patients with prostate carcinoma. CD8+ lymphocytes were significantly less than CD4+ lymphocytes. IFNγ and perforin were downregulated on infiltrating lymphocytes compared to cells of healthy prostate tissue. Very few lymphocytes were detected within cancerous lesions whereas surrounding tissues showed extensive lymphocyte cluster formation. The TCR repertoire of infiltrating lymphocytes was broad and similar to that of healthy prostate tissue, giving no evidence for specific lymphocyte recruitment.CONCLUSIONSIn the prostate cancer microenvironment, CD4+ T lymphocytes dominated while CD8+ T cells were sparse. The lymphocytes exhibited signs of disturbed effector function. Consequently, the immune response against autologous tumor cells is likely to be inefficient in controlling tumor growth. Prostate 68: 1–10, 2008. © 2007 Wiley‐Liss, Inc.
Accounting for variability in individual hierarchical clinical trial data
Authors: Tibaldi Fabián , Renard Didier , Molenberghs Geert 
Published: October 2007

AbstractMeta‐analytical approaches have been extensively used to analyze medical data. In most cases, the data come from different studies or independent trials with similar characteristics. However, these methods can be applied in a broader sense. In this paper, we show how existing meta‐analytic techniques can also be used as well when dealing with parameters estimated from individual hierarchical data. Specifically, we propose to apply statistical methods that account for the variances (and possibly covariances) of such measures.The estimated parameters together with their estimated variances can be incorporated into a general linear mixed model framework. We illustrate the methodology by using data from a first‐in‐man study and a simulated data set. The analysis was implemented with the SAS procedure MIXED and example code is offered. Copyright © 2007 John Wiley & Sons, Ltd.
Liquid chromatography/mass spectrometry analysis of PHY906, a Chinese medicine formulation for cancer therapy
Authors: Ye Min , Liu Shwu‐Huey , Jiang Zaoli , Lee Yashang , Tilton Robert , Cheng Yung‐Chi 
Published: October 2007

AbstractPHY906 is a Chinese medicine formulation prepared from four medicinal herbs for adjuvant cancer chemotherapy. In this paper, liquid chromatography/electrospray ionization time‐of‐flight mass spectrometry (LC/ESI‐TOFMS) was used to clarify the chemical composition of PHY906. The aqueous extract of PHY906 was separated on a Waters Atlantis C18 column, and was eluted with acetonitrile/0.05% (v/v) formic acid. The separated compounds were identified with pure standards, or tentatively characterized by analyzing their mass spectra recorded in both negative and positive ion polarity modes. Further structural information was obtained from in‐source fragmentation. Based on the LC/MS analysis, we proposed the structures for 64 bioactive compounds, including flavonoids, triterpene saponins, and monoterpene glycosides. All the compounds identified from PHY906 were further assigned in the four individual herbs, and some of them are reported for the first time. Copyright © 2007 John Wiley & Sons, Ltd.