bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental assessment of new stent technologies: Validation of a comparative paired rabbit iliac artery study model
Authors: Robert R. , Rioufol G. , Finet G. , Cottin Y. , Tabib A. , Zeller M. , Wolf J. E. , Lievre M. , Bricca G. 
Published: April 2004

AbstractPreventing coronary in‐stent restenosis is a major challenge for physicians and industry. To assess new stent technologies, a comparative paired iliac artery model in rabbits is proposed. One tubular stent was implanted in each external iliac artery in 12 rabbits (i.e., 24 stents). An artery overdilatation level of 20% was strictly observed. Restenosis was examined at 30 days by angiography, intravascular ultrasound (IVUS) examination, and histomorphometry. On quantitative angiography, the mean loss of angiographic diameter was 9.8 ± 4.4% in the right as compared to 9.3 ± 55% in the left artery (p = 0.75). On IVUS, the volume of intrastent neointimal proliferation was 26.6 ± 4.9 mm3 in the right and 25.8 ± 3.5 mm3 in the left artery (p = 0.58). In histomorphometry, the neointimal proliferation area was 0.78 ± 17 mm2 in the right and 0.76 ± 0.17 mm2 in the left artery (p = 0.87). Intrastent neointimal proliferation was comparable between the left and right arteries of all rabbits. The model has three main advantages: (1) arterial dilatation and thus arterial wall aggression are controlled, (2) pairing makes each animal its own control subject, and (3) the statistical power for comparative testing is maximized. The model enables the effect of a new drug‐delivery device to be assessed. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 303–310, 2004
Vascular graft healing. III. FTIR analysis of ePTFE graft samples from implanted bigrafts
Authors: Murray‐Wijelath Jacqueline , Lyman Donald J. , Wijelath Errol S. 
Published: April 2004

AbstractA bigraft, composed of a 30‐μm internodal distance expanded polytetrafluoroethylene (ePTFE) arterial graft segment and a preclotted polyethylene terephthalate arterial graft segment, was used to study the healing process of two different materials in the same dog. Healing was followed by FTIR‐ATR spectroscopy and correlated with ELISA analyses of selected growth factors and matrix proteins. The FTIR analyses of the ePTFE explants from 1 and 3 h; 3, 5, 7, 10, and 14 days; and 4 and 8 weeks showed that the ePTFE grafts did not heal (endothelialize), but appeared to remain in overlapping inflammation and proliferation stages of wound healing. Although FN was found in the fibrin layer coating the luminal surface of the ePTFE, VEGF was not present. The inability of VEGF to complex with FN may be the result of FN binding sites being blocked or hidden by the conformation of the fibrin clot that forms on ePTFE. Also, TGF‐β was not present beyond the initial clot formation at 3 h postimplantation. The absence of these two growth factors may be an important factor in the lack of healing of 30‐μm ePTFE grafts, because both were found to be present during the early stages of healing for the preclotted polyester grafts that did endothelialize. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 223–232, 2004
Improved model core potentials for the second‐ and third‐row transition metals
Authors: Lovallo Christopher C. , Klobukowski Mariusz 
Published: April 2004

AbstractNew nonrelativistic and scalar‐relativistic pseudopotentials for the second‐ and third‐row transition metals have been developed. These improved Model Core Potentials were used in calculations for a variety of transition metal complexes to test their ability to reproduce experimental structures and vibrational frequencies. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1206–1213, 2004
MT1‐MMP: A tethered collagenase
Authors: Holmbeck Kenn , Bianco Paolo , Yamada Susan , Birkedal‐Hansen Henning 
Published: April 2004

AbstractGene ablation in mice offers a powerful tool to assay in vivo the role of selected molecules. Numerous new mouse models of matrix metalloproteinases (MMP) deficiency have been developed in the past 5 years and have yielded a new understanding of the role of MMPs while also putting to rest assumptions based on data predating the days of mouse models. The phenotype of the MT1‐MMP deficient mouse is one example which illustrates the sometimes rather surprising insights into extracellular matrix remodeling in development and growth that can be gained with mouse genetics. While MT1‐MMP appears to play little or no role in embryonic development, loss of this enzyme results in progressive impairment of postnatal growth and development affecting both the skeleton and the soft connective tissues. The underlying pathologic mechanism is loss of an indispensable collagenolytic activity, which remains essentially uncompensated. Our findings demonstrate that growth and maintenance of the skeleton requires coordinated and simultaneous MT1‐MMP‐dependent remodeling of all soft tissue attachments (ligaments, tendons, joint capsules). We note that the phenotype of the MT1‐MMP deficient mouse bears no resemblance to those of mice deficient in MMP‐2 and tissue inhibitors of metallo‐proteinase (TIMP)‐2 all but dispelling the view that activation of MMP‐2 by the MT1‐MMP/TIMP‐2/proMMP‐2 axis plays a significant role in growth and development throughout life. It is of interest to note that loss of a single catabolic function such as selective collagen degradation mediated by MT1‐MMP gives rise to profound impairment of a number of both anabolic and catabolic functions. © 2004 Wiley‐Liss, Inc.
Unusual sonographic appearance of a gastrointestinal stromal tumor presenting as a large multilocular cystic mass
Authors: Chang Chi‐Yang , Wang Hsiu‐Po , Mao Tasui‐Lien , Hu Rey‐Heng , Yang Pei‐Ming , Lai Ming‐Yang , Lin Jaw‐Town 
Published: April 2004

AbstractCystic change is uncommon in gastrointestinal stromal tumor, (GISTs). This report describes 1 case in which a GIST presented as a large multilocular cystic mass. Sonography of the abdomen showed a huge cystic lesion with multiple septa in the left upper quadrant of the abdomen, compressing the left lobe of the liver. Esophagogastroscopy showed only a small submucosal tumor at the anterior wall of the mid portion of the gastric body. Endoscopic sonography revealed a hypoechoic mass, measuring 0.9 × 0.7 cm, arising from the fourth layer of the anterior wall of the mid portion of the gastric body. A huge cystic tumor, containing multiple septa and continuous with the small submucosal lesion, was found. Doppler signals were detected within the septa. Laparotomy revealed a huge exophytic cystic tumor arising from the stomach. Immunohistochemical analysis confirmed that the lesion was a GIST by detecting expression of the c‐kit and CD34 proteins. GIST that has undergone cystic change must be differentiated from other cystic lesions to guide the treatment approach. Imatinib mesylate is a new therapeutic alternative for patients who have advanced GIST, but surgery remains the therapy of choice for resectable disease. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:200–203, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20010
Contrast‐enhanced power Doppler sonography of ductal pancreatic adenocarcinomas: Correlation with digital subtraction angiography findings
Authors: Chen Chien‐Hua , Yang Chi‐Chieh , Yeh Yung‐Hsiang , Huang Min‐Ho 
Published: April 2004

AbstractPurposeThe purpose of this prospective study was to utilize contrast‐enhanced power Doppler sonography to evaluate the enhancement characteristics of ductal pancreatic adenocarcinomas and correlate them with the tumor vascularity observed on digital subtraction angiography (DSA).MethodsTwenty consecutive patients with ductal pancreatic adenocarcinoma underwent power Doppler sonography and DSA. Tumor vascularity was assessed using unenhanced and contrast‐enhanced power Doppler sonography. The contrast agent Levovist was administered intravenously by bolus injection of a dose of 2.5 g at a concentration of 350 mg/mL; saline was administered immediately thereafter. The patients were asked to hold their breath for 30 seconds (for the period 15–45 seconds after saline injection) while the early phase of enhancement was studied; the delayed phase of enhancement was observed between 60 and 120 seconds after saline administration, while patients breathed gently.ResultsNone of the 20 pancreatic carcinomas showed any color signals on power Doppler sonography before administration of the contrast medium. Seventeen (85%) of the 20 pancreatic carcinomas also showed no enhancement in the early and delayed phases of contrast‐enhanced power Doppler sonography. However, in the early phase of contrast‐enhanced power Doppler sonography; 1 lesion showed pronounced enhancement and 2 showed mild enhancement. On DSA, the 17 carcinomas showing no enhancement on power Doppler sonography were found to be hypovascular, whereas the remaining 3 carcinomas with contrast enhancement on power Doppler sonography were found to be hypervascular.ConclusionsThe enhancement characteristics of the ductal pancreatic adenocarcinomas correlated well with the tumor vascularity observed on DSA. However, further study is needed to determine the accuracy of contrast‐enhanced sonography in the diagnosis of pancreatic masses. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:179–185, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20018
Unusual hepatic‐portal‐systemic shunting demonstrated by Doppler sonography in children with congenital hepatic vein ostial occlusion
Authors: Barakat Maha 
Published: April 2004

AbstractPurposeThis report describes unusual changes in the hepatic vasculature in 3 children presenting with upper gastrointestinal hemorrhage.MethodsThe study included 3 children (ages 5–8 years) who presented with hematemesis. All had mild hepatosplenomegaly and normal liver function. Esophageal varices were demonstrated in all on upper endoscopy. Color and spectral Doppler sonography was performed to assess the hepatic vasculature, including the hepatic veins (HVs), portal vein (PV), hepatic artery (HA), and inferior vena cava (IVC).ResultsThe HVs were all patent but with ostial occlusion at the point of their communication with the IVC. Complete flow reversal was shown inside the HVs, with blood draining into collateral vessels at the liver surface and paraumbilical vein. In one patient, the paraumbilical vein could be traced to its communication with the right external iliac vein. In all children, the direction of flow in the PV, HA, and IVC was normal. After endoscopic sclerotherapy, all children were shown to be in good general condition and to have normal liver function for a follow‐up period of 15–36 months.ConclusionsOstial occlusion of the HV is a rare cause of hepatic outflow obstruction in children. Doppler sonography is a valuable, noninvasive imaging technique for evaluation of the hepatic vasculature and the accompaning shunting pathways in such cases. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:172–178, 2004; Published online in Wiley InterScience (www. interscience.wiley.com). DOI: 10.1002/jcu.20019
Influence of packaging material on pomegranate juice colour and bioactive compounds, during storage
Authors: Pérez‐Vicente A , Serrano P , Abellán P , García‐Viguera C 
Published: April 2004

AbstractPomegranate juices were assessed after pasteurisation and storage in different packaging materials: transparent and green glass, and paperboard carton with polyethylene layers (Minibrik‐200). The main objective was to establish the influence of the container on the stability of colour and bioactive compounds (anthocyanins, ellagic acid and other non‐coloured phenols). Results showed that non‐coloured phenols and ellagic acid were quite stable during the storage period. In contrast, anthocyanins degraded, to an extent directly proportional to colour loss, less for those juices stored in glass bottles than for those stored in Minibrik. These results indicated that these paperboard carton containers are oxygen permeable, and that oxygen has a greater influence on anthocyanin, and consequently on colour degradation, than light on pomegranate juice during storage. Nevertheless, the antioxidant activity was not influenced by the packaging material employed. Copyright © 2004 Society of Chemical Industry
Screening of oxazepine indole enantiomers by means of high performance liquid chromatography with imprinted polymer stationary phase
Authors: Machtejevas Egidijus , Sellergren Börje , Martynaitis Vytas , Owens Paul K. , Maruška Audrius 
Published: April 2004

AbstractChromatographic enantiomer separations of different oxazepine indole derivatives were performed using a molecularly imprinted polymer. A 5aR,12R,13S‐trans‐6,6‐dimethyl‐12,13‐dihydro‐6H‐5a,13‐methanoindolo[2,1‐b][1,3]naphthoxazepine‐12‐carboxamide enantiomer derivative was used as a template and the resultant polymer has shown enantiomer recognition for series of template related compounds. The mechanistic description of the chiral discrimination process is scrutinised, comparing the discrimination between the different conformations and substituents of the oxazepine indoles.
Chiroptical Properties of Terthiophene Chromophores Dispersed in Oriented and Unoriented Polyethylene Films
Authors: Pucci Andrea , Nannizzi Silvia , Pescitelli Gennaro , Di Bari Lorenzo , Ruggeri Giacomo 
Published: April 2004

AbstractSummary: Two new chiral terthiophene chromophores II and III were prepared with 99% enantiomeric excess. Chiroptical properties of these dyes dispersed in ultra high molecular weight polyethylene (UHMWPE) films were determined and compared with the same properties in solution. In the solid state, the optical activity strongly depends on the interaction mechanisms within small crystalline aggregates of chromophores. The film morphology and chromophore dispersion were also investigated by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The good correlation between chromophore aggregation and chiroptical activity of the binary films promotes circular dichroism (CD) as an effective technique for monitoring the phase dispersion behaviour of dichroic dyes into polymer matrices. By mechanical stretching of the film a linearly dichroic orientation of the chromophores is obtained which results in a high degree of linear dichroism. The influence of the uniaxial orientation of terthiophene molecules along the drawing direction of UHMWPE on the chiroptical properties of the films, and the possible application of the oriented devices as linear polarizers are discussed.Absorption and CD spectra of unoriented UHMWPEII film at different rotation angles θ.magnified imageAbsorption and CD spectra of unoriented UHMWPEII film at different rotation angles θ.
Novel Biodegradable Aliphatic Polycarbonate Based on Ketal Protected Dihydroxyacetone
Authors: Wang Lian‐Sheng , Cheng Si‐Xue , Zhuo Ren‐Xi 
Published: April 2004

AbstractSummary: A novel aliphatic polycarbonate based on ketal protected dihydroxyacetone was synthesized by ring‐opening polymerization of cyclic carbonate monomer, 2,2‐ethylenedioxypropane‐1,3‐diol carbonate (EOPDC), in bulk. Effects of polymerization conditions such as catalysts, catalyst concentration, reaction temperature and reaction time on the polymerization were investigated. The polycarbonate obtained was characterized by GPC, FTIR, 1H NMR, 13C NMR and DSC. The study on in vitro degradation of PEOPDC shows that the degradation mainly results from surface erosion.Synthesis of an aliphatic polycarbonate with a high molecular weight by ring‐opening polymerization of cyclic carbonate monomer EOPDC.imageSynthesis of an aliphatic polycarbonate with a high molecular weight by ring‐opening polymerization of cyclic carbonate monomer EOPDC.
Tremor induced by thalamic deep brain stimulation in patients with complex regional facial pain
Authors: Constantoyannis Constantine , Kumar Ajit , Stoessl A. Jon , Honey Christopher R. 
Published: April 2004

AbstractWe report on two patients who developed a new postural and action tremor after chronic stimulation of the contralateral thalamus (VPM nucleus) during treatment of a complex regional facial pain syndrome. The tremor was only present during deep brain stimulation (DBS) and was suppressed with adjustment of the stimulation parameters. Tremor was seen only with low frequency stimulation (50 Hz or lower) and disappeared with higher stimulation frequencies. In addition to being an unusual side effect of thalamic DBS, we believe that this phenomenon affords insight into one possible mechanism underlying essential tremor (ET). A central oscillatory mechanism involving the olivocerebellar complex and the thalamus, which is a part of the cerebro–cerebello–cerebral circuit, is thought to play an important role in the genesis of ET. Induction of a tremor resembling ET in our patients indicates an active role for low frequency stimulation. A plausible explanation for this is that low frequency stimulation in the thalamic area enhances the output of the tremor‐producing network. This leads credence to the concept of central oscillations in a “tremor circuit,” of which the thalamus is a part, as being important in ET. © 2004 Movement Disorder Society
Wide expressivity variation and high but no gender‐related penetrance in two dopa‐responsive dystonia families with a novel GCH‐I mutation
Authors: Uncini Antonino , De Angelis Maria Vittoria , Di Fulvio Patrizia , Ragno Michele , Annesi Grazia , Filla Alessandro , Stuppia Liborio , Gambi Domenico 
Published: April 2004

AbstractWe describe the clinical and molecular correlates in two Italian families with dopa‐responsive dystonia (DRD) and the same novel mutation of GTP‐cyclohydrolase I (GCH‐I) gene. Thirty‐five subjects were examined and the genotype correlated to phenotype. Childhood onset foot dystonia is present in 7 subjects currently under the age of 40. In 1 patient bilateral foot dystonia was evident at birth suggesting that dystonia may be active as early as in utero. In another patient, dystonia spontaneously remitted in adolescence, to relapse 8 years later, as writer's cramp. Dystonia and parkinsonian signs are present in 5 other patients. In 2 subjects an isolated parkinsonism started over the age of 45. A 5‐base pair insertion at codon 242 within exon 6 of GTP‐cyclohydrolase I (GCH‐I) gene that shifts the reading frame and results in a premature stop at codon 247 with truncation of the polypeptide has been detected in 21 subjects. Considering dystonia and parkinsonism the overall penetrance is 0.71 and not significantly different in men (0.69) and women (0.75). Genealogical studies seem to exclude that these families are related but haplotype analysis suggests a single founder. Our findings in subjects with the same mutation indicate a wide intrafamilial variation in expressivity and high penetrance in DRD but do not confirm the reported influence of gender on GCH‐I gene mutation penetrance. © 2004 Movement Disorder Society
Differences in age at onset and familial aggregation between clinical types of idiopathic Parkinson's disease
Authors: Korchounov Alexei , Schipper Hayo I. , Preobrazhenskaya Irina S. , Kessler Kirn R. , Yakhno Nikolay N. 
Published: April 2004

AbstractIdiopathic Parkinson's disease (PD) can be subdivided by its patterns of motor symptoms into tremor‐dominant (TDT), akinetic‐rigid (ART), and mixed type (MT). Our objective was to determine whether age at onset and family history are different in these three types. In total, 366 patients with PD were assigned in a standardized approach to one of the three subtypes. Age at onset and family history were obtained in all patients and all presumably affected family members were examined. Mean ages at disease onset were similar in all three groups, but distribution of age at onset was markedly different: monophasic in TDT with a peak around 60 years, biphasic in ART with two peaks, one in the middle of the sixth decade (earlier onset, ART‐EO), another during the first half of the seventh decade (later onset, ART‐LO), and increasing with age only in MT patients A positive family history was significantly associated only with TDT (odds ratio = 5.7) and ART‐EO (odds ratio = 7.8), but not with MT or ART‐LO patients. Segregation analysis suggested an autosomal recessive mode of transmission in ART‐EO and an autosomal dominant mode of transmission in TDT. © 2004 Movement Disorder Society
GIAO/DFT evaluation of 13C NMR chemical shifts of selected acetals based on DFT optimized geometries
Authors: Migda Wojciech , Rys Barbara 
Published: April 2004

AbstractDFT/B3LYP calculations of the ground‐state conformation of eight cyclic and acyclic acetals are presented and compared with experimental data. Results of single‐point GIAO/DFT calculations at five different levels of theory show that isotropic shieldings need to be empirically scaled to achieve agreement with experimental chemical shifts. Statistical evaluation of data indicates that the most accurate prediction of 13C chemical shifts is achieved at the MPW1PW91/6–311G** level of theory. An empirical equation describing the relationship between δ values and shielding constants is postulated. This equation has been applied to the non‐chair ground‐state conformation of the six‐membered acetonide and to the conformationally flexible benzodioxonine derivative. The agreement observed between the experimental and predicted chemical shifts shows that calculations at the MPW1PW91/6–311G** level of theory are adequate for addressing questions of conformation. Copyright © 2004 John Wiley & Sons, Ltd.
Multinuclear magnetic resonance and molecular modeling investigations as unambiguous methods for the determination of silacycle 3D structures
Authors: Mahieux Cédric , Laguerre Michel , Landais Yannick , Pianet Isabelle 
Published: April 2004

AbstractAn unexpected six‐membered silacycle was obtained using ring‐closing metathesis of diallylsilane 3. The ring size of the compound formed was derived using a 2D 13C–13C inadequate experiment. All proton and carbon‐13 resonances were assigned from classical 2D NMR experiments and the proton coupling pattern was clarified. Molecular modeling calculation was then applied using NMR data as constraints, giving the 3D structure of the synthesized compound. Copyright © 2004 John Wiley & Sons, Ltd.