bluuebunny/crossref_metadata_2025_split huggingface dataset:
SWI/SNF chromatin remodeling complex is obligatory for BMP2‐induced, Runx2‐dependent skeletal gene expression that controls osteoblast differentiation
Authors: Young Daniel W. , Pratap Jitesh , Javed Amjad , Weiner Brian , Ohkawa Yasuyuki , van Wijnen Andre , Montecino Martin , Stein Gary S. , Stein Janet L. , Imbalzano Anthony N. , Lian Jane B. 
Published: November 2004

AbstractDevelopment of bone tissue requires maturation of osteoblasts from mesenchymal precursors. BMP2, a member of the TGFβ superfamily, and the Runx2 (AML3/Cbfa1) transcription factor, a downstream BMP2 effector, are regulatory signals required for osteoblast differentiation. While Runx2 responsive osteogenic gene expression has been functionally linked to alterations in chromatin structure, the factors that govern this chromatin remodeling remain to be identified. Here, we address the role of the SWI/SNF chromatin remodeling enzymes in BMP2‐induced, Runx2‐dependent development of the osteoblast phenotype. For these studies, we have examined calvarial cells from wild‐type (WT) mice and mice that are homozygous for the Runx2 null allele, as well as the C2C12 model of BMP2‐induced osteogenesis. By the analysis of microarray data, we find that several components of the SWI/SNF complex are regulated during BMP2‐mediated osteoblast differentiation. Brg1 is an essential DNA dependent ATPase subunit of the SWI/SNF complex. Thus, functional studies were carried out using a fibroblast cell line that conditionally expresses a mutant Brg1 protein, which exerts a dominant negative effect on SWI/SNF function. Our findings demonstrate that SWI/SNF is required for BMP2‐induced expression of alkaline phosphatase (APase), an early marker reflecting Runx2 control of osteoblast differentiation. In addition, Brg1 is expressed in cells within the developing skeleton of the mouse embryo as well as in osteoblasts ex vivo. Taken together these results support the concept that BMP2‐mediated osteogenesis requires Runx2, and demonstrates that initiation of BMP2‐induced, Runx2‐dependent skeletal gene expression requires SWI/SNF chromatin remodeling complexes. © 2004 Wiley‐Liss, Inc.
BH4 (tetrahydrobiopterin)‐dependent activation, but not the expression, of inducible NOS (nitric oxide synthase)‐2 in proinflammatory cytokine‐stimulated, cultured normal human astrocytes is mediated by MEK–ERK kinases
Authors: Chiarini Anna , Dal Pra Ilaria , Gottardo Rossella , Bortolotti Federica , Whitfield James F. , Armato Ubaldo 
Published: November 2004

AbstractNitric oxide (NO) from astrocytes is one of the signalers used by the brain's extensive glial‐neuronal‐vascular network, but its excessive production by pro‐inflammatory cytokine‐stimulated glial cells can be cytodestructive. Here, we show how three pro‐inflammatory cytokines (IL‐1β, TNF‐α, and IFN‐γ) together stimulated the activation, but not the prior expression, of NOS‐2 protein via a mechanism involving MEK–ERKs protein kinases in astrocytes from adult human cerebral temporal cortex. The cytokines triggered a transient burst of p38 MAPK activity and the production of NOS‐2 mRNA which were followed by bursts of MEK–ERK activities, synthesis of the NOS‐2 co‐factor tetrahydrobiopterin (BH4), a build‐up of NOS‐2 protein and from it active NOS‐2 enzyme. Selectively inhibiting MEK1/MEK2, but not the earlier burst of p38 MAPK activity, with a brief exposure to U0126 between 24 and 24.5 h after adding the cytokine triad affected neither NOS‐2 expression nor NOS‐2 protein accumulation but stopped BH4 synthesis and the assembly of the NOS‐2 protein into active NOS‐2 enzyme. The complete blockage of active NOS‐2 production by the brief exposure to U0126 was bypassed by simply adding BH4 to the culture medium. Therefore, this cytokine triad triggered two completely separable, tandem operating mechanisms in normal human astrocytes, the first being NOS‐2 gene expression and accumulation of NOS‐2 protein and the second being the synthesis of the BH4 factor needed to dimerize the NOS‐2 protein into active, NO‐making NOS‐2 enzyme. © 2004 Wiley‐Liss, Inc.
Effects of chronic administered guanosine on behavioral parameters and brain glutamate uptake in rats
Authors: Vinadé Elsa R. , Schmidt André P. , Frizzo Marcos E.S. , Portela Luis V. , Soares Félix A. , Schwalm Fábio D. , Elisabetsky Elaine , Izquierdo Ivan , Souza Diogo O. 
Published: November 2004

AbstractOral and intraperitoneal administration of the nucleoside guanosine have been shown to prevent quinolinic acid‐ (QA) and α‐dendrotoxin‐induced seizures, impair memory, and impair anxiety in rats and mice. We investigated the effect of 2‐weeks ad lib orally administered guanosine (0.5 mg/ml) on seizures induced by QA, inhibitory avoidance memory, and locomotor performance in rats. We also studied the mechanism of action of guanosine through the measurement of its concentration in the cerebrospinal fluid (CSF) and its effect on glutamate uptake in cortical slices of rats. QA produced seizures in 85% of rats, an effect partially prevented by guanosine (53% of seizures; P = 0.0208). Guanosine also impaired retention on the inhibitory avoidance task (P = 0.0278) and decreased locomotor activity on the open field test (P = 0.0101). The CSF guanosine concentration increased twofold in the treated group compared to that in the vehicle group (P = 0.0178). Additionally, QA promoted a 30% decrease in glutamate uptake as compared to that with intracerebroventricular saline administration, an effect prevented by guanosine in animals protected against QA‐induced seizures. Altogether, these findings suggest a potential role of guanosine for treating diseases involving glutamatergic excitotoxicity such as epilepsy. These effects seem to be related to modulation of glutamate uptake. © 2004 Wiley‐Liss, Inc.
Prognostic significance of the age factor in the thyroid cancer: Statistical analysis
Authors: Falvo Laura , Catania Antonio , Sorrenti Salvatore , D'Andrea Vito , Berni Alberto , Stefano Matteo De , Antoni Enrico De 
Published: November 2004

AbstractBackground and ObjectivesTo determine whether thyroid carcinoma in elderly patients presents any peculiar characteristics, whether the greater biological aggressiveness of the neoplasm modifies the surgical treatment selected, and whether age greater than 70 years represents an independent prognostic factor.MethodsRetrospective analysis of case histories from the Department of Surgery of “La Sapienza” University of Rome; 403 patients subjected to total thyroidectomy between 1993 and 1999, with a minimum follow‐up period of 3 years subdivided into three groups: group I (patients aged between 20 and 50 years), group II (patients aged between 51 and 70 years) and group III (patients aged >70 years). The surgical and postoperative treatment is uniform in all study groups.ResultsAge greater than 70 years entails a significant increase in mortality; the mortality rate in the three groups was found to be 3%, 9% and 54%, respectively. Prognosis is significantly worse in the elderly patients group (group III) than in group I (P ≤ 0.001) and in group II (P ≤ 0.001); group II mortality was significantly higher than that of group I (P = 0.005); in group III, the neoplasm displays features of greater biological aggressiveness (greater incidence of undifferentiated forms, presence of lymph nodes at diagnosis and vascular invasion, locally advanced forms, greater incidence of stage IV).ConclusionsStatistical analysis shows that the greater biological aggressiveness of the neoplasm in elderly patients worsens the prognosis, although an age exceeding 70 years itself represents an unfavourable prognostic factor; total thyroidectomy does not present any counter‐indications in elderly patients. J. Surg. Oncol. 2004;88:217–222. © 2004 Wiley‐Liss, Inc.
Simultaneous repair of abdominal aortic aneurysm and resection of unexpected, associated abdominal malignancies
Authors: Illuminati Giulio , Calio' Francesco G. , D'Urso Antonio , Lorusso Riccardo , Ceccanei Gianluca , Vietri Francesco 
Published: November 2004

AbstractBackground and ObjectivesThe management of unexpected intra‐abdominal malignancy, discovered at laparotomy for elective treatment of an abdominal aortic aneurysm (AAA), is controversial. It is still unclear whether both conditions should be treated simultaneously or a staged approach is to be preferred. To contribute in improving treatment guidelines, we retrospectively reviewed the records of patients undergoing laparotomy for elective AAA repair.MethodsFrom January 1994 to March 2003, 253 patients underwent elective, trans‐peritoneal repair of an AAA. In four patients (1.6%), an associated, unexpected neoplasm was detected at abdominal exploration, consisting of one renal, one gastric, one ileal carcinoid, and one ascending colon tumor. All of them were treated at the same operation, after aortic repair and careful isolation of the prosthetic graft.ResultsThe whole series' operative mortality was 3.6%. None of the patients simultaneously treated for AAA and tumor resection died in the postoperative period. No graft‐related infections were observed. Simultaneous treatment of AAA and tumor did not prolong significantly the mean length of stay in the hospital, compared to standard treatment of AAA alone.ConclusionsExcept for malignancies of organs requiring major surgical resections, simultaneous AAA repair and resection of an associated, unexpected abdominal neoplasm can be safely performed, in most of the patients, sparing the need for a second procedure. Endovascular grafting of the AAA can be a valuable tool in simplifying simultaneous treatment, or in staging the procedures with a very short delay. J. Surg. Oncol. 2004;88:234–239. © 2004 Wiley‐Liss, Inc.
p53 and DPC4 alterations in the bile of patients with pancreatic carcinoma
Authors: Pantalone Desiree , Pelo Elisbetta , Minuti Barbara , Giotti Irene , Mazza Ernesto , Falchini Massimo , Neri Bruno , Nesi Gabriella , Roberta Girardi Lucia , Pulli Raffaele , Credi Giovanni , Torricelli Francesca 
Published: November 2004

AbstractIntroductionPancreatic cancer is still predominantly diagnosed in advanced stages, and 85%–90% of patients are not eligible for surgery at diagnosis. This is mainly due to the great difficulty in detecting the tumour at an early stage and presently no satisfactory results have been obtained to overcome this problem. Studies on molecular genetic profile of pancreatic cancer may represent an important approach. This study was focused on the mutations of p53 and DPC4 detectable in the bile of patients with histologically proven pancreatic cancers.Materials and PatientsWe analysed specimens of bile collected through percutaneous transhepatic biliary catheters, placed to treat malignant biliary obstruction in 25 patients with pancreatic adenocarcinoma. A percentage of mutation was obtained of 43 % for the microsatellite D17S945 (p53), 54% and 50 % for D18S46 and D18S474 (DPC4), respectively. The percentage of amplification was 67%, 93,6%, and 80%.ConclusionWe consider the results encouraging enough to decide to enlarge the number of patients examined. The aim is to determine if a test for DPC4 and p53 mutations is eligible for introduction in clinical routine use. More sets of samples are required to satisfactorily answer this question. J. Surg. Oncol. 2004;88:210–216. © 2004 Wiley‐Liss, Inc.
Two colons‐two cancers: Paradigm shift and clinical implications
Authors: Gervaz Pascal , Bucher Pascal , Morel Philippe 
Published: November 2004

AbstractEmbryological and physiological data suggest that proximal (in relation to the splenic flexure) and distal parts of the colon represent distinct anatomical and functional entities. Since 1990, molecular biologists have identified two distinct pathways, microsatellite instability (MSI) and chromosomal instability (CIN), which are involved in the pathogenesis of colon cancer (CC). Thus, a new paradigm has emerged with the discovery that CC is a heterogeneous disease; furthermore recent data have demonstrated that these two distinct pathways in colorectal carcinogenesis are characterized by a different clinical outcome. The implications for the clinicians are twofold; (1) tumors originating from the proximal colon have a better prognosis due to a high percentage of MSI‐positive lesions; and (2) location of the neoplasm in reference to the splenic flexure should be documented before group stratification in ongoing trials of adjuvant chemotherapy for CC. In the future, clinical decision‐making regarding adjuvant chemotherapy might be stratified according to the MSI status of cancers located proximally to the splenic flexure. J. Surg. Oncol. 2004;88:261–266. © 2004 Wiley‐Liss, Inc.
Hepatic arterial catheterization combining interventional radiological and laparotomic approaches
Authors: Watanabe Masashi , Takita Wataru , Nakazaki Haruhiro , Tanemura Hiroyuki , Kaneko Hironori , Kobayashi Kazuo 
Published: November 2004

AbstractBackground and ObjectivesThis report describes a modified method of implanting a catheter‐port system for hepatic arterial infusion chemotherapy (HAIC) that combines interventional radiological (IVR) and laparotomic approaches.Methods and ResultsIn patients, scheduled for HAIC and laparotomic surgery, we now employ a modified method of implanting the catheter‐port system. In our method, an IVR approach is used to implant the catheter‐port, and arterial occlusions are primarily carried out using a laparotomic approach. Following celiac and superior mesenteric arteriographies, a tapered microcatheter with a side hole is inserted by a catheter exchange method. The catheter tip is advanced far into the gastroepiploic artery via the gastroduodenal artery (GDA). The side hole is located at the orifice of the proper hepatic artery, and its location is confirmed by injection of contrast media. The microcatheter is connected to the port, and the port is buried in the subcutaneous pocket. During the laparotomy stage, the GDA lumen and the catheter lumen are clipped, and the right gastric artery (RGA) and all small branches supplying the stomach, duodenum, and pancreas are ligated. Among the 13 patients successfully implanted with a port‐catheter system using our combined approach, no patients had hepatic artery occlusion or occlusion of the catheter system.ConclusionsInitial results from a study of a new method of implanting a microcatheter‐port system in the hepatic artery using combined IVR and laparotomic approaches suggest that this method may enable operators to avoid complicated selective coiling and may lower the incidence of hepatic artery occlusion in patients receiving long‐term HAIC. J. Surg. Oncol. 2004;88:256–260. © 2004 Wiley‐Liss, Inc.
X‐Ray and Electron Diffraction Study of Poly(p‐dioxanone)
Authors: Furuhashi Yukiko , Nakayama Atsushi , Monno Teruo , Kawahara Yutaka , Yamane Hideki , Kimura Yoshiharu , Iwata Tadahisa 
Published: November 2004

AbstractSummary: Solution‐grown lamellar crystals of poly(p‐dioxanone) (PPDX) have been crystallized isothermally from butane‐1,4‐diol at 100 °C. The crystal structure of PPDX has been determined by interpretation of X‐ray fiber diagrams of PPDX fibers and electron diffraction diagrams of lozenge‐shaped chain‐folder lamellar crystals. The unit cell of PPDX is orthorhombic with space group P212121 and parameters: a = 0.970 nm, b = 0.742 nm, and c (chain axis) = 0.682 nm. There are two chains per unit cell, which exist in an antiparallel arrangement.Transmission electron micrograph of PPDX chain‐folded lamellar crystals obtained by isothermal crystallization and its electron diffraction diagram.imageTransmission electron micrograph of PPDX chain‐folded lamellar crystals obtained by isothermal crystallization and its electron diffraction diagram.
Einfluß stochastischer Erregungen auf das Verhalten der Querdynamik eines Eisenbahnradsatzes
Authors: Cichon Martin , Wedig Walter 
Published: November 2004

AbstractDer Eisenbahnradsatz spielt in der Systemdynamik der Eisenbahnfahrzeuge aufgrund seiner außerordentlich hohen Beanspruchung und seiner absoluten Sicherheitsrelevanz die zentrale Rolle. Als passives Bauelement sorgt er f ür das Tragen, Führen und Antreiben bzw. Bremsen des Fahrzeugs. Die Querdynamik beschäftigt sich mit dem Führen des Radsatzes im Gleis innerhalb des vorgegebenen Spurspiels.Wie alle technischen Gebilde ist auch das Gleis und der Radsatz nicht frei von Abweichungen zu einem definierten Sollzustand. Das hinsichtlich der Querdynamik in Betracht gezogene vereinfachte Modell berücksichtigt lediglich Gleislagefehler und hierbei zunächst nur den Gleisquerlagefehler.Für ein stark vereinfachtes Modell zur Untersuchung der Radprofilpaarung unter dem Einfluß einer weißen Rauschanregung ist das invariante Maß durch Lösung der zugehörigen Fokker‐Planck‐Kolmogorow‐Gleichung analytisch geschlossen angebbar. Mittels Monte‐Carlo Simulationen läßt sich das Querdynamikverhalten komplizierterer Systeme und der Realität angepaßter Anregungen besser untersuchen. Zur Anregung werden Filter benötigt, die Trajektorien mit gleichen statistischen Eigenschaften erzeugen, wie sie bei realen Gleisen auftreten.Die gewonnenen Ergebnisse werden diskutiert und mit Messungen verglichen. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Brake vibrations at very low driving velocities
Authors: Hetzler H. , Seemann W. 
Published: November 2004

AbstractVibrations in vehicle brake systems have been subject to research for a long time. One simple phenomenological model ist the classical friction oscillator, consisting of a mass on a belt. A closer look to a real brake system reveals that from the tyre's contact on the street to the disc the brake torque is transmitted via the tyre, which also possesses elastic, dissipative and inertial properties. Motivated by this fact an extended 2‐DOF friction oscillator model is developed featuring the rim's inertia and the dissipative and elastic behaviour of the tyre. In this article the model is given and simulation results are presented. It is found, that additional torsional elasticity und damping can induce very low frequent vibrations. In addition an outlook on further studies is given. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rauheitseinfluss auf die Adhäsion von Elastomeren
Authors: Kröger Matthias 
Published: November 2004

AbstractIm Kontakt zwischen einem Elastomer und einem rauen Reibpartner wird Reibung durch Hysterese‐ und durch Adhäsioneffekte verursacht. Mit dem hier vorgestellten Adhäsionspendel werden die Hysterese‐ und Adhäsionsverluste beim Aufprall und beim Trennen einer flächigen Elastomerprobe im radialen Kontakt zu einem Zylinder untersucht. Die Rauheit des Kontaktpartners wird durch Bekleben des Zylinders mit Schmirgelpapier variiert. Es zeigt sich, dass auf Schmirgelpapier der Adhäsionseffekt kleiner ist als auf einer geschliffenen Stahloberfläche. Die Adhäsion besitzt aber immer noch nennenswerten Einfluss auf den gesamten Energieverlust. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the Dynamics of Bundled Conductors in Overhead Transmission Lines
Authors: Verma Himanshu , Dighe Ashish M. , Hagedorn Peter 
Published: November 2004

AbstractThe Energy Balance Principle (EBP) is well established for estimating the vibration levels of wind induced oscillations of single overhead transmission lines. The mathematical model, wherein a conductor is treated as a continuous system, results in a transcendental eigenvalue problem (EVP), which gives numerical difficulties in the case of bundled conductors. In this paper, different approaches for solving transcendental EVP and their relative merits are discussed. A new method named continuous spectrum approach provides a good engineering solution. Results from different approaches are compared. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral projectors and their applications in structural dynamics
Authors: Wagner N. 
Published: November 2004

AbstractSpectral projectors exhibit some powerful properties. For example, the trace of a spectral projector can be used to determine the number of eigenvalues enclosed by a curve. Here some other nice features of spectral projectors are investigated. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibrations of Piezoceramic Rods
Authors: Wauer Jörg 
Published: November 2004

AbstractPresently, most of the research on vibrations of monolithic piezoelectric rods at weak electric fields is restricted to longitudinal oscillations of such structural members where free and forced vibrations have been dealt with and in the case of resonance conditions not only linear but also nonlinear effects within the constitutive relations have been incorporated. On the other hand, bending and torsional vibrations of piezoceramic one‐parametric rods have not been examined yet. The present contribution develops a linear vibration theory of rods with a focus to bending vibrations taking into account rotatory inertia and shear deformation. The governing boundary value problem for beams with both longitudinal and as well transversal polarization is derived, in particular free vibrations are analyzed. Also nonlinear extensions not only of physical nature but also geometrical ones are addressed. A possible technical application is given. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of virtual measurements in nonlinear observation problem
Authors: Shcherbak V. F. 
Published: November 2004

AbstractThe method of the observation problems reducing to the algebraic ones is considered for the systems, which are linear with respect to unknown components of the phase vector. The approach proposed is based on the methods of the controlled stabilization of nonlinear system with respect to the part of variables. The equations of the initial observable system are supplemented by the equations of its controlled prototype. Then control law synthesied in such way that any given manifold becomes an invariant for extended system. For ensuring of this manifold attracting property the partial differential equations are obtained. Finally, the chosen in such way algebraic relations are considered as additional virtual measurements of unknown state. As example the problem of the angular velocity determination of a rigid body is considered. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multibody Dynamics of Cargo Airships During the Load Exchange Process
Authors: Bockstedte Andreas , Kreuzer Edwin 
Published: November 2004

AbstractProjected cargo airships for the flexible transport of large loads exceed the dimensions of existing aircrafts and gave rise to various technical problems.In order to study the dynamics of the load exchange process mathematical models of the airship including the oscillating load frame are developed. The hull and the load frame are represented by a multibody system. Crucial aspects contributing to the system's dynamics are the floatation of the flying crane and nonlinear couplings between hull and load frame.Furthermore, added masses of the surrounding air are considered. Oscillations of the load frame are excited by wind loads, airship maneuvers, and winding up the cables. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of flexible link manipulators
Authors: Mladenova Clementina , Rashkov Ivan 
Published: November 2004

AbstractThe purpose of this work is to present a method for symbolic generation of the dynamic equations within the Hamiltonian formalism of flexible robots with open‐chain linkage mechanisms using the so‐called vector‐parameterization of the SO(3) group as it is quite effective for many rotational degrees‐of‐freedom. The both, an exact treatment and approximated model of the differential equations of motion are considered. The authors step on their long experience of using the vector‐parameterization for modelling of rigid body mechanical systems. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)