bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological study of naphthalene derivatives with antiinflammatory activities
Authors: Huang Mei‐Han , Wu Sheng‐Nan , Wang Jih‐Pyang , Lin Chen‐Hsing , Lu Shih‐I , Liao Li‐Fang , Shen Ai‐Yu 
Published: November 2003

AbstractIn this study, 18 synthetic naphthalene derivatives were tested for their inhibitory effects on the activation of neutrophils stimulated with N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) or phorbol myristic acetate (PMA). Some of these compounds showed significant antiinflammatory activities. In general, esterification of 1‐naphthalene to compound 14 (2‐hydroxymethyl‐1‐naphthol diacetate; TAC) enhanced the antioxidant activity. Compound 15, N,N‐bis(2‐hydroxy‐1‐naphthylmethyl) amine, has moderate inhibitory activity on neutrophils stimulated with fMLP as compared to Mannich bases of naphthylene derivatives. Either substitution at 1 or 2 position, except TAC, disfavored the inhibitory effects evoked by PMA stimulation. The influence of these compounds on the release of granule enzyme lysozyme‐induced by fMLP was measured. TAC had the highest potency on the inhibition of lysozyme release from rat neutrophil degranulation. The effects of TAC on ionic currents in a mouse neuroblastoma and rat glioma hybrid cell line, NG105‐18, were also investigated with the aid of the whole‐cell patch‐clamp technique. TAC caused an inhibitory effect on voltage‐dependent L‐type Ca2+ current (ICa,L) with an IC50 value of 0.8 µM. The inhibitory effect of TAC on ICa,L may not be caused by its inhibition of superoxide formation. Such an effect may, also in part, affect neuronal function. Drug. Dev. Res. 60:261–269, 2003. © 2003 Wiley‐Liss, Inc.
N‐n‐alkylnicotinium and N‐n‐alkylpyridinium analogs inhibit the dopamine transporter: Selectivity as nicotinic receptor antagonists
Authors: Zhu J. , Crooks P. A. , Ayers J. T. , Sumithran S. P. , Dwoskin L. P. 
Published: November 2003

AbstractN‐n‐Alkylnicotinium and N‐n‐alkylpyridinium analogs act as antagonists at nicotinic acetylcholine receptors (nAChRs) mediating nicotine‐evoked [3H]dopamine (DA) overflow from superfused rat striatal slices in the presence of a DA transporter (DAT) inhibitor. However, the potential interaction of these nAChR antagonists with DAT has not been evaluated. In the present study, analog inhibition of [3H]DA uptake into striatal synaptosomes and inhibition of [3H]GBR 12935 binding to striatal membranes was determined. N‐n‐Alkylnicotinium analogs with n‐alkyl chains of C6–12 and N‐n‐alkylpyridinium analogs with n‐alkyl chains of C7–20 inhibited [3H]DA uptake with a wide affinity range. With the exception of the C20 N‐n‐alkylpyridinium, a linear relationship between chain length and inhibition of [3H]DA uptake was found in both analog series. Similarly, these analogs inhibited [3H]GBR 12935 binding (Ki=5.7–250 μM), and a linear relationship with chain length was observed, with the exception of the C8 N‐n‐alkylnicotinium analog. Kinetic analyses of inhibition of [3H]DA uptake and [3H]GBR 12935 binding using representative C12 analogs from each series revealed decreases in maximal [3H]DA transport velocity and maximal [3H]GBR 12935 binding without alterations in affinity, indicating noncompetitive interactions with DAT. In comparison, classical nAChR antagonists (mecamylamine, dihydro‐β‐erythroidine and methyllycaconitine) did not inhibit [3H]DA uptake or [3H]GBR 12935 binding. Moreover, inhibition of DAT function occurred at analog concentrations 10–120‐fold higher than those inhibiting nAChR function. Taken together with the inability of these analogs to inhibit field‐stimulation‐evoked [3H]DA overflow, the results indicate that these analogs act selectively as antagonists at nAChRs mediating nicotine‐evoked [3H]DA overflow. Drug Dev. Res. 60:270–284, 2003. © 2003 Wiley‐Liss, Inc.
Flow resistance in gravel‐bed channels with large‐scale roughness
Authors: Ferro Vito 
Published: November 2003

AbstractA previously published mixing length (ML) model for evaluating the Darcy–Weisbach friction factor for a large‐scale roughness condition (depth to sediment height ratio ranging from 1 to 4) is brieﬂy reviewed and modiﬁed (MML). Then the MML model and a modiﬁed drag (MD) model are experimentally tested using laboratory measurements carried out for gravel‐bed channels and large‐scale roughness condition. This analysis showed that the MML gives accurate estimates of the Darcy–Weisbach coefﬁcient and for Froude number values greater than 0·5 the MML model coincides with the ML one. Testing of the MD model shows limited accuracy in estimating ﬂow resistance.Finally, the MML and MD models are compared with the performance of a quasi‐theoretical (QT) model deduced applying the P‐theorem of the dimensional analysis and the incomplete self‐similarity condition for the depth/sediment ratio and the Froude number. Using the experimental gravel‐bed data to calibrate the QT model, a constant value of the exponent of the Froude number is determined while two relationships are proposed for estimating the scale factor and the exponent of the depth/sediment ratio. This indirect estimate procedure of the coefﬁcients (b0, b1 and b2) of the QT model can produce a negligible overestimation or underestimation of the friction factor. Copyright © 2003 John Wiley & Sons, Ltd.
Post‐fire thin debris flows: sediment transport and numerical modelling
Authors: Gabet Emmanuel J. 
Published: November 2003

AbstractThe creation of a hydrophobic layer in the soil during ﬁres in semi‐arid environments inhibits the inﬁltration of rainfall. This leads to increased rates of runoff and associated sediment transport. When the hydrophobic layer is deposited beneath the soil surface, a perched water table develops which may cause thin (1–2 cm) hillslope failures that are distinguishable from features caused by rilling and sheetﬂow. Evidence for these failures was observed after a ﬁre near Santa Barbara, California. The amount of sediment eroded from some hillslopes was substantial, with 290 kg of sediment per metre width of hillslope delivered to the valley ﬂoor. The mechanics of these failures are examined with a numerical model that incorporates a stability analysis with subsurface ﬂow routing along a typical hillslope proﬁle. The model correctly predicts the location of the failures as well as the rainfall amount necessary to trigger them. Copyright © 2003 John Wiley & Sons, Ltd.
Fluvial thermal erosion investigations along a rapidly eroding river bank: application to the Lena River (central Siberia)
Authors: Costard F. , Dupeyrat L. , Gautier E. , Carey‐Gailhardis E. 
Published: November 2003

AbstractIn Central Yakutia, frozen river banks are affected by a combination of thermal and mechanical erosion. Exceptional bank retreat of up to 40 m per year is observed. This results from ground thawing produced by heat transfer from the ﬂow of water through the frozen ground, followed by mechanical transport of the thawed sediments. A one‐dimensional model is proposed to estimate the thermal erosion efﬁciency. A test of this model is a comparison of results obtained from experiments carried out in a cold room. A hydraulic channel allows measurements of the thaw front propagation, as well as the thermal erosion rate, in simulated ground ice that is subjected to warm water ﬂow. Various laboratory simulations demonstrate the validity of the mathematical model for the range of laboratory conditions. A hierarchy of parameters (Reynolds number, water and ground ice temperatures) is proposed to explain the present efﬁciency of thermal erosion along the Siberian rivers. From the characteristics of the Lena River (geometry, temperature and discharge) during the ﬂood season, the erosion of banks with different ice content predicted by the model is in agreement with ﬁeld observations. Copyright © 2003 John Wiley & Sons, Ltd.
High density of immobilized galactose ligand enhances hepatocyte attachment and function
Authors: Yin Chao , Ying Lei , Zhang Peng‐Chi , Zhuo Ren‐Xi , Kang En‐Tang , Leong Kam W. , Mao Hai‐Quan 
Published: November 2003

AbstractGalactosylated surface is an attractive substrate for hepatocyte culture because of the specific interaction between the galactose ligand and the asialoglycoprotein receptor on hepatocytes. In this study, we described a scheme to achieve high density of immobilized galactose ligands on polyethylene terephthalate (PET) surface by first surface‐grafting polyacrylic acid on plasma‐pretreated PET film under UV irradiation, followed by conjugation of a galactose derivative (1‐O‐(6′‐aminohexyl)‐D‐galactopyranoside) to the grafted polyacrylic acid chains. A high galactose density of 513 nmol/cm2 on the PET surface was used in this study to investigate the behavior of cultured hepatocyte. This engineered substrate showed high affinity to fluorescein isothiocyanate‐lectin binding. Primary rat hepatocytes, when seeded at a density of 2 × 105 cells/cm2, attached to the galactosylated PET substrate at a similar efficiency compared with collagen‐coated substrate. The hepatocytes spontaneously formed aggregates 1 day after cell seeding and showed better maintenance of albumin secretion and urea synthesis functions than those cultured on collagen‐coated surface. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1093–1104, 2003
Corrosion behavior of nitinol wires in body fluid environments
Authors: Carroll W. M. , Kelly M. J. 
Published: November 2003

AbstractIn this study, breakdown potentials were measured for unpolished and mechanically polished nitinol wires in simulated body fluids. These wires are similar to those used in the manufacture of stents. Considerable scatter was observed in the results indicating a variable surface state. After appropriate heat treatments, the measured breakdown values were lower but more reproducible for the mechanically polished samples. Significantly higher breakdown potentials were observed for cross‐section wire samples. Some wires were tested in human blood and the breakdown values were higher than in Ringer and 0.9% NaCl solutions. Energy dispersive X‐ray analysis of the surface layers indicated that oxide thickening occurred after heat treatments. Dynamic secondary ion mass spectroscopy also revealed thickened surface oxides on the wires. The oxide was predominantly made up of TiO2 with a very thin layer of NiO at the outer surface. Galvanic corrosion tests were performed on nitinol wires coupled with gold, elgiloy/phynox, and stainless steel. Nitinol was found to be anodic in all cases yet the currents measured were small. In tests in which nitinol–gold couples were immersed in 0.9% NaCl for periods up to 12 months, only very small amounts of nickel (in the part per billion range) were released into solution and scanning electron microscopy examination revealed no corrosion. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1123–1130, 2003
Remineralization of demineralized albumin‐calcium phosphate coatings
Authors: Liu Y. , Hunziker E. B. , Layrolle P. , Van Blitterswijk C. , Calvert P. D. , de Groot K. 
Published: November 2003

AbstractCalcium phosphate and bovine serum albumin were coprecipitated (under physiological conditions of temperature and pH) upon the surfaces of titanium‐alloy samples, which thereby became coated with a dense, proteinaceous mineral layer 30–50 μm in thickness. Dissolution of the inorganic phase by treatment with acidic saline yielded a self‐supporting protein scaffold, 7–10 μm in thickness. Energy‐dispersive X‐ray analysis and Fourier‐transform infrared spectroscopy confirmed the absence of inorganic components from the demineralized albumin scaffolds. When titanium‐alloy samples bearing these demineralized protein scaffolds were immersed in a supersaturated solution of calcium phosphate (again at physiological temperature and pH), they remineralized. These redux albumin‐calcium phosphate layers corresponded in thickness to the original coatings. When titanium‐alloy discs bearing the demineralized protein scaffolds were implanted ectopically (subcutaneously) in mice, they, too, remineralized. No uniform mineral layer was deposited upon the surfaces of naked titanium‐alloy implants. To the best of our knowledge, this is the first demonstration of remineralization within the interstices of a noncollagenous protein scaffold, either in vitro or in vivo. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1155–1162, 2003
Antibacterial properties of nitric oxide–releasing sol‐gels
Authors: Nablo Brian J. , Schoenfisch Mark H. 
Published: November 2003

AbstractThe antibacterial characteristics of nitric oxide (NO)‐releasing sol‐gel coatings are described. The NO release from these surfaces is steady over short periods (≈1 h) and measurable over several days. The ability of NO to prevent bacterial adhesion is evaluated by exposing controls and NO‐releasing sol‐gels to ≈108 colony‐forming units (cfu)/mL saline suspensions of Pseudomonas aeruginosa. Pseudomonas aeruginosa adhesion to sol‐gel controls varies depending on the sol‐gel formulation. Sol‐gel surfaces capable of NO release decrease bacterial adhesion by 30% to 95% relative to controls. The contact angle measurements of control and NO‐releasing surfaces are similar, supporting NO's action as an antibacterial agent against bacterial adhesion. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1276–1283, 2003
Change in electrophoretic mobility of PC12 cells after culturing on PVA membranes modified with different diamines
Authors: Young Tai‐Horng , Hung Chih‐Huang 
Published: November 2003

AbstractThe cell–biomaterial interaction is of extreme importance in regulating the numerous functions necessary for cell adhesion, growth, and differentiation. In the current study, electrophoresis was used to investigate the interactions between cells and biomaterials by measuring the change in electrophoretic mobility of pheochromocytoma (PC12) cells after they were cultured on the poly (vinyl alcohol) membranes modified with different diamines. Variations in cellular activity and electrophoretic mobility of cultured cells were compared. It was found that the intracellular metabolism and the cell surface charge properties were altered after cells contacting biomaterials and the variation of the latter occurred earlier than that of the former. Although the precise mechanism by which the variation of electrophoretic mobility of cultured PC12 cells was unknown, the biomaterials could influence the cell mobility within a short incubation time. It was hypothesized that changes in extracellular matrix components of cell surface may be in part responsible. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1238–1244, 2003
Bone regeneration by grafting of an autogenous cultured bone/ceramic construct
Authors: Yoshikawa Takafumi , Iida Jin , Ueda Yurito , Koizumi Munehisa , Takakura Yoshinori , Nonomura Akitaka 
Published: November 2003

AbstractThe in vivo osteogenic potential of autogenous cultured bone/ceramic constructs in large animals or humans is unknown, and thus we performed a preliminary study of this issue prior to clinical application. All autogenous cultured–bone/ceramic constructs at 3 weeks after implantation in dogs showed obvious histological bone formation within the ceramic pores. In many pores, the HE staining of decalcified specimens revealed thick lamellar bone formation on the pore surface of ceramic. On the surface of bone tissue, numerous active cuboidal osteoblasts were evident. Biochemically, high alkaline phosphatase activity was detected in all dogs. Histological examination of the constructs at 8 weeks postimplantation showed lamellar bone formation with vascular system invasion into the pores, and regenerated hematopoietic bone marrow was often detected in association with the new bone in grafting of human cultured bone/ceramic constructs. Trilineage hematopoietic cells (i.e., granulocytic, erythroblastic, and megakaryocytic cells) were identified in the ceramic pores. Biochemically, high alkaline phosphatase activity and significant human osteocalcin content was detected in the constructs. Based on these findings, in the near future, this technique (grafting of patient‐derived cultured bone/HA constructs) will be able to be applied to various bone reconstruction surgical treatments. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1437–1441, 2003
Effect of calcium salt content in the poly(ε‐caprolactone)/silica nanocomposite on the nucleation and growth behavior of apatite layer
Authors: Rhee Sang‐Hoon 
Published: November 2003

AbstractThe effect of calcium salt content in the poly(ε‐caprolactone) (PCL)/silica nanocomposite on the nucleation and growth behavior of apatite layer in simulated body fluid (SBF) was investigated. The specimens were prepared with low (L) and high (H) concentrations of calcium nitrate tetrahydrate through a sol‐gel method. After soaking in the SBF at 36.5°C for 1 week, a densely packed apatite layer that had a smooth surface and a Ca/P ratio similar to bone was formed on specimens containing a low concentration of calcium salt while a loosely packed apatite layer with a rugged surface and a higher Ca/P ratio than that of bone occurred on specimens containing a high concentration of calcium salt. The results are explained in terms of the degree of supersaturation of apatite in the SBF, as determined by the concentrations of constituent ions of apatite and pH. The practical implication of the results is that a dense and bone‐like apatite layer on the PCL/silica nanocomposite in vitro, and perhaps in vivo, can be achieved by adopting an appropriate calcium salt content. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1131–1138, 2003
Engineering porous polyurethane scaffolds by photografting polymerization of methacrylic acid for improved endothelial cell compatibility
Authors: Zhu Yabin , Gao Changyou , Guan Jianjun , Shen Jiacong 
Published: November 2003

AbstractUsing a preadsorbing‐monomer method, polyurethane (PU) porous scaffolds were modified by grafting polymerization of methacrylic acid (MAA) initiated under UV light. Fourier transform infrared–attenuated total reflection spectroscopy and X‐ray photoelectron spectroscopy characterizations confirmed the occurrence of the grafting polymerization of poly(methacrylic acid) (PMAA) on PU scaffolds and the measurement of water adsorption also demonstrated enhanced hydrophilicity. The PMAA grafting degree correlated to the amount of MAA adsorbed, the pore average diameter, and the porosity. It was verified that the higher porosity the scaffold has, the larger porous area (or the larger contact area with MAA) it has, and therefore the higher amount of MAA adsorbed and higher grafting degree obtained. The results of human endothelial cells cultured in vitro showed that the PU scaffolds modified with the hydrophilic PMAA had more improved cell compatibility than the control matrix. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 1367–1373, 2003
Human cytomegalovirus proteins PP65 and IEP72 are targeted to distinct compartments in nuclei and nuclear matrices of infected human embryo fibroblasts
Authors: Arcangeletti M.C. , De Conto F. , Ferraglia F. , Pinardi F. , Gatti R. , Orlandini G. , Calderaro A. , Motta F. , Medici M.C. , Martinelli M. , Valcavi P. , Razin S.V. , Chezzi C. , Dettori G. 
Published: November 2003

AbstractThe cellular distribution of the human cytomegalovirus (HCMV)‐specific UL83 phosphoprotein (pp65) and UL123 immediate‐early protein (IEp72) in lytically infected human embryo fibroblasts was studied by means of indirect immunofluorescence and confocal microscopy. Both proteins were found to have a nuclear localization, but they were concentrated in different compartments within the nuclei. The pp65 was located predominantly in the nucleoli; this was already evident with the parental viral protein, which was targeted to the above nuclear compartment very soon after infection. The nucleolar localization of pp65 was also observed at later stages of the HCMV infectious cycle. After chromatin extraction (in the so‐called in situ nuclear matrices), a significant portion of the pp65 remained associated with nucleoli within the first hour after infection, then gradually redistributed in a perinucleolar area, as well as throughout the nucleus, with a granular pattern. A quite different distribution was observed for IEp72 at very early stages after infection of human embryo fibroblasts with HCMV; indeed, this viral protein was found in bright foci, clearly observable in both non‐extracted nuclei and in nuclear matrices. At later stages of infection, IEp72 became almost homogeneously distributed within the whole nucleus, while the foci increased in size and were more evenly spread; in several infected cells some of them lay within nucleoli. This peculiar nuclear distribution of IEp72 was preserved in nuclear matrices as well. The entire set of data is discussed in terms of the necessity of integration for HCMV‐specific products into the pre‐existing nuclear architecture, with the possibility of subsequent adaptation of nuclear compartments to fit the needs of the HCMV replicative cycle. © 2003 Wiley‐Liss, Inc.
Role of PTEN and Akt in the regulation of growth and apoptosis in human osteoblastic cells
Authors: Nielsen‐Preiss Sheila M. , Silva Selina R. , Gillette Jennifer M. 
Published: November 2003

AbstractCancer cells are characterized by either an increased ability to proliferate or a diminished capacity to undergo programmed cell death. PTEN is instrumental in regulating the balance between growth and death in several cell types and has been described as a tumor suppressor. The chromosome arm on which PTEN is located is deleted in a subset of human osteosarcoma tumors. Therefore, we predicted that the loss of PTEN expression was contributing to increased Akt activation and the subsequent growth and survival of osteosarcoma tumor cells. Immunoblot analyses of several human osteosarcoma cell lines and normal osteoblasts revealed relatively abundant levels of PTEN. Furthermore, stimulation of cell growth or induction of apoptosis in osteosarcoma cells failed to affect PTEN expression or activity. Therefore, routine regulation of osteosarcoma cell growth and survival appears to be independent of changes in PTEN. Subsequently, the activation of a downstream target of PTEN activity, the survival factor Akt, was analyzed. Inappropriate activation of Akt could bypass the negative regulation by PTEN. Analyses of Akt expression in several osteosarcoma cell lines and normal osteoblasts revealed uniformly low basal levels of phosphorylated Akt. The levels of phosphorylated Akt did not increase following growth stimulation. In addition, osteosarcoma cell growth was unaffected by inhibitors of phosphatidylinositol‐3 kinase, an upstream activator of the Akt signaling pathway. These data further suggest that the Akt pathway is not the predominant signaling cascade required for osteoblastic growth. However, inhibition of PTEN activity resulted in increased levels of Akt phosphorylation and enhanced cell proliferation. These data suggest that while abundant levels of PTEN normally maintain Akt in an inactive form in osteoblastic cells, the Akt signaling pathway is intact and functional. © 2003 Wiley‐Liss, Inc.