bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facial node involvement in head and neck cancer
Authors: Sheahan Patrick , Colreavy Michael , Toner Mary , Timon Conrad V. I. 
Published: April 2004

AbstractBackground.Facial node involvement in head and neck cancer is rarely documented. Furthermore, facial node removal may increase the risk of damage to the marginal mandibular nerve. Thus, although they may receive afferent lymphatic drainage from the oral cavity, facial nodes are rarely removed during neck dissection.Methods.We retrospectively reviewed the records of 29 patients with oral cavity or oropharyngeal carcinomas who underwent facial node sampling in 32 heminecks during neck dissection for oral cavity or oropharyngeal cancer.Results.Facial node metastases were present in seven patients. Facial node involvement was much more common among patients with palpable cervical lymphadenopathy. Positive facial nodes were associated with an increased risk of treatment failure and a poorer survival.Conclusions.In patients with oral cavity/oropharyngeal primary tumors and palpable cervical lymphadenopathy, consideration should be given to removal of facial nodes during neck dissection; however, further data are awaited before any benefits can be quantified. © 2004 Wiley Periodicals, Inc. Head Neck 26: 531–536, 2004
Transoral carbon dioxide laser microsurgery for recurrent glottic carcinoma after radiotherapy
Authors: Steiner Wolfgang , Vogt Petra , Ambrosch Petra , Kron Martina 
Published: April 2004

AbstractBackground.Transoral laser microsurgery is successfully performed in the treatment of primary laryngeal carcinomas. Few publications deal with the application in patients with recurrent glottic carcinomas after radiation failure. Our study aims to review our experience with transoral laser microsurgery in these patients.Methods.Thirty‐four patients with early and advanced recurrent glottic carcinoma after full‐course radiotherapy (rT1, n = 11; rT2, n = 10; rT3, n = 10; rT4, n = 3) had CO2 laser treatment with curative intent between 1987 and 1998.Results.Twenty‐four patients (71%) were cured with one or more laser procedures. In nine patients, recurrences could not be controlled by laser microsurgery: six patients underwent total laryngectomy and three palliative treatment. One patient received total laryngectomy because of chondronecrosis after laser treatment. With a median follow‐up interval of 38.6 months, the 3‐year and 5‐year disease‐specific survival was 86%. The overall 3‐year survival rate was 74%; the corresponding 5‐year survival rate was 53%. No major complications occurred. In three cases, temporary tracheostomy was needed.Conclusions.In early‐stage and advanced‐stage recurrent glottic carcinomas after radiotherapy, CO2 laser treatment can successfully be used as a curative organ‐preserving procedure. Compared with salvage laryngectomy, results are superior with respect to preservation of laryngeal function. Great expertise is required, especially in resections of advanced‐stage recurrent carcinomas. © 2004 Wiley Periodicals, Inc. Head Neck 26: 477–484, 2004
Constitutive expression of interleukin‐18 in head and neck squamous carcinoma cells
Authors: Martone Tiziana , Bellone Graziella , Pagano Marco , Beatrice Fabio , Palonta Francesca , Emanuelli Giorgio , Cortesina Giorgio 
Published: April 2004

AbstractBackground.Interleukin (IL)‐18 is a potent immunomodulatory cytokine promoting TH‐1 and cytotoxic immune responses through interferon (IFN)‐γ induction. The aim of this study was to investigate the production of IL‐18 by squamous cell carcinoma of the head and neck (HNSCC).Methods.The expression of IL‐18 was analyzed by reverse transcriptase‐polymerase chain reaction, Western blot, and ELISA in untreated and 5‐fluorouracil (5‐FU)–treated HNSCC cell lines. Immunohistochemical analysis was performed on tumor specimens from 16 patients with primary invasive HNSCC.Results.We have demonstrated that HNSCC cell lines express IL‐18 at the mRNA, as well as the protein, level. However, the IL‐18 protein was expressed intracellularly and predominantly released as an unprocessed inactive 24‐kDa form. After exposure to 5‐FU, the processed form of IL‐18 was detected in the supernatants of both HNSCC cell lines.Conclusions.These results indicate that HNSCC cells are a potential source of IL‐18 cytokine. The finding that the exposure to 5‐FU can elicit its processing suggests a novel target for immunomodulatory intervention in patients with HNSCC. © 2004 Wiley Periodicals, Inc. Head Neck 26: 494–503, 2004
Surgical variables affecting swallowing in patients treated for oral/oropharyngeal cancer
Authors: Pauloski Barbara Roa , Rademaker Alfred W. , Logemann Jerilyn A. , McConnel Fred M. S. , Heiser Mary Anne , Cardinale Salvatore , Lazarus Cathy L. , Pelzer Harold , Stein David , Beery Quinter 
Published: April 2004

AbstractBackground.Postoperative swallowing function may be influenced by a number of treatment variables; this study examines the relationship of various treatment factors to measures of swallow function.Methods.Swallowing was examined with the modified barium swallow procedure in 144 patients surgically treated for oral or oropharyngeal cancer 3 months after healing. Univariate and multivariate correlations were used to examine the relationship between swallowing function and treatment.Results.Percent tongue base resected and total volume resected were most often correlated with swallowing function in the univariate analyses. Multivariate analyses identified the following combinations with the strongest correlations: (1) percent tongue base resected and closure type for liquids; (2) percent tongue base resected and unreconstructed mandible for pastes; (3) total volume resected, percent lateral floor of mouth resected, and postoperative radiotherapy dose for masticated boluses.Conclusions.Total volume resected and percent tongue base resected had a profound impact on postoperative swallowing function. Combinations of percent tongue base resected with other surgical variables had the strongest relationships with overall swallowing function. © 2004 Wiley Periodicals, Inc. Head Neck 26: 625–636, 2004
The in vivo calcification capacity of a copolymer, based on methacryloyloxyethyl phosphate, does not favor osteoconduction
Authors: Stancu I.C. , Filmon R. , Grizon F. , Zaharia C. , Cincu C. , Baslé M.F. , Chappard D. 
Published: April 2004

AbstractPolymers can be interesting alternatives to bone grafts; they must present suitable mechanical and osteoconductive properties. Biomimetic properties may be a key factor for the recognition by bone cells. Methacryloyloxyethyl phosphate (MOEP) was found to enhance hydroxyapatite deposition. The copolymer containing MOEP and 1‐vinyl‐2‐pyrrolidinone (50–50%) binds large amounts of calcium. Particles of the copolymer were used to fill large cranial bone defects in the rat. After a 12‐week healing period, the animals were euthanized and the skulls examined by X‐ray, histology, and electron microscopy (EM). The high phosphate content of the polymer conferred a marked calcium‐binding capacity, and the particles were heavily calcified. They were embedded in a light fibrous stroma containing numerous capillaries and multinucleated giant cells. The osteoconductive properties were poor: only few trabeculae developed centripetally from the margins of the defects. There was no bone bonding and no osteoblast on the surface of the calcified material. Backscattered EM revealed that the degree of calcification was homogeneous in all particles. Calcium‐phosphorus calcospherites were never observed. The material appeared to trap calcium but to impair nucleation because only small hydroxyapatite tablets were occasionally observed. Polyphosphated materials do not represent a suitable source of potentially usable bone substitutes. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 584–589, 2004
Determining relevance of a weight‐bearing ovine model for bone ingrowth assessment
Authors: Willie Bettina M. , Bloebaum Roy D. , Bireley William R. , Bachus Kent N. , Hofmann Aaron A. 
Published: April 2004

AbstractA weight‐bearing ovine model was used to quantify cancellous bone ingrowth and remodeling in porous‐coated implants over 6, 12, and 24 weeks in situ. The null hypothesis for the investigation was that there would be no significant difference between the amount of cancellous bone ingrowth and rate of remodeling in this ovine model compared to a reported human bilateral implant model. Bone ingrowth progressed from 20.1 ± 8.2% at 6 weeks in situ to 23.8 ± 7.9% at 12 weeks, and 30 ± 5.1% at 24 weeks. Fluorochrome analysis demonstrated a mineral apposition rate of 1.07 ± 0.28 μm/day for bone at the porous‐coating interface, whereas host bone remodeling at 0.89 ± 0.23 μm/day. Histological analysis showed no adverse tissue or inflammatory response. The null hypothesis was supported in that regression analysis demonstrated that the amount of cancellous bone ingrowth over time (p = 0.545) and mineral apposition rate over time (p = 0.089) in this ovine model was not significantly different than reported human bilateral knee data. The results of this study appear to validate the ovine model for use in understanding skeletal attachment of porous‐coated implants to cancellous bone in humans. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 567–576, 2004
Chemical extraction and direct adsorptive purification of recombinant human antigen Ro52
Authors: Saccodossi Natalia , Cabrera Rosa B. , Oliver Fernando , Gelmi Lucila , Magglio Daniel G. , Fernández‐Lahore Héctor M. , Leoni Juliana , Stumpo Rita R. 
Published: April 2004

AbstractThe antigenic protein Ro52 was expressed in the E. coli system harboring a 6×His tag in the form of insoluble inclusion bodies. Direct chemical extraction of the product using 6–8 M urea proved to be effective. Furthermore, the tagged protein was recovered by direct adsorption on Ni2+‐loaded commercial adsorbents derivatized with iminodiacetic acid. Screening experiments in small packed columns revealed that selective binding and elution were possible using a denaturing buffer at pH 4.5. The hydrodynamic evaluation of scaled‐up fluidized systems showed values for the φ (dynamic zone) parameter in the range 0.95–1.00 for fluidization in buffer and in the range 0.70–0.85 for the biomass‐containing feedstock. Removal of macromolecular DNA released by the disrupted biomass was mandatory. Under optimized process conditions good recovery (60–70%) was achieved and a highly purified (95%) product obtained. The purified Ro52 retained its immunoreactivity against sera of patients with systemic lupus erythematosus (SLE) and Sjögren's syndrome‐related disorders. The production and application of new recombinant antigens may contribute to increasing the sensitivity and specificity of the detection of anti‐Ro antibodies in these autoimmune diseases.
Synthesis and Thermal Characterization of Perfluorocyclobutyl (PFCB) Polymers Containing Crown Ether Vertebrae
Authors: Ligon S. Clark , Topping Chris M. , Jin Jianyong , Fallis Stephen , Irvin Jennifer A. , Desmarteau Darryl D. , Smith Dennis W. 
Published: April 2004

AbstractSummary: The synthesis and polymerization of novel 18‐crown‐6 and 24‐crown‐8 bis aryl trifluorovinyl ethers is described. Thermally induced polymerization yields linear crown ether fluoropolymers with hexafluorocyclobutyl linkages. The polymers exhibit Tg's above 120 °C and show good thermal stability with no appreciable weight loss below 350 °C. Incorporation of crown ether macrocycles into the polymer is expected to increase cationic uptake of an otherwise electroneutral fluoropolymer.magnified image
Monolayer Assemblies of Comb Polymers Containing Different Kinds of Fluorocarbon Side‐Chains
Authors: Fujimori Atsuhiro , Shibasaki Yoshio , Araki Tohru , Nakahara Hiroo 
Published: April 2004

AbstractSummary: Langmuir monolayers and organized molecular films of comb polymers containing different kinds of fluorocarbon side‐chains with various chain lengths and substituted atoms at the ω‐position were characterized by surface pressure‐area isotherms as well as Brewster angle microscopy on a water surface and by scanning probe microscopies (AFM and FFM) and the out‐of and in‐plane X‐ray diffractions on the solid substrates, respectively. When compared with monolayers of fluorinated amphiphilic vinyl monomers, those of the corresponding comb polymers were significantly stabilized. The nanostructures of these organized molecular films changed considerably with the film fabrication method used (such as mixed monolayers with hydrogenated amphiphiles) and the deposition conditions as well as with minor chemical modification of the fluorinated comb polymers with different hydrophilic esters and fluorocarbon side‐chains. The characteristic friction behavior for films built up of the fluorinated amphiphiles and comb polymers was found to depend strongly on the chemical constituents of the outermost layer of the film surface.magnified image
Synthesis and Ring‐Opening Metathesis Polymerization (ROMP) Reactivity of endo‐and exo‐Norbornenylazlactone Using Ruthenium Catalysts
Authors: Lapinte Vincent , Brosse Jean‐Claude , Fontaine Laurent 
Published: April 2004

AbstractSummary: Norbornenylazlactone (NBAz) was prepared by a Diels‐Alder cycloaddition between cyclopentadiene and 2‐vinyl‐4,4‐dimethyl‐5‐oxazolone. The stereoselectivity of this pericyclic reaction was in favour of endo isomers. The ring‐opening metathesis polymerization (ROMP) of NBAz was carried out in presence of ruthenium catalysts [(PCy3)2(Cl)2RuCHPh 1; (SIMes)(PCy3)(Cl)2RuCHPh 2 (SIMes: 1,3‐dimesityl‐4,5‐dihydroimidazol‐2‐ylidene); (PiPr3)2(Cl)2RuCHSPh 3; (PiPr3)(Cl)2RuCH(CH2)2C, N‐2‐C5H4N 4]. It was found that the exo isomer is much more reactive than the corresponding endo isomer. Some hypotheses of mechanism are suggested to justify the low polymerization rate of endo isomer using the results of NBAz derivatives as the hydrolyzed NBAz, 5, and the coupling product between NBAz and glycine methyl ester hydrochloride, 6. For exo‐NBAz, the propagating rate constant, kp, was determined with the four Ru‐initiators and their activity decreases in the order 2 > 1 > 3 > 4. Complementary kinetic measurements with 1 and 2 were given as kp/ki ratio. The ROMP of exo isomer was faster with 2 than 1 in spite of a worse control of the chains size. The azlactone ring survived intact during the polymerization and may be used for further reactions with nucleophiles.ROMP of NBAz by ruthenium initiators.magnified imageROMP of NBAz by ruthenium initiators.
Synthesis and Properties of a New Poly(arylene ethynylene) Containing 1,3,5‐Triazine Units
Authors: Fang Qiang , Yamamoto Takakazu 
Published: April 2004

AbstractSummary: A new photoluminescent poly(arylene ethynylene) containing 1,3,5‐triazine units was prepared by polycondensation between 2,4‐diphenyl‐6‐N,N‐bis(4‐bromophenyl)amino‐1,3,5‐triazine and 1,4‐didodecyloxy‐2,5‐diethynylbenzene using Pd(PPh3)4 and CuI as the catalysts in the presence of triethylamine. The polymer showed good solubility in common organic solvents and had a number average molecular weight, $\overline M _{\rm n}$, of 3 400, and a weight average molecular weight, $\overline M _{\rm w}$, of 8 100. In toluene the polymer exhibited an intrinsic viscosity [η] of 0.11 dL · g−1 at 30 °C. The polymer showed photoluminescence (PL) with emission peaks at 479 nm in CHCl3 and at 509 nm in the solid state; quantum yield of the PL in CHCl3 was 21%. Electrochemical reduction (or n‐doping) of the polymer started at about −2.05 V versus Ag/AgNO3 and gave a peak at −2.30 V versus Ag/AgNO3.The 1,2,3‐triazine unit‐containing poly(arylene ethynylene) (PATZ) polymer synthesized and investigated here.magnified imageThe 1,2,3‐triazine unit‐containing poly(arylene ethynylene) (PATZ) polymer synthesized and investigated here.
High‐Temperature Propagation and Termination Kinetics of Styrene to High Conversion Investigated by Electron Paramagnetic Resonance Spectroscopy
Authors: Zetterlund Per B. , Yamauchi Satoru , Yamada Bunichiro 
Published: April 2004

AbstractSummary: The free radical bulk polymerization of styrene at 120 °C has been investigated over almost the entire conversion range using electron paramagnetic resonance spectroscopy, Fourier‐transform near‐infrared spectroscopy and gel permeation chromatography. The free radical concentration went through a sharp maximum that coincided with the peak in the rate of polymerization during the gel effect, and shifted to higher conversion with increasing initiator concentration. The termination rate coefficient (kt), decoupled from the initiator efficiency (f) by use of the instantaneous degree of polymerization, remained close to constant up to as high as approximately 80% conversion, at which a dramatic decrease occurred. Both the propagation rate coefficient (kp) and f fell orders of magnitude near 80% conversion in spite of the temperature being above the glass transition temperature of the system. The value of kp increased with the initiator concentration at a given conversion in the highest (diffusion‐controlled) conversion range.Termination rate coefficient (kt) versus conversion for bulk free radical polymerization of St initiated by TBP at 120 °C. [TBP] = 0.15 (○), 0.10 (▴) and 0.05 M ().magnified imageTermination rate coefficient (kt) versus conversion for bulk free radical polymerization of St initiated by TBP at 120 °C. [TBP] = 0.15 (○), 0.10 (▴) and 0.05 M ().
Miscibility and Intermolecular Specific Interactions in Blends of Poly(hydroxyether sulfone) and Poly(N‐vinylpyrrolidone)
Authors: Lü Han , Zheng Sixun , Zhang Bing , Tang Xiaozhen 
Published: April 2004

AbstractSummary:The blends of poly(hydroxyether sulfone) (PHES) with poly(N‐vinylpyrrolidone) (PVPy) were investigated by means of differential scanning calorimetry (DSC) and FTIR spectroscopy. The miscibility of the blend system was established on the basis of the thermal analysis results. DSC showed that the PHES/PVPy blends prepared by casting fromN,N‐dimethylformamide (DMF) possessed single, composition‐dependent glass transition temperatures, indicating that the blends are miscible in the entire composition. The experimental glass transition temperatures have higher values than those calculated on the basis of additive behavior; the variation of the glass transition temperatures of the blends was accounted for by the Kwei equation. FTIR studies indicate that competitive hydrogen bonding interactions exist upon addition of PVPy to the system, which were involved in the self‐ and cross‐association, i.e., OH···OS, OH···OH of PHES and OH···OC< of PVPy. The FTIR spectra in the range of the sulfonyl stretching vibrations showed that the hydroxyl‐associated sulfonyl groups are partially “set free” upon addition of PVPy to the system. The IR spectroscopic investigation of both the model compounds and the PHES/PVPy blends suggests that the strength of the hydrogen bonding interactions in the blend system increases in the following order: OH···OS, OH···OH and OH···OC<.Plot of glass transition temperature for PHES/PVPy blends as a function of weight fraction of PVPy. The prediction of the Kwei equation yields the values ofk = 1 andq = 122.magnified imagePlot of glass transition temperature for PHES/PVPy blends as a function of weight fraction of PVPy. The prediction of the Kwei equation yields the values ofk = 1 andq = 122.
Swelling, Elasticity and Spatial Inhomogeneity of Poly(N,N‐dimethylacrylamide) Hydrogels Formed at Various Polymer Concentrations
Authors: Gundogan Nermin , Okay Oguz , Oppermann Wilhelm 
Published: April 2004

AbstractSummary: The equilibrium swelling degree, modulus of elasticity and the spatial inhomogeneity of poly(N,N‐dimethylacrylamide) (PDMAAm) hydrogels were investigated over the entire range of the initial monomer concentration. The degree of dilution of the networks after their preparation was denoted by ν, the volume fraction of crosslinked polymer after the gel preparation. The linear swelling ratio of the gels increased linearly with increasing ν. Depending on the value of ν, three different gel regimes were observed: (1) For ν < 0.3, increasing ν decreases the extent of cyclization during crosslinking so that the effective crosslink density of gels increases with rising ν. (2) For 0.3 < ν < 0.7, increasing ν reduces the accessibility of the pendant vinyl groups during crosslinking due to steric hindrance at high polymer concentrations. As a result, the effective crosslink density of gels decreases with increasing ν. (3) For ν > 0.7, the modulus of elasticity increases sharply with increasing ν due to the increasing extent of chain entanglements in this high concentration regime. Static light scattering measurements on the gels show that the degree of spatial gel inhomogeneity in PDMAAm gels attains a maximum value at ν = 0.06. The appearance of a maximum as well as the ν‐dependence of scattered light intensities from gels was successfully reproduced by the theory proposed by Panyukov and Rabin.Effective crosslink density νe of the hydrogels shown as a function of ν.magnified imageEffective crosslink density νe of the hydrogels shown as a function of ν.
Synthesis of Macromonomers via Catalytic Chain Transfer (CCT) Polymerization and their Characterization via NMR Spectroscopy and Electrospray Ionization Mass Spectrometry (ESI‐MS)
Authors: Chiu T. Y. Joan , Heuts Johan P. A. , Davis Thomas P. , Stenzel Martina H. , Barner‐Kowollik Christopher 
Published: April 2004

AbstractSummary: Macromonomers consisting of a butyl acrylate (BA) tail and α‐methyl styrene (AMS) or benzyl methacrylate (BzMA) unsaturated termini were synthesized via catalytic chain transfer (CCT) polymerization employing the low spin bis(difluoroboryl)dimethylglyoximato cobalt (II) (COBF) complex. The structures of the generated macromonomers were characterized via 1H and 13C NMR spectroscopy and electrospray ionization mass spectrometry (ESI‐MS). A variety of low molecular weight ($\overline M _{\rm n}$ < 4 000 g · mol−1) BA/AMS and BA/BzMA macromonomers were generated by varying the reaction conditions. The generated BA/AMS macromonomers are shown to be terminated by an AMS moiety while consisting of n units of BA plus 1 to 3 units of AMS. The structures of the synthesized BA/BzMA macromonomers give a more complex mixture. Apart from BzMA terminated macromonomer chains consisting of n units of BA plus 1 to 3 units of BzMA, pure BA macromonomers were also generated.Possible structure of BA/AMS macromonomers with various length of the BA tail and a different number of AMS units.magnified imagePossible structure of BA/AMS macromonomers with various length of the BA tail and a different number of AMS units.