bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chitosan/poly(vinyl alcohol) blending hydrogel coating improves the surface characteristics of segmented polyurethane urethral catheters
Authors: Yang Shu‐Hua , Lee Yu‐Sheng J. , Lin Feng‐Huei , Yang Jen‐Ming , Chen Ko‐shau 
Published: April 2007

AbstractSegmented polyurethane (SPU) is commonly used to manufacture urethral catheters. Surface modifications for SPU catheters are needed to reduce friction and protein adsorption, in order to minimize catheter‐related complications, including urethral trauma, encrustation, catheter obstruction, bacterial colonization, and infection. In this study, a four‐step surface modification method was developed to create a thin lubricious layer of chitosan/poly(vinyl alcohol) (PVA) hydrogel on the SPU catheter. Modification steps included oxidation of the SPU surface, functionalities modification, carbodiimide reaction and coupling, and hydrogel crosslinking. The success of each modification step was confirmed by Fourier transform infrared spectroscopy. Measurement of the water contact angle revealed that hydrogel coating created a highly hydrophilic surface and atomic force microscope analyses demonstrated that the surface was slippery. Protein absorption of the SPU catheter was significantly reduced by coating hydrogel. Chitosan in the hydrogel could provide antimicrobial activity, and the hydrogel coating SPU samples showed significant antibacterial effects in this study. In summary, the four‐step modification method developed in this study provided a simple and effective way to coat the surface of SPU catheters with a chitosan/PVA blending hydrogel that could help to minimize the risk of complications related to the use of urethral catheters. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
Effects of a ferric chloride primer on collagen‐depleted dentin bonding between tri‐n‐butylborane initiated self‐curing resin and dentin
Authors: Soeno Kohyoh , Taira Yohsuke , Ito Shuichi , Atsuta Mitsuru , Pashley David. H. 
Published: April 2007

AbstractThis study was designed to evaluate the micro‐tensile bond strength between a carboxylic resin and dentin, when the dentin surface was modified with an experimental dentin primer. The three primers tested were ED primer II (ED), 0.3% ferric chloride aqueous solution (FE), and ED containing 0.3% ferric chloride (ED/FE). Three commercial dentin conditioners [40% phosphoric acid, 10% NaOCl, and 10% citric acid with 3% ferric chloride (10‐3)] were also used. The coronal surfaces of extracted human molars were ground flat to dentin. The dentin surfaces were treated with phosphoric acid, NaOCl, or with one of the primers. The 10‐3 was used without phosphoric acid or NaOCl as a control. A composite material rod was bonded to the dentin surface with 4‐META/MMA‐TBB resin. After 24‐h immersion in 37°C distilled water, 0.9 mm × 0.9 mm composite‐dentin beams cut from the bonded specimens were stressed to failure in tension at 0.6 mm/min. The bond strengths were also evaluated after 5000 thermocycles. The bond strength of the group ED/FE was significantly higher than those of the 10‐3, ED, and FE. After 5000 thermocycling, 10‐3, ED and FE showed significant decrease in bond strength, although no significant decrease was seen for ED/FE. It was concluded that dentin surface treatment with phosphoric acid, NaOCl, and the ED/FE primer improved the bonding (p < 0.05) between 4‐META/MMA‐TBB resin and dentin, with or without thermocycling, while the bond strengths in the control group fell 34% following 5000 thermocycles. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
Ofloxacin‐delivery system of a polyanhydride and polylactide blend used in the treatment of bone infection
Authors: Chen Liaobin , Wang Hui , Wang Jun , Chen Man , Shang Liang 
Published: April 2007

AbstractWe developed a local drug‐release system consisting of two biodegradable polymers, poly(sebacic anhydride) (PSA) and poly‐D,L‐lactide (PLA), for the treatment of chronic osteomyelitis. PSA and PLA were dissolved and blended at different ratios in tetrahydrofuran. Ofloxacin was loaded with an 8:1 weight ratio of the blend to the drug. The ofloxacin‐containing beads of the PSA/PLA blend were made by preheating and compressing them in a mold. The in vitro drug release showed that changing the ratio between the two polymers caused the effective ofloxacin‐release duration to vary from 6 to 68 days. The ofloxacin‐containing beads with 10% PSA and 90% PLA produced an inhibition zone for the bacteria Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa within 89 days of the experiment. The in vivo drug release of the beads in rabbits demonstrated that the average ofloxacin concentration in the local bone was 20.1 ± 10.3 μg/g, while that in the plasma was 35.6 ± 18.8 ng/mL, within 8 weeks. Roentgenography, bacterial cultures, and histological examinations showed that the local release of ofloxacin by the beads could cure osteomyelitis in rabbits. Our findings suggested that using PSA/PLA blends with different ratios as carriers for antibiotics might be useful in the treatment of chronic osteomyelitis and in the prophylaxis of bone infection. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
First‐trimester sonography: Is the fetus exposed to high levels of acoustic energy?
Authors: Sheiner Eyal , Shoham‐Vardi Ilana , Hussey Michael J. , Pombar Xavier , Strassner Howard T. , Freeman Jody , Abramowicz Jacques S. 
Published: April 2007

AbstractPurpose.As a form of energy, diagnostic ultrasound has bioeffects on living tissues. The thermal index (TI), TIS (TI for soft tissue), TIB (TI for bone), TIC (TI for cranial bone) expresses the potential for rise in temperature at the ultrasound beam's focal point. The mechanical index (MI) indicates the potential for the ultrasound beam to induce inertial cavitation in tissues. The goal of this study was to characterize the acoustic output of clinical ultrasound instruments, as expressed by TI and MI, during routine first‐trimester sonographic examinations.Methods.A prospective observational study was conducted. First‐trimester patients were randomly selected from those scheduled for viability scans. An obstetrician collected data. Sonographers were blinded to the data being sought, which included gestational age, duration of the examination, and every variation in the MI and TI during each sonographic examination.Results.A total of 52 first‐trimester examinations were evaluated. The mean gestational age was 8.9 ± 1.9 weeks. The mean duration of the sonographic examinations was 8.1± 1.4 minutes. During the examinations, there were 178 MI variations (mean ± SD, 0.9 ± 0.3) and 167 TI variations (mean ± SD, 0.2 ± 0.1).Conclusion.First‐trimester sonographic examinations are associated with a negligible rise in TI. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Short humerus: An additional antenatal sonographic feature of OFDS type II
Authors: Pradhan Mandakini , Manisha  , Sankar Hariharan 
Published: April 2007

AbstractThe prevalence of skeletal dysplasia in the neonatal period is 2.4/10,000 births; it accounts for 1–2% of perinatal deaths, mainly stillbirths. A long bone measurement of less than −4 standard deviations is a definitive indication of skeletal dysplasia, whereas measurement between −2 and −4 standard deviations warrants detailed sonographic examination for other associated anomalies to arrive at a diagnosis. We report a case of oral‐facial‐digital syndrome type II that presented antenatally with polyhydramnios, short humerus, polydactyly, and duplicated thumb. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Sonographic diagnosis of uncomplicated first‐trimester pregnancy in the rudimentary horn of a unicornuate uterus
Authors: Taori Kishor , Saha Bimal Kumar , Shah Deepal , Khadaria Narottam , Jadhav Vijay , Jawale Rajesh 
Published: April 2007

AbstractAlthough pregnancy in a rudimentary uterine horn is rare, the correct diagnosis of this condition on routine sonographic examination is critical, because its natural history usually involves the rupture of the pregnant horn during the second or third trimester, resulting in life‐threatening bleeding. We report a case in which the diagnosis of right unicornuate uterus with a left noncommunicating rudimentary horn was made in the first trimester on routine sonographic examination. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Prolonged expression of a lysosomal enzyme in mouse liver after Sleeping Beauty transposon‐mediated gene delivery: implications for non‐viral gene therapy of mucopolysaccharidoses
Authors: Aronovich Elena L. , Bell Jason B. , Belur Lalitha R. , Gunther Roland , Koniar Brenda , Erickson David C. C. , Schachern Patricia A. , Matise Ilze , McIvor R. Scott , Whitley Chester B. , Hackett Perry B. 
Published: April 2007

AbstractBackgroundThe Sleeping Beauty (SB) transposon system is a non‐viral vector system that can integrate precise sequences into chromosomes. We evaluated the SB transposon system as a tool for gene therapy of mucopolysaccharidosis (MPS) types I and VII.MethodsWe constructed SB transposon plasmids for high‐level expression of human β‐glucuronidase (hGUSB) or α‐L‐iduronidase (hIDUA). Plasmids were delivered with and without SB transposase to mouse liver by rapid, high‐volume tail‐vein injection. We studied the duration of expressed therapeutic enzyme activity, transgene presence by PCR, lysosomal pathology by toluidine blue staining and cell‐mediated immune response histologically and by immunohistochemical staining.ResultsTransgene frequency, distribution of transgene and enzyme expression in liver and the level of transgenic enzyme required for amelioration of lysosomal pathology were estimated in MPS I and VII mice. Without immunomodulation, initial GUSB and IDUA activities in plasma reached > 100‐fold of wild‐type (WT) levels but fell to background within 4 weeks post‐injection. In immunomodulated transposon‐treated MPS I mice plasma IDUA persisted for over 3 months at up to 100‐fold WT activity in one‐third of MPS I mice, which was sufficient to reverse lysosomal pathology in the liver and, partially, in distant organs. Histological and immunohistochemical examination of liver sections in IDUA transposon‐treated WT mice revealed inflammation 10 days post‐injection consisting predominantly of mononuclear cells, some of which were CD4‐ or CD8‐positive.ConclusionsOur results demonstrate the feasibility of achieving prolonged expression of lysosomal enzymes in the liver and reversing MPS disease in adult mice with a single dose of therapeutic SB transposons. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of polyadenylation signals on plasmid nuclease‐resistance and transgene expression
Authors: Azzoni Adriano R. , Ribeiro Sofia C. , Monteiro Gabriel A. , Prazeres Duarte M.F. 
Published: April 2007

AbstractBackgroundEfficient delivery and expression of plasmids (pDNA) is a major concern in gene therapy and DNA vaccination using non‐viral vectors. Besides the use of adjuvants, the pDNA vector itself can be designed to maximize survival in nuclease‐rich environments. Homopurine‐rich tracts in polyadenylation sequences have been previously shown to be especially important in pDNA resistance.MethodologyThe effect of modifications in the poly A sequence of a model pDNA vector (pVAX1GFP) on nuclease resistance and transgene expression was investigated. Four poly A sequences were studied: bovine growth hormone (BGH), mutant BGH, SV40 and a synthetic poly A. Plasmid resistance (half‐life) was assessed through in vitro incubations with mammalian nucleases. The impact in transgene expression was studied by quantifying pDNA, mRNA, and GFP expression in CHO, hybridoma and HeLa cells.Results and conclusionsIn vitro and cell culture studies indicate that plasmids containing the SV40 and the synthetic poly A sequences present significant improvements in nuclease resistance (up to two‐fold increase in half‐life). However, RT‐PCR analysis demonstrated that significant reduction in mRNA steady‐state levels were responsible for a decrease in transgene expression and detected transfection level of CHO and hybridoma cells when using the more resistant plasmids. Interestingly, transfection of HeLa cells demonstrated that both poly A efficiency and plasmid resistance interfere significantly in transgene expression. The results strongly suggest that the choice of the poly A is important, not only for mRNA maturation/stability, but also for pDNA resistance, and should thus be taken into consideration in the design and evaluation of pDNA vectors. Copyright © 2007 John Wiley & Sons, Ltd.
Docking and molecular dynamics simulation of the Azurin–Cytochrome c551 electron transfer complex
Authors: Bizzarri Anna Rita , Brunori Elena , Bonanni Beatrice , Cannistraro Salvatore 
Published: April 2007

AbstractWe coupled protein–protein docking procedure with molecular dynamics (MD) simulation to investigate the electron transfer (ET) complex Azurin–Cytochrome c551 whose transient character makes difficult a direct experimental investigation. The ensemble of complexes generated by the docking algorithm are filtered according to both the distance between the metal ions in the redox centres of the two proteins and to the involvement of suitable residues at the interface. The resulting best complex (BC) is characterized by a distance of 1.59 nm and involves Val23 and Ile59 of Cytochrome c551. The ET properties have been evaluated in the framework of the Pathways model and compared with experimental data. A 60 ns long MD simulation, carried on at full hydration, evidenced that the two protein molecules retain their mutual spatial positions upon forming the complex. An analysis of the ET properties of the complex, monitored at regular time intervals, has revealed that several different ET paths are possible, with the occasional intervening of water molecules. Furthermore, the temporal evolution of the geometric distance between the two redox centres is characterized by very fast fluctuations around an average value of 1.6 nm, with periodic jumps at 2 nm with a frequency of about 70 MHz. Such a behaviour is discussed in connection with a nonlinear dynamics of protein systems and its possible implications in the ET process are explored. Copyright © 2007 John Wiley & Sons, Ltd.
Biomolecular recognition of glycosylated β3‐peptides by GalNAc specific lectins
Authors: Norgren Anna S. , Geitmann Matthis , Danielson U. Helena , Arvidsson Per I. 
Published: April 2007

AbstractThe molecular recognition of a novel kind of hybrid conjugates, composed of artificial biomimetic β‐peptide oligomers with an O‐linked natural N‐acetyl‐galactosamine (the Tn‐antigen) residue, by four different GalNAc specific lectins was investigated using surface plasmon biosensor technology. The influence of the peptide and the glycosyl moiety on the recognition was studied using two glycosylated β3‐heptapeptides, a glycosylated α‐heptapeptide, two β‐amino acid containing dipeptides, and monomeric αGalNAc‐O‐Thr.Although all four lectins displayed a decreased affinity for the carbohydrate residue when attached to a peptide, as compared to the monomeric Tn‐antigen, the peptide part was found to have distinct effects on the binding kinetics—indicating that varying degrees of protein–peptide interactions occurred in the recognition process. Likewise, the lectins did not discriminate between β3‐peptides and the α‐peptide, but the β‐linkage of the galactose had a detrimental effect for at least two of the lectins. Copyright © 2007 John Wiley & Sons, Ltd.
Functional lung imaging using hyperpolarized gas MRI
Authors: Fain Sean B. , Korosec Frank R. , Holmes James H. , O'Halloran Rafael , Sorkness Ronald L. , Grist Thomas M. 
Published: April 2007

AbstractThe noninvasive assessment of lung function using imaging is increasingly of interest for the study of lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma. Hyperpolarized gas MRI (HP MRI) has demonstrated the ability to detect changes in ventilation, perfusion, and lung microstructure that appear to be associated with both normal lung development and disease progression. The physical characteristics of HP gases and their application to MRI are presented with an emphasis on current applications. Clinical investigations using HP MRI to study asthma, COPD, cystic fibrosis, pediatric chronic lung disease, and lung transplant are reviewed. Recent advances in polarization, pulse sequence development for imaging with Xe‐129, and prototype low magnetic field systems dedicated to lung imaging are highlighted as areas of future development for this rapidly evolving technology. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Time‐resolved contrast‐enhanced carotid imaging using undersampled projection reconstruction acquisition
Authors: Du Jiang , Fain Sean B. , Korosec Frank R. , Grist Thomas M. , Mistretta Charles A. 
Published: April 2007

AbstractPurposeTo investigate the utility of nonuniform angular spacing of projections in a three‐dimensional (3D) hybrid undersampled projection reconstruction (PR) acquisition for contrast‐enhanced (CE) time‐resolved carotid imaging.Materials and MethodsCarotid CE magnetic resonance angiography (CE‐MRA) was performed on seven healthy volunteers using a time‐resolved hybrid sequence that combined undersampled PR acquisition in‐plane and Cartesian slice encoding through‐plane. The undersampling streak artifact comes mainly from the superior–inferior (S/I) direction in carotid imaging and is suppressed by nonuniform distribution of the projections. Phantom and volunteer studies were performed to demonstrate its efficacy.ResultsThe undersampling streak artifact was significantly suppressed through a nonuniform distribution of the projection angles with more projections aligned along the S/I direction. The hybrid PR sequence combined with nonuniform distribution of the projection angles provided time‐resolved images of the carotid arteries with high temporal resolution (two seconds per frame) and high spatial resolution (1.0 × 1.0 × 1.5 mm3) simultaneously.ConclusionHigh‐resolution dynamic imaging of the carotid arteries is feasible with the use of a hybrid undersampled PR acquisition. Undersampling streak artifact can be suppressed significantly through nonuniform distribution of the projections. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Transient signal changes in diffusion‐weighted stimulated echoes during neuronal stimulation at 3T
Authors: Goerke Ute , Möller Harald E. 
Published: April 2007

AbstractPurposeTo develop a sensitive method for detecting minute transient signal changes that can arise due to variations in the extravascular apparent self‐diffusion coefficient, D, during neuronal activation.Materials and MethodsA three‐pulse sequence that reads out a moderately diffusion‐weighted (DW) primary echo (PRE) and a heavily DW stimulated echo (STE) was employed to investigate whether small transient signal changes in extravascular D occur in response to a visual stimulus. Contributions to signal changes caused by subtle differences in the transient variations of the apparent transverse relaxation constant, T2, between the PRE and STE were also quantified.ResultsOn z‐maps obtained from the STE, more voxels showed significant stimulus‐related signal changes compared to maps of the PRE. The average maximum signal change of the STE was larger than that of the PRE. The observed increase in the relative signal change was independent of the strength of the diffusion weighting.ConclusionThe STE is more sensitive to neuronal activity than the PRE. The discrepancy between the two echoes does not arise from transient changes in D, but from subtle differences in stimulus‐related variations of T2 between the two echoes. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
MRCP imaging at 3.0 T vs. 1.5 T: Preliminary experience in healthy volunteers
Authors: Isoda Hiroyoshi , Kataoka Masako , Maetani Yoji , Kido Aki , Umeoka Shigeaki , Tamai Ken , Koyama Takashi , Nakamoto Yuji , Miki Yukio , Saga Tsuneo , Togashi Kaori 
Published: April 2007

AbstractPurposeTo evaluate the impact of magnetic resonance cholangiopancreatography (MRCP) imaging at 1.5T and 3.0T on image quality.Materials and MethodsFourteen volunteers were examined at both 1.5T and 3.0T using MRCP imaging performed with a breath‐held two‐dimensional (2D) half‐Fourier acquired single‐shot turbo spin‐echo (HASTE) thick‐slab sequence, a free‐breathing navigator‐triggered three‐dimensional (3D) turbo spin‐echo (TSE) sequence with prospective acquisition correction, and a heavily T2‐weighted (T2W) sequence with breath‐held multislice HASTE. All images were scored for visualization of the biliary and pancreatic ducts, severity of artifacts, image noise, and overall image quality.ResultsMRCP imaging at 3.0T yielded a significant improvement in overall image quality compared to 1.5T. We found a trend for superior visualization of the biliary and pancreatic ducts at 3.0T. Heavily T2W imaging with thin sections (1.4 mm) at 3.0T provided diagnostic images and better visualization of the biliary and pancreatic ducts than heavily T2W imaging with standard sections (2.8 mm) at 3.0T.ConclusionOur experience suggests that MRCP imaging at 3.0T has the potential to provide excellent images. High‐resolution heavily T2W imaging with a small voxel size (1.3 × 1.3 × 1.4 mm) at 3.0T can provide diagnostic images and allow evaluation of small pathologies of the bile and pancreatic ducts, which 1.5T MRI cannot sufficiently visualize. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
T1 measurement of flowing blood and arterial input function determination for quantitative 3D T1‐weighted DCE‐MRI
Authors: Cheng Hai‐Ling Margaret 
Published: April 2007

AbstractPurposeTo propose a simple, accurate method for measuring T1 in flowing blood and the arterial input function (AIF), and to evaluate the impact on dynamic contrast‐enhanced MRI (DCE‐MRI) quantification of pharmacokinetic parameters.Materials and MethodsA total of 10 rabbits were scanned at 1.5 Tesla and administered a bolus of Gadomer. Preinjection T1 and AIF measurements were acquired in the iliac arteries using a rapid three‐dimensional (3D) spoiled gradient recalled echo (SPGR) approach. Correction was made for imperfect B1 fields, in‐flow, and partial volume effects. DCE‐MRI parameters blood volume (vb) and endothelial transfer constant (Ktrans) in resting skeletal muscle were estimated from pharmacokinetic analysis using individually measured AIFs. Literature comparisons were made to assess accuracy.ResultsBlood T1 was more accurate and precise after correction for B1 and partial volume errors (1267 ± 72 msec). Measured AIFs followed reported biexponential decay characteristics for Gadomer clearance in rabbits. Parameters vb (2.47 ± 0.65%) and Ktrans (3.6 ± 1.0 × 10–3 minute–1) derived from AIFs based on corrected blood T1s were more reproducible and in better agreement with literature values.ConclusionThe proposed method enables accurate in vivo blood T1 and AIF measurements and can be easily implemented in a range of DCE‐MRI applications to improve both the accuracy and reproducibility of pharmacokinetic parameters. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.