bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface characteristics, biocompatibility, and mechanical properties of nickel‐titanium plasma‐implanted with nitrogen at different implantation voltages
Authors: Liu X.M. , Wu S.L. , Chan Y.L. , Chu Paul K. , Chung C.Y. , Chu C.L. , Yeung K.W.K. , Lu W.W. , Cheung K.M.C. , Luk K.D.K. 
Published: February 2007

AbstractNiTi shape memory alloy is one of the promising orthopedic materials due to the unique shape memory effect and superelasticity. However, the large amount of Ni in the alloy may cause allergic reactions and toxic effects thereby limiting its applications. In this work, the surface of NiTi alloy was modified by nitrogen plasma immersion ion implantation (N‐PIII) at various voltages. The materials were characterized by X‐ray photoelectron spectroscopy (XPS). The topography and roughness before and after N‐PIII were measured by atomic force microscope. The effects of the modified surfaces on nickel release and cytotoxicity were assessed by immersion tests and cell cultures. The XPS results reveal that near‐surface Ni concentration is significantly reduced by PIII and the surface TiN layer suppresses nickel release and favors osteoblast proliferation, especially for samples implanted at higher voltages. The surfaces produced at higher voltages of 30 and 40 kV show better adhesion ability to osteoblasts compared to the unimplanted and 20 kV PIII samples. The effects of heating during PIII on the phase transformation behavior and cyclic deformation response of the materials were investigated by differential scanning calorimetry and three‐point bending tests. Our results show that N‐PIII conducted using the proper conditions improves the biocompatibility and mechanical properties of the NiTi alloy significantly. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Effects of cefuroxime on human osteoblasts in vitro
Authors: Salzmann G.M. , Naal F.D. , von Knoch F. , Tuebel J. , Gradinger R. , Imhoff A.B. , Schauwecker J. 
Published: February 2007

AbstractThe local application of antibiotics in bone cement achieves high local effective antibiotic concentrations. Cefuroxime is widely used for antibiotic prophylaxis in orthopedic surgery, and several reports highlighted a beneficial outcome if cefuroxime‐impregnated bone cement was used, but there is a lack of information of direct cefuroxime effects on human bone cells. We, therefore, cultured osteoblasts, previously derived from human trabecular bone specimens and used as a cell‐pool further on, with different concentrations of cefuroxime (0–1000 μg/mL) for 24, 48, or 72 h. For reversibility testing, osteoblasts were cultivated for 24 h with cefuroxime followed by 48 h without antibiotics. Cell proliferation (MTT), cytotoxicity (lactate dehydrogenase (LDH)‐activity), cell metabolism (alkaline phosphatase (ALP)‐activity), and extracellular matrix calcification (Alizarin staining) were assessed after antibiotic treatment. Cefuroxime concentrations of 25–100 μg/mL had little or no effect on cellular proliferation. Proliferation was significantly stimulated at 250 and 1000 μg/mL at each time. LDH‐activity significantly increased at the highest concentration of 1000 μg/mL at 72 h. ALP‐activity first increased at lower concentrations and then significantly decreased at 1000 μg/mL at 48 and 72 h. Similar to ALP‐activity, calcification increased at lower concentrations and was not detectable at 1000 μg/mL. All revealed effects at 24 h were at least partially reversible. In the present study, we demonstrated that cefuroxime at lower concentrations had no inhibiting effects on human osteoblasts. In contrast, higher concentrations significantly altered osteoblastic function. When administered locally in total joint arthroplasty, for example, in antibiotic‐impregnated bone cement, cefuroxime might critically impair osteoblastic function and periprosthetic bone metabolism. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Biomedical modification of poly(L‐lactide) by blending with lecithin
Authors: Zhu N. , Cui F.Z. , Hu K. , Zhu L. 
Published: February 2007

AbstractLecithin was, for the first time, blended with PLLA to prepare scaffold material for tissue engineering applications in the present study. Solution blending was used to incorporate Lecithin (containing 0–10 wt %) with PLLA to enhance the blend films biocompatibility, hydrophilicity and toughness while maintaining mechanical strength of PLLA. The results of FTIR‐ATR analysis indicated that the amino groups of lecitin existed in the films. DSC analysis indicated that Tg decreased with the increase of lecithin content in the blend films. The percentage elongation markedly increased with increase of lecithin content. The proliferation and viability of the vascular smooth muscle cell cultures on PLLA/Lecithin (containing 3–7 wt %) films were significantly enhanced compared to pure PLLA on tissue culture plates. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Electrophoretic deposition of zirconia‐Bioglass® composite coatings for biomedical implants
Authors: Radice S. , Kern P. , Bürki G. , Michler J. , Textor M. 
Published: February 2007

AbstractComposite bilayer coatings on Ti6Al4V substrates were prepared by electrophoretic deposition, a simple and fast low temperature coating technique. Biocompatible yttrium‐stabilized zirconia (YSZ) in the form of nanoparticles and bioactive Bioglass® (45S5) in the form of microparticles were chosen as coating materials. The first layer consisted of 5 μm of YSZ, deposited with the intention to avoid any metal tissue contact. The second layer consisted of 15‐μm thick 45S5‐YSZ composite, supposed to react with the surrounding bone tissue and to enhance implant fixation. The adsorption of YSZ nanoparticles on 45S5 microparticles in organic suspension was found to invert the surface charge of the 45S5 particles from negative to positive. This enabled cathodic electrophoretic deposition of 45S5, avoiding uncontrolled anodization (oxidation) of the substrate. The coatings were sintered at 900°C for 2 h under argon flow. The characterization was performed using SEM, EDX, and nanoindentation (cross section). Potential applications in the orthopedics field are discussed. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Poly‐L‐lactic acid/hydroxyapatite hybrid membrane for bone tissue regeneration
Authors: Sui Gang , Yang Xiaoping , Mei Fang , Hu Xiaoyang , Chen Guoqiang , Deng Xuliang , Ryu Seungkon 
Published: February 2007

AbstractPoly‐L‐lactic acid (PLLA)/hydroxyapatite (HA) hybrid membranes were fabricated via electrospinning of the PLLA/HA dispersion for use in bone tissue regeneration. The structural properties and morphologies of PLLA and PLLA/HA hybrid membrane were investigated by measuring the Brunauer‐Emmett‐Teller specific surface area, observations of SEM, and TEM. The dispersion and integrating of HA nanoparticles in the hybrid membrane were studied by energy dispersion X‐ray analysis and FTIR. The mechanical properties of PLLA/HA membrane were also measured by tensile tests. For exploring biological behaviors of the hybrid membrane, in vitro degradation tests were carried out. The osteoblast cell (MG‐63) was cultured in PLLA/HA hybrid membrane extract containing medium; the cell adhesion and growth capability were investigated by SEM observation and MTT assay. HA nanoparticles were not only dispersed in the PLLA but also reacted with the functional group of PLLA, resulting in strong surface bonding and high tensile strength of hybrid membrane. The cell adhesion and growth on the PLLA/HA hybrid membrane were far better than those on the pure PLLA membrane, which proves that the PLLA/HA hybrid membrane can be one of the promising biomaterials for bone tissue regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Elevation of transforming growth factor beta (TGFβ) and its downstream mediators in subcutaneous foreign body capsule tissue
Authors: Li Allen G. , Quinn Matthew J. , Siddiqui Yasmin , Wood Michael D. , Federiuk Isaac F. , Duman Heather M. , Ward W. Kenneth 
Published: February 2007

AbstractForeign body encapsulation represents a chronic fibrotic response and has been a major obstacle that reduces the useful life of implanted biomedical devices. The precise mechanism underlying such an encapsulation is still unknown. We hypothesized that, considering its central role in many other fibrotic conditions, transforming growth factor β (TGFβ) may play an important role during the formation of foreign body capsule (FBC). In the present study, we implanted mock sensors in rats subcutaneously and excised FBC samples at day 7, 21, and 48–55 postimplantation. The most abundant TGFβ isoform in all tissues was TGFβ1, which was expressed minimally in control tissue. The expression of both TGFβ1 RNA and protein was significantly increased in FBC tissues at all time points, with the highest level in day 7 FBC. The number of cells stained for phosphorylated Smad2, an indication of activated TGFβ signaling, paralleled the expression of TGFβ. A similar dynamic change was also observed in the numbers of FBC myofibroblasts, which in response to TGFβ, differentiate from quiescent fibroblasts and synthesize collagen. Type I collagen, the most prominent downstream target of TGFβ in fibrosis, was found in abundance in the FBC, especially during the latter time periods. We suggest that TGFβ plays an important role in the FBC formation. Inhibition of TGFβ signaling could be a promising strategy in the prevention of FBC formation, thereby extending the useful life of subcutaneous implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
The effect of yield damage on the viscoelastic properties of cortical bone tissue as measured by dynamic mechanical analysis
Authors: Yeni Yener N. , Shaffer Richard R. , Baker Kevin C. , Dong X. Neil , Grimm Michele J. , Les Clifford M. , Fyhrie David P. 
Published: February 2007

AbstractWe have previously shown, using Dynamic Mechanical Analysis (DMA), that the presence of a defect in cortical bone tissue affects the apparent viscoelastic properties of that bone. However, mechanically induced damage is more complex than a machined defect making it difficult to predict its effect on bone viscoelasticity. We performed DMA measurements before and after introduction of yield damage into cortical bone beams from sheep radii. The specimens were placed in a DMA machine and baseline measurements of storage modulus (E1) and loss factor (tanδ) were performed using a 3‐point bending configuration for a frequency range of 1–10 Hz. Measurements were done in all four bending directions (cranial, caudal, medial, and lateral) in random order. After subjecting the specimens to monotonic yield damage in a servohydraulic testing machine with the load applied to the cranial surface, oscillatory tests were repeated. To supplement results from the current experiment, additional analyses were performed on data from experiments where bone was either cut or fatigue‐loaded between viscoelasticity measurements. Introduction of mechanical damage increased tan δ and frequency sensitivity of E1, consistent with the assertion that increased energy dissipation in damaged bone might contribute to its increased resistance to fatigue and fracture. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Bacteria–surface interaction in the presence of proteins and surface attached poly(ethylene glycol) methacrylate chains
Authors: Tedjo Chrysanty , Neoh K.G. , Kang E.T. , Fang Ning , Chan Vincent 
Published: February 2007

AbstractThis study analyzes the adhesion behavior of the gram positive bacteria, Staphylococcus aureus (S. aureus), and the gram negative bacteria, Escherichia coli (E. coli), on polypyrrole (PPY) surfaces in the presence of poly(ethylene glycol) methacrylate (PEGMA) chains and plasma proteins (bovine serum albumin and bovine plasma fibrinogen) either preadsorbed on the film surface or in the bacterial suspension. Bacterial adhesion experiments performed in a suspension of bacterial cells and protein may give important insights on the behavior of bacterial adhesion in an in vivo environment. Protein adsorption and bacterial adhesion on PEGMA‐grafted PPY films were reduced by about a factor of 2–4 compared with those on the pristine PPY films. In addition, the number of bacterial cells adhering on the substrate is dependent not only on the type of protein present, but also the sequence of exposure to the protein relative to the bacteria. Furthermore, bacteria–surface adhesion force was measured using the atomic force microscopy with increasing lateral force to detach the individual cell. The adhesion force of S. aureus is influenced by PEGMA and plasma protein modification and is significantly higher than that of E. coli for all substrates tested. The number of adherent cells on the substrate is shown to be directly correlated to the bacterial adhesion force. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Roles of MMP/TIMP in regulating matrix swelling and cell migration during chick corneal development
Authors: Huh Man‐Il , Lee Young‐Mi , Seo Seong‐Kyung , Kang Bong‐Seok , Chang Yongmin , Lee Young‐Sup , Fini M. Elizabeth , Kang Shin‐Sung , Jung Jae‐Chang 
Published: February 2007

AbstractTissue remodeling is central to embryonic development. Here, we used immunohistochemistry, Western blotting, and RT‐PCR analysis to investigate the roles of matrix metalloproteinases (MMPs) and the related “a disintegrin and metalloproteinase“ (ADAM) family proteinases in chick corneal development. While MMP‐13 was expressed in developing chick corneas from embryonic day (ED) 5 to ED 10, its inhibitor, tissue inhibitors of metalloproteinase‐1 (TIMP‐1), was expressed from ED 18 to 2 days post‐hatching (P2). Early MMP‐13 activity may be associated with degradation of type IX collagen from the primary stroma, which loosens the collagen fibrils and facilitates neural crest (NC) cell migration. The membrane‐bound and secreted forms of ADAM10 were both detected throughout corneal development, and active ADAM10 formed a cleavage complex with CD44v6, a CD44 splice variant that is a major cell surface adhesion molecule for hyaluronic acid (HA) and has been implicated in cell migration. Both CD44v6 and its ectodomain cleavage products were detected from ED 5 to ED 14, and a broad‐spectrum MMP inhibitor blocked ectodomain cleavage in cultured stromal cells. These findings suggest that ADAM10 mediates CD44v6 cleavage in the developing cornea, facilitating NC cell‐derived mesenchymal cell migration. Finally, we identified high levels of active membrane‐type 3‐MMP (MT3‐MMP) in developing corneas at ED 7, ED 14, and ED 18. MT3‐MMP takes part in MMP‐2 activation and possibly also CD44v6 shedding, suggesting that this pathway may be involved in cell migration. These findings collectively show for the first time that multiple MMPs, ADAMs, and TIMPs appear to functionally interact during corneal development. J. Cell. Biochem. 101:1222–1237, 2007. © 2007 Wiley‐Liss, Inc.
E2F5 and LEK1 Translocation to the nucleus is an early event demarcating myoblast quiescence
Authors: Reed Sarah A. , Ouellette Sara E. , Liu Xiaosong , Allen Ronald E. , Johnson Sally E. 
Published: February 2007

AbstractRaf/MEK/ERK signaling in skeletal muscle cells affects several aspects of myogenesis that are correlated with the duration and intensity of the input signal. 23A2RafERDD myoblasts directing elevated levels of Raf kinase for 24 h are mitotically inactive. Removal of the stimulus results in cell cycle re‐entry and proliferation. Using a proteomic approach, E2F5 and LEK1 were detected in the nuclei of Raf‐arrested myoblasts. Disruption of MEK1 activity prevents phosphorylation of ERK1/2 and nuclear translocation of E2F5 and LEK1. The pocket proteins, p107 and p130, remain in the cytoplasm of growth arrested myoblasts irrespective of Raf/ERK activation while pRb translocates to the nucleus. Importantly, both E2F5 and LEK1 are found in the nuclei of non‐dividing satellite cells and myonuclei in vivo and in vitro. Our results indicate that Raf‐arrested myoblasts may serve as a model system for satellite cell cycle studies and that E2F5 and LEK1 translocation to the nucleus is an important first step during entry into quiescence. J. Cell. Biochem. 101: 1394–1408, 2007. © 2007 Wiley‐Liss, Inc.
FGFR1/PI3K/AKT signaling pathway is a novel target for antiangiogenic effects of the cancer drug Fumagillin (TNP‐470)
Authors: Chen Gregory J. , Weylie Brian , Hu Chen , Zhu James , Forough Reza 
Published: February 2007

AbstractFibroblast growth factor‐1 (FGF1), a prototypic member of the FGF family, is a potent angiogenic factor. Although FGF‐stimulated angiogenesis has been extensively studied, the molecular mechanisms regulating FGF1‐induced angiogenesis are poorly understood in vivo. Fumagillin, an antiangiogenic fungal metabolite, has the ability to inhibit FGF‐stimulated angiogenesis in the chicken chorioallantoic membrane (CAM). In the current study, chicken CAMs were transfected with a signal peptide‐containing version of the FGF1 gene construct (sp‐FGF1). Transfected CAMs were then analyzed in the presence and absence of fumagillin treatment with respect to the mRNA expression levels and protein activity of the FGF1 receptor protein (FGFR1), phosphatidylinositol 3‐kinase (PI3K), and its immediate downstream target, AKT‐1 (protein kinase B). Treatment of sp‐FGF1‐transfected CAMs with fumagillin showed downregulation for both PI3K and AKT‐1 proteins in mRNA expression and protein activity. In contrast, no major alterations in FGFR1 mRNA expression level were observed. Similar patterns of mRNA expression for the above three proteins were observed when the CAMs were treated with recombinant FGF1 protein in place of sp‐FGF1 gene transfection. Investigation using biotin‐labeled fumagillin showed that only the FGF1 receptor protein containing the cytoplasmic domain demonstrated binding to fumagillin. Furthermore, we demonstrated endothelial‐specificity of the proposed antiangiogenic signaling cascade using an in vitro system. Based on these findings, we conclude that the binding of fumagillin to the cytoplasmic domain of the FGF1 receptor inhibited FGF1‐stimulated angiogenesis both in vitro and in vivo. J. Cell. Biochem. 101: 1492–1504, 2007. © 2007 Wiley‐Liss, Inc.
Enterolith ileus in a patient with jejunal diverticulosis: Sonographic findings
Authors: Liu Chen‐Hua , Huang Kai‐Wen , Mo Yuan‐Heng , Yang Pei‐Ming 
Published: February 2007

AbstractJejunal diverticula are rare. Enterolith ileus, the least‐encountered complication among patients with jejunal diverticula, is incidentally found at surgery or during imaging studies such as radiography, CT, or endoscopy. We report the case of a 71‐year‐old man with enterolith ileus involving the jejunum that was initially detected using abdominal sonography and subsequently confirmed with abdominal CT and surgery. Enterolith ileus should be considered in the differential diagnosis of small bowel obstruction. Abdominal sonography may contribute to the early diagnosis of this condition. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Gastric glomus tumor: A hypervascular submucosal tumor on power doppler endosonography
Authors: Yan Sheng‐Lei , Yeh Yung‐Hsiang , Chen Chien‐Hua , Yang Chi‐Chieh , Kuo Chien‐Long , Wu Hurng‐Sheng 
Published: February 2007

AbstractGastric glomus tumors are rare submucosal lesions that typically occur in the fourth endosonographic layer. We describe a 69‐year‐old patient who presented with intermittent epigastric pain and in whom a submucosal tumor was encountered during upper gastrointestinal endoscopy. Endosonography revealed a heterogeneous, hypoechoic fourth‐layer tumor. Power Doppler imaging revealed prominent intratumoral vascular signals demonstrating its hypervascular nature. A diagnosis of glomus tumor was made via histopathologic evaluation of the resected tumor. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Alagille syndrome: Prenatal sonographic findings
Authors: Ghidini Alessandro , Incerti Maddalena , Andreani Marianna 
Published: February 2007

AbstractWe report a case of Alagille syndrome in which sonographic examination revealed the presence of angulation of the fetal spine due to vertebral fusion as well as tetralogy of Fallot. Histologic examination after pregnancy termination revealed the presence of agenesis of the gallbladder with a paucity of intrahepatic bile ducts, leading to the diagnosis of Alagille syndrome. In the presence of cardiac and axial skeletal anomalies, attention should be paid to the fetal gallbladder, whose absence would signal a diagnosis of Alagille syndrome. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Transcranial doppler ultrasonographic evaluation of cerebral circulation during passive tilting in patients with Parkinson's disease
Authors: Mihci Ebru , Dora Babür , Balkan Sevin 
Published: February 2007

AbstractPurpose.To assess the effects of the tilt test on cerebral blood flow velocity (CBFV), blood pressure, and heart rate in patients with Parkinson's disease (PD) without symptomatic orthostatic dysautonomia.Methods.Thirty patients with idiopathic PD and 15 healthy controls were included. Mean middle cerebral artery blood flow velocity (CBFV) was recorded with transcranial Doppler sonography, while systolic (SBP), diastolic (DBP), and mean (MBP) blood pressure and heart rate were measured in the supine position and after passive tilting.Results.There was no difference in resting SBP, DBP, or MBP between patients and controls. CBFV was lower at rest in patients than in controls and dropped significantly and similarly after tilting in both groups. SBP decreased in patients during the first 5 minutes of tilting (p < 0.05), whereas it increased progressively after the first minute in controls. In patients, DBP decreased slightly and MBP dropped during the first 2 minutes, then increased. Baseline heart rate was higher in patients than in controls (p < 0.05) and increased in both groups during tilting.Conclusion.Our results suggest that cardiovascular responses to tilting are delayed in PD patients and that subclinical autonomic dysfunction may be present even in the absence of symptomatic orthostatic dysautonomia. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Characterization of focal liver lesions: Comparison of pulse‐inversion harmonic contrast‐enhanced sonography with contrast‐enhanced CT
Authors: Li Rui , Guo Yanli , Hua Xing , He Yun , Ding Jun , Guo Aiming , Luo Mingkui 
Published: February 2007

AbstractPurpose.To compare the efficacy of contrast‐enhanced pulse‐inversion harmonic sonography for the characterization of focal liver lesions with that of contrast‐enhanced helical CT.Methods.Real‐time contrast‐enhanced sonography (CEUS) using Sonovue and contrast‐enhanced CT (CECT) were performed on 109 patients with focal liver lesions, including 61 hepatocellular carcinomas, 15 liver metastases, 5 cholangiocellular carcinomas, 12 hemangiomas, 5 regenerative nodules, 3 adenomas, 3 focal nodular hyperplasias, 4 focal necroses, and 1 angiomyolipoma prior to surgery or percutaneous needle biopsy. The diagnostic performance was assessed by using histopathological results as reference standards.Results.Three cases were missed on CEUS, and 7 cases were missed on CECT. These 10 missed cases were excluded from paired statistical comparison. Ten cases were misdiagnosed on CEUS and 17 cases were misdiagnosed on CECT. The overall accuracy was 89.9% (89/99) for CEUS and 82.8% (82/99) for CECT. The difference between CEUS and CECT was not statistically significant. Concordance between CEUS and CECT was observed in 90.9% (90/99) cases.Conclusion.Real‐time pulse‐inversion harmonic CEUS with Sonovue is comparable with CECT in the characterization of focal liver lesions. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007